Acylated flavonol glycosides as probing stimulants of a bean aphid, Megoura crassicauda, from Vicia angustifolia

Chemical ecology of insect–plant interactions: ecological significance of plant secondary metabolites

“…Two specific probing stimulants were isolated from one of its favorite hosts, narrowleaf vetch, V. angustifolia, and were characterized as acylated flavonol diglycosides (25 and its glucosidic isomer). 28) These compounds strongly induced formation of a proteinous stylet sheath on a parafilm membrane when applied as a solution in distilled water, suggesting that they act as a factor in navigating the stylet towards the phloem in step (3). In contrast, their corresponding deacyl analogs, present abundantly in the host tissues, were suggested to serve as a negative stimulus to allow the aphid to refrain from sucking during tissue penetration before tapping the phloem, although the distribution of these analogs in the plant tissues remains unknown.…”

“…1), and may possibly disrupt the oviposition stimulant activity due to its structural resemblance, competing for the same chemoreceptor neurons on the foretarsi. Further, two hydroxybenzoic acid derivatives were characterized as potent deterrents of both oviposition and larval feeding in P. xuthus: a glycosylated hydroxybenzoic acid (27) and disyringoyl glucaric acid (28). 32) Simultaneous occurrence of these compounds in O. japonica appears to provide an effective chemical barrier against P. xuthus.…”

A new flavonol glycoside from Hylomecon vernalis

“…They were identified as quercetin (Yoshitama et al, 1997), querce- (Takemura et al, 2002), quercetin 3-O-β-D-galactopyranoside (4) (Lee et al, 2002), kaempferol 3,7-O-α-L-dirhamnopyranoside (5) (Mulinacci et al, 1995), diosmetin 7-O-β-D-glucopyranoside (6) (Son et al, 1994) (Park et al, 2009), p-hydroxybenzoic acid (8) (Lee et al, 2008), protocatechuic acid (9) (Sun et al, 2006), caffeic acid (10) (Lee et al, 2009), 6-hydroxy-3,4-dihydro-1-oxo-β-carboline (11) (Julia et al, 1973), (Z)-3-hexenyl-β-D-glucopyranoside (12), (E)-2-hexenyl-β-D-glucopyranoside (13) (Mizutani et al, 1988), (Z)-3-hexenyl-α-L-arabinopyranosyl-(1''→6')-β-D-glucopyranoside (14) (Kishida et al, 2005) , benzyl-β-D-apiofuranosyl-(1''→6')-β-D-glucopyranoside (16) , benzyl-α-L-arabinopyranosyl-(1''→6')-β-D-glucopyranoside (17) (Rosa et al, 1996), benzyl-β-D-xylopyranosyl-(1''→6')-β-D-glucopyranoside (18) (Otsuka et al, 1990) (Ma et al, 2001), and aryl-β-D-glucopyranoside (21) (Schwab et al, 1988). Compounds 2-21 were isolated for the first time from this plant.…”

“…In the 13 C-NMR spectrum of 1, the signals at δ C 102.6 and 103.5 corresponded to the galatosyl and arabinosyl anomeric carbon. The glycosidic position was established by an HMBC experiment, in which the long-range correlations were observed between the H-1'' (δ 5.26) of Dgalatose and the C-3 (δ 134.2) of aglycone, and H-1''' (δ 4.06) of L-arabinose and C-6'' of D-galatose (Takemura et al, 2002). The 1 H-and 13 C-NMR spectra of 1 showed also acetyl group signals at δ H 1.98 (3H, s) and δ C 21.6 and 170.6, respectively.…”

“…This indicated the presence of an acetyl group at C-4''' in 1. The O-deacetylation of 1 afforded quercetin 3-O-α-L-arabinopyranosyl-(1→6)-β-D-galactopyranoside (1a), which was identified by co-TLC (R f , 0.25, CHCl 3 -MeOH-H 2 O = 9:4:0.5) with 3 and by its 1 H-NMR (Takemura et al, 2002). Acid hydrolysis of quercetin 3-O-α-L-arabinopyranosyl-(1→6)-β-Dgalactopyranoside yielded the aglycone, quercetin and a sugar (Takemura et al, 2002).…”