Abstract One pot allylic oxidation of 3β-acetoxypregna-5,16-diene-20-one (2) and nucleophilic add... more Abstract One pot allylic oxidation of 3β-acetoxypregna-5,16-diene-20-one (2) and nucleophilic addition at C-16 position of 3β-hydroxypregna-5,16-diene-20-one (3) yielded 3β-acetoxypregna-5,16-diene-7,20-dione (4) and 3β-hydroxy-16α-(5′-hydroxypentyloxy)-pregn-5-ene-20-one (5) respectively in high yield. A detailed theoretical study supported by X-ray analysis of compounds 4 and 5 has been carried out. Conformational analysis of compounds 4 and 5 was done with the help of crystal structure, which crystallize out in orthorhombic form having P212121 space group. Structural characterization of compounds 4 and 5 was done with the aid of 1H, 13C NMR, IR, UV, ESI-MS and ESI-HRMS. The molecular geometries and vibrational frequencies for compounds 4 and 5 in the ground state were calculated using the Density functional theory (DFT) with 6-31G(d,p) basis set and compared with experimental data. 1H and 13C nuclear magnetic resonance magnetic shifts of 4 and 5 were calculated using GIAO method and compared with the experimental data. UV–Vis spectra of both the compounds were recorded and electronic properties such as HOMO–LUMO energies were calculated by time dependent TD-DFT approach. The compounds were screened for their anti-hyperlipidemic and anti-oxidant activity.
Abstract In the current research work synthesis of novel steroids, PGLCROBB, PGLCROMBT, and PGLCR... more Abstract In the current research work synthesis of novel steroids, PGLCROBB, PGLCROMBT, and PGLCROB are being reported employing palladium catalyzed Mizoroki-Heck reaction. Structure elucidation of all the synthesized compounds was done by 1H NMR, 13C NMR, IR, and mass spectrometry. These prodrugs PGL, PGLCRO, PGLCROBB, PGLCROMBT, and PGLCROB were tested on human lung cancer cell line (A549). The results were very promising as PGLCROB has shown significant anticancer activity against lung cancer cells. In order to look into the structural stability and electronic feature analyses, quantum chemical calculations have been performed using the DFT approach. To spot, describe, and estimate competently the weak C-H⋯O H-bonding and H⋯H (conventional) as well as C⋯H (unconventional) non-covalent interactions (NCIs) involved therein, the Bader's QTAIM and NCI-plot have also been executed. The H⋯H bond paths range from 2.021 A to 2.039 A however the C⋯H bond paths fall between 2.806 A and 2.871 A and such type of interactions demonstrate all the characteristics of a closed-shell interaction. The analyzed chemical reactivity mainly emphasized for PGLCRO, PGLCROB, PGLCROBB and PGLCROMBT systems shows that the PGLCROB (with a very marginal difference with the PGLCROBB) is chemically more reactive (highly sensitive) species among all steroids. This work represents another instance of the utilization and successful application of the concept of bond path and the QTAIM.
Objective:: In the present research article, we synthesized novel pregnane derivatives from 16- d... more Objective:: In the present research article, we synthesized novel pregnane derivatives from 16- dehydropregnenolone acetate (1) obtained by the degradation of naturally occurring plant productdiosgenin. The oxime esters, 3β-acetoxy-pregn-5,16-diene, 20-one O-(2-(6-methoxynaphthalene-2yl) propionyl) oxime (5) and 3β-hydroxy-pregn-5, 16-diene, 20-one O-(2-(4-isobutyl phenyl) propionyl) oxime (6) have been synthesized by reaction of 3β-acetoxy-5,16-pregnadien-20-oxime (3) with NSAIDs Ibuprofen and naproxen, respectively. Methods:: The epoxide derivative 3β-hydroxy-16α, 17α-epoxypregn-5-ene-20-one (4) was opened by BF3.Et2O and yielding product 3,16-di-hydroxy pregn-5-ene-20-one (7) and 3,16,17-tri-hydroxy pregn-5- ene-20-one (8), both the synthesized compounds underwent esterification with Ibuprofen affording 3,16- di-(2-(4-isobutyl phenyl) propionoxy) pregn-5-ene-20-one (9) and 3,16-di-(2-(4-isobutyl phenyl) propionoxy) 17-hydroxy pregn-5-ene-20-one (10), respectively. Results: A one ...
Abstract This chapter discusses about the structural aspects, chemical reactivity, biological sig... more Abstract This chapter discusses about the structural aspects, chemical reactivity, biological significance and synthesis of diverse saturated, partially saturated and unsaturated eight membered heterocycles. It starts with a brief discussion about the structural characterization and reactivity of various nitrogen, oxygen, sulfur and mixed heteroatom containing eight membered systems. The next section is devoted towards the importance of these scaffolds in medicinally relevant naturally occurring molecules. In addition, a variety of synthetic strategies for the construction of eight membered isolated and aryl-fused heterocycles along with their chemical transformations are presented. Besides these traditional heterocyclic systems, the synthesis of an eight-membered oxazaborocine analogue by using ring expansion strategy has also been described.
