Characterization of diterpenoids in the bark of Pseudolarix kaempferi by HPLC-ESI/MSn / 药学学报

Fragmentation behavior of diterpenoids was investigated by ESI/MSn and the qualitative