Synthetic Chemistry

proteins previously derivatized with the cross-coupling reagent sulfo-sMcc (4-(N-maleimidomethyl)cyclohexane-1-carboxylic acid 3-sulfo-N-hydroxy-succinimide ester sodium salt) can be easily labeled in high radiochemical yields with the silicon-fluoride acceptor (siFa) reagent [ 18 F]siFa-sH, obtained via isotopic exchange, by thiol-maleimide coupling chemistry (n = 10). the specific activity of siFa-sH obtained in a one-step labeling reaction was >18.5 GBq mol − 1 (>500 ci mmol − 1). the number of siFa building blocks per protein molecule is defined by the previously introduced number of maleimide groups, which can be determined by a simple and convenient ellman's assay. not more than two maleimide groups are introduced using sulfo-sMcc, thereby keeping the modification of the protein low and preserving its biological activity.

The photochemical behavior of the phototoxic antidepressant drug venlafaxine (VLF, 1) was studied under aerobic conditions in UV-A light. Irradiation of a phosphate buffer solution of the drug produces N-Demethylated (2) and O-Demethylated (3) as two major photoproducts. The formation of photoproducts (2) and (3) occurs through a singlet oxygen-mediated mechanism, i.e., type-II photodynamic action, involving an irreversible trapping of the self-photogenerated singlet molecular oxygen (1 O 2) and through free radical-mediated mechanism, i.e., type 1 photodynamic action, respectively. The generation of singlet oxygen and free radicals during photolysis was confirmed by singlet oxygen scavenger sodium azide (NaN 3) and free radical scavenger reduced glutathione (GSH). In addition, the comparative antioxidant potentials of the parent drug and its photoproducts were examined utilizing in-silico molecular docking against tyrosinase to better understand the in vivo relevance of drug pharmacological action as a result of drug-light interaction. Photoproduct (2) exhibited less activity as compared to the parent drug, VLF (1), whereas photoproduct (3) formed a stable protein-ligand complex. In order to determine the nature of stability of complex between protein and ligand, further, molecular dynamics (MD) simulation on photoproduct (3) was performed for 100 ns, and the results were analyzed by monitoring root mean square deviations (RMSD), the radius of gyration (Rg), and solvent accessible surface area (SASA). The results proved the formation of a better protein-ligand complex with photoproduct (3). These findings imply that drug users should avoid their exposure to light (natural or artificial) to prevent drug-induced photosensitivity. This study also opens new vistas for the development of novel drugs with desired tyrosinase binding affinity, improved biological features, and low phototoxic manifestations.

Some aryl pyrazolines including 3-(substituted phenyl)-5-(naphthalen-1-yl)-1-phenyl-4,5dihydro-1H-pyrazoles were prepared by microwave irradiation promoted cyclization of aryl enones and phenylhydrazine in the presence of solid acidic bentonite/FeCl3 catalyst under solvent-free conditions. In this cyclization the obtained yields are more than 75%. The structural analysis of these pyrazoline derivatives were confirmed through analytical and spectral techniques. The effect of catalyst and solvent on this cyclization also investigated through the obtained yields. The antimicrobial activities of these pyrazoline derivatives were assessed through measurement of mm of zone of inhibition against their micro stains using well known Bauer-Kirby disc diffusion method.

Methyl tris-dialkyl and alkylenedithiophosphates, HC[S2P(OR)2]3 where R = Et, n-Pr, i-Pr, i-Bu and Ph and HC[S2POGO]3, where G =-CMe2, CMe2,-, CH2CMe2CH2-, and-CH2CEt2CH2-, have been synthesized for the first time by the reactions of iodoform with the alkali metal salt of the corresponding ligand in anhydrous toluene in 1:3 molar ratio respectively. These compounds are powdery solids or viscous liquids and are soluble in common organic solvents, in which they show monomeric behavior. Based on elemental analyses, molecular weight determinations, IR and NMR (1 H and 31 P) spectral data, chelate tetrahedral structures have been proposed for these derivatives

Diacylglycerol lipases (DAGL) produce the endocannabinoid 2-arachidonoylglycerol, a key modulator of neurotransmitter release. Chemical tools that visualize endogenous DAGL activity are desired. Here, we report the design, synthesis and application of a triazole urea probe for DAGL equipped with a norbornene as a biorthogonal handle. The activity and selectivity of the probe was assessed with activity-based protein profiling. This probe was potent against endogenous DAGLα (IC50 = 5 nM) and it was successfully applied as a two-step activity-based probe for labeling of DAGLα using an inverse electron-demand Diels-Alder ligation in living cells.

