Triterpene glycosides of Cephalaria kotschyi and C. nachiczevanica
Methanolic extracts of the flowers and roots of each species were evaporated to dryness separately, the residues were dissolved in water, and the solutions were washed with chloroform and ethyl acetate and were then extracted with n-butanol. The concentrated butanolic extracts were purified by chromatography on KSK silica gel in the butan-l-ol-methanol (3:1) system. According to thin-layer chromatography (TLC) on silica gel in the butan-l-ol-methanoi--25% ammonia (10:2:5) system, the combined saponins isolated contained seven triterpene glycosides, which were called, in order of increasing polarity, cephalarosides A, B, C, D, E, F, and G. The compositions of the glycosides of the two plants proved to be identical.
Structural elucidations and spectral assigments of two novel triterpene glycosides from Cephalaria paphlagonica
Two novel triterpene glycosides, paphlagonoside A (1) and B (2), were characterised as 28-O-[β-D-glucopyranosyl(1 → 2)-α- L-arabinopyranosyl(1 → 4)-β-D-glucopyranosyl]-hederagenin (1) and 28-O-[β-D-xylopyranosyl(1 → 4)-α- L-rhamnopyranosyl(1 → 3)-β-D-xylopyranosyl (1 → 6)-β-D-glucopyranosyl(1 → 2)-β-D-glucopyranosyl]-hederagenin (2) from Cephalaria paphlagonica (Dipsacaceae). In addition to these, a common natural product (hederagenin) (3) was also isolated. The structures of all compounds were identified by spectroscopic and chemical methods. The antimicrobial and antioxidant activities of the plant extracts were examined by MIC and DPPH activity methods, respectively.
THIN-LAYER CHROMATOGRAPHY OF CARBOHYDRATES IN THE PRESENCE OF BISULFITE.
Abstract A rapid method for separating carbohydrates by means of thin-layer chromatography on silica gel G mixed with a small amount of sodium bisulfite has been developed. The solvent system propanol—water (85:15) gave the best resolution of the carbohydrates but did not separate some pentoses. Five spray reagents, viz.o-amino-diphenyl—orthophosphoric acid, carbazole—sulfuric acid, dimedone—orthophosphoric acid, phenol—sulfuric acid and thymol—sulfuric acid, were used for the detection of carbohydrates. Quantities as small as 0.1 μg could be easily detected with these reagents, with one exception, viz. carbazole—sulfuric acid reagent. The carbohydrates gave characteristic colors with the reagents, thus making identification easier.