Three isoflavonoids from Iris germanica

From the rhizome of Iris germanica one new hexaoxygenated isoflavone, two new polyoxygenated isoflavone glucosides, the known isoflavonoids irisolidone, irigenin and iridin and acetovanillone, sitosterol, α-amyrin and β-amyrin were isolated. The structures of the new compounds were established by chemical and spectroscopic means and by correlation with known constitutents.     

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.     

Two new flavone glycosides from Cirsium lineare

An examination of four species of Cirsium disclosed the presence of two new flavonoids in C. lineare. The structure of one was 5,4′-dihydroxy-6,7,3′-trimethoxyflavone (cirsilineol) 4′-monoglucoside and the other 5,3′,4′-trihydroxy-6,7-dimethoxyflavone (cirsiliol) 4′-monoglucoside. Luteolin 7-glucoside was found in C. suffultum, and pectolinarin and linarin in C. kamtschaticum and C. pectinellum.     

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.     

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.     

HPLC法测定岩青兰地上全草与不同部位中柚皮素-7-O-葡萄糖苷及北美圣草素-7-O-葡萄糖苷的含量

建立HPLC法测定岩青兰中柚皮素-7-O-葡萄糖苷及北美圣草素-7-O-葡萄糖苷的含量的方法,考察岩青兰地上全草与不同部位中两种二氢黄酮类成分的含量。采用Phenomenex C18柱,甲醇-乙腈-水(32：8：60)为流动相,流速1ml／min,紫外检测器284nm波长进行检测。测得岩青兰叶中两种二氢黄酮含量最高,茎中含量极低,根中未测到。建立的方法分析简便、灵敏、准确。     

The leaf flavonoids of the orchidaceae

In a leaf survey of 142 species from 75 genera of the Orchidaceae, flavone C-glycosides (in 53%) and flavonols (in 37 %) were found to be the most common constituents. However, since these compounds are not found uniformly and their distribution shows a strong correlation with plant geography, it is not possible to represent the Orchidaceae by a single flavonoid profile. Thus, flavone C-glycosides are most common in tropical and subtropical species of the Epidendroid and Vandoid tribes (in 63%) and flavonol glycosides are more characteristic of temperate species of the Neottioid tribes (in 78%). By contrast 6-hydroxyflavones (in 6 species), luteolin (in 2 species) and tricin as the 5-glucoside (in 1 species) are all rare. Three new glycosides were characterised: scutellarein 6-methyl ether 7-rutinoside from Oncidium excavatum and O. sphacelatum, pectolinarigenin 7-glucoside from 0. excavatutn and Eria javanica, and luteolin 3′,4′-diglucoside from Listera ovata. The xanthones, mangiferin and isomangiferin were found in Mormolyca ringens, Maxillaria aff. luteo-alba and 5 Polystachya species and a mangiferin sulphate tentatively identified in P. nyanzensis. Other unusual phenolic constituents include 6,7-methylenedioxy- and 6,7-dimethoxycoumarins from Dendrobium densiflorum and D. farmeri, formed by the rearrangement during the extraction process from the corresponding O-glucosyloxycinnamic acids. The origin and relationship of the Orchidaceae to other monocot groups are discussed in the light of the flavonoid evidence.     

Auriculoside,a new flavan glycoside from Acacia auriculiformis

The structural elucidation of auriculoside, a new flavan glucoside from Acacia auriculiformis, is described. This is the third report of a flavan glycoside unsubstituted in the heterocyclic ring.     

Luteolin 7-glucuronide-3′-mono(trans)ferulylglucoside and other unusual flavonoids in the aquatic liverwort complex, Riccia fluitans

Thirteen flavonoid glycosides, including eight which are new have been identified in Riccia fluitans; aquatic and terrestrial forms of this plant have the same pattern. Luteolin 7-O-glucuronide-3′-O-mono(trans)ferulylglucoside is proposed as the type flavonoid for this species. Its absence from, and the presence of chrysoeriol in R. duplex, support the proposed separation of R. duplex from the R. fluitans complex. A micro-deacylation technique is described which can also be used for specific deglycosylation of luteolin glycosides at the 4′-hydroxyl.     

Les constituants flavonoïdes de Cephalanthus spathelliferus

We have isolated from Cephalanthus spathelliferus (Rubiaceae) five compounds: umbelliferone, skimmin, 7,4′-dimethylkaempferol,7,4′-dimethylaromadendrin and its 5-glucoside. The latter two are new compounds.     

Species-specific kaempferol derivatives in ferns of the appalachian Asplenium complex

A series of kaempferol derivatives have been identified in fronds of three parental species of the Appalachian Asplenium complex. Asplenium platyneuron is characterised by the presence of the 7-glucoside of kaempferol 3,4′-dimethyl ether and also contains kaempferol 3,7-diglucoside, free and with an aliphatic acyl attachment. By contrast, A. rhizophyllum contains a remarkable caffeoyl complex of kaempferol glycosides, which appears to be chromatographically homogenous. However, on deacylation, the complex yields caffeic acid and the 7-glucoside, 3,7-diglucoside, 3-sophoroside-7-glucoside and 7,4′-diglucoside of kaempferol. Asplenium montanum, in addition to having previously characterised glycosylxanthones, has two further kaempferol derivatives. It has been confirmed that these various species specific flavonoids are inherited in an additive fashion in three interspecific hybrids.     

Flavans from Zephyranthes flava

A new optically active flavan aglucone, 7-hydroxy-3′,4′-methylenedioxyflavan, and its 7-glucoside have been isolated from the bulbs of Zephyranthes flava, collected at flowering. Additionally, two known flavans, 7,4′-dihydroxy-3′-methoxyflavan and 7-methoxy-2′-hydroxy-4′,5′-methylenedioxyflavan, have been isolated for the first time from this species. The structures of these flavans have been established by comprehensive analyses (UV, IR, ¹H NMR, ¹³C NMR, mass spectrometry, [α]_D) of the compounds and their acetates, and also by chemical correlation.