Background, aim, and scope Indiscriminate use of insecticides leads to environmental problems and poses a great threat to beneficial microorganisms. The aim of the present work was to study chlorpyrifos degradation by a rice field cyanobacterium Synechocystis sp. strain PUPCCC 64 so that the organism is able to reduce insecticide pollution in situ. Material and methods The unicellular cyanobacterium isolated and purified from a rice field was identified by partial 16S rRNA gene sequence as Synechocystis sp. strain PUPCCC 64. Tolerance limit of the organism was determined by studying its growth in graded concentrations (2.5-20 mg/L) of chlorpyrifos. Chlorpyrifos removal was studied by its depletion from the insecticide supplemented growth medium, and its biodegradation products were identified in the cell extract, biomass wash, and growth medium. Results and discussion The organism tolerated chlorpyrifos up to 15 mg/L. Major fraction of chlorpyrifos was removed by the organism during the first day followed by slow uptake. Biomass, pH, and temperature influenced the insecticide removal and the organism exhibited maximum chlorpyrifos removal at 100 mg protein/L biomass, pH 7.0, and 30°C. The cyanobacterium metabolized chlorpyrifos producing a number of degradation products as evidenced by GC-MS chromatogram. One of the degradation products was identified as 3,5,6trichloro-2-pyridinol. Conclusion and recommendations Present study reports the biodegradation of chlorpyrifos by Synechocystis sp. Biodegradation of the insecticide by the cyanobacterium is significant as it can be biologically removed from the environment. The cyanobacterium may be used for bioremediation of chlorpyrifos-contaminated soils.

N-alkyl oxaziridines may be used as reagents for the oxidation of sulfides in acid-promoted reactions. This study describes the synthesis of two new oxaziridines. The reactivity of the latter was investigated in acidic medium both in presence and in absence of sulfides. In the absence of sulfides, a new nitrone was produced

Starting material 4-hydroxy-1-phenyl/methyl-quinolin-2-(1H)-one was treated with phosphorous oxychloride and then subjected to Mannich reaction to yield title 4-chloro-1-phenyl/methyl-3-[3-(substituted) propanoyl] quinolin-2(1H)-one derivatives compounds IIa (1-7)/ IIb (1-7). Molecular docking studies of the compounds were carried out using Molegro Virtual Docker. All the synthesized compounds were characterized by IR, 1 H-NMR and Mass Spectral data and were tested for their antidepressant activity. Amongst the synthesized compounds, compound 4-chloro-1-phenyl-3-[3-(morpholinopropanoyl] quinolin-2(1H)-one [IIa4] was found to show the most potent antidepressant activity with immobility time of 98.17± 4.806. Compound 4-chloro-1-phenyl-3-[3-(4-methylpiperazin-1-yl) propanoyl] quinolin-2(1H)one [IIa 3] and 4-chloro-1-methyl-3-[3-(pyrrolidin-1-yl) propanoyl] quinolin-2(1H)-one [IIb 2] showed moderate antidepressant activity with immobility time of 126.5 ± 1.945s and 120.3 ± 2.376s, respectively, compared to standard imipramine.

We have recently reported the synthesis of different acyl pyranoses, bearing only one free hydroxyl group, obtained by regioselective enzymatic hydrolysis of the peracetylated precursors and subsequent acyl migration of the hydrolyzed products. 1 As a part of this ongoing research, we have focused our attention onto the pure regioisomers of 2-acetamido-2-deoxy-1,3,4,6-tetra-O-acetyl-α-D-glucopyranose (1) as key intermediate for the preparation of a large number of oligosaccharides. Particularly, we have developed an efficient process to obtain a deprotected derivative of 1 having only one free hydroxyl group at the C-4 position (3) as a valuable synthon for the preparation of N-acetyl-α-D-lactosamine heptaacetate (4), building-block in a new synthetic pathway for oligosaccharides like Sialyl Lewis x. Our chemo-enzymatic strategy allows to obtain the disaccharide (4) in good overall yield, starting from a commercially available cheap compound and without any intermediate purification. Our approach is, indeed, an interesting alternative to the classical multi-step chemical procedures that are often plagued by low yields and formation of undesired by-products.

