On observing table-1for IR of copper complexes, it was revealed that the complexation involves the oxygen of oxo -group at 4th position and N-of hydrazone group .During these complex formation, it seems that the ligands react through their
enolic form because a strong peak appeared in all ligands, at ~1498 cm-1, due to -NCO-shifted towards lower frequency 1452 cm-1 after complex formation, this C=O was not involved in metal complexation.
NSAID classification Non-selective inhibition Acetic acid Proprionic acid Fenamate derivatives derivatives derivatives * Diclofenac * Fenoprofen * Meclofenamate * Etodolac * Flurbiprofen * Mefenamic acid * Indomethacin * Ibuprofen * Sulindac * Ketoprofen * Tolmetin * Naproxen * Oxaprozin Naphthyl alkanone Salicylates * Nabumetone * Aspirin * Diflunisal * Choline magnesium trisalicylate * Salicylate
Enolic acid derivatives * Piroxicam * Meloxicam Selective COX-2 inhibition * Celecoxib * Rofecoxib Table 9.
Antidiabetic
enolic glucoside of phenylpyruvic acid.
Moreover, an interesting observation appeared in the IR spectra of Schiff's base derived from the isatin 6, where broad absorption bands shown at 3214-3454 [cm.sup.-1] were attributed to the contribution of
enolic OH and NH groups.
The proposal pathway of the reaction is given as Scheme 1 where potassium permanganate in alkaline medium oxidizes FEX from
enolic to ketonic form and yields the bluish green color due to the production of manganate ion.
Polysaccharide, protein, and reducing sugar existed in the PFVM while no phenol hydroxyl, starch, uronic acid, and
enolic hydroxyl existed in it.
There action is initiated by the nucleophilic attack of sulphydryl electrons on
enolic carbon atom of the [beta]-diketone followed by loss of water molecule.
Meloxicam is a nonsteroidal anti-inflammatory drug of the
enolic acid class of compounds used in the treatment of rheumatoid arthritis and osteoarthritis.
On TLC the compound gave a violet spot with p-nitroaniline spray reagent indicating that it is either phenolic or
enolic, a dark brown colour with anisaldehyde spray reagent and a bright yellow colour with, 2,4 DNP spray reagent, suggesting that a carbonyl group might be present.
From the literature and the types of vibration found in Table 2, it can be concluded that the extracted humic acid contains a variety of functional groups, including carboxylic acid (COOH), phenolic hydroxy (OH),
enolic (OH), alcoholic (OH), quinone, hydroxyl quinone, lactone, and ether [14].
Humified material is often a stronger sorbent due to the presence of oxygen-containing functional groups such as -COOH, phenolic, aliphatic,
enolic, -OH, and C=O.
