H.Dietmar Zinsmeister

The first identification of isoflavones from a bryophyte

Abstract Bryum capillare is shown to accumulate the isoflavones orobol and pratensein as the 7- O -glucosides and predominantly, as the 7-(6″-malonylglucosides). This is the first finding of isoflavonoids in bryophytes. The phylogenetic relevance of this observation is briefly discussed.

A new cyanogenic glycoside from Hordeum vulgare

Abstract From leaf extracts of 10-day-old seedlings of barley, a new cyanogenic glycoside has been isolated. This compound is 2-β- d -glucopyranosyl-oxy-3-methyl-(2R )-butyronitrile, the epimer of heterodendrin.

Mass spectrometry of silylated flavone and flavanone glycosides

Abstract The electron impact mass spectra of 14 trimethylsilylated flavone and flavanone mono- and diglycosides are reported for the first time. All spectra show well defined molecular ion peaks and those of O -glycosides additionally give evidence of the aglycone and the sugar(s), the sugar attachment, the sugar sequence and the interglycosidic linkage (of flavone and flavanone biosides).

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

Abstract 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.

Flavonoids of Plagiochila asplenioides

Abstract Besides an apigenin- and a luteolin-di- C -glycoside, 5 previously unknown di- C -glycosides of tricetin were identified in the gametophytic and sporophytic tissues of Plagiochila asplenioides . Two of them were new 6,8-di- C -hexopyranosyltricetins, and two were new 6- C - hexopyranosyl-8-C-pentopyranosyltricetins. 6- C -Hexopyranosyl-8-C-pentopyranosyltricetin-5′-methyl ether was also found.

Flavone C-glycosides of two Metzgeria species

Abstract Six known tricin and apigenin di- C -glycosides, including 2″- O -ferulylisoschaftoside, have been identified in gametophytic material of Metzgeria conjugata. M. leptoneura contains a new di- C -glycoside, tricin 6- C -xyloside-8- C -hexoside. The chemotaxonomic relevance of the flavonoid patterns is briefly discussed.

Bryoflavone and Heterobryoflavone, Two New Isoflavone-flavone Dimers from Bryum capillare

From the moss Bryum capillare (Bryaceae) two new biflavonoids-bryoflavone and hetero bryoflavone - have been isolated. They are the first examples of a new class of biflavonoids formed by oxidative coupling of a flavone and an isoflavone moiety. The structures of both compounds are proved spectroscopically.

Isoorientin 3′-O-sophoroside and 3′-O-neohesperidoside from the moss Plagiomnium affine

Abstract From Plagiomnium affine isoorientin, isoorientin 3′- O -sophoroside and isoorientin 3′- O -neohesperidoside were isolated. The two di- O -glycosides are new natural compounds. The flavonoid pattern of P. affine was constant, irrespective of geographical and seasonal sampling.

The structures of new flavone di-C-glycosides from Apometzgeria pubescens

Abstract The structures of seven flavone C-glycosides from Apometzgeria pubescens were determined with the aid of 13CNMR spectroscopy. They were all

NMR Spectra of Flavone Di-C-glycosides from Apometzgeria pubescens and the Detection of Rotational Isomerism in 8-C-Hexosylflavones

1H and 13C NMR spectra are documented for the novel flavone-6,8-di-C-glycosides isolated from the liverwort, Apometzgeria pubescens. The existence of rotational isomerism evident from these spectra is shown to be general for 8-C-monohexosylflavones and of possible diagnostic value.