Coumarins and dihydrocinnamic acid derivatives from Micromelum falcatum

Micromelosides A–D, four new coumarins from the stem bark of Micromelum falcatum

“…[1,2] In preliminary investigation, two alkaloids, six coumarins and three dihydrocinnamic acid derivatives had been gained from the leaves and roots of M. falcatum. [3,4] Now, in our further chemical investigation on the stem bark of this plant, four new coumarins, named micromelosides A-D, 7methoxy-8-[1 ,4 -dihydro-3 -ene-2 -hydroxy-1 -furanyl]coumarin (1), 7-methoxy-6-[1 ,4 -dihydro-3 -methyl-3 -methoxy-2 -hydroxy-4 -oxo-1 -furanyl]coumarin (2), 7-methoxy-8-[1 -methoxy-2 ,4dihydroxy-3 -methylene-4 -O-isovaleryl-butyl]coumarin (3) and 7-methoxy-6-[1 ,4 -dihydro-3 -methyl-3 -ethoxy-2 -hydroxy-4oxo-1 -furanyl]coumarin (4), are obtained along with four known coumarins, murrangatin (5), [5,6] micromelin (6), [7 -9] minumicrolin (7) [10] and hydramicromelin A (8). [11] This paper deals with the isolation and structural elucidation of these new coumarins from M. falcatum.…”

Rapid Identification of Coumarins from Micromelum falcatum by UPLC-HRMS/MS and Targeted Isolation of Three New Derivatives

“…The UV spectrum in methanol revealed the characteristic absorption maxima for 7-oxygenated coumarins at 206 and 319 nm [5]. Its molecular formula was deduced as C15H16O6, implying eight degrees of unsaturation, based on the adduct ion The NMR spectra of compound 1 (Table 2) revealed the presence of a 7-methoxylated coumarin and in particular the occurrence of a 3-methylene-1,2,4-n-butanotriol chain in position 8 of the core coumarin structure.…”

“…Both leaves and barks have been reported as remedies for rheumatism [2][3][4]. Previous studies on M. falcatum have revealed the presence of several groups of secondary metabolites such as derivatives of dihydrocinnamic acid [5] and most importantly, alkaloids and coumarins. Specifically, numerous alkaloids belonging to the quinolone, quinoldione [6], indole and carbazole [7] groups have been isolated from the bark of the plant.…”

“…Specifically, numerous alkaloids belonging to the quinolone, quinoldione [6], indole and carbazole [7] groups have been isolated from the bark of the plant. In addition, several 6-and 8-prenylated derivatives of 7-oxygenated and specifically 7-methoxylated coumarins have been reported from the bark and the leaves of M. falcatum [5,[7][8][9].…”

C-7 oxygenated coumarins from the fruits of Micromelum minutum

“…The leaves are used traditionally as a febrifuge, the stems as a carminative, and the flowers and fruits as an expectorant and a purgative, respectively (Pongboonrod, 1958). 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).…”