A strategy for the synthesis of anthraquinone-based aryl-C-glycosides.

An efficient and simple strategy for the synthesis of a diverse range of anthraquinone-based aryl-C-glycosides has been developed. It involves the sequential Diels-Alder reaction and oxidative aromatization with the preformed glycosyl diene and dienophiles. The glycosyl dienes were obtained from simple sugars by tandem one-pot substitution and elimination reaction.

Accessing a small library of pluripotent 1,4,5-trisubstituted 1H-1,2,3-triazoles via diversity-oriented synthesis.

Diversity-oriented synthesis of structurally different, novel and small drug like molecules based on 1,4,5-trisubstituted 1,2,3-triazoles is developed in a streamlined sequence of different sets of reactions. The method involves the use of simple, readily available and highly economical substrates and reagents. The molecules developed herein have potential to be exploited either as chemotherapeutic agents or as scaffolds for other biologically active compounds.

Synthesis and bio-evaluation of alkylaminoaryl phenyl cyclopropyl methanones as antitubercular and antimalarial agents.

A series of 4-alkylaminoaryl phenyl cyclopropyl methanones (6a-6u and 8a-8c) were synthesized from 4-fluorochalcones (3a and 3b) by cyclopropanation of double bond followed by nucleophilic substitution of F with different amines. The compounds were screened for their antitubercular and antimalarial activities against Mycobacterium tuberculosis H37Rv and Plasmodium falciparum 3D7 strains in vitro respectively. Several compounds (6a, 6d-6h, 6p, 6q and 8a-8c) exhibited good in vitro antitubercular activities with MIC values 3.12-12.5µg/mL and preferentially inhibited the growth of P. falciparum in vitro (4a, 4c, 6a-6d, 6f, 6s, 8a and 8c) with IC50 as low as 0.080 and 0.035µg/mL and SI values 4975 and 6948, respectively. Molecular docking studies and in vitro evaluation against FAS-II enzymes using reporter gene assays were carried out to elucidate the mode of action of these molecules. Two compounds 4a and 6g showed significant inhibition at 25µM concentration of the compound.

Triazole analog 1-(1-benzyl-5-(4-chlorophenyl)-1H-1,2,3-triazol-4-yl)-2-(4-bromophenylamino)-1-(4-chlorophenyl)ethanol induces reactive oxygen species and autophagy-dependent apoptosis in both in vitro and in vivo breast cancer models.

Autophagy is considered as an important cell death mechanism that closely interacts with other common cell death programs like apoptosis. Critical role of autophagy in cell death makes it a promising, yet challenging therapeutic target for cancer. We identified a series of 1,2,3-triazole analogs having significant breast cancer inhibition property. Therefore, we attempted to study whether autophagy and apoptosis were involved in the process of cancer cell inhibition. The lead molecule, 1-(1-benzyl-5-(4-chlorophenyl)-1H-1,2,3-triazol-4-yl)-2-(4-bromophenylamino)-1-(4-chlorophenyl)ethanol (T-12) induced significant cell cycle arrest, mitochondrial membrane depolarization, apoptosis and autophagy in MCF-7 and MDA-MB-231 cells. T-12 increased reactive oxygen species and its inhibition by N-acetyl-L-cysteine protected breast cancer cells from autophagy and apoptosis. Autophagy inhibitor, 3-methyladenine abolished T-12 induced apoptosis, mitochondrial membrane depolarization and reactive oxygen species generation. This suggested that T-12 induced autophagy facilitated cell death rather than cell survival. Pan-caspase inhibition did not abrogate T-12 induced autophagy, suggesting that autophagy precedes apoptosis. In addition, T-12 inhibited cell survival pathway signaling proteins, Akt, mTOR and Erk1/2. T-12 also induced significant regression of tumor with oral dose of as low as 10mg/kg bodyweight in rat mammary tumor model without any apparent toxicity. In presence of reactive oxygen species inhibitor (N-acetyl-L-cysteine) and autophagy inhibitor (chloroquine), T-12 induced tumor regression was significantly decreased. In conclusion, T-12 is a potent inducer of autophagy-dependent apoptosis in breast cancer cells both in vitro and in vivo and can serve as an important lead in development of new anti-tumor therapy.

Diversity oriented synthesis of pyran based polyfunctional stereogenic macrocyles and their conformational studies.

A new approach to synthesize a homologous series of 14-, 15-, and 16-membered drug-like, macrocyclic glycoconjugates involving TBAHS promoted azide-propenone intramolecular cycloaddition in designed C-glycopyranosyl butenones from a simple sugar d-glucose and d-mannose is reported.

Application of Huisgen (3+2) cycloaddition reaction: synthesis of 1-(2,3-dihydrobenzofuran-2-yl-methyl [1,2,3]-triazoles and their antitubercular evaluations.

1,4-Disubstituted-1,2,3-triazoles (3-27) have been synthesized by [3+2] cycloaddition of different 2-(azidomethyl)-dihydronaptho(benzo)furans (2a, 2b, 2c and 2d) with different alkynes. All the compounds were screened for antitubercular activity against Mycobacterium tuberculosis H37Rv. Compounds 2a, 7, 9, 12 and 14 exhibited antitubercular activities with MIC ranging from 12.5 to 3.12 microg/ml.

Towards novel antifilarial drugs: challenges and recent developments.

Filariasis is caused by thread-like nematode worms, classified according to their presence in the vertebrate host. The cutaneous group includes Onchocerca volvulus, Loa loa and Mansonella streptocerca; the lymphatic group includes Wuchereria bancrofti, Brugia malayi and Brugia timori and the body cavity group includes Mansonella perstans and Mansonella ozzardi. Lymphatic filariasis, a mosquito-borne disease, is one of the most prevalent diseases in tropical and subtropical countries and is accompanied by a number of pathological conditions. In recent years, there has been rapid progress in filariasis research, which has provided new insights into the pathogenesis of filarial disease, diagnosis, chemotherapy, the host-parasite relationship and the genomics of the parasite. Together, these insights are assisting the identification of novel drug targets and the discovery of antifilarial agents and candidate vaccine molecules. This review discusses the antifilarial activity of various chemical entities, the merits and demerits of antifilarial drugs currently in use, their mechanisms of action, in addition to antifilarial drug targets and their validation.