In the current study, α-aminophosphonates containing thiadiazole moiety (1-4) was synthesized, characterized and their antioxidant and anticancer activities were carried out. The compounds (1-4) were synthesized from the reaction of 2-amino-5-methyl-1,3,4-thiadiazole with various aldehydes, triphenylphosphite and mixed valence Cu(I)/Cu(II) inorganic coordination polymer as a catalyst. The elucidation of compounds structures were carried out using different spectroscopic techniques. The antioxidant properties were carried out using radical scavenging methods (DPPH) which exhibited excellent scavenging activity particularly with compound 3. The cytotoxic effects of the five compounds on the human hepato cellular carcinoma (HepG2) and breast adeno carcinoma (MCF7) cell lines were evaluated using MTT assay which revealed the presence of cytotoxic effect with highest activity for 2 compound 3 on HepG2 and compound 1 on MCF7. This suggests that these five compounds, particularly compounds 1 and 3, have antioxidant and anticancer effect and could be used as novel chemotherapeutic compounds but this needs further in vivo investigation to confirm our in vitro results.

Nitrogen-containing heterocyclic combinations are widely explored in the synthesis and development of a variety of chemicals in therapeutic sciences. Pyrazolines are one of the major heterocyclic molecules that take a crucial part by the virtue of their pharmacological properties, pyrazolines are remarkable and enormousnitrogen-containing 5-membered heterocyclic combinations and various methods for their mixing have been shown. Several subordinates of pyrazoline were found to have significant normal activities, which revived the development of assessment in this area. They have a couple of prominent effects, similar to antimicrobial, antimycobacterial, antifungal, antiamoebic, alleviating, torment easing, upper and anticancer activities. 2-pyrazolines give off an impression of being the regularly pondered pyrazoline-type compounds. These combinations are by and large prepared from the cyclization of chalcones with hydrazine and its auxiliaries under alcoholic conditions. Pyrazolines are the diminished types of pyrazoles Subsequently, a tremendous number of such pyrazolines using particularly designed methods for their arranging have been portrayed in this article. The current study gives an understanding viewpoint to pyrazolines synthesis and its biological activities.

Establishing structure-activity relationships is crucial to understand and optimize the activity of peptide-based inhibitors of protein-protein interactions. Single alanine substitutions provide limited information on the residues that tolerate simultaneous modifications with retention of biological activity. To guide optimization of peptide binders, we use combinatorial peptide libraries of over 4,000 variants-in which each position is varied with either the wildtype residue or alanine-with a label-free affinity selection platform to study protein-ligand interactions. Applying this platform to a peptide binder to the oncogenic protein MDM2, several multi-alanine-substituted analogs with picomolar binding affinity were discovered. We reveal a non-additive substitution pattern in the selected sequences. The alanine substitution tolerances for peptide ligands of the 12ca5 antibody and 14-3-3 regulatory protein are also characterized, demonstrating the general applicability of this new platform. We envision that binary combinatorial alanine scanning will be a powerful tool for investigating structure-activity relationships.

A novel DFT-based Reaction Kinetics (DFT-RK) simulation approach, employed in combination with real-time data from reaction monitoring instrumentation (like UV-vis, FTIR, Raman, and 2D NMR benchtop spectrometers), is shown to provide a detailed methodology for the analysis and design of complex synthetic chemistry schemes. As an example, it is applied to the opening of epoxides by titanocene in THF, a catalytic system with abundant experimental data available. Through a DFT-RK analysis of real-time IR data, we have developed a comprehensive mechanistic model that opens new perspectives to understand previous experiments. Although derived specifically from the opening of epoxides, the prediction capabilities of the model, built on elementary reactions, together with its practical side (reaction kinetics simulations of real experimental conditions) make it a useful simulation tool for the design of new experiments, as well as for the conception and development of improved versions of ...

Light has a profound effect on us. We may not be conscious enough as regards the existences of many phototoxic substances and chemicals. A phototoxic substance is a chemical compound which becomes toxic when exposed to light. Phototoxicity may be manifested in various ways. Proper use of sunscreens may play a vital role in the prevention of many such reactions.

Thiadiazole and its derivatives are important organic reaction intermediates and they have been widely used as anticonvulsant, antidepressant, analgesic, antiinflammatory, antiplatelet, antimalarial, antimicrobial, antimycobacterial, antitumoral, antiviral, diuretic and muscles relaxant activity. Generally, synthesis of the thiadiazole derivations needs high temperature (≥ 100 0 C) or low temperature (< 0 0 C) or high pressure (at least higher than 1 atmospheric pressure), and the yields of those reactions are low. Otherwise, they could be synthesized by reacting thiocarbonyl dichloride with dithizone. A series of thiadiazole have been synthesized using an appropriate synthetic route and characterized by elemental analysis and spectral data.

