A new coumarin and triterpenes from MalaysianMicromelum minutum

Abstract

A new coumarin, 8,4''-dihydroxy-3'',4''-dihydrocapnolactone-2',3'-diol (1) and two known triterpenes, 5(6)-gluten-3-one (2) and 5(6)-gluten-3alpha-ol (3) were isolated from the leaves of Micromelum minutum (Rutaceae) collected from Sepilok, Sabah, Malaysia and their structures were characterized by spectroscopic methods.

Cytotoxic activity of coumarins fromMicromelum minutum

“…Further isolation of the chloroform extract of the leaves resulted in the identification of five coumarins 3,4-dihydrocapnolactone (1), 2' ,3'-epoxyisocapnolactone (2), 8-hydroxyisocapnolactone-29,39-diol (3), 8-hydroxy-3,4-dihydrocapnolactone-29,39-diol (4) and 8,4-dihydroxy-3,4-dihydrocapnolactone-29,39-diol (5) and two triterpenes 5(6)-gluten-3-one (6) and 5(6)-gluten-3-ol (7). These have been reported previously (Rahmani et al, 2003;Susidarti et al, 2006).…”

“…Detailed extraction, isolation, and spectral data of compounds 1-7 have been reported in our previous publications (Rahmani et al, 2003;Susidarti et al, 2006).…”

“…In Indochina, the roasted and crushed leaves are rubbed on to skin irritated by scabies and are also considered to be emmenagogues (Perry, 1980). The species is well known to contain coumarins, but depending on the collection location, the compounds isolated can also be different (Rahmani et al, 1994(Rahmani et al, , 2003Susidarti et al, 2006;Tantivatana et al, 1983;Das et al, 1984). The first sample collected in Peninsula Malaysia yielded micromelin and a new dihydrocinnamic acid derivative of micromelin, while another sample from a different location (also in Peninsular Malaysia) yielded tetracyclic microminutinin and 6-methoxymicrominutinin (Rahmani et al, 1994).…”

“…The first sample collected in Peninsula Malaysia yielded micromelin and a new dihydrocinnamic acid derivative of micromelin, while another sample from a different location (also in Peninsular Malaysia) yielded tetracyclic microminutinin and 6-methoxymicrominutinin (Rahmani et al, 1994). However, the third sample collected in Sabah yielded five new capnolactone derivatives (Rahmani et al, 2003;Susidarti et al, 2006). Coumarins have attracted intense interest in recent years because of their diverse pharmacological properties, and their cytotoxic properties have been extensively examined (Kostova, 2005;Budzisz et al, 2003;Thornes et al, 1994).…”

C-7 oxygenated coumarins from the fruits of Micromelum minutum

“…The genus Micromelum species are known to contain 6-and 8-prenylated coumarins (Lamberton et al, 1967;Cassady et al, 1979;Das et al, 1984;Kamperdick et al, 1999;). Previous investigation of the leaves of M. minutum led to the isolation of bioactive coumarin derivatives such as microminutin (Tantivatana et al, 1983), flindersine, 7,8-dioxygenated coumarins, and triterpenes (Tantivatana et al, 1983;Tantishaiyakul et al, 1986;Rahmani et al, 2003;Susidarti et al, 2006), as well as a pyranoquinoline alkaloid (Tantivatana et al, 1983). In our continuing search for bioactive constituents from Thai plants, we noted that the hexane, EtOAc, and MeOH extracts from the fruits of M. minutum, showed cytotoxicity against the cholangiocarcinoma cell line, KKU-100 (IC 50 5.1, 4.2 and 1.9 µg/mL, respectively).…”