Methylated Chalcones from Bidens torta

Four new natural products, all methylated chalcones, including an acetylated glycoside, were isolated from Bidens torta. Their structures were determined by spectroscopic methods as okanin 3,4,3′,4′-tetramethyl ether, okanin 3,4,3′-trimethyl ether 4′-glucoside, okanin 4-methyl ether 4′-glucoside and okanin 4-methyl ether 4′-glucoside monoacetate. Okanin 3,4-dimethyl ether 4′-glucoside was also isolated.     

A chemotaxonomic study of flavonoids in the leaves of six Trichosanthes species

The 7-, 3′- and 4′-glucosides of luteolin, the 7-glucoside and 6,8-di-C-glucoside of apigenin were isolated from Trichosanthes kirilowii var. japonica. Kaempferol 3,7-di-rhamnoside and 3-glucoside-7-rhamnoside were identified from T. cucumeroides, kaempferol 3-galactoside and 3-sophoroside were also identified from T. anguina. Quercetin-3-rutinoside was detected from T. multiloba and T. rostrata. T. bracteata afforded luteolin 3′-glucoside and kaempferol 3-rutinoside, and T. kirilowii afforded luteolin 7-, 3′- and 4′-glucosides and apigenin 7-glucoside.     

Chalcone glycosides of Antirrhinum majus

Three chalcones have been found in yellow flowers of A. majus, two of which have been identified as chalcononaringenin 4′-glucoside and 3,4,2′,4′,6′-pentahydroxychalcone 4′-glucoside.     

Flavone C-glycosides from Coronilla varia

One new and 5 known flavone C-glycosides were isolated from leaves and stems of Coronilla varia. The new compound was shown to be isoorientin 2″-O-rhamnoside. The known compounds were isovitexin, isoorientin, isovitexin 4′-O-glucoside, isoorientin 4′-O-glucoside, and isoorientin 7-O-glucoside.     

Flavonoid pigments of butterflies in the genus Melanargia

Flavonoid pigments (18) were identified in the wings and body of Melanargia galathea: tricin, tricin 7-glucoside, tricin 7-diglucoside, tricin 4′-glucoside, luteolin, luteolin 7-glucoside, luteolin 7-diglucoside, luteolin 7-triglucoside, apigenin, apigenin 7-glucoside, orientin, orientin 7-glucoside, iso-orientin, iso-orientin 7-glucoside, vitexin 7-glucoside, vitexin 7-glucoside, isovitexin, isovitexin 7-glucoside and a novel but incompletely identified tricin 4′-conjugate. Examination of the wings and bodies of individual M. galathea, M. galathea var. procida, M. lachesis, M. russiae, M. larissa, M. occitanica and M. ines butterflies from a number of different populations in Europe by 2D PC revealed that variation in their flavonoid patterns was so minor that the flavonoid pattern of these Melanargia spp. may be considered constant. The concentration of flavonoids in the wings of each butterfly was greater than that in the body, as is the covering of scales. Not all flavonoids are located in the scales; some are also located in the reproductive tissues of the female. With the exception of the tricin 4′-conjugate which was absent from the egg and first instar larvae before feeding commences, these flavonoids were present in all the life stages of M. galathea. The presence of tricin 4′-conjugate in Melanargia but its absence from the larval food plants suggests that this compound is synthesized by the insect and that flavonoids are not merely sequestered from the diet but are also partly metabolized.     

Flavonoids from Haplophyllum pedicellatum, H. robustum AND H. glabrinum

Haplophyllum pedicellatum, H. robustum and H. glabrinum all yielded the known compound gossypetin 8,3′-dimethyl ether 3-rutinoside. In addition the first two species afforded isorhamnetin and its 3-rutinoside. A new glycoside, gossypetin 8,3′-dimethyl ether 3-glucoside was obtained from H. pedicellatum together with the 3-malonylrutinoside, 3-malonylglucoside and 3-galactoside of isorhamnetin plus kaempferol 3-malonylglucoside. H. robustum yielded isorhamnetin 7-glucoside and 3-glucoside and quercetin 3-galactoside, while H. glabrinum was found to contain gossypetin 8-methyl ether 3-malonylrutinoside in addition to kaempferol and isorhamnetin 3-glucoside.     

