The interaction of tubulin-microtubule poison complexes with anti-tubulin antisera has been investigated using radioimmunoassay. The binding of the major antiserum used in this study to tubulin does not interfere with the binding of colchicine to the tubulin or affect the decay of the colchicine-binding activity of the tubulin. Conversely, if colchicine is incubated with the tubulin, forming tu...

Some potent chemotherapy drugs including tubulin-binding agents had been developed from nature plants, such as podophyllotoxin and paclitaxel. However, poor cytotoxic selectivity, serious side-effects, and limited effectiveness are still the major concerns in their therapeutic application. We developed a fully synthetic podophyllotoxin derivative named Ching001 and investigated its anti-tumor g...

* Author for correspondence: Department of Biochemical Engineering and Biotechnology, Indian Institute of Technology Delhi, New Delhi-110016, India. Tel: 91-11-26591707, Fax: 91-11-26582286, Email: vbisaria@dbeb. iitd.ac.in. Abstract. Arbuscular mycorrhizal fungi (AMF) are widespread and the most ancient symbiosis in the world. However, because of the absence of authentic pure cultures, commerc...

Podophyllum hexandrum Royle syn P. emodi Wall. ex Hook.f. & Thoms. is an endangered and valuable medicinal plant, distributed in the Himalayan zone at an altitudes ranging from 2000 to 4000 m above MSL. It is an herbaceous and rhizomatous perennial plant also found in few pockets of Indian cold desert (Ladakh and Lahaul-Spiti). Its rhizomes and roots contain about 8% of podophylloresin from whi...

Photocatalytic hydrogen atom transfer is a very powerful strategy for the regioselective C(sp3)–H functionalization of organic molecules. Herein, we report on unprecedented combination decatungstate photocatalysis with oxidative radical–polar crossover concept to access direct net-oxidative heteroarylation. The present methodology demonstrates high functional group tolerance (40 examples) and s...

Despite prevention and treatment options, breast cancer (BC) has become one of the most important issues in the present day. Therefore, the need for more specific and efficient compounds remains paramount. We evaluated four previously isolated aryltetralin lignans: 5'-demethoxy-β-peltatin-A-methylether (1), acetylpodophyllotoxin (2), 5'-demethoxydeoxypodophyllotoxin (3), and 7',8'-dehydroacetyl...

A series of N-cinnamoyl aryl hydrazones 2a-2i were synthesized in good yields by microwave irradiation technique. The title compounds were formed by nucleophilic condensation of various N1substituted benzylidene-2-cyano aceto hydrazides with N,N-dimethyl amino benzaldehyde. The intermediate N1substituted benzylidene-2-cyano aceto hydrazide was obtained by condensing various substituted benzalde...

Human DNA ligase was purified from both normal and leukemic peripheral lymphocytes and normal thymocytes. The activity of the purified enzymes was assayed in the presence of several widely used antileukemic drugs. Melphalan and prednisone at 5 mM had no effect. Carmustine, chlorambucil, and cyclophosphamide were more effective at inhibiting the enzyme from leukemic cells, whereas Adriamycin and...

Bioassay-guided fractionation was used to isolate the lignan polygamain as the microtubule-active constituent in the crude extract of the Mountain torchwood, Amyris madrensis. Similar to the effects of the crude plant extract, polygamain caused dose-dependent loss of cellular microtubules and the formation of aberrant mitotic spindles that led to G(2)/M arrest. Polygamain has potent antiprolife...

Flow microfluorometric analysis of human lymphoid cells exposed in vitro to cytostatic concentrations of podophyllotoxin (0.01-5 mug/ml for 24 h) shows that a major part of this population (40-60%) has the DNA content of cells in the G2-M part of the cell cycle, and that approximately 60% of these cells are arrested in mitosis. Although a similar pattern of DNA distribution is seen in cultures ...