N. Renuka

Synthesis and biological evaluation of novel formyl-pyrazoles bearing coumarin moiety as potent antimicrobial and antioxidant agents.

A series of coumarin appended formyl-pyrazoles 14-18 were synthesized by a simple and accessible approach. The reaction of 8-acetyl-4-methyl-7-hydroxy coumarin 3 and phenyl hydrazine hydrochlorides 4-8 produces the intermediate compounds 8-acetyl-4-methyl-7-hydroxy coumarin hydrazones 9-13. The reaction of compounds 9-13 and DMF in the presence of POCl3 yielded formyl-pyrazoles bearing coumarin moiety 14-18 in good yield. The synthesized new compounds 14-18 and the intermediates 8-acetyl-4-methyl-7-hydroxy coumarin hydrazones 9-13 prepared were screened in vitro for their antibacterial, antifungal antioxidant activities. The compounds 12 and 17 having chloro substitution exhibited promising antifungal and antibacterial activity against the different organisms tested. The compound 17 showed remarkable DPPH radical scavenging ability.

Synthesis of lignan conjugates via cyclopropanation: Antimicrobial and antioxidant studies.

Ethyl 2-(4-methoxyphenyl)-3-(thiophene-2-carbonyl)cyclopropanecarboxylates 2(a-f) and ethyl 4-aryl-7-oxo-4,5,6,7-tetrahydrobenzo[b]thiophene-5-carboxylates 4(a-f) were synthesized by simple procedure. The synthesized new compounds were screened in vitro for their antimicrobial and antioxidant activities. The compounds 2b and 4f showed excellent antibacterial activity; while 2b and 4f showed remarkable antifungal properties. The results of antioxidant activity studies revealed that compounds 4b and 4f manifested profound antioxidant potential. The docking studies were done for the final compounds. The ADME result indicates that all these molecules possess pharmaceutical properties in the range of 95% of drugs.

Synthesis of coumarin appended pyrazolyl-1,3,4-oxadiazoles and pyrazolyl-1,3,4-thiadiazoles: Evaluation of their in vitro antimicrobial and antioxidant activities and molecular docking studies

A series of semicarbazones, thiocarbazones, 1,3,4-oxadiazoles, and 1,3,4-thiadiazoles bearing coumarin and pyrazole moiety have been synthesized. The new synthesized compounds were screened in vitro for their antimicrobial and antioxidant activities. Preliminary studies showed that among the synthesized new compounds, chloro-substituted thiosemicarbazone showed excellent activities against all tested organisms; at the same time, methyl substituted thiosemicarbazone showed greater activity against E. coli. Chloro-substituted 1,3,4-oxadiazole and 1,3,4-thiadiazole demonstrated greater DPPH and hydroxyl radical scavenging abilities. Molecular docking studies indicate that 1,3,4-oxadiazoles and 1,3,4-thiadiazoles manifest better interaction with CAT (catalase) and GPx (glutathione peroxidase) than that with SOD (superoxide dismutase). Studies on the antimicrobial and antioxidant activities of the synthesized compounds compared with those of their starting compounds are discussed.

2-(4-Fluoro­phen­yl)-4-(thio­phen-2-yl)-2,3-di­hydro-1,5-benzothia­zepine

In the title compound, C19H14FNS2, the seven-membered thiazepine ring adopts a slightly distorted twist boat conformation. The dihedral angle between the benzene rings is 53.6 (1)°. The mean plane of the thiazepine ring is twisted by 34.3 (7)° and 36.6 (7)° from the benezene rings. A C—H⋯F interaction generates stacking of molecules along the ab plane.

Synthesis of New 3, 5-Diaryl-4, 5-Dihydroisoxazole-4- Carbonitriles via 1, 3-Dipolar Cycloaddition Reaction

Abstract : Aromatic aldoximes 1a-i undergo oxidative dehydrogenation with CrO 2 to give nitrile oxides, which are trapped in situ by 4-methoxycinnamonitrile 2 to afford of ethyl 3,5-diaryl-4,5-dihydroisoxazole-4-carbonitriles 3a-i in good yield . Key words : Isoxazoles, isoxazolines, magtreive TM , antimicrobial, antioxidant. I. Introduction Isoxazoles and isoxazolines are very useful heterocycles in organic and heterocyclic chemistry [1]. Isoxazolines also serves as important building blocks for the synthesis of various biologically active molecules [2]. The isoxazoles are known to exhibit significant number of biological applications such as hypoglycemic, analgesic, anti-inflammatory and HIV-inhibitory activity [3], also found to exhibit antibacterial [4], antifungal [5], antioxidant [6], potent selective agonists at human cloned dopamine D4 receptors [7], COX-2 inhibitory [8], antinociceptive [9], anticancer [10], and antibiotic, antitumour, insecticidal activities [1,2]. They serve as prodrug for the anti-arithretic agent [11]. Vijay V. Dabholkar and co-workers [12] reported the synthesis and their antimicrobial activity of fused isoxazolines. Joshi and et al [13] reported that isoxazoles acts as potential antitubercular agents. The most convenient synthesis of isoxazoline and isoxazole ring system has been executed in the literature via 1, 3-dipolar cycloaddition reactions of alkenes and alkynes with nitrile oxides generated

An Accessible Route for the Synthesis of Novel Lignan Derivatives and Their Biological Evaluation

2-(Aryl(thiophen-2-yl)methyl)succinic acids (4a – 4d), 3-(aryl(thiophen-2-yl)methyl)dihydrofuran-2,5-diones (5a – 5d), 7-aryl-4-oxo-4,5,6,7-tetrahydrobenzo[b]thiophene-6-carboxylic acids (6a – 6d), and ethyl 7-aryl-4-oxo-4,5,6,7-tetrahydrobenzo[b]thiophene-6-carboxylates (7a – 7d) were synthesized via Stobbe condensation of aryl(thiophen-2-yl)methanones and diethyl succinate. The newly synthesized compounds (5a – 5d, 6a – 6d, and 7a - 7d) were screened in vitro for their antimicrobial and antioxidant properties. Compounds 5b, 6d, and 7d exhibited promising antifungal and antibacterial activity against various microorganisms tested. Compounds 7d and 7b showed remarkable DPPH radical scavenging abilities.