Flavonoids of Artemisia judaica,A. Monosperma and A. herba-alba

Seventeen flavonoid glycosides were isolated and identified from Artemisia judaica: the 7-glucoside, 7-glucuronide, 4′-glucoside, 7-gentiobioside     

Chalcones and other flavonoids from Asarum sensu lato (Aristolochiaceae)

Seventy-five taxa belonging to the genus Asarum sensu lato were studied for their composition of flavonoids. Three chalcones and an aurone were found as major components. The chalcones were identified as chalcononaringenin 2′,4′-di-O-glucoside, 4,2′,4′-tri-O-glucoside, 4-O-glucoside, and the aurone as aureisidin 4,6-di-O-glucoside. The glycoside, 2′,4′-di-O-glucoside was detected in all taxa examined, and is a chemotaxonomical feature of Asarum sensu lato. 4,2′,4′-Tri-O-glucoside was found from the taxa classified into the genera Asiasarum, Geotaenium and Heterotropa by Maekawa's system. On the other hand, the glycoside was not detected from three Asarum sensu stricto species, A. caudigerum, A. caulescens and A. leptophyllum. In contrast, aurone, aureusidin 4,6-di-O-glucoside occurred in two Asarum s.s., A. caulescens and A. leptophyllum. Thus, the Asarum s.s. and other Maekawa's genera, Asiasarum, Geotaenium and Heterotropa could distinguish by the presence or absence of some anthochlor pigments. Other flavonoids were isolated from the selected 18 Asarum species. They were characterized as some flavonol 3- or 3,7-O-glycosides based on kaempferol, quercetin and isorhamnetin, flavone, apigenin 6,8-di-C-glycoside, flavanone, naringenin 5,7-di-O-glucoside, and xanthone, mangiferin.     

Biologically-active flavonoids from Gossypium arboreum

A new flavonol glycoside, gossypetin 8-O-rhamnoside, was isolated from flower petals of Gossypium arboreum along with quercetin 7-O-glucoside, quercetin 3-O-glucoside and quercetin 3′-O-glucoside. These compounds showed antibacterial activity against Pseudomonas maltophilia and Enterobacter cloacae.     

Identification de C-glucosides flavoniques dans le genre Gentiana (section coelanthe)

Isoorientin, isovitexin, isoorientin-4′-O-glucoside and isovitexin-4′-O-glucoside have been identified in the leaves and roots of Gentiana punctata L., and in the leaves of G. purpurea L., G. pannonica Scop., G. villarsii Ronn., and G. burseri Lapeyr. Comparison with other gentians is discussed.     

Flavonoids from Gutierrezia grandis

Thirteen flavonoids, including three new compounds, were isolated from Gutierrezia grandis. The structures of the new compounds were 3,5,7,3′,4′-pentahydroxy-6,8-dimethoxyflavone, 5,7,3′-trihydroxy-3,6,8,4′,5′-pentamethoxyflavone and 5,7,3′,5′-tetrahydroxy-3,6,8,4′-tetramethoxyflavone 3′-O-glucoside.     

The flavonoids of phragmites australis flowers

The major flavonoid constituents of Phragmites australis flowers are the C-glycosylflavones swertiajaponin, isoswertiajaponin and two new O-glycosides, the 3′-O-gentiobioside and the 3′-O-glucoside of swertiajaponin. Two unusual flavonol glycosides, rhamnetin 3-O-rutinoside and rhamnetin 3-O-glucoside, were also characterized from the same tissue.     

Localization of partially methylated flavonol glucosides in Chrysosplenium americanum. I. Preparation and some properties of a trimethyl flavonol glucoside antibody

5,2′,5′-Trihydroxy-3,7,4′-trimethoxyflavone-2′-O-glucoside, a major flavonoid constituent of Chrysosplenium americanum Schwein. ex Hooker was conjugated to bovine serum albumin (BSA) by the diazo reaction in good yield and with a molar ratio of 11.5:1. Antibody raised against the latter conjugate had a titer value of 1:1600 and was found to be specific for the 2′-O-glucosides of tri- and tetramethoxyflavones. Some cross reactivity (about 55%) was observed against the pentamethoxyflavone-5′-O-glucoside; but almost none with the parent hydroxyflavone, quercetin, or any of its partially methylated (3,7,4′-tri- or 3,7,3′,4′-tetramethyl-) derivatives. The specificity of antibodies raised against the 2′-O-glucosides of Chrysosplenium makes them useful for the intracellular localization of these natural constituents.     