In this chapter chemistry, structural and reactivity aspects of selenophene, selenolane, and thei... more In this chapter chemistry, structural and reactivity aspects of selenophene, selenolane, and their benzo-analogs have been discussed. Importance of these heterocycles in natural products, medicines, and material science is also described.
This chapter contains a compilation of a general discussion about the structural and reactivity a... more This chapter contains a compilation of a general discussion about the structural and reactivity aspects, biological activity and synthetic details of some phosphorus containing heterocycles. In particular, the chemistry of phospholes and phosphinines including their physical properties synthetic strategies, organic transformations, and applications are delineated.
Abstract In this chapter the chemistry and structural aspects of three-membered saturated and uns... more Abstract In this chapter the chemistry and structural aspects of three-membered saturated and unsaturated nitrogen, oxygen, and sulfur heterocycles with monoheteroatoms such as aziridine, 1H-azirine, 2H-azirine, oxirane, oxirene, thiirane, thiirane-1,1-dioxide, thiirene, thiirene-1-oxide, and thirene-1,1-dioxide are described. Analogously the structural aspect and chemistry of saturated and unsaturated heterocycles with two similar heteroatoms such as diaziridine, diazirine, dioxirane, dithiirane, and with mixed heteroatoms such as oxaziridine, oxathiirane, and thiazirine are also delineated. The importance of these heterocycles in natural products, medicine, and material science has been introduced.
Abstract In this chapter, chemistry and structural aspects along with medicinal importance of fou... more Abstract In this chapter, chemistry and structural aspects along with medicinal importance of four-membered saturated and unsaturated mono N, O, and S heterocycles such as azetidine, azetidin-2-ones, azetines, azete oxetane, oxetanone, oxetene, and thietane are discussed. Besides monoheteroatom heterocycles the chemistry of compounds with two similar and dissimilar heteroatoms such as 1,2-diazetidine, 1,3-diazetidine, 1,2-dioxetane, dithietanes, oxazetidines, thiazetidines, and 1,2-oxathietane are also delineated.
Abstract This chapter deals the chemistry, structural and reactivity aspects of saturated, and un... more Abstract This chapter deals the chemistry, structural and reactivity aspects of saturated, and unsaturated five membered monocyclic and benzene fused heterocycles with mono nitrogen, oxygen and sulfur heteroatom such as pyrrole, pyrrolidine, indole, isoindole, indolizine, carbazole, furan, reduced furan, benzofuran, isobenzofuran, thiophene, reduced thiophenes benzothiophenes, and dibenzothiophene. Besides these, heterocycles with two similar or dissimilar heteroatoms, such as pyrazole, reducedpyrazoles, indazole, imidazole, imidazolidine, benzimidazole, dioxolane, dithioles and dithiolanes are delineated. The synthesis, reactivity and different applications of five-membered heterocycles with three or more similar or dissimilar heteroatms in five-membered and their benzofused analogs such as 1,2,3-, 1,2,4-triazoles, 1,2,3-benzotriazole and 1,2,3,4-tetrazoles, isoxazole, benzo[c]isoxazole, benzo[d]isoxazole, oxazole, benzoxazole isothiazole benzoisothiazole thiazole, benzothiazole, 1,2,3-, 1,2,4-, 1,2,5-, 1,3,4-oxadiazole/thiadiazoles are described.
Abstract The regioselective opening of ring F in diosgenin derivatives, in the presence of 2-subs... more Abstract The regioselective opening of ring F in diosgenin derivatives, in the presence of 2-substituted 1,3-propanediol, yielded new furostans bearing a 1,3-dioxane ring at C-26. The structures of these synthesized compounds 1e, 2a, 2b, 2c, 2d and 2e were established on the basis of spectroscopic data, including 1D and 2D NMR and ESI-HRMS. Single crystal X-ray diffraction analysis of 2e (22R,25R)-26-(5-bromo-5-nitro-1,3-dioxanyl)furost-5-en-3-yl acetate not only helped in structural identification but also helped in ascertaining its stereochemistry. The molecular geometry of these compounds was calculated in ground state by density functional theory (DFT/B3LYP) using 6-31G (d, p) basis set. The electronic properties such as HOMO and LUMO energy were calculated by using time dependent density functional theory (TD-DFT). The topological parameters-electron density (ρBCP), Laplacian of electron density ( ∇ 2ρ(rBCP)), energy parameters-kinetic electron energy density (GBCP), potential electron density (VBCP) and the total electron energy density (HBCP) at the bond critical points (BCP) were analyzed by ‘Atoms in molecules’ AIM theory. The Hirshfeld surface analysis helped in identifying important intermolecular interactions in 2e. Global reactivity descriptors and molecular electrostatic potential for compounds have also been determined. First hyperpolarizability (β0) of compounds has been computed to evaluate non-linear optical (NLO) response.
