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The alkaloidal components of the Bhutanese medicinal plant Corydalis calliantha Long, which is used for the treatment of malaria, have been assessed. Four known alkaloids, protopine (1), scoulerine (2), cheilanthifoline (3) and stylopine (4) are reported from this plant for the first time. The protopine alkaloid, protopine, and the tetrahydroprotoberine(More)
Betulinic acid, oleanolic acid and ursolic acid have been modified at the C-3 position to cinnamate-based esters and in vitro antimycobacterial activity against Mycobacterium tuberculosis H(37)Ra has been determined. The results indicated that modification of the parent structures of betulinic acid, oleanolic acid and ursolic acid to the p-coumarate and, in(More)
Conjugation of the NorA substrate berberine and the NorA inhibitor 5-nitro-2-phenyl-1H-indole via a methylene ether linking group gave the 13-substituted berberine-NorA inhibitor hybrid, 3. A series of simpler arylmethyl ether hybrid structures were also synthesized. The hybrid 3 showed excellent antibacterial activity (MIC Staphylococcus aureus, 1.7(More)
Many marine invertebrates deposit benthic egg masses that are potentially vulnerable to microbial infection. To help counter this threat these species may have evolved some form of chemical protection for their encapsulated embryos. In this study the egg masses from 7 marine mollusks were tested for antibacterial activity against 4 marine pathogens:(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)
In bacteria, multidrug-resistance pumps (MDRs) confer resistance to chemically unrelated amphipathic toxins. A major challenge in developing efficacious antibiotics is identifying antimicrobial compounds that are not rapidly pumped out of bacterial cells. The plant antimicrobial berberine, the active component of the medicinal plants echinacea and golden(More)
Investigation of Aconitum orochryseum, a Bhutanese traditional medicine ("gSo-ba Rig-pa") plant locally known as "Bong-kar", resulted in the isolation of three new hetisine-type diterpenoid alkaloids, named orochrine (1), 2-O-acetylorochrine (2), and 2-O-acetyl-7alpha-hydroxyorochrine (3), together with the previously reported alkaloids atisinium chloride(More)
Fractionation of the aerial parts of Chromolaena odorata afforded a new flavonoid, 5,7-dihydroxy-6,4'-dimethoxyflavanone, in addition to 14 known flavonoid compounds, six of which had not been isolated previously from this plant. The structure of the new compound was determined by spectroscopic methods particularly 2D-NMR analysis.
ETHNOPHARMACOLOGICAL RELEVANCE The plant Aconitum orochryseum Stapf. (Ranunculaceae) is employed together with other plants in Bhutanese traditional medicine and is indicated for malaria-associated fever. AIM OF THE STUDY To study the in vitro antiplasmodial activity of atisinium chloride, the major alkaloid from Aconitum orochryseum. MATERIALS AND(More)