The flavonoids of tetragonotheca (compositae)

Fifteen flavonols, five aglycones and ten glucosides were isolated from the four species of Tetragonotheca, T. repanda, T. helianthoides, T. texana and T. ludoviciana. Included among the isolated flavonols are four previously unreported 7-O-glucosides, 6-hydroxykaempferol 7-O-glucoside, 6-hydroxykaempferol 6-methyl ether 7-O-glucoside, quercetagetin 6,3′-dimethyl ether 7-O-glucoside and quercetagetin 3,6-dimethyl ether 7-O-glucoside.     

6-Hydroxy- and 6-methoxyflavonoids from Neurolaena lobata and N. macrocephala

Twelve flavonoids including one new sulfate were isolated from Neurolaena lobata, and six known flavonoids were obtained from N. macrocephala. The new compound isolated from N. lobata is 6-hydroxykaempferol 3-methyl ether 7-sulfate, and the known flavonoids are 6-hydroxykaempferol 3,7-di-dimethyl ether, 6-hydroxykaempferol, 3-methyl ether 7-glucoside, 6-hydroxykaempferol 7-glucoside, quercetagetin and its 7-glucoside, quercetagetin 3,6- and 3,7-dimethyl ethers, quercetagetin 3-methyl ether 7-glucoside and 7-sulfate, 6-hydroxyluteolin 3′-methyl ether and 6-hydroxyluteolin 7-glucoside. The known flavonoids identified from N. macrocephala are quercetagetin 3,6- and 3, 7-dimethyl ethers, quercetagetin 6-methyl ether 7-glucoside, quercetagetin 3,6-dimethyl ether 7-glucoside, quercetagetin 7-glucoside and quercetagetin 3-methyl ether 7-sulfate.     

Isomollupentin-O-glucosides from Cerastium arvense

Eight C-glycosylflavone O-glycosides including three new compounds: isomollupentin 7-O-glucoside, isomollupentin 4′-O-glucoside and isomollupentin 2″-O-glucoside have been isolated from the leaves and flowers of Cerastium arvense. The 27 C-glycosylflavones identified in this plant are tabulated.     

Flavonol glycosides of Carya pecan

The flavonol glycosides characterized from the branches of Carya pecan include three new compounds, azaleatin 3-glucoside azaleatin 3-diglycoside and caryatin 3′- (or 4′-) rhamnoglucoside. together with azaleatin 3-rhamnoside. In the leaf tissue, quercetin 3-glucoside, quercetin 3-galactoside, quercetin 3-rhamnoside, quercetin 3-arabinoside and a small amount of kaempferol 3-monomethyl ether were identified.     

Three dihydroisocoumarin glucosides from Hydrangea macrophylla subsp. serrata

Three new dihydroisocoumarin glucosides, macrophyllosides A, B and C were obtained from dry leaves of Hydrangea macrophylla subsp. serrata, together with the previously known hydrangenol 8-β-glucoside. Using NMR and CD techniques and some chemical transformation, the structures were elucidated as (3S)-3′,4′,5′-trimethoxyphenyl-8-β-D-glucopyranosyl dihydroisocoumarin, (3R and (3S)-3′,5′-dimethoxy-4′-hydroxyphenyl-8-β-D-glucopyranosyl dihydroisocoumarins. CD experiments indicated that hydrangenol 8-β-glucoside was the mixture of 3S- and 3R- stereoisomers.     

Der substitutionsspezifische einfluss von chalkonen auf die anthocyanbiosynthese bei Petunia hybrida

The effect of two chalcones, 3,4,2′,4′,6′-pentahydroxy- and the 4, 2 ′,4′,6′ -tetrahydroxy- 3-methoxy-chalcone- 4′-glucoside, on the synthesis of different flower anthocyanins in isolated petals of Petunia hybrida has been investigated. The results show that the synthesis of those anthocyanins, which have the same substitution pattern as the chalcone used was increased. This suggests that the chalcones are incorporated into the anthocyanins concerned. When the chalcones were fed together with acetic acid-[1-¹⁴C], this specific substitution effect was detectable only for the 3,4,2′,4′,6′-pentahydroxy-chalcone-4′-glucoside.     

Evidence of biosynthetic simplicity in the flavonoid chemistry of the ricciaceae

The major flavonoids in Riccia crystallina are naringenin and its 7-O-glucoside, apigenin 7-O-glucoside and apigenin 7-O-glucuronide and derivatives. Ricciocarpus natans is a rich source of luteolin 7,3′-di-O-glucuronide and also contains the 7-O-glucuronides of apigenin and luteolin and the 3′-O-glucuronide of luteolin. A parallel between the production of biosynthetically simple flavonoids and reduced morphology is evident among these liverworts.