This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
Novel sulphur derivatives have been synthesized for the first time from 16-Dehydropregnenolone ac... more Novel sulphur derivatives have been synthesized for the first time from 16-Dehydropregnenolone acetate (16-DPA) by adopting thia-Michael addition reaction yielding 2-[(3b-acetoxy) pregne5-ene-20-one À16 ethio] propanoic acid, 2-[(3b-acetoxy) pregne5-ene-20-onee16ethio] ethanoic acid, 3b-acetoxy 16a-(2hydroxyethylthio)-pregn-5-ene-20-one and 3b-acetoxy-16b-(2-amino phenylthio)-pregn-5-ene-20-one. All the compounds were characterized with the help of 1 H, 13 C NMR, FT-IR spectroscopy and mass spectrometry. The molecular geometry and vibrational frequency of these compounds were calculated in ground state by density functional theory (DFT/B3LYP) using 6-31G (d, p) basis set. Conformational analysis of all the compounds was carried out to determine the most stable conformation. The electronic properties such as HOMO-LUMO energy were calculated by using time dependent density functional theory (TD-DFT). The topological parameters-electron density (rBCP), Laplacian of electron density (V 2 r(rBCP)), energy parameters-kinetic electron energy density (G BCP), potential electron density (V BCP) and the total electron energy density (H BCP) at the bond critical points (BCP) were analyzed by 'Atoms in molecules' AIM theory. Local reactivity descriptors like Fukui functions (f k þ , f k À , f k 0), local softness (s k þ , Sk À , Sk 0) and local electrophilicity indices (u k þ , u k À , u k 0) analysis were performed to find out the reactive sites within the molecules. Molecular electrostatic potential of the synthesized compounds were also determined. Lastly a nonlinear mathematical model has been proposed and analyzed to study the effect of catalysts on these reactions. Local and global stability analysis of the mathematical model along with the persistence of the system was checked using theory of nonlinear ordinary differential equations.
Abstract This chapter is entirely devoted on the nomenclature of various monocyclic, bicyclic, tr... more Abstract This chapter is entirely devoted on the nomenclature of various monocyclic, bicyclic, tricyclic, and polycyclic, including ortho-fused, ortho-peri-fused, bridged, and spiro, heterocycles with one or more similar or dissimilar heteroatoms present in the cyclic system. In heterocyclic chemistry every heterocyclic system has a special name, while individual compounds are named also by a trivial name based on their origin of occurrence or on their special properties. Hantzsch and Widman introduced methods for naming the five- and six-membered heterocycles, which later on extended to saturated, unsaturated, and other ring sizes of heterocyclic compounds. In this system an appropriate prefix is used for heteroatoms and their ring size. The stem ol (ole) has been used in the case of five-membered heterocycles, while the in (ine) stem is used for six-membered heterocycles. Difficulties arose in naming some ortho or ortho-peri-fused, bridged, and spiro heterocyclic ring systems by the Hantsch-Widman nomenclature, and a set of rules were framed for systematic names of such heterocycles by the International Union of Pure and Applied Chemistry, which is used most frequently worldwide. Replacement nomenclature, also known as “a” nomenclature, has been used to name the heterocyclic compounds in which prefixes end with “a” and the position and prefix for each heteroatom precede the name of corresponding hydrocarbons.
Red rot disease caused by Colletotrichum falcatum leads to acute sucrose losses in sugarcane. Min... more Red rot disease caused by Colletotrichum falcatum leads to acute sucrose losses in sugarcane. Minimising sucrose losses through Trichoderma elicitors will fetch an eco-friendly technology to sugarcane growers. An experiment was conducted for evaluating the effects of elicitors from Trichoderma strains (STr 83, STr 108 and STr 116) against Colletotrichum falcatum for minimising sucrose losses. Following Trichoderma elicitor perception, a chemical barrier against C. falcatum was activated in sugarcane through enhanced accumulation of phenols, enhanced polyphenol oxidase, peroxidase, superoxidase dismutase, phenylalanine ammonia lyase, tyrosine ammonia lyase, chitinase and β-1,3 glucanase activities arrayed in setts at 45 days after pathogen inoculation (dpi). Phenol fluxes and enhanced activities of polyphenol oxidase, peroxidase, superoxidase dismutase, phenylalanine ammonia lyase, tyrosine ammonia lyase, chitinase and β-1,3 glucanase in foliar tissues were carried forward till 330 dpi (harvest stage). STr 83 elicitors exhibited maximum increase in phenols (106%), chitinase (540%), 1, 3 β-glucanases (160%) and activities of polyphenol oxidase (125%), peroxidase (346%), superoxide dismutase (54%), phenylalanine ammonia lyase (162%) and tyrosine ammonia lyase (206%) at 210 dpi. This chemical barrier orchestrated the diverse biochemical pathways for induced systemic resistance and minimised sucrose losses by 0.19-0.26 t ha −1 at cane harvest stage.