Historically, the alkylation of allylic acetates with non-stabilized C(sp 3) nucleophiles has been challenging. The metal-catalyzed alkylation of allylic acetates and carbonates with organotin and organoboron reagents has significantly increased the scope of nucleophiles available to participate in such reactions; however, the generation of C(sp 3)-C(sp 3) bonds in this manner remains difficult. We therefore designed a substrate in order to explore the intramolecular transition metalcatalyzed alkylation of an allylic acetate with a C(sp 3) organotin nucleophile. From this substrate we were able to successfully synthesize a number of 3-vinylindolines in modest to good yields in as little as seven steps through the palladium-catalyzed intramolecular allylic alkylation of cinnamyl acetates with tethered organotin nucleophiles. To the best of our knowledge this represents the first example of such a transformation, resulting in the formation of novel C(sp 3)-C(sp 3) bonds. It has been shown that polyphenolic procyandins, members of the flavonoid class of compounds, possess moderate affinity for a synthetic model of a proline rich region of the microtubule associated protein tau. The phosphorylation of this region of tau is thought to be correlated with the development of intraneuronal protein deposits, a hallmark of Alzheimer's disease physiopathology. In the second part of this thesis, we set out to utilize the domino Friedel-Crafts alkylation/acylation of benzylidene Meldrum's acids with phenols previously developed in our group for the synthesis of a number of polyphenolic 4-aryl-3,4-dihydrocoumarins, members of the neoflavonoid class of compounds. By synthesizing a library of polyphenolic neoflavonoids in this manner, which possessed variation in the number and position of hydroxyl groups about the xii

Historically, the alkylation of allylic acetates with non-stabilized C(sp 3) nucleophiles has been challenging. The metal-catalyzed alkylation of allylic acetates and carbonates with organotin and organoboron reagents has significantly increased the scope of nucleophiles available to participate in such reactions; however, the generation of C(sp 3)-C(sp 3) bonds in this manner remains difficult. We therefore designed a substrate in order to explore the intramolecular transition metalcatalyzed alkylation of an allylic acetate with a C(sp 3) organotin nucleophile. From this substrate we were able to successfully synthesize a number of 3-vinylindolines in modest to good yields in as little as seven steps through the palladium-catalyzed intramolecular allylic alkylation of cinnamyl acetates with tethered organotin nucleophiles. To the best of our knowledge this represents the first example of such a transformation, resulting in the formation of novel C(sp 3)-C(sp 3) bonds. It has been shown that polyphenolic procyandins, members of the flavonoid class of compounds, possess moderate affinity for a synthetic model of a proline rich region of the microtubule associated protein tau. The phosphorylation of this region of tau is thought to be correlated with the development of intraneuronal protein deposits, a hallmark of Alzheimer's disease physiopathology. In the second part of this thesis, we set out to utilize the domino Friedel-Crafts alkylation/acylation of benzylidene Meldrum's acids with phenols previously developed in our group for the synthesis of a number of polyphenolic 4-aryl-3,4-dihydrocoumarins, members of the neoflavonoid class of compounds. By synthesizing a library of polyphenolic neoflavonoids in this manner, which possessed variation in the number and position of hydroxyl groups about the xii

2-Pyrazolines display a broad spectrum of potential pharmacological activities and are present in a number of pharmacologically active molecules such as phenazone/ amidopyrene/ methampyrone (analgesic and antipyretic), azolid/ tandearil (anti-inflammatory), indoxacarb (insecticide) and anturane (uricosuric). Changes in their structure have offered a high degree of diversity that has proven useful for the development of new therapeutic agents having improved potency and lesser toxicity. In this context, the recently synthesized 2-pyrazoline derivatives possessing important pharmacological activities have been highlighted.

The regioselectivity of the acetylation of D-xylopyranosides attached to polyethylene glycol monomethyl ether (MeOPEG) catalyzed by lipases from Pseudomonas cepacia and Candida antartica in organic solvent was examined. Partially acetylated derivatives can be obtained with high regioselectivity by acetylation or deacetylation in the presence of the appropriate lipase.

