Browsing by Author "Satish K. Awasthi"

Now showing 1 - 12 of 12

1-Prop-2-ynyl-1H-benzimidazol-2-amine
(2011) Alka Agarwal; Manavendra K. Singh; Satish K. Awasthi
In the title compound, C10H9N3, the benzimidazol-2-amine and CH2 -C≡CH units are not coplanar, with a dihedral angle of 60.36°between their mean planes. The crystal structure is stabilized by intermolecular N-H⋯N hydrogen bonding and π-π interactions [centroid-centroid distances 3.677 (1) and 3.580 (1) Å], assembling the molecules into a supra-molecular structure with a three-dimensional network.
2-(4-Chlorophenyl)chromen-4-one
(2011) Shailja Singh; Manavendra K. Singh; Alka Agarwal; Satish K. Awasthi
The title compound, C15H9ClO2, is a synthetic flavonoid obtained by the cyclization of 3-(4-chloro-phen-yl)-1-(2-hy- droxy-phen-yl)prop-2-en-1-one. The 4-chloro-phenyl ring is twisted at an angle of 11.54°with respect to the chromen-4-one skeleton. In the crystal, pairs of molecules are interconnected by weak Cl⋯Cl interactions [3.3089 (10) Å] forming dimmers which are further peripherally connected through intermolecular C-H⋯O hydrogen bonds..
(2E)-1-(4-Amino-phen-yl)-3-(2,4-dichloro-phen-yl)prop-2-en-1-one
(2011) Shailja Singh; Manavendra K. Singh; Alka Agarwal; Firasat Hussain; Satish K. Awasthi
The title compound, C 15H 11C l2NO, is approximately planar (r.m.s. deviation = 0.062 Å) and contains a single C=C double bond in a trans (E) configuration. The crystal packing is stabilized by intermolecular N - H⋯N and N - H⋯O inter-molecular hydrogen bonding. © Singh et al. 2011.
Benzyl N-(3-chloro-4-fluorophenyl)-carbamate
(2011) Manavendra K. Singh; Alka Agarwal; Satish K. Awasthi
The title compound, C14H11ClFNO2, the phenyl ring (A), the chlorofluorophenyl ring (B) and the central ketone O/C/O group (C) are not coplanar, with dihedral angles B/C = 31.6 (2), A/B = 21.3 (2) and A/C = 50.1 (2)°. The crystal packing is stabilized byN-H⋯O and C-H⋯O interactions.
Design, synthesis and antimicrobial activity of novel benzothiazole analogs
(2013) Manavendra K. Singh; Ragini Tilak; Gopal Nath; Satish K. Awasthi; Alka Agarwal
In an attempt to design and synthesize a new class of antimicrobials, dialkyne substituted 2-aminobenzothiazole was reacted with various substituted aryl azides to generate a small library of 20 compounds (3a-t) by click chemistry. Structures of the newly synthesized compounds were established on the basis of spectral data. These compounds were screened for their antibacterial activity against Gram+ bacteria (Staphylococcus aureus and Enterococcus faecalis), Gram- bacteria (Salmonella typhi, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Shigella boydii) and antifungal activity against Candida tropicalis, Candida albicans, Candida krusei, Cryptococcus neoformans) as well as molds (Aspergillus niger, Aspergillus fumigatus). The compound 3e showed maximum potency against all Gram+/gram- bacterial strains with MIC value 3.12 μg/ml, which is two fold more active as compared to standard drug ciprofloxacin (MIC 6.25 μg/ml). However, all compounds were found ineffective against S. boydii (clinical isolate). Further, only one compound 3n was found to be the most active against all fungal strains with MIC value in the range of 1.56 μg/ml-12.5 μg/ml while the remaining compounds showed moderate to weak antifungal activity. © 2013 Elsevier Masson SAS. All rights reserved.
Efficient: N -formylation of primary aromatic amines using novel solid acid magnetic nanocatalyst
(Royal Society of Chemistry, 2020) Jitendra Kumar Yadav; Priyanka Yadav; Satish K. Awasthi; Alka Agarwal
Sulfonic acid functionalized over biguanidine fabricated silica-coated heterogeneous magnetic nanoparticles (NP@SO3H) have been synthesized, well characterized and explored for the first time, as an efficient and recyclable catalyst for N-formylation of primary amines under mild reaction conditions. Exploiting the magnetic nature of Fe3O4, the prepared catalyst was readily recovered from the reaction mixture via an external magnet. The catalyst can be reused for up to six cycles without any substantial loss of catalytic activity. The cost effectiveness, simple methodology, wide substrate tolerance, excellent yield and easy work-up are the additional advantages of present catalytic system. This journal is © The Royal Society of Chemistry.
In vivo antifilarial activity of some cyclic and acylic alcohols
(2011) Alka Agarwal; Satish K. Awasthi; P.K. Murthy
The filarial nematodes, Wuchereria bancrofti, Brugia malayi, and Brugia timori are the causative agents of lymphatic filariasis. 2-Substituted propanol, cyclohexanol, and cyclooctanol compounds were evaluated for microfilaricidal and macrofilaricidal activity in vivo against Acanthocheilonema viteae and Litomosoides carinii in rodents. In the cyclohexanol series, 2-(piperidin-1-yl) cyclohexanol (2b) showed 88.9% macrofilaricidal activity against A. viteae in vivo, while cyclooctanol series, 2-(4- benzyl piperdin-1-yl) cyclooctanol (2f) showed 100% macrofilaricidal activity against A. viteae. Further, compounds 1-(furan-2-ylamino) ethanol (4a) and 1-(4-benzylpiperidin- 1-yl)-ethyl acetate (5b) showed 81.3% and 83.4% macrofilaricidal activity, respectively, against the same parasite. Interestingly, compounds 2f and 4a showed significant sterilization of female worms in A. viteae. However, these compounds were found inactive against L. carinii. Therefore, the new class of compounds appeared to have promising antifilarial activity. © 2011 Springer Science+Business Media, LLC.
