New Dihydrochalcones and Anti-Platelet Aggregation Constituents from the Leaves of Muntingia calabura

Abstract

Two new dihydrochalcones, 2,3-dihydroxy-4,3',4',5'-tetramethoxydihydrochalcone (1) and 4,2',4'-trihydroxy-3'-methoxydihydrochalcone (2), and a new flavanone, (2R,3R)-(-)-3,5-dihydroxy-6,7-dimethoxyflavanone (3), together with nineteen known compounds have been isolated from the leaves of Muntingia calabura. The structures of three new compounds were determined through spectral analyses including extensive 2D-NMR data. Among the isolates, 2,3-dihydroxy-4,3',4',5'-tetramethoxydihydrochalcone, 5,7-dihydroxy-3-methoxyflavone, 5,7-dihydroxy-6-methoxyflavone, 5,4'-dihydroxy-3,7-dimethoxyflavone, (2S)-7,8,3',4',5'-pentamethoxyflavan, (2S)-5'-hydroxy-7,8,3',4'-tetramethoxyflavan, and methyl gallate exhibited significant anti-platelet aggregation activity in vitro.

Muntingia calabura: A review of its traditional uses, chemical properties, and pharmacological observations

“…This was followed a year later by another report from the same group on the isolation of chalcones and flavonoids from the leaves of M. calabura (Chen et al, 2007), collected from Kaohsiung City, Taiwan, in June 2001. Prior to the isolation processes, the MEMC L was partitioned using H 2 O-CHCl 3 to obtain the water-soluble and CHCl 3 -soluble partitions with the former also further partitioned using H 2 O and n-BuOH to afford an n-BuOH-soluble and H 2 O-soluble fractions.…”

“…Then 2 years later, upon vigorous phytochemistry studies on the same sample of M. calabura leaves that were collected in Kaohsiung City, Taiwan, in June 2001, Chen et al (2007) again reported on the isolation of 22 compounds from the CHCl 3 -soluble partitions and n-BuOH-soluble fraction prepared from the MEMC L as described earlier (Chen et al, 2005). Of the isolated compounds, three were new compounds [2,3-dihydroxy-4,3 0 ,4 0 ,5 0 -tetramethoxydihydrochalcone (65), 4,2 0 ,4 0 -trihydroxy-3 0 -methoxydihydrochalcone (66), and (2R,3R)-(À)-3,5-dihydroxy-6,7-dimethoxyflavanone (67)], and the others were known compounds [b-sitostenone (41), mixture of b-sitosterol (43) and stigmasterol (68), 7-methoxyflavone (69), 5,7-dihydroxy-3-methoxyflavone (70), 5,7-dihydroxy-6-methoxyflavone (71), 5,4 …”

“…Studies were performed to determine the antiplatelet aggregation of 22 compounds isolated from the leaves of M. calabura (Chen et al, 2007). The platelets were obtained from rabbit's blood and platelet aggregation was measured by an in vitro turbidimetric method using a Chrono-Log Lumi aggregometer.…”

Orthoquinone and Naphthalenone Derivatives from Berrya ammonilla and Their Anti-Inflammatory Activity

“…1) and eleven known compounds(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16). Berryammone A (1) was isolated as a reddish gum, and the sodium adduct ion [M + Na] + (m/z 283.0948) in HR-ESI-MS was consistent with the formula C15 H 16 O 4 Na.…”

“…(Tiliaceae) is a large tree, distributed in southern India, Ceylon, Philippines, and Taiwan [1]. The plants of the family Tiliaceae are rich in flavonoids with flavones, flavanones, flavans, and biflavans as the major constituents [2][3][4][5][6][7], some of which have demonstrated cytotoxic [2, 3-5] and antiplatelet aggregation activities [7]. In our studies on constituents of Formosan plants for in vitro inhibitory activity on neutrophil proinflammatory responses, B. ammonilla has been found to be an active species.…”