Herein, we report the synthesis of DNA-functionalized infinite coordination polymer (ICP) nanoparticles as biocompatible gene regulation agents. ICP nanoparticles were synthesized from ferric nitrate and a ditopic 3-hydroxy-4-pyridinone (HOPO) ligand bearing a pendant azide. Addition of Fe III to a solution of the ligand produced nanoparticles, which were colloidally unstable in the presence of salts. Conjugation of DNA to the Fe III-HOPO ICP particles, via

While looking for some appropriate research projects, I had been impressed by and interested in the work of Danishefsky1 and others2 regarding the use of Eschenmoser\u27s salt (1). During the course of a literature search on an industrial project, we came across an article by Gold,3 which described the preparation of a rather interesting vinylogous iminium salt (2). The name assigned to this compound was [3-(dimethylamino)-2-azaprop-2-en-1-ylidene]dimethylammonium chloride. This terminology seemed a little cumbersome for routine discussions so we adopted the name Gold\u27s Reagent for compound 2. Although the reagent had been prepared3 in 1960, very little research4 had been performed on this substance in the intervening years. We therefore decided to begin an exhaustive study to delineate and define what, if any, useful synthetic chemistry could be developed from Gold\u27s Reagent

This protocol describes a workflow for utilizing large-scale cross-linking with mass spectrometry (XL-MS) to make systems-level structural biology measurements in complex biological samples, including cells, isolated organelles, and tissue samples. XL-MS is a structural biology technique that provides information on the molecular structure of proteins and protein complexes using chemical probes that report the proximity of probe-reactive amino acids within proteins, typically lysine residues. Information gained through XL-MS studies is often complementary to more traditional methods, such as X-ray crystallography, nuclear magnetic resonance, and cryo-electron microscopy. The use of MS-cleavable crosslinkers, including protein interaction reporter (PIR) technologies, enables XL-MS studies on protein structures and interactions in extremely complex biological samples, including intact living cells. PIR cross-linkers are designed to contain chemical bonds at specific locations within the cross-linker molecule that can be selectively cleaved by collisioninduced dissociation or UV light. When broken, these bonds release the intact peptides that were cross-linked, as well as a reporter ion. Conservation of mass dictates that the sum of the two released peptide masses and the reporter mass equals the measured precursor mass. This relationship is used to identify cross-linked peptide pairs. Release of the individual peptides permits accurate measurement of their masses and independent amino acid sequence determination by tandem MS, allowing the use of standard proteomics search engines such as Comet for peptide sequence assignment, greatly simplifying data analysis of cross-linked peptide pairs. Search results are processed with XLinkProphet for validation and can be uploaded into XlinkDB for interaction network and structural analysis.

Ionic liquids have been found to provide a new platform for metal-and quinoline-free decarboxylation of various N-heteroaryl and aryl carboxylic acids under microwave irradiation in aqueous condition. The method was found to possess a wide substrate scope towards the synthesis of various pharmacologically and industrially important aromatic compounds including indoles, styrenes, stilbenes, and nitro-or hydroxyarene derivatives. The decarboxylation of indole and a-phenylcinnamic acids proceeded well without addition of any catalyst in neat 1-hexyl-3-methylimidazolium bromide ([hmim]Br) and 1-methylimidazolium p-toluenesulfonic acid ([Hmim]PTSA), respectively, while addition of a mild base like aqueous sodium hydrogen carbonate (NaHCO 3) to [hmim]Br further improved the decarboxylation of hydroxylated cinnamic and aromatic acid substrates. The developed methodology not only precludes the usage of toxic metal/quinoline and harsh organic bases but also offers several inherent benefits like recyclability of reagent system, reduction in waste and hazards, short reaction time besides ease of product recovery.

Ionic liquids have been found to provide a new platform for metal-and quinoline-free decarboxylation of various N-heteroaryl and aryl carboxylic acids under microwave irradiation in aqueous condition. The method was found to possess a wide substrate scope towards the synthesis of various pharmacologically and industrially important aromatic compounds including indoles, styrenes, stilbenes, and nitro-or hydroxyarene derivatives. The decarboxylation of indole and a-phenylcinnamic acids proceeded well without addition of any catalyst in neat 1-hexyl-3-methylimidazolium bromide ([hmim]Br) and 1-methylimidazolium p-toluenesulfonic acid ([Hmim]PTSA), respectively, while addition of a mild base like aqueous sodium hydrogen carbonate (NaHCO 3) to [hmim]Br further improved the decarboxylation of hydroxylated cinnamic and aromatic acid substrates. The developed methodology not only precludes the usage of toxic metal/quinoline and harsh organic bases but also offers several inherent benefits like recyclability of reagent system, reduction in waste and hazards, short reaction time besides ease of product recovery.

