ABSTRACT
Four new compounds, microminutin B (1), microminutin C (2), micromarinate (3), and secomicromelin (4) as well as 17 known compounds were isolated from the fruits of Micromelum falcatum. All compounds were evaluated for antifungal activity against Pythium insidiosum using disc diffusion assay. P. insidiosum is a fungus-like microorganism for which antifungal agents now available are not effective. The results show that four compounds including secomicromelin (4), 7-methoxy-8-(4'-methyl-3'-furanyl)coumarin (10), micromarin B (17), and isomicromelin (19) could inhibit the mycelia growth of P. insidiosum.
Subject(s)
Antifungal Agents/chemistry , Coumarins/chemistry , Plant Extracts/chemistry , Pythium/drug effects , Rutaceae/chemistry , Antifungal Agents/isolation & purification , Antifungal Agents/pharmacology , Coumarins/isolation & purification , Coumarins/pharmacology , Dose-Response Relationship, Drug , Fruit/chemistry , Magnetic Resonance Spectroscopy , Microbial Sensitivity Tests , Molecular Structure , Plant Extracts/isolation & purification , Plant Extracts/pharmacology , Pythium/growth & developmentABSTRACT
Nineteen carbazole alkaloids modified from heptaphylline (I) and 7-methoxyheptaphylline (II) isolated from Clausena harmandiana were synthesized. Among these derivatives, Ih and IIi showed cytotoxicity against the NCI-H187 cell line with IC(50) values of 0.02 and 0.66 µM, respectively, which are about 138 and 4 fold stronger than the ellipticine standard. In addition, oxime Ih displayed cytotoxicity against KB cells with an IC(50) value of 0.17 µM which is about 10 times stronger than the ellipticine. This compound demonstrated weak cytotoxicity against Vero cells (IC(50) = 66.01 µM). The results show convincingly that Ih may be a promising lead for the development of cytotoxic agents.
