Publications by authors named "Venkanna A"

Lysine methyltransferases are important regulators of epigenetic signaling and are emerging as a novel drug target for drug discovery. This work demonstrates the positioning of novel 1,5-oxaza spiroquinone scaffold into selective SET and MYND domain-containing proteins 2 methyltransferases inhibitors. Selectivity of the scaffold was identified by epigenetic target screening followed by SAR study for the scaffold.

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As a non-covalent interaction of a chiral scaffold in catalysis, pnicogen bonding of cinchonidine (), a cinchona alkaloid, was simulated to consider whether the interaction can have the potential controlling enantiotopic face like hydrogen bonding. Among five reactive functional groups in , two stable complexes of the hydroxyl group (X-epi-CD1) at C and of the quinoline ring (X-epi-CD2) at N with pnictide family analytes [X = substituted phosphine (PX), i.e.

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In-house 1,5-oxaza spiroquinone 1, with spiro[5.5]undeca ring system, was announced as an unprecedented anti-inflammatory scaffold through chemistry-oriented synthesis (ChOS), a chemocentric approach. Herein, we studied how to best position the spiro[5.

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Here we first time report an unprecedented and unnatural six-membered 1,5-oxaza spiroquinone scaffold with structural novelty, a convenient and efficient synthetic route was developed for the synthesis of new 1,5-oxaza spiroquinone derivatives (1a-1r) in high yields from readily available starting materials. The logic of the present work consists of (1) the identification of a promising unprecedented scaffold from privileged scaffolds of biological active molecules through our 'Chemistry-oriented Synthesis' (ChOS) approach, a compensatory strategy for target-based drug discovery, (2) the positioning of the identified 1,5-oxaza spiroquinone scaffold on neuroinflammation and neurodegenerative disease through nitric oxide (NO) inhibitory activity without cytotoxicity in hyper-activated microglia (IC of NO production: 0.07-1.

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In this study, pharmacophore based 3D QSAR models for human acetylcholinesterase (AChE) inhibitors were generated, with good significance, statistical values (r = 0.73) and predictability (q = 0.67).

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Rational drug design against a determined target (disease, pathway, or protein) is the main strategy in drug discovery. However, regardless of the main strategy, chemists really wonder how to maximize the utility of their new compounds by drug repositioning them as clinical drug candidates in drug discovery. In this study, we started our drug discovery "from curiosity in the chemical structure of a drug scaffold itself" rather than "for a specific target".

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A series of Nimbolide-triazole conjugates were synthesized through copper(I)- catalyzed azide-alkyne "click" chemistry approach and these derivatives (2-4, 2a-2l) were characterized using modern spectroscopic techniques. Antifeedant activities of these derivatives were studied on Tobacco Caterpillar, Spodoptera litura (F.) using no-choice leaf disk bioassay.

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As part of pharmacological-phytochemical integrated studies on medicinal flora, Gomisin B (1) was isolated as major phytochemical lead from schisandra grandiflora, a plant traditionally used in different Asian systems of medicine. A series of 1,2,3-triazoles derivatives were synthesized at the C-7' position of the gomisin B core through diastereoselective Michael addition followed by regioselective Huisgen 1,3-dipolar cycloaddition reactions. All these triazolyl derivatives (5a-5q) were well characterized using modern spectroscopic techniques and evaluated for their anti-cancer activity against a panel of five human cancerous cell-lines.

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A comprehensive reinvestigation of chemical constituents from CHCl-soluble extract of Cipadessa baccifera led to the isolation of two new limonoids 1, 2 together with six known compounds 3-8. Their structures were established on the basis of extensive analysis of spectroscopic (IR, MS, 2D NMR) data. Further, a series of cipaferen G (3) derivatives were efficiently synthesized utilizing Yamaguchi esterification (2, 4, 6-trichlorobenzoyl chloride, EtN, THF, DMAP, toluene) at the C-3 position of the limonoids core, which is being reported for the first time.

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Free radicals scavenging and advanced glycation end-products (AGEs) inhibitory potentials in crude chloroform extract of Schisandra grandiflora were evaluated. Bioassay-guided isolation of the chloroform extract led to the identification of 24 compounds. Among the isolates, ( ± ) gomisin M1, arisantetralone C and D, macelignan, saurulignan B and SZ-MO displayed potent-free radical scavenging as well as AGEs inhibitory potentials.

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Phytochemical investigation of hexane extract from the fruits of Schisandra grandiflora afforded three novel sesquiterpenes (1-3) along with the three known compounds (4-6). The structures of these isolates were determined by extensive analysis of spectroscopic data (1D, 2D NMR). Further, a series of triazole analogues of 3 and 4 were prepared using "Click" reaction protocol.

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Phytochemical investigation of ethanolic extract from the fruits of Schisandra chinensis led to the isolation of four new sesquiterpenes (1-4); their structures were determined by a combination of NMR (1D and 2D) and MS spectroscopic techniques. In addition, all these isolates were screened for their cytotoxic activities against MCF-7, Caco-2, Hela, Lncap, Hep G2 and MDA-MB231 cancer cell lines. Results indicated that compounds 2 and 3 displayed potent cytotoxic activity against Caco2 cell lines with IC50 values of 17.

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Six new methyl angolensate type (1-6) and three new mexicanolide-type (7-9) limonoids, along with six known limonoids (10-15), were isolated from the seeds of Cipadessa baccifera. The structures of all these compounds were established by extensive 1D, 2D NMR, and HRESIMS experiments, and structures of 11 and 13 were further confirmed by a single crystal X-ray diffraction analysis, which are reported for the first time. The cytotoxic activities of these isolates were also studied against A549, MCF7, ME-180, HT-29, B-16, ACHN cancer cell lines using MTT assay, and results indicated that compounds 4, 10, and 14 displayed potent cytotoxic activity against B-16, ACHN cell lines with an IC50 values of 8.

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