Background, aim, and scope Indiscriminate use of insecticides leads to environmental problems and poses a great threat to beneficial microorganisms. The aim of the present work was to study chlorpyrifos degradation by a rice field cyanobacterium Synechocystis sp. strain PUPCCC 64 so that the organism is able to reduce insecticide pollution in situ. Material and methods The unicellular cyanobacterium isolated and purified from a rice field was identified by partial 16S rRNA gene sequence as Synechocystis sp. strain PUPCCC 64. Tolerance limit of the organism was determined by studying its growth in graded concentrations (2.5-20 mg/L) of chlorpyrifos. Chlorpyrifos removal was studied by its depletion from the insecticide supplemented growth medium, and its biodegradation products were identified in the cell extract, biomass wash, and growth medium. Results and discussion The organism tolerated chlorpyrifos up to 15 mg/L. Major fraction of chlorpyrifos was removed by the organism during the first day followed by slow uptake. Biomass, pH, and temperature influenced the insecticide removal and the organism exhibited maximum chlorpyrifos removal at 100 mg protein/L biomass, pH 7.0, and 30°C. The cyanobacterium metabolized chlorpyrifos producing a number of degradation products as evidenced by GC-MS chromatogram. One of the degradation products was identified as 3,5,6trichloro-2-pyridinol. Conclusion and recommendations Present study reports the biodegradation of chlorpyrifos by Synechocystis sp. Biodegradation of the insecticide by the cyanobacterium is significant as it can be biologically removed from the environment. The cyanobacterium may be used for bioremediation of chlorpyrifos-contaminated soils.

Ionic liquids have been found to provide a new platform for metal-and quinoline-free decarboxylation of various N-heteroaryl and aryl carboxylic acids under microwave irradiation in aqueous condition. The method was found to possess a wide substrate scope towards the synthesis of various pharmacologically and industrially important aromatic compounds including indoles, styrenes, stilbenes, and nitro-or hydroxyarene derivatives. The decarboxylation of indole and a-phenylcinnamic acids proceeded well without addition of any catalyst in neat 1-hexyl-3-methylimidazolium bromide ([hmim]Br) and 1-methylimidazolium p-toluenesulfonic acid ([Hmim]PTSA), respectively, while addition of a mild base like aqueous sodium hydrogen carbonate (NaHCO 3) to [hmim]Br further improved the decarboxylation of hydroxylated cinnamic and aromatic acid substrates. The developed methodology not only precludes the usage of toxic metal/quinoline and harsh organic bases but also offers several inherent benefits like recyclability of reagent system, reduction in waste and hazards, short reaction time besides ease of product recovery.

Chalcone and its derivatives have a wide range of antiproliferative, antifungal, antibacterial, antiviral, antimalarial, and antisteroidal pharmacological effects because they contain a reactive alpha, betaunsaturated carbonyl group. Due to the presence of the CO-CH=CH-ketoethylenic moiety, chalcone derivatives are sought-after species. Chalcone derivatives were created as a result of recent advances in heterocyclic chemistry and were biologically tested against specific targets. According to a survey of the literature, numerous chalcone-heterocycle hybrids show promise as potential new medication candidates because of their comparable or superior activities to those of the industry norms. So, based on previously established methods, this review may prove useful for the creation of fresh, strong therapeutic medications. This review's main focus is on the most recent synthesis of chalcones with benzene rings incorporating pyrazolines, which reveals their biological potential over the previous 10 years.

Ionic liquids have been found to provide a new platform for metal-and quinoline-free decarboxylation of various N-heteroaryl and aryl carboxylic acids under microwave irradiation in aqueous condition. The method was found to possess a wide substrate scope towards the synthesis of various pharmacologically and industrially important aromatic compounds including indoles, styrenes, stilbenes, and nitro-or hydroxyarene derivatives. The decarboxylation of indole and a-phenylcinnamic acids proceeded well without addition of any catalyst in neat 1-hexyl-3-methylimidazolium bromide ([hmim]Br) and 1-methylimidazolium p-toluenesulfonic acid ([Hmim]PTSA), respectively, while addition of a mild base like aqueous sodium hydrogen carbonate (NaHCO 3) to [hmim]Br further improved the decarboxylation of hydroxylated cinnamic and aromatic acid substrates. The developed methodology not only precludes the usage of toxic metal/quinoline and harsh organic bases but also offers several inherent benefits like recyclability of reagent system, reduction in waste and hazards, short reaction time besides ease of product recovery.