Insights into the interaction of potent antimicrobial chalcone triazole analogs with human serum albumin: Spectroscopy and molecular docking approaches
(Royal Society of Chemistry, 2019) Priyanka Yadav; Jitendra Kumar Yadav; Alka Agarwal; Satish K. Awasthi
Mechanistic insights into the interaction of five previously chemically synthesized triazole-linked chalcone analogs (CTs) with human serum albumin (HSA) were sought using various spectroscopic techniques (UV-visible absorption, fluorescence, and circular dichroism) and molecular docking. The fluorescence quenching experiments performed at three different temperatures (288, 298 and 308 K) revealed the static mode of quenching and the binding constants (Kb ∼ 106-9) obtained indicated the strong affinity of these analogs for HSA. Furthermore, significant changes in the secondary structure of HSA in the presence of these analogs were also confirmed by far UV-CD spectroscopy. The thermodynamic properties such as the enthalpy change (ΔH°), Gibbs free energy change (ΔG°) and entropy change (ΔS°) revealed that the binding process was spontaneous and exothermic. Theoretical studies, viz., DFT and molecular docking corroborated the experimental results as these five analogs could bind with HSA through hydrogen bonding and hydrophobic interactions. The present study provides useful information regarding the interaction mechanism of these analogs with HSA, which can provide a new avenue to design more potent chalcone triazole analogs for use in the biomedical field. © The Royal Society of Chemistry 2019.
N-(Prop-2-yn-1-yl)-1,3-benzothiazol-2-amine
(2011) Alka Agarwal; Manavendra Kumar Singh; Suryabhan Singh; S. Bhattacharya; Satish K. Awasthi
In the title compound, C 10H 8N 2S, the 2-amino-benzothia-zole and propyne groups are not coplanar [dihedral angle = 71.51 (1)°]. The crystal structure is stabilized by strong inter-molecular N-H⋯N hydrogen bonds and C-H⋯C, C-H⋯π and F-type aromatic-aromatic [centroid-centroid distance = 3.7826 (12) Å] interactions are also observed.
Short report: antifilarial activity of 1,3-diarylpropen-1-one: effect on glutathione-s-transferase, a phase ii detoxification enzyme
(American Society of Tropical Medicine and Hygiene, 2009) Satish K. Awasthi; Nidhi Mishra; Sandeep Kumar Dixit; Alka Singh; Marshleen Yadav; Sudhanshu S. Yadav; Sushma Rathaur
Chalcone derivatives were evaluated for their antifilarial activity on Setaria cervi using glutathione-s-transferase (GST) as a drug target. The compounds 1-(4-benzotriazol-1-yl-phenyl)-3-(4-methoxyphenyl)prop-2-en-1-one (5), and 3-(4-methoxyphenyl)-1-(4-pyrrolidin-1-yl-phenyl) prop-2-en-1-one (7) showed a significant suppression (P < 0.01) in GST activity of adult female parasite extract at 3 μM concentration in vitro. However, GST activity was detected along with depletion in GSH level. Except Compounds 1 and 2, all exhibited a significant effect on the motility and viability of adult parasites. Compounds 3-(4-chlorophenyl)-1-(4-piperidin-1-yl-phenyl)prop-2-en-1-one (3), 1-4-ben-zotriazol-1-yl-phenyl)-3-(4-methoxyphenyl)prop-2-en-1-one (5), and 3-(4-methoxyphenyl)-1-(4-pyrrolidin-1-yl-phenyl) prop-2-en-1-one (7) exhibited major irreversible effects on viability and resulted in parasite death and also inhibited the GST activity by 84-100% in vitro. We report for the first time the antifilarial activity of chalcones on GST of adult para-sites. This study also strengthens our previous findings where GST is reported as a potential drug target for antifilarials. Copyright © 2009 by The American Society of Tropical Medicine and Hygiene.
Synthesis and in vitro antiplasmodial activities of fluoroquinolone analogs
(2012) Sandeep K. Dixit; Nidhi Mishra; Manish Sharma; Shailja Singh; Alka Agarwal; Satish K. Awasthi; V.K. Bhasin
Fluoroquinolone analogs were synthesized by simple alkylation followed by click chemistry and evaluated for their antimalarial in vitro against chloroquine sensitive strain of Plasmodium falciparum while ciprofloxacin was used as standard. Our results showed that the compound 12 was found most active with IC 50 value of 1.33 μg/mL while ciprofloxacin showed IC 50 = 8.81 μg/mL. Therefore, screening of either known or unknown quinolone/fluoroquinolone analogs are worthwhile to find more potent antimalarial drugs which might prove useful in the treatment of mild or severe malaria in human either alone or in combination with existing antimalarial drugs. © 2012 Elsevier Masson SAS. All rights reserved.
Tert-Butyl N-{2-[bis-(prop-2-yn-1yl)amino]phenyl}carbamate
(2011) Manavendra K. Singh; Alka Agarwal; Charu Mahawar; Satish K. Awasthi
In the crystal of the title compound, C17H20N 2O2, the molecules are linked by C-H⋯O interactions. Intra-molecular C-H⋯O and N-H⋯N hydrogen bonds also occur.