Stephen G. Pyne

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ETHNOPHARMACOLOGICAL RELEVANCE As many as 229 medicinal plants have been currently used in the Bhutanese Traditional Medicine (BTM) as a chief ingredient of polyherbal formulations and these plants have been individually indicated for treating various types of infections including malaria, tumor, and microbial. We have focused our study only on seven(More)
ETHNOPHARMACOLOGICAL RELEVANCE Corydalis dubia is used in Bhutanese traditional medicine as a febrifuge and for treating infections in the blood, liver and bile which correlate to the signs and symptoms of malarial and microbial infections. AIM OF THE STUDY To validate the ethnopharmacological uses of the plant and to discover potential new therapeutic(More)
The chemical constituents and biological activities of Corydalis crispa (Fumariaceae) were investigated for the first time. The phytochemical study resulted in the isolation of nine known isoquinoline alkaloids: protopine (1), 13-oxoprotopine (2), 13-oxocryptopine (3), stylopine (4), coreximine (5), rheagenine (6), ochrobirine (7), sibiricine (8) and(More)
The known phenanthrenone trigonostemone (1), along with a new phenanthrenone, 9-O-demethyltrigonostemone (2), and two new phenanthropolones, 3,6,9-trimethoxyphenanthropolone (3) and 4,6,9-trimethoxyphenanthropolone (4), were isolated from the roots of Strophioblachia fimbricalyx. Compound 2 showed cytotoxicity against NCI-H187, KB, and MCF7 cancer cells(More)
A urokinase targeting conjugate of 2'-deoxy-5-fluorouridine (5-FUdr) was synthesized and tested for tumor-cell selective cytotoxicity in vitro. The 5-FUdr prodrug 2'-deoxy-5-fluoro-3'-O-(3-carboxypropanoyl)uridine (5-FUdrsuccOH) containing an ester-labile succinate linker was attached to the specific urokinase inhibitor plasminogen activator inhibitor type(More)
A range of N-phenethyl, N-phenacyl, and N-(1- and 2-naphthylmethyl) derivatives of 5,7-dibromoisatin 2 were prepared by N-alkylation reactions. Their activity against human monocyte-like histiocytic lymphoma (U937), leukemia (Jurkat), and breast carcinoma (MDA-MB-231) cell lines was assessed. The results allowed further development of structure-activity(More)
ETHNOPHARMACOLOGICAL RELEVANCE The Bhutanese form of g.so-ba-rig-pa medicine, which is a scholarly medical system, belongs to a larger system of medicinal corpus that spreads from Mongolia to India. It uses medicinal plants as a bulk ingredient but only 'Higher Elevation Medicinal Plants' have been botanically identified so far. Our study reports the(More)
ETHNOPHARMACOLOGICAL RELEVANCE Seven studied medicinal plants; Aconitum laciniatum, Ajania nubigena, Codonopsis bhutanica, Corydalis crispa, Corydalis dubia, Meconopsis simplicifolia and Pleurospermum amabile, are currently used in the Bhutanese Traditional Medicine (BTM) for the management of different types of disorders including the diseases that bore(More)
Resistance to chemotherapy in cancer patients has been correlated to the overexpression of the ATP-binding cassette (ABC) drug transporters including P-glycoprotein (P-gp) that actively efflux chemotherapeutic drugs from cancer cells. We examined the multidrug resistance reversing property of stemofoline derivatives in drug-resistance human cervical(More)
A new pentacyclic Stemona alkaloid, stemocurtisinol (3), with a pyrido[1,2-a]azepine A,B-ring system, and the known pyrrolo[1,2-a]azepine alkaloid oxyprotostemonine (4) have been isolated from a root extract of S. curtisii. The structure and relative stereochemistry of stemocurtisinol was determined by spectral data interpretation and X-ray crystallography.(More)