this protocol details the preparation of low-molecular-weight hydrogels (lMWGs) in which the gelation time and mechanical stiffness of the final gel can be tuned with the concentration of the catalyst used in the in situ formation of the hydrogelator. By altering the rate of formation of the hydrazone-based gelator from two water-soluble compounds-an oligoethylene functionalized benzaldehyde and a cyclohexane-derived trishydrazide-in the presence of acid or aniline as catalyst, the kinetics of gelation can be tuned from hours to minutes. the resulting materials display controllable stiffness in the 5-50 kpa range. this protocol works at ambient temperatures in water, at either neutral or moderately acidic pH (phosphate buffer, pH 5) depending on the catalyst used. the hydrazide and aldehyde precursors take a total of 5 d to prepare. the final gel is prepared by mixing aqueous solutions of the two precursors and can take between minutes and hours to set, depending on the catalytic conditions. We also describe analysis of the hydrogels by critical gel concentration (cGc) tests, rheology and confocal laser-scanning microscopy (clsM).

Ionic liquids have been found to provide a new platform for metal-and quinoline-free decarboxylation of various N-heteroaryl and aryl carboxylic acids under microwave irradiation in aqueous condition. The method was found to possess a wide substrate scope towards the synthesis of various pharmacologically and industrially important aromatic compounds including indoles, styrenes, stilbenes, and nitro-or hydroxyarene derivatives. The decarboxylation of indole and a-phenylcinnamic acids proceeded well without addition of any catalyst in neat 1-hexyl-3-methylimidazolium bromide ([hmim]Br) and 1-methylimidazolium p-toluenesulfonic acid ([Hmim]PTSA), respectively, while addition of a mild base like aqueous sodium hydrogen carbonate (NaHCO 3) to [hmim]Br further improved the decarboxylation of hydroxylated cinnamic and aromatic acid substrates. The developed methodology not only precludes the usage of toxic metal/quinoline and harsh organic bases but also offers several inherent benefits like recyclability of reagent system, reduction in waste and hazards, short reaction time besides ease of product recovery.

I am also thankful for the other members of the Roy lab. They have all taught me something and have made my time in the lab such an enjoyable experience. I am especially grateful for Sweta. She's been an amazing mentor and has always been there to answer my many questions, and I could not have made it without her. Lastly, I want to thank my friends and family, who have supported me throughout this entire process and helped motivate me on my worst days. Your support means more than you all can ever know.

Ionic liquids have been found to provide a new platform for metal-and quinoline-free decarboxylation of various N-heteroaryl and aryl carboxylic acids under microwave irradiation in aqueous condition. The method was found to possess a wide substrate scope towards the synthesis of various pharmacologically and industrially important aromatic compounds including indoles, styrenes, stilbenes, and nitro-or hydroxyarene derivatives. The decarboxylation of indole and a-phenylcinnamic acids proceeded well without addition of any catalyst in neat 1-hexyl-3-methylimidazolium bromide ([hmim]Br) and 1-methylimidazolium p-toluenesulfonic acid ([Hmim]PTSA), respectively, while addition of a mild base like aqueous sodium hydrogen carbonate (NaHCO 3) to [hmim]Br further improved the decarboxylation of hydroxylated cinnamic and aromatic acid substrates. The developed methodology not only precludes the usage of toxic metal/quinoline and harsh organic bases but also offers several inherent benefits like recyclability of reagent system, reduction in waste and hazards, short reaction time besides ease of product recovery.

A multi-step methodology for the synthesis of 4-acetyl-2(3H)-benzothiazolone was developed in order to prepare a new biomimetic analogue of benzoxazolone allelochemicals. The compound was prepared from commercially available o-toluidine in 23 % overall yield. The structure of 4-acethyl-2(3H)-benzothiazolone was confirmed by NMR spectroscopy and X-ray crystallography.

Ionic liquids have been found to provide a new platform for metal-and quinoline-free decarboxylation of various N-heteroaryl and aryl carboxylic acids under microwave irradiation in aqueous condition. The method was found to possess a wide substrate scope towards the synthesis of various pharmacologically and industrially important aromatic compounds including indoles, styrenes, stilbenes, and nitro-or hydroxyarene derivatives. The decarboxylation of indole and a-phenylcinnamic acids proceeded well without addition of any catalyst in neat 1-hexyl-3-methylimidazolium bromide ([hmim]Br) and 1-methylimidazolium p-toluenesulfonic acid ([Hmim]PTSA), respectively, while addition of a mild base like aqueous sodium hydrogen carbonate (NaHCO 3) to [hmim]Br further improved the decarboxylation of hydroxylated cinnamic and aromatic acid substrates. The developed methodology not only precludes the usage of toxic metal/quinoline and harsh organic bases but also offers several inherent benefits like recyclability of reagent system, reduction in waste and hazards, short reaction time besides ease of product recovery.

