Anti-tuberculosis constituents from the stem bark of Micromelum hirsutum.
Anti-TB bioassay-directed fractionation led to the isolation of six carbazole alkaloids, as well as the gamma-lactone derivative of oleic acid, from the CH (2)Cl (2) extract of the stem bark of Micromelum hirsutum. The carbazoles include the new micromeline ( 2) and five known alkaloids: lansine ( 3), 3-methylcarbazole ( 4), methyl carbazole-3-carboxylate ( 5), 3-formylcarbazole ( 6), and 3-formyl-6-methoxycarbazole ( 7). Compound 1 was identified as the lactone derivative of oleic acid, (-)- Z-9-octadecene-4-olide, for which the trivial name micromolide ( 1) is suggested. It showed potent in vitro anti-TB activity against H37R v (MIC: 1.5 microg/mL), a selectivity index (SI) of 63, and exhibited activity against the Erdman strain of M. tuberculosis in a J774 mouse macrophage model (EC (90) : 5.6 microg/mL). Thus, 1 appears worthy of further evaluation as a potential new anti-TB agent. Isolates 2, 3, 6 and 7 had anti-TB MIC values between 14.3 and 42.3 microg/mL, while compounds 4 and 5 were considered inactive (MIC > 128 microg/mL). Structure elucidation and identification were based on spectroscopic analysis, including MS, 1D/2D NMR, and a full (1)H spin system analysis of 1.
Ma
Cuiying
C
Program for Collaborative Research in the Pharmaceutical Sciences, M/C 781, Department of Medicinal Chemistry & Pharmacognosy, College of Pharmacy, the University of Illinois at Chicago, 833 S. Wood Street, Chicago, IL 60612, USA.
Case
Ryan J
RJ
Wang
Yuehong
Y
Zhang
Hong-Jie
HJ
Tan
Ghee Teng
GT
Van Hung
Nguyen
N
Cuong
Nguyen Manh
NM
Franzblau
Scott G
SG
Soejarto
Djaja Djendoel
DD
Fong
Harry H
HH
Pauli
Guido F
GF
D000818:Animals; D000995:Antitubercular Agents / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use; D006801:Humans; D008264:Macrophages / Q000382:microbiology; D051379:Mice; D008826:Microbial Sensitivity Tests; D009169:Mycobacterium tuberculosis / Q000187:drug effects* / Q000472:pathogenicity; D008517:Phytotherapy; D024301:Plant Bark; D010936:Plant Extracts / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use; D027821:Rutaceae
D000995:Antitubercular Agents; D010936:Plant Extracts