Antimycobacterial triterpenes from Melia volkensii.
In a bioassay-guided search for antimycobacterial compounds from higher plants, we have chemically investigated methanolic extracts of seeds of Melia volkensii. Chromatographic fractions provided two new euphane (20R)-type triterpenoids. The structures of the new compounds, 12beta-hydroxykulactone (1) and 6beta-hydroxykulactone (2), were elucidated by 1D and 2D NMR (13C, 1H, 1H-1H COSY, HMQC, HMBC, and NOESY spectra) and FABMS studies and shown to be hydroxyl derivatives of kulactone (3). Also isolated was the known kulonate (4). In a radiorespirometric bioassay against Mycobacterium tuberculosis, compounds 1, 2, and 4 exhibited minimum inhibitory concentrations of 16, 4, and 16 microg/mL, respectively.
Cantrell
C L
CL
Department of Chemistry, Louisiana State University, Baton Rouge, Louisiana 70803-1804, and GWL Hansen's Disease Center, P.O. Box 25072, Baton Rouge, Louisiana 70894, USA.
Rajab
M S
MS
Franzblau
S G
SG
Fischer
N H
NH
D000995:Antitubercular Agents / Q000302:isolation & purification / Q000494:pharmacology*; D002851:Chromatography, High Pressure Liquid; D007630:Kenya; D007783:Lactones / Q000302:isolation & purification / Q000494:pharmacology*; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D000432:Methanol; D009169:Mycobacterium tuberculosis / Q000187:drug effects* / Q000378:metabolism; D010100:Oxygen / Q000378:metabolism; D010946:Plants, Medicinal / Q000737:chemistry*; D012639:Seeds / Q000737:chemistry; D013056:Spectrophotometry, Ultraviolet
D000995:Antitubercular Agents; D007783:Lactones; C119441:hydroxykulactone; D010100:Oxygen; D000432:Methanol