Flavonoid C- and O-glycosides from the Mongolian medicinal plant Dianthus versicolor Fisch.

Eighteen flavonoids were identified from an aqueous extract of the aerial parts of Dianthus versicolor, a plant used in traditional Mongolian medicine against liver diseases. The flavonoid C- and O-glycosides isoorientin-7-O-rutinoside, isoorientin-7-O-rhamnosyl-galactoside, isovitexin-7-O-rutinoside, isovitexin-7-O-rhamnosyl-galactoside, isoscoparin-7-O-rutinoside, isoscoparin-7-O-rhamnosyl-galactoside, isoscoparin-7-O-galactoside, and isoorientin-7-O-galactoside were isolated and structurally elucidated. Their structures were established on the basis of extensive spectroscopic techniques including LC-UV-DAD, LC-MS(n), LC-HRMS, 1D and 2D NMR spectroscopy, and by GC-MS analysis after hydrolysis. Flavonoids with such a high glycosylation pattern are rare within the genus Dianthus. Furthermore, isovitexin-7-O-glucoside (saponarin), isovitexin-2″-O-rhamnoside, apigenin-6-glucoside (isovitexin), luteolin-7-O-glucoside, apigenin-7-O-glucoside, as well as the aglycons luteolin, apigenin, chrysoeriol, diosmetin, and acacetin were identified by TLC and LC-DAD-MS(n) in comparison to reference substances or literature data. The NMR data of seven structures have not been reported in the literature to date.

In vitro anti-inflammatory activity of larch (Larix decidua L.) sawdust.

The influence of larch (Larix decidua L.) sawdust extracts on arachidonate metabolism has been evaluated in vitro. Extracts of different polarities were tested for their ability to inhibit prostaglandin formation by COX-1 and COX-2 and LTB(4) formation by 5-LOX. The lipophilic n-heptane extract showed the highest activity (IC(50) values: COX-1, 5 microg/mL; COX-2, 0.1 microg/mL; LTB(4) assay, 11.1 microg/mL). A series of abietane, pimarane, and labdane type diterpenes isolated from this extract turned out to be potent inhibitors of LTB(4) product formation, whereas their COX inhibitory activity was less pronounced. From the abietane type diterpenes, compounds possessing a 7,13-abietadiene skeleton were better inhibitors of LTB(4) formation than those with an 8,11,13-abietatriene skeleton. Compounds bearing an OH group in position 4 were more active than those substituted with a COOH group, and methylation of the COOH group led to an almost complete loss of LTB(4) formation inhibitory activity.

Morphological, chemical and functional analysis of catuaba preparations.

Fourteen commercial samples of the popular Brazilian aphrodisiac Catuaba specified as bark drugs of Anemopaegma, Erythroxylum and Trichilia species were examined for identity and purity. Only a minority of the examined Catuaba samples contained the crude drugs claimed on the labels. More than half of the products were adulterated with different crude drugs. The majority of the samples contained a bark originating from Trichilia catigua. The TLC fingerprints confirmed the heterogeneity, in 50% of the samples tropane alkaloids of various concentrations were detected. TLC and HPLC methods for separation and identification of the tropane alkaloids were developed and their analytical data (RF values, retention times, ESI-MS) given. The structure elucidation of the two main alkaloids, catuabine D and its hydroxymethyl derivative, is presented. The 1H- and 13C-NMR assignments of these alkaloids are discussed with regard to literature data. Neither aqueous nor methanolic extracts of the Trichilia catigua reference material nor alkaloid-enriched fractions of commercial samples showed any effect on the rabbit corpus cavernosum in an in vitro test.

Anthrone C-glucosides from Rheum emodi.

In a study of the anthraderivatives in roots of Rheum emodi, three new anthrone C-glucosides, named 10-hydroxycascaroside C (1), 10-hydroxycascaroside D (2) and 10R-chrysaloin 1-O-beta-D-glucopyranoside (3) were isolated besides the rare compounds cascaroside C (4), cascaroside D (5) and cassialoin (6). Additionally the investigation resulted in the isolation of an acetylated chrysophanol glucoside, 8-O-beta-D-(6'-O-acetyl)glucopyranosyl-chrysophanol (7). The structures were established by comprehensive spectroscopic investigations.

Sulfemodin 8-O-beta-D-glucoside, a new sulfated anthraquinone glycoside, and antioxidant phenolic compounds from Rheum emodi.

A sulfated emodin glucoside, emodin 8-O-beta-D-glucopyranosyl-6-O-sulfate (1), was isolated from the roots of Rheum emodi in an investigation of the active constituents of this Nepalese medicinal plant, and its structure was determined by spectroscopic and chemical methods. Additionally, two rare auronols, carpusin (2) and maesopsin (3), besides other anthraquinones and phenolics, were isolated and identified. Compounds 2 and 3 showed significant antioxidant activity in the DPPH assay, while chrysophanol, physcion, and emodin and their 8-O-glucosides were found to be inactive.

Sesquiterpenes from Achillea pannonica Scheele.

From dichloromethane extracts of flowerheads of Achillea pannonica Scheele three sesquiterpenes were isolated and identified: 11,13-dehydrodesacetylmatricarin, (6E)-5-tigloxy-9-hydroxynerolidol and alpha-longipin-2-en-1-one. The structures were determined by MS, IR and NMR spectroscopic analyses, (6E)-5-Tigloxy-9-hydroxynerolidol is reported here for the first time. Additionally spathulenol, a compound of the essential oil was identified using GC-MS and GC-FTIR.

Sesquiterpenes and flavonoid aglycones from a Hungarian taxon of the Achillea millefolium group.

The investigation of a dichloromethane extract of flower heads of a Hungarian taxon of the Achillea millefolium group led to the isolation of three flavonoid aglycones, one triterpene, one germacranolide and five guaianolides. Their structures were elucidated by UV-VIS, EI- and CI-MS, 1H NMR and 13C NMR spectroscopic methods as well as by 2D-NMR studies and by selective 1D-NOE experiments. Besides apigenin, luteolin and centaureidin, beta-sitosterol, 3beta-hydroxy-11alpha,13-dihydro-costunolide, desacetylmatricarin, leucodin, achillin, 8alpha-angeloxy-leucodin and 8alpha-angeloxy-achillin were isolated. Both latter substances are reported here for the first time. Their NMR data were compared with those of the other guaianolides. The stereochemistry of 3beta-hydroxy-11alpha,13-dihydro-costunolide was discussed and compared with data of the literature.