Antimicrobial Substances from Rhizomes of the Giant Knotweed Polygonum sachalinense against the Fish Pathogen Photobacterium damselae subsp. piscicida
The antimicrobial compounds against the fish pathogen Photobacterium damselae subsp. piscicida were isolated from Polygonum sachalinense rhizomes. The structures of the antimicrobial compounds 1 and 2 were determined by 1H and 13C NMR, 2D-NMR (COSY, HSQC, HMBC and ROESY) and FAB-MS to be phenylpropanoid glycosides, vanicoside A and B, respectively. Both compounds have feruloyl and p-coumaroyl groups bonded to a sucrose moiety in their structures. Vanicoside A also has an acetyl group in the sucrose moiety. The MIC values for vanicoside A and B against Ph. damselae subsp. piscicida DPp-1 were 32 and 64 μg/ml, respectively. The antimicrobial activities of these vanicosides were modest, in contrast to higher activities (MICs at <4 μg/ml) of antibiotics, florphenicol, ampicillin and amoxicillin, which have been generally used for treating pasteurellosis. The activities of the vanicosides, however, were higher than those (MICs at 256 μg/ml) of ferulic acid and p-coumaric acid. It was suggested that the structure of phenylpropanoids esterified with sucrose was essential for higher antimicrobial activity of vanicosides and also acetylation of sucrose might affect the activity against the bacterium.
Bitter phenylpropanoid glycosides from Lilium speciosum var. rubrum
Abstract Seven bitter ferulic acid esters of sucrose have been isolated from Lilium speciosum var. rubrum . These compounds were identified as 3,6′-diferuloylsucrose, 4-acetyl-3,6′-diferuloylsucrose, 6-acetyl-3,6′-diferuloylsucrose, 4′-acetyl-3,6′-diferuloylsucrose, 4,6-diacetyl-3,6′-diferuloylsucrose, 6,3′-diacetyl-3,6′-diferuloylsucrose and 4,6,3′-triacetyl-3,6′-diferuloylsucrose on the basis of spectroscopic studies.
The systematic distribution of ferulic Acid-sucrose esters in anthers of the liliaceae1.
In an anther survey of 157 di- and monocotyledons, two very rare cinnamic acid conjugates-di- and triferuloylsucrose-were found to occur exclusively in the Liliales and most predominantly in the Liliaceae (Tulipeae, Lilieae, Lloydieae). Whereas the triferuloyl ester was found to be abundant in most of the 20 species and cultivars of TULIPA investigated, only the diferuloyl ester could be detected by the applied methods in FRITILLARIA and LILIUM, in 12 and 9 species and cultivars, respectively. Di- and/or triferuloylsucrose could also be detected in one GAGEA and three ERYTHRONIUM species. Three out of 20 IRIS species investigated, also show the occurrence of these rare esters. This sporadic appearance in IRIS is, at present, considered to be erratic. We suggest that the ferulic acid-sucrose esters might be useful as marker substances for the Liliaceae.