Identification of three hydroxyflavan phytoalexins from daffodil bulbs

Flavonoid Function and Activity to Plants and Other Organisms

“…Fagus sylvatica Nectria coccinea (with beech scale) (Dübeler et al, 1997) taxifolin 4´-methyl ether Vicia sativa (Leguminosae) Rhizobium leguminosarum* (Zaat et al, 1989) Flavan broussin Broussonetia papyrifera (Moraceae) Bipolaris leersiae (Takasugi et al, 1980) cassiaflavan Narcissus pseudonarcissus (Amaryllidaceae), commercial agent Botrytis cinerea (Coxon et al, 1980;O'Neill & Mansfield, 1982), Cladosporium herbarum (O'Neill & Mansfield, 1982) 7,4´-dihydoxy-8-methylflavan Narcissus pseudonarcissus, commercial agent Botrytis cinerea (Coxon et al, 1980;O'Neill & Mansfield, 1982), Cladosporium herbarum (O'Neill & Mansfield, 1982) flavan commercial agent Botrytis cinerea, Cladosporium herbarum (O'Neill & Mansfield, 1982) 7-hydroxyflavan Narcissus pseudonarcissus, commercial agent Botrytis cinerea (Coxon et al, 1980;O'Neill & Mansfield, 1982), Cladosporium herbarum (O'Neill & Mansfield, 1982) Flavan 3-ol (+)-catechin commercial agent Aspergillus spp. (Weidenbörner et al, 1990b) Flavanone betagarin Beta vulgaris Cercospora beticola (Johnson et al, 1976;Martin, 1977;Geigert et al, 1973), Rhizoctonia solani (Takahashi et al, 1987) liquiritigenin Medicago sativa, commercial agent Rhizobium meliloti* Maxwell et al, 1989), Rhizobium spp.…”

Three spirostanol saponins and a flavane-O-glucoside from the fresh rhizomes of Tupistra chinensis

“…The HR-ESI-MS showed a [M + Na] + ion at m/z 471.1629 (calcd 471.1626), consistent with the molecular formula C 23 H 28 O 9 . In the 1 H NMR spectrum of 4, signals that are characteristic of the 8-methylflavan-3-ol aglycone skeleton were observed [23]. Two signals at δ 2.10 (3H, s) and 3.78 (3H, s) were assigned to the methyl group on C-8 and the methoxyl group attached to C-7 in ring A, respectively.…”

“…The protons at δ 6.87 (1H, d, J = 8.4 Hz) and 6.52 (1H, d, J = 8.4 Hz) were assigned to H-5 and H-6, respectively. Furthermore, the aromatic protons at δ 7.45 (2H, d, J = 8.7 Hz) and 7.11 (2H, d, J = 8.7 Hz) were assigned to H-2′/6′ and H-3′/5′, respectively [23]. The 13 C NMR spectrum showed the characteristic flavan-3-ol aglycone signals at δ 79.8, 67.5, and 34.4, corresponding to C-2 (OCH), C-3 (OCH), and C-4 (CH 2 ), respectively [24,25].…”

Defesas químicas de plantas: fitoalexinas

“…Vcirias fitoalexinas de natureza e estrutura quimica diversas tern sido isola.das e identificadas em faml1ias de mono e dicotiledoneas como: Amaryllidaceae (COXON et al, 1980), CaryophyUaceae (PONCHET et aI., 1984), Convo1vulaceae (KATO et aI., 1983;OBA et al, 1984), Euphorbiaceae (SITTON e WEST, 1975), Linaceae (KEEN e LITTEE-FIELD, 1979), Malvaceae (COXON, 1982;ZERINGUE, 1984), Moraceae (TAKASUGE et aI., 1980e 1984, Orchidaceae (WARD et al, 1975), Rubiaceae (WIJNSMA et aI., 1985), Rutaceae (HARTMAN e NEINHUS, 1974), Umbelliferae (HARDING e HEALE, 1980), Vitaceae (LANGCAKE e PRYCE, 1976;LANGCAKE, 1981) e Zingiberaceae (KUMAR et aI., 1984). Existem tambem registros da presen<;:a dessas substancias em girnnospermas pertencentes as familias Ginkgoaceae (CHRISTENSEN, 1972) e Pinaceae (cf.…”