[Show abstract][Hide abstract] ABSTRACT: From a high-throughput screening (HTS) hit with inhibitory activity against virus-induced cytophathic in the low micromolar range, we have developed a potent anti-influenza lead through careful optimization without compromising the drug-like properties of the compound. An orally bioavailable compound was identified as a lead agent with nanomolar activity against influenza, representing a 140-fold improvement over the initial hit.
[Show abstract][Hide abstract] ABSTRACT: By using a cell-based high throughput screening campaign, a novel angelicin derivative 6a was identified to inhibit influenza A (H1N1) virus induced cytopathic effect in Madin-Darby canine kidney cell culture in low micromolar range. Detailed structure-activity relationship studies of 6a revealed that the angelicin scaffold is essential for activity in pharmacophore B, while meta-substituted phenyl/2-thiophene rings are optimal in pharmacophore A and C. The optimized lead 4-methyl-9-phenyl-8-(thiophene-2-carbonyl)-furo[2,3-h]chromen-2-one (8g, IC(50) = 70 nM) showed 64-fold enhanced activity compared to the high throughput screening (HTS) hit 6a. Also, 8g was found effective in case of influenza A (H3N2) and influenza B virus strains similar to approved anti-influenza drug zanamivir (4). Preliminary mechanistic studies suggest that these compounds act as anti-influenza agents by inhibiting ribonucleoprotein (RNP) complex associated activity and have the potential to be developed further, which could form the basis for developing additional defense against influenza pandemics.
Journal of Medicinal Chemistry 02/2010; 53(4):1519-33. · 5.48 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: BPR0L075 (2) is a potential anticancer drug candidate designed from Combretastatin A-4 (1) based on the bioisosterism principle. Metabolites of 2, proposed from in vitro human microsome studies, were synthesized, leading to the identification of metabolite-derived analogue 10 with 40-350 pM potency against various cancer cell lines. Insights gained from the major inactive metabolite of 2 led to the development of 29, with better pharmacokinetics and improved potency in the tumor xenograft model than 2.
Journal of Medicinal Chemistry 08/2009; 52(15):4941-5. · 5.48 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The synthesis and study of the structure-activity relationships of two new classes of synthetic antitubulin compounds based on 1-aroylindole and 3-aroylindole skeletons are described. Lead compounds 3, 10, and 14 displayed potent cytotoxicities with IC50 = 0.9-26 nM against human NUGC3 stomach, MKN45 stomach, MESSA uterine, A549 lung, and MCF-7 breast carcinoma cell lines. The inhibition of proliferation correlated with in vitro polymerization inhibitory activities. Structure-activity relationships revealed that 6-methoxy substitution of 3-aroylindoles and 5-methoxy substitution of 1-aroylindoles contribute to a significant extent for maximal activity by mimicking the para substitution of the methoxy group to the carbonyl group in the case of aminobenzophenones. Addition of a methyl group at the C-2 position on the indole ring exerts an increased potency. The 3,4,5-trimethoxybenzoyl moiety was necessary for better activity but not essential and can be replaced by 3,5-dimethoxybenzoyl and 3,4,5-trimethoxybenzyl moieties. We conclude that 1- and 3-aroylindoles constitute an interesting new class of antitubulin agents with the potential to be clinically developed for cancer treatment.
Journal of Medicinal Chemistry 09/2004; 47(17):4247-57. · 5.48 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: A new series of 3-aminobenzophenone compounds as potent inhibitors of tubulin polymerization was discovered based on the mimic of the aminocombretastatin molecular skeleton. Lead compounds 5 and 11, with alkoxy groups at the C-4 position of B-ring, were potent cytotoxic agents and inhibitors of tubulin polymerization through the binding to the colchicine-binding site of tubulin. The corresponding antitubulin activities of 5 and 11 were similar to or greater than combretastatin A-4 and AVE-8063. Replacement of the methoxy group with a chloro group in the B ring of aminobenzopheneones (3, 8, and 9) caused drastic decrease in cytotoxic and antitubulin activity except in compounds 4 and 10, which could result from a unique alignment between chloro and amino groups located at the para position to each other. SAR information revealed that introduction of an amino group at the C-3 position in B ring of benzophenones, in addition to a methoxy group at the C-4 position, plays an important role for maximal cytotoxicity.
Journal of Medicinal Chemistry 06/2004; 47(11):2897-905. · 5.48 Impact Factor