Two new antiprotozoal 5-methylcoumarins from Vernonia brachycalyx.
Two new isomeric 5-methylcoumarins, 2'-epicycloisobrachycoumarinone epoxide (1) and cycloisobrachycoumarinone epoxide (2), have been isolated from the roots of Vernonia brachycalyx by means of bioactivity-guided fractionation. The structures were elucidated by MS and NMR spectroscopic methods. Compounds 1 and 2 showed in vitro activity against Leishmania major promastigotes and against Plasmodium falciparum schizonts and demonstrated an inhibition on the proliferation of human lymphocytes, which was significantly weaker than the antiparasitic effects.
Oketch-Rabah
H A
HA
Phytochemistry Department, National Museums of Kenya, Nairobi, Kenya.
Lemmich
E
E
Dossaji
S F
SF
Theander
T G
TG
Olsen
C E
CE
Cornett
C
C
Kharazmi
A
A
Christensen
S B
SB
D000818:Animals; D000962:Antimalarials / Q000302:isolation & purification / Q000494:pharmacology; D000981:Antiprotozoal Agents / Q000302:isolation & purification* / Q000494:pharmacology; D003374:Coumarins / Q000302:isolation & purification* / Q000494:pharmacology; D005663:Furans / Q000302:isolation & purification* / Q000494:pharmacology; D018320:Leishmania major / Q000187:drug effects; D008213:Lymphocyte Activation / Q000187:drug effects; D009682:Magnetic Resonance Spectroscopy; D018517:Plant Roots / Q000737:chemistry*; D010946:Plants, Medicinal / Q000737:chemistry*; D010963:Plasmodium falciparum / Q000187:drug effects
C106390:2'-epicycloisobrachycoumarinone epoxide; D000962:Antimalarials; D000981:Antiprotozoal Agents; D003374:Coumarins; D005663:Furans; C106391:cycloisobrachycoumarinone epoxide