Cytotoxic and Antimalarial Bisbenzylisoquinolme Alkaloids from Stephania erecta

Abstract

(+)-2-N-Methyltelobine [1], a new alkaloid, together with twelve known bisbenzylisoquinolines, was isolated from the tubers of Stephania erecta. The structure determination and the complete 1H- and unambiguous 13C-nmr assignments of 1 were obtained through extensive use of several 1D and 2D nmr techniques. All alkaloids inhibited the growth of cultured Plasmodium falciparum strains D-6 and W-2 and displayed nonselective cytotoxicity with a battery of cultured mammalian cells. These data were used for the calculation of selectivity indices. Relative to known antimalarial agents, these bisbenzylisoquinoline alkaloids do not appear to be promising clinical candidates at the present time.

Potent Cytotoxic Rocaglamide Derivatives from the Fruits of Amoora cucullata

“…The relative configuration of 1 was established primarily by analysis of the splitting patterns, and the coupling constant values between H-1, H-2, and H-3 indicating a 1a, 2a, 3b configuration, as well as a cis-BC ring junction. [8][9][10] These relative configurations were confirmed by NOESY experiments, wherein correlations were observed from H-1 to H-2 and H-6Ј and from H-2 to H-3. Due to their structural similarity, all rocaglamide-related natural products that have so far been examined display CD spectra very similar to that of rocaglamide itself.…”

Synthesis and Cytotoxic Activity of Ursolic Acid Derivatives

“…Cytotoxic assays were performed according to Likhiwitayawuid et al [8] and Skehan et al [9] at different concentrations in 96-well plates. The Hep-G2, KB and MCF-7 cell lines were maintained in the RPMI-1640 culture medium with 10 % fetal bovine serum (FBS).…”

Bio-activities of the methanol extracts from some species belonging to the family Asteraceae in Lam Dong province

“…Dùa vµo ho¹t ®éng cña nh÷ng enzim dehydrogenaza ty thÓ trong c¸c tÕ bµo sèng sÏ xóc t¸c chuyÓn c¬ chÊt mµu vµng tan trong n−íc MTT [3-(4,5 dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] thµnh tinh thÓ formazan cã mµu xanh ®en kh«ng tan ®−îc trong n−íc. Sè l−îng tinh thÓ formazan ®−îc ®o b»ng ph−¬ng ph¸p ®o mËt ®é quang OD ë b−íc sãng 570 nm -lµ b−íc sãng hÊp thu cña tinh thÓ formazan [3].…”