Megastigmane and Iridoid glucosides from Avicennia Germinans: Two Isomeric Forms of an Iridoid

Iridoid Glucosides and Flavones from the Aerial Parts of Avicennia marina

“…1.5) [15] [16]. In addition, the chemical-shift as well as coupling-constant values of the iridoid moiety of 1 were very similar to those reported for 2'-caffeoylmussaenosidic acid [17] and 2'-coumaroylmussaenosidic acid (3) [8], two acylated iridoid glucosides that were previously isolated from A. germinans, suggesting that 1 possesses the same configuration as these two compounds.…”

“…Acyl moiety: C-NMR spectral data (Table) indicated that the chemical structure of compound 1 was very similar to that of 2'-coumaroylmussaenosidic acid (3), an acylated iridoid glucoside that was previously isolated from a mangrove plant of A. germinans [8]. However, instead of the coumaroyl ( ¼ (E)-3-(4-hydroxyphenyl)prop-2-enoyl) moiety, the (2E,4E)-5-phenylpenta-2,4-dienoyl unit was present in 1.…”

“…Consistent with the determined molecular formula, the 13 C-NMR spectrum of 2 exhibited 26 13 C signals including six quaternary, 15 CH, three CH 2 , and two Me C-atoms (Table). These spectral data indicated the presence of a mussaenosidic acid skeleon with a 4-methoxycinnamoyl substituent of 2 [8] Table) indicated that the structure of compound 2 was very similar to that of 1. However, instead of the (2E,4E)-5-phenylpenta-2,4-dienoyl unit in 1, the 4-methoxycinnamoyl group was present in 2.…”

“…Iridoid glucosides [4], sterols, fatty acids, hydrocarbons [5], flavonoids [6], and triterpines [7] have previously been isolated from this species. The present investigation on the aerial parts of A. marina that were collected from Hainan island of southern China sea waters has resulted in the isolation of two new iridoid glucosides, namely, 2'-O-[(2E,4E)-5-phenylpenta-2,4-dienoyl)mussaenosidic acid (1; mussaenosidic acid ¼ [1S-(1a,4aa, 7a,7aa)]-1-(b-d-glucopyranosyloxy)-1,4a,5,6,7,7a-hexahydro-7-hydroxy-7-methylcyclopenta[c]pyran-4-carboxylic acid) and 2'-O-(4-methoxycinnamoyl)mussaenosidic acid (2), one known iridoid glucoside, 2'-O-coumaroylmussaenosidic acid (3) [8], and four known flavones (flavone ¼ 2-phenyl-4H-1-benzopyran-4-one) including 4',5-dihydroxy-3',7-dimethoxyflavone (4) [9], 4',5-dihydroxy-3',5',7-trimethoxyflavone (5) [10], 4',5,7-trihydroxyflavone (6) [11], and 3',4',5-trihydroxy-7-methoxyflavone (7) [12]. The structures of these compounds were established on the basis of the NMR ( Results and Discussion.…”

Natural products from true mangrove flora: source, chemistry and bioactivities

“…22 2.1.2 Iridoid glucosides. Fifteen iridoid glucosides (17)(18)(19)(20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30)(31) were isolated from A. officinalis and A. germinans. Ko ¨nig and his coworkers isolated avicennioside (16), 7-O-cinnamoyl-8epiloganic acid sodium salt (18), geniposidic acid (19), 2 0 -cinnamoyl-mussaenosidic acid (20), from the air-dried leaves of the Sri Lanka A. officinalis.…”