Although chalcones symbolize an important pharmacophore for variety of biological actions, however their analogues are also reported to be equally important for plethora of biological actions. In the present review, a comprehensive study of chalcones derived molecules (like pyrazoles, isoxazoles, pyridine, pyrimidine) their pharmacological actions, mechanism of action, structure activity relationship studies have been described. which includes anti-proliferative, anti-inflammatory, antioxidant, proapoptotic, anti-bacterial and anti-adhesive effects [18].

Light has a profound effect on us. We may not be conscious enough as regards the existences of many phototoxic substances and chemicals. A phototoxic substance is a chemical compound which becomes toxic when exposed to light. Phototoxicity may be manifested in various ways. Proper use of sunscreens may play a vital role in the prevention of many such reactions.

Background: The peracetylation is a simple chemical modification that can be used to enhance the bioavailability of hydrophilic products and to obtain safe and stable pro-drugs.Results: A totally green, solvent-free and catalyst-free microwave (MW)-assisted method for peracetylation of natural products such as oleuropein, alpha-hederin, quercetin and rutin is presented. By simply tuning the MW heating program, polyols with chemical diverse –OH groups or thermolabile functionalities can be peracetylated to improve the biological activity without degradation of the natural starting molecules. An evaluation of the process greenness was performed.Conclusion: The method is potentially universally applicable for green acetylation of hydrophilic biological molecules, potentially easily scalable for industrial applications, including pharmaceutical, cosmetic and food industry.

In the present work, some new imidazole derivatives (3i-xii) were synthesized as per design synthetic protocol scheme. The structures of newly prepared compounds were confirmed by modern analytical technique (IR, 1H-NMR, Mass spectral data) and elemental analysis, results found in full agreement with their assigned structures. All the synthetic compounds were screened for their antimicrobial activity against bacterial strains viz. Escherichia coli (E. coli, MTCC 2961), Staphylococcus aureus (S. aureus, MTCC 3160), Bacillus subtilis (B. subtilis, MTCC 121), Klebsiella pneumoniae (K. pneumoniae, MTCC 3040) and Micrococcus luteus (M. luteus, MTCC 7527)) and fungal strains viz. Candida albicans (C. albicans, MTCC 227), Aspergillus niger (A. niger, MTCC 277) and Aspergillus flavus (A. flavus, MTCC 418) ; results showed good to remarkable activity. The MIC (minimum inhibitory concentration) values were determined by comparison to ciprofloxacin (anti-bacterial) and fluconazole (anti-fungal...

Establishing structure–activity relationships is crucial to understand and optimize the activity of peptide-based inhibitors of protein–protein interactions. Single alanine substitutions provide limited information on the residues that tolerate simultaneous modifications with retention of biological activity. To guide optimization of peptide binders, we use combinatorial peptide libraries of over 4,000 variants—in which each position is varied with either the wild-type residue or alanine—with a label-free affinity selection platform to study protein–ligand interactions. Applying this platform to a peptide binder to the oncogenic protein MDM2, several multi-alanine-substituted analogs with picomolar binding affinity were discovered. We reveal a non-additive substitution pattern in the selected sequences. The alanine substitution tolerances for peptide ligands of the 12ca5 antibody and 14-3-3 regulatory protein are also characterized, demonstrating the general applicability of this ne...

Pyrazoline is a five member heterocyclic ring which is a versatile lead compound for designing potent bioactive agents. The review of the literature shows that the pyrazoline derivatives are quite stable and has inspired the chemists to synthesize the new pyrazoline derivatives. The past studies of pyrazoline derivative revealed that they are useful in pharmaceutical and agrochemical research. Pyrazoline derivatives display various pharmacological activities such as antitumor, antitubercular, antimicrobial, antibacterial, antiinflammatory and antioxidant etc. and the pharmacological activities of different synthesized compound are reviewed in the present article. Key words: Pyrazoline, antimicrobial, anti-inflammatory, antitumor activity

Diphenyl (4′-aminobiphenyl-4-ylamino)(pyridin-3-yl)methylphosphonate (1) was synthesized in 88% yield from reaction of pyridine-3-carboxaldehyde with benzidine and triphenylphosphite in the presence of titanium tetrachloride as a catalyst. Diazotization of 1 gave the corresponding diazonium salt 2 which was coupled with several hydroxyl or amino compounds to give the corresponding azo dyes 3-8 in 82-88% yields aer crystallization. e dyes produced were applied to polyesters as disperse dyes and their fastness properties were elevated.