Synthesis, spectroscopic analysis (FT-IR, UV and NMR) and DFT analysis of novel prodrugs of pregn... more Synthesis, spectroscopic analysis (FT-IR, UV and NMR) and DFT analysis of novel prodrugs of pregnane, their apoptotic activity in cervical cancer cell lines
Novel pregnane-diosgenin prodrugs have been synthesized. The route involved preparation of 3β-25R... more Novel pregnane-diosgenin prodrugs have been synthesized. The route involved preparation of 3β-25R-spirost-5ene 3yl-benzoate-2-carboxylic acid (2) by the esterification of diosgenin (1) with phthalic anhydride. The pregnane-diosgenin prodrugs 5 & 6 were synthesized by treating 3β-25R-spirost-5ene 3yl-benzoate-2-carboxylic acid (2) with 3β-hydroxy16α-methoxy pregn-5ene-20-one (3) and 3β-hydroxypregn-5, 16-diene-20-one (4) respectively. The synthesized compounds have been characterized with the help of spectroscopic techniques like 1 H, 13 C NMR, FT-IR, UV-visible spectroscopy and mass spectrometry. Density functional theory (DFT) with B3LYP functional and 6-31G (d, p) basis set has been used for the Quantum chemical calculations. UV-Vis spectra of the synthesized compounds were also recorded and electronic properties such as frontier orbitals and band gap energies were calculated by TD-DFT approach. Intramolecular interactions have been identified by AIM approach and vibrational wavenumbers have been calculated using DFT method. The reactivity and reactive site within the synthesized prodrugs were examined with reactivity descriptors (global and local). Dipole moment, polarizability and first static hyperpolarizability were calculated to get a better insight of the properties of synthesized prodrugs. The probable reaction paths of prodrugs were calculated with molecular electrostatic potential (MEP) surface analysis.
Abstract Four novel pregnane-NSAIDs prodrugs 3β-(2-(6-methoxynaphthalene-2yl) propionoxy)-16α-met... more Abstract Four novel pregnane-NSAIDs prodrugs 3β-(2-(6-methoxynaphthalene-2yl) propionoxy)-16α-methoxy-pregn-5-ene-20-one (3), 16α-methoxy-pregn-5-ene-20-one-3yl-2(4-iso butyl phenyl) propanoate (4), 3β-(2-(6-methoxynaphthalene-2yl) propionoxy) 20-hydroxy-16α-methoxy-pregn-5-ene (5) and 20-hydroxy-16α-methoxy-pregn-5-ene-20-one-3yl-2(4-iso butyl phenyl) propanoate (6) have been synthesized. They were analyzed experimentally by spectroscopic techniques like 1H, 13C NMR, FT-IR, UV–visible spectroscopy, mass spectrometry and correlated by theoretical calculations. The structure and conformations of 3 was established by single crystal X-ray diffraction, which crystallized in orthorhombic form having P212121 space group. Absolute configuration of C-20 hydroxy derivatives 5 and 6 was established by circular dichroism (CD) analysis. Conformational analysis of 5 was carried out to determine the most stable conformation. The electronic properties, such as frontier orbitals, band gap energies, oscillator strength and wavelength have been calculated using time dependent density functional theory (TD-DFT). The vibrational wavenumbers have been calculated using DFT method and assigned with the help of potential energy distribution (PED). Global and local reactivity descriptors have been computed to predict reactivity and reactive sites in the molecule. First hyperpolarizability (β0) of synthesized compounds has been computed to evaluate non-linear optical (NLO) response. Molecular electrostatic potential (MEP) for synthesized compounds have also been determined to check their electrophilic or nucleophilic reactivity as well as reaction path.
This is a PDF file of an unedited manuscript that has been accepted for publication. As a service... more This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. Novel synthetic ester of Brassicasterol, DFT investigation including NBO, NLO response, reactivity descriptor and its intramolecular interactions analyzed by AIM theory
A novel labdane diterpene, medigenin, and its glycoside, medinin, have been isolated from the dri... more A novel labdane diterpene, medigenin, and its glycoside, medinin, have been isolated from the dried root bark of Melodinus monogynus. On the basis of chemical and spectroscopic data the structures have been established as 16,19-dihydroxy-entlabda-8(17)13-diene-15oic lactone and its 19-0-b-cellobioside, respectively.
Abstract One pot allylic oxidation of 3β-acetoxypregna-5,16-diene-20-one (2) and nucleophilic add... more Abstract One pot allylic oxidation of 3β-acetoxypregna-5,16-diene-20-one (2) and nucleophilic addition at C-16 position of 3β-hydroxypregna-5,16-diene-20-one (3) yielded 3β-acetoxypregna-5,16-diene-7,20-dione (4) and 3β-hydroxy-16α-(5′-hydroxypentyloxy)-pregn-5-ene-20-one (5) respectively in high yield. A detailed theoretical study supported by X-ray analysis of compounds 4 and 5 has been carried out. Conformational analysis of compounds 4 and 5 was done with the help of crystal structure, which crystallize out in orthorhombic form having P212121 space group. Structural characterization of compounds 4 and 5 was done with the aid of 1H, 13C NMR, IR, UV, ESI-MS and ESI-HRMS. The molecular geometries and vibrational frequencies for compounds 4 and 5 in the ground state were calculated using the Density functional theory (DFT) with 6-31G(d,p) basis set and compared with experimental data. 1H and 13C nuclear magnetic resonance magnetic shifts of 4 and 5 were calculated using GIAO method and compared with the experimental data. UV–Vis spectra of both the compounds were recorded and electronic properties such as HOMO–LUMO energies were calculated by time dependent TD-DFT approach. The compounds were screened for their anti-hyperlipidemic and anti-oxidant activity.
Abstract In the current research work synthesis of novel steroids, PGLCROBB, PGLCROMBT, and PGLCR... more Abstract In the current research work synthesis of novel steroids, PGLCROBB, PGLCROMBT, and PGLCROB are being reported employing palladium catalyzed Mizoroki-Heck reaction. Structure elucidation of all the synthesized compounds was done by 1H NMR, 13C NMR, IR, and mass spectrometry. These prodrugs PGL, PGLCRO, PGLCROBB, PGLCROMBT, and PGLCROB were tested on human lung cancer cell line (A549). The results were very promising as PGLCROB has shown significant anticancer activity against lung cancer cells. In order to look into the structural stability and electronic feature analyses, quantum chemical calculations have been performed using the DFT approach. To spot, describe, and estimate competently the weak C-H⋯O H-bonding and H⋯H (conventional) as well as C⋯H (unconventional) non-covalent interactions (NCIs) involved therein, the Bader's QTAIM and NCI-plot have also been executed. The H⋯H bond paths range from 2.021 A to 2.039 A however the C⋯H bond paths fall between 2.806 A and 2.871 A and such type of interactions demonstrate all the characteristics of a closed-shell interaction. The analyzed chemical reactivity mainly emphasized for PGLCRO, PGLCROB, PGLCROBB and PGLCROMBT systems shows that the PGLCROB (with a very marginal difference with the PGLCROBB) is chemically more reactive (highly sensitive) species among all steroids. This work represents another instance of the utilization and successful application of the concept of bond path and the QTAIM.
Objective:: In the present research article, we synthesized novel pregnane derivatives from 16- d... more Objective:: In the present research article, we synthesized novel pregnane derivatives from 16- dehydropregnenolone acetate (1) obtained by the degradation of naturally occurring plant productdiosgenin. The oxime esters, 3β-acetoxy-pregn-5,16-diene, 20-one O-(2-(6-methoxynaphthalene-2yl) propionyl) oxime (5) and 3β-hydroxy-pregn-5, 16-diene, 20-one O-(2-(4-isobutyl phenyl) propionyl) oxime (6) have been synthesized by reaction of 3β-acetoxy-5,16-pregnadien-20-oxime (3) with NSAIDs Ibuprofen and naproxen, respectively. Methods:: The epoxide derivative 3β-hydroxy-16α, 17α-epoxypregn-5-ene-20-one (4) was opened by BF3.Et2O and yielding product 3,16-di-hydroxy pregn-5-ene-20-one (7) and 3,16,17-tri-hydroxy pregn-5- ene-20-one (8), both the synthesized compounds underwent esterification with Ibuprofen affording 3,16- di-(2-(4-isobutyl phenyl) propionoxy) pregn-5-ene-20-one (9) and 3,16-di-(2-(4-isobutyl phenyl) propionoxy) 17-hydroxy pregn-5-ene-20-one (10), respectively. Results: A one ...
Abstract This chapter discusses about the structural aspects, chemical reactivity, biological sig... more Abstract This chapter discusses about the structural aspects, chemical reactivity, biological significance and synthesis of diverse saturated, partially saturated and unsaturated eight membered heterocycles. It starts with a brief discussion about the structural characterization and reactivity of various nitrogen, oxygen, sulfur and mixed heteroatom containing eight membered systems. The next section is devoted towards the importance of these scaffolds in medicinally relevant naturally occurring molecules. In addition, a variety of synthetic strategies for the construction of eight membered isolated and aryl-fused heterocycles along with their chemical transformations are presented. Besides these traditional heterocyclic systems, the synthesis of an eight-membered oxazaborocine analogue by using ring expansion strategy has also been described.
In this chapter chemistry, structural and reactivity aspects of selenophene, selenolane, and thei... more In this chapter chemistry, structural and reactivity aspects of selenophene, selenolane, and their benzo-analogs have been discussed. Importance of these heterocycles in natural products, medicines, and material science is also described.
This chapter contains a compilation of a general discussion about the structural and reactivity a... more This chapter contains a compilation of a general discussion about the structural and reactivity aspects, biological activity and synthetic details of some phosphorus containing heterocycles. In particular, the chemistry of phospholes and phosphinines including their physical properties synthetic strategies, organic transformations, and applications are delineated.
Abstract In this chapter the chemistry and structural aspects of three-membered saturated and uns... more Abstract In this chapter the chemistry and structural aspects of three-membered saturated and unsaturated nitrogen, oxygen, and sulfur heterocycles with monoheteroatoms such as aziridine, 1H-azirine, 2H-azirine, oxirane, oxirene, thiirane, thiirane-1,1-dioxide, thiirene, thiirene-1-oxide, and thirene-1,1-dioxide are described. Analogously the structural aspect and chemistry of saturated and unsaturated heterocycles with two similar heteroatoms such as diaziridine, diazirine, dioxirane, dithiirane, and with mixed heteroatoms such as oxaziridine, oxathiirane, and thiazirine are also delineated. The importance of these heterocycles in natural products, medicine, and material science has been introduced.
Abstract In this chapter, chemistry and structural aspects along with medicinal importance of fou... more Abstract In this chapter, chemistry and structural aspects along with medicinal importance of four-membered saturated and unsaturated mono N, O, and S heterocycles such as azetidine, azetidin-2-ones, azetines, azete oxetane, oxetanone, oxetene, and thietane are discussed. Besides monoheteroatom heterocycles the chemistry of compounds with two similar and dissimilar heteroatoms such as 1,2-diazetidine, 1,3-diazetidine, 1,2-dioxetane, dithietanes, oxazetidines, thiazetidines, and 1,2-oxathietane are also delineated.
Abstract This chapter deals the chemistry, structural and reactivity aspects of saturated, and un... more Abstract This chapter deals the chemistry, structural and reactivity aspects of saturated, and unsaturated five membered monocyclic and benzene fused heterocycles with mono nitrogen, oxygen and sulfur heteroatom such as pyrrole, pyrrolidine, indole, isoindole, indolizine, carbazole, furan, reduced furan, benzofuran, isobenzofuran, thiophene, reduced thiophenes benzothiophenes, and dibenzothiophene. Besides these, heterocycles with two similar or dissimilar heteroatoms, such as pyrazole, reducedpyrazoles, indazole, imidazole, imidazolidine, benzimidazole, dioxolane, dithioles and dithiolanes are delineated. The synthesis, reactivity and different applications of five-membered heterocycles with three or more similar or dissimilar heteroatms in five-membered and their benzofused analogs such as 1,2,3-, 1,2,4-triazoles, 1,2,3-benzotriazole and 1,2,3,4-tetrazoles, isoxazole, benzo[c]isoxazole, benzo[d]isoxazole, oxazole, benzoxazole isothiazole benzoisothiazole thiazole, benzothiazole, 1,2,3-, 1,2,4-, 1,2,5-, 1,3,4-oxadiazole/thiadiazoles are described.
Abstract The regioselective opening of ring F in diosgenin derivatives, in the presence of 2-subs... more Abstract The regioselective opening of ring F in diosgenin derivatives, in the presence of 2-substituted 1,3-propanediol, yielded new furostans bearing a 1,3-dioxane ring at C-26. The structures of these synthesized compounds 1e, 2a, 2b, 2c, 2d and 2e were established on the basis of spectroscopic data, including 1D and 2D NMR and ESI-HRMS. Single crystal X-ray diffraction analysis of 2e (22R,25R)-26-(5-bromo-5-nitro-1,3-dioxanyl)furost-5-en-3-yl acetate not only helped in structural identification but also helped in ascertaining its stereochemistry. The molecular geometry of these compounds was calculated in ground state by density functional theory (DFT/B3LYP) using 6-31G (d, p) basis set. The electronic properties such as HOMO and LUMO energy were calculated by using time dependent density functional theory (TD-DFT). The topological parameters-electron density (ρBCP), Laplacian of electron density ( ∇ 2ρ(rBCP)), energy parameters-kinetic electron energy density (GBCP), potential electron density (VBCP) and the total electron energy density (HBCP) at the bond critical points (BCP) were analyzed by ‘Atoms in molecules’ AIM theory. The Hirshfeld surface analysis helped in identifying important intermolecular interactions in 2e. Global reactivity descriptors and molecular electrostatic potential for compounds have also been determined. First hyperpolarizability (β0) of compounds has been computed to evaluate non-linear optical (NLO) response.
This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
Novel sulphur derivatives have been synthesized for the first time from 16-Dehydropregnenolone ac... more Novel sulphur derivatives have been synthesized for the first time from 16-Dehydropregnenolone acetate (16-DPA) by adopting thia-Michael addition reaction yielding 2-[(3b-acetoxy) pregne5-ene-20-one À16 ethio] propanoic acid, 2-[(3b-acetoxy) pregne5-ene-20-onee16ethio] ethanoic acid, 3b-acetoxy 16a-(2hydroxyethylthio)-pregn-5-ene-20-one and 3b-acetoxy-16b-(2-amino phenylthio)-pregn-5-ene-20-one. All the compounds were characterized with the help of 1 H, 13 C NMR, FT-IR spectroscopy and mass spectrometry. The molecular geometry and vibrational frequency of these compounds were calculated in ground state by density functional theory (DFT/B3LYP) using 6-31G (d, p) basis set. Conformational analysis of all the compounds was carried out to determine the most stable conformation. The electronic properties such as HOMO-LUMO energy were calculated by using time dependent density functional theory (TD-DFT). The topological parameters-electron density (rBCP), Laplacian of electron density (V 2 r(rBCP)), energy parameters-kinetic electron energy density (G BCP), potential electron density (V BCP) and the total electron energy density (H BCP) at the bond critical points (BCP) were analyzed by 'Atoms in molecules' AIM theory. Local reactivity descriptors like Fukui functions (f k þ , f k À , f k 0), local softness (s k þ , Sk À , Sk 0) and local electrophilicity indices (u k þ , u k À , u k 0) analysis were performed to find out the reactive sites within the molecules. Molecular electrostatic potential of the synthesized compounds were also determined. Lastly a nonlinear mathematical model has been proposed and analyzed to study the effect of catalysts on these reactions. Local and global stability analysis of the mathematical model along with the persistence of the system was checked using theory of nonlinear ordinary differential equations.
Abstract This chapter is entirely devoted on the nomenclature of various monocyclic, bicyclic, tr... more Abstract This chapter is entirely devoted on the nomenclature of various monocyclic, bicyclic, tricyclic, and polycyclic, including ortho-fused, ortho-peri-fused, bridged, and spiro, heterocycles with one or more similar or dissimilar heteroatoms present in the cyclic system. In heterocyclic chemistry every heterocyclic system has a special name, while individual compounds are named also by a trivial name based on their origin of occurrence or on their special properties. Hantzsch and Widman introduced methods for naming the five- and six-membered heterocycles, which later on extended to saturated, unsaturated, and other ring sizes of heterocyclic compounds. In this system an appropriate prefix is used for heteroatoms and their ring size. The stem ol (ole) has been used in the case of five-membered heterocycles, while the in (ine) stem is used for six-membered heterocycles. Difficulties arose in naming some ortho or ortho-peri-fused, bridged, and spiro heterocyclic ring systems by the Hantsch-Widman nomenclature, and a set of rules were framed for systematic names of such heterocycles by the International Union of Pure and Applied Chemistry, which is used most frequently worldwide. Replacement nomenclature, also known as “a” nomenclature, has been used to name the heterocyclic compounds in which prefixes end with “a” and the position and prefix for each heteroatom precede the name of corresponding hydrocarbons.
Red rot disease caused by Colletotrichum falcatum leads to acute sucrose losses in sugarcane. Min... more Red rot disease caused by Colletotrichum falcatum leads to acute sucrose losses in sugarcane. Minimising sucrose losses through Trichoderma elicitors will fetch an eco-friendly technology to sugarcane growers. An experiment was conducted for evaluating the effects of elicitors from Trichoderma strains (STr 83, STr 108 and STr 116) against Colletotrichum falcatum for minimising sucrose losses. Following Trichoderma elicitor perception, a chemical barrier against C. falcatum was activated in sugarcane through enhanced accumulation of phenols, enhanced polyphenol oxidase, peroxidase, superoxidase dismutase, phenylalanine ammonia lyase, tyrosine ammonia lyase, chitinase and β-1,3 glucanase activities arrayed in setts at 45 days after pathogen inoculation (dpi). Phenol fluxes and enhanced activities of polyphenol oxidase, peroxidase, superoxidase dismutase, phenylalanine ammonia lyase, tyrosine ammonia lyase, chitinase and β-1,3 glucanase in foliar tissues were carried forward till 330 dpi (harvest stage). STr 83 elicitors exhibited maximum increase in phenols (106%), chitinase (540%), 1, 3 β-glucanases (160%) and activities of polyphenol oxidase (125%), peroxidase (346%), superoxide dismutase (54%), phenylalanine ammonia lyase (162%) and tyrosine ammonia lyase (206%) at 210 dpi. This chemical barrier orchestrated the diverse biochemical pathways for induced systemic resistance and minimised sucrose losses by 0.19-0.26 t ha −1 at cane harvest stage.
Synthesis, spectroscopic analysis (FT-IR, UV and NMR) and DFT analysis of novel prodrugs of pregn... more Synthesis, spectroscopic analysis (FT-IR, UV and NMR) and DFT analysis of novel prodrugs of pregnane, their apoptotic activity in cervical cancer cell lines
Novel pregnane-diosgenin prodrugs have been synthesized. The route involved preparation of 3β-25R... more Novel pregnane-diosgenin prodrugs have been synthesized. The route involved preparation of 3β-25R-spirost-5ene 3yl-benzoate-2-carboxylic acid (2) by the esterification of diosgenin (1) with phthalic anhydride. The pregnane-diosgenin prodrugs 5 & 6 were synthesized by treating 3β-25R-spirost-5ene 3yl-benzoate-2-carboxylic acid (2) with 3β-hydroxy16α-methoxy pregn-5ene-20-one (3) and 3β-hydroxypregn-5, 16-diene-20-one (4) respectively. The synthesized compounds have been characterized with the help of spectroscopic techniques like 1 H, 13 C NMR, FT-IR, UV-visible spectroscopy and mass spectrometry. Density functional theory (DFT) with B3LYP functional and 6-31G (d, p) basis set has been used for the Quantum chemical calculations. UV-Vis spectra of the synthesized compounds were also recorded and electronic properties such as frontier orbitals and band gap energies were calculated by TD-DFT approach. Intramolecular interactions have been identified by AIM approach and vibrational wavenumbers have been calculated using DFT method. The reactivity and reactive site within the synthesized prodrugs were examined with reactivity descriptors (global and local). Dipole moment, polarizability and first static hyperpolarizability were calculated to get a better insight of the properties of synthesized prodrugs. The probable reaction paths of prodrugs were calculated with molecular electrostatic potential (MEP) surface analysis.
Abstract Four novel pregnane-NSAIDs prodrugs 3β-(2-(6-methoxynaphthalene-2yl) propionoxy)-16α-met... more Abstract Four novel pregnane-NSAIDs prodrugs 3β-(2-(6-methoxynaphthalene-2yl) propionoxy)-16α-methoxy-pregn-5-ene-20-one (3), 16α-methoxy-pregn-5-ene-20-one-3yl-2(4-iso butyl phenyl) propanoate (4), 3β-(2-(6-methoxynaphthalene-2yl) propionoxy) 20-hydroxy-16α-methoxy-pregn-5-ene (5) and 20-hydroxy-16α-methoxy-pregn-5-ene-20-one-3yl-2(4-iso butyl phenyl) propanoate (6) have been synthesized. They were analyzed experimentally by spectroscopic techniques like 1H, 13C NMR, FT-IR, UV–visible spectroscopy, mass spectrometry and correlated by theoretical calculations. The structure and conformations of 3 was established by single crystal X-ray diffraction, which crystallized in orthorhombic form having P212121 space group. Absolute configuration of C-20 hydroxy derivatives 5 and 6 was established by circular dichroism (CD) analysis. Conformational analysis of 5 was carried out to determine the most stable conformation. The electronic properties, such as frontier orbitals, band gap energies, oscillator strength and wavelength have been calculated using time dependent density functional theory (TD-DFT). The vibrational wavenumbers have been calculated using DFT method and assigned with the help of potential energy distribution (PED). Global and local reactivity descriptors have been computed to predict reactivity and reactive sites in the molecule. First hyperpolarizability (β0) of synthesized compounds has been computed to evaluate non-linear optical (NLO) response. Molecular electrostatic potential (MEP) for synthesized compounds have also been determined to check their electrophilic or nucleophilic reactivity as well as reaction path.
This is a PDF file of an unedited manuscript that has been accepted for publication. As a service... more This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. Novel synthetic ester of Brassicasterol, DFT investigation including NBO, NLO response, reactivity descriptor and its intramolecular interactions analyzed by AIM theory
A novel labdane diterpene, medigenin, and its glycoside, medinin, have been isolated from the dri... more A novel labdane diterpene, medigenin, and its glycoside, medinin, have been isolated from the dried root bark of Melodinus monogynus. On the basis of chemical and spectroscopic data the structures have been established as 16,19-dihydroxy-entlabda-8(17)13-diene-15oic lactone and its 19-0-b-cellobioside, respectively.
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