Rapid identification of chemical constituents in traditional Chinese medicine fufang preparation xianling gubao capsule by LC-linear ion trap/Orbitrap mass spectrometry.

The traditional Chinese medicine fufang preparation "Xian-Ling-Gu-Bao" capsule (XLGB), which is composed of six herbal medicines, is popularly used for the treatment of osteoporosis. A reliable and effective method using LC-linear ion trap (LTQ)/Orbitrap mass spectrometry for rapid screening and identification of chemical constituents in "Xian-Ling-Gu-Bao" capsule is described in this paper. Based on the UV spectrum, mass spectrum, and the chemical components isolated from the original plants of XLGB, 118 compounds were identified or tentatively characterized, including 58 flavonoid glycosides, six prenylated flavonones, five prenylated isoflavones, six prenylated chalcones, four xanthone C-glycosides, 13 saponins, eight phenolic acids, five coumarins, three lignans, three iridoids, five phenethyl alcohol glycosides, one tanshinone and one alkaloid. This work might be helpful for the quality control and further pharmacokinetic studies of XLGB, and provided a good example for the rapid identification of chemical constituents in traditional Chinese medicine fufang preparation. Moreover, the identification strategy for the linkages of sugar residues in flavonol O-glycosides was summarized in the study. The diagnostic fragment ions at m/z 185 [C12H9O2] and 157 [C11H9O], which distinguish C-6 and C-8 prenylated flavonoids, were reported for the first time.

Design and synthesis of biphenyl derivatives as mushroom tyrosinase inhibitors.

Two new series of biphenyls, analogs of aglycone of natural product fortuneanoside E, were prepared using Suzuki-Miyaura cross-coupling and selective magnesium iodide demethylation/debenzylation, and their mushroom tyrosinase inhibitory activity was evaluated. Most of the 4-hydroxy-3,5-dimethoxyphenyl biphenyl compounds (series II, 20-36) were in general more active than 3,4,5-trimethoxyphenyl biphenyl compounds (series I, 1-19). Structure-activity relationships study showed that monosaccharide substituents, such as glucose, were not necessary and the presence of 4-hydroxy-3,5-dimethoxyphenyl moiety was crucial for inhibitory activity. Among the compounds synthesised, compound 21 (IC50=0.02 mM) was found to be the most active one, which exhibited an activity that was 7 times higher than that of fortuneanoside E (IC50=0.14 mM) and 10 times higher than that of arbutin (IC50=0.21 mM), known as potent tyrosinase inhibitors. The inhibition kinetics analyzed by Lineweaver-Burk plots revealed that compound 21 was a competitive inhibitor (Ki=0.015 mM).

Two new monoterpene glucosides from Paeonia lactiflora Pall.

Two new monoterpene glucosides, 4'-O-benzoylpaeoniflorin (1) and 4-O-galloylalbiflorin (2), were isolated from the 60% ethanol extract of the dried roots of Paeonia lactiflora Pall. Their structures were established on the basis of spectroscopic data.

Copacamphane, picrotoxane and cyclocopacamphane sesquiterpenes from Dendrobium nobile.

Dendronobilins K - N, four new sesquiterpenes with copacamphane-type (1), picrotoxane-type (2, 3) and cyclocopacamphane-type (4) skeletons, were isolated from the n-BuOH soluble fraction of the 60% ethanol extract of the stems of Dendrobium nobile. Their structures were established as 2beta,11,12-trihydroxycopacamphan-15-one (1), (2beta,3beta,4beta,5beta)-2,4,11,12-tetrahydroxypicrotoxan-3(15)-olactone (2), (2beta,3beta,5beta)-2,11,12,13-tetrahydroxypicrotoxan-3(15)-olactone (3), and (5beta,8beta)-cyclocopacamphane-5,8,12,15-tetrol (4) on the basis of spectroscopic analysis. Compounds 3 and 4 were inactive in both immunomodulatory and antioxidant bioassay in vitro.