Venuloxanthone, a new pyranoxanthone from the stem bark of Calophyllum venulosum

Abstract

A new pyranoxanthone, venuloxanthone (1), was isolated from the stem bark of Calophyllum venulosum, together with three other xanthones, tovopyrifolin C (2), ananixanthone (3) and caloxanthone I (4), along with two common triterpenes, friedelin (5) and lupeol (6). The structures of these compounds were identified using several spectroscopic analyses which are NMR, GCMS and FTIR experiments.

Chemical Constituents from the Root Bark of Calophyllum inophyllum

“…Several coumarins [2][3][4], xanthones [5,6], flavonoids [7] and triterpenes [8] have also been isolated from this plant. In the course of our searching for new cytotoxic agents from Thai medicinal plants [9][10][11], a new compound, caloinophyllin B (1) (Figure 1A), along with one known chromanone derivative, caloinophyllin A (2), two known flavonoids, 3,3',4',5,7pentamethoxyflavone (3) [12] and 5,7,4'-trimethoxyflavone (4) [7], and fourteen known xanthones (5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18), 1,5-dihydroxy-xanthone (5) [13], 1,8-dimethoxyxanthone (6), caloxanthone B (7) [14], 1,6dihydroxy-7-methoxyxanthone (8) [15] 4-hydroxy-xanthone (9) [16], 2-hydroxyxanthone (10) [17], 3-hydroxy-4-methoxyxanthone (11) [18], 3-hydroxy-2-methoxyxanthone (12) [19], 2,3dimethoxyxanthone (13) [20], 1,6-dihydroxyxanthone ( 14) [21], 1,7-dihydroxyxanthone (15) [22], 1,3,5-trihydroxyxanthone ( 16) [23], tovopyrifolin C (17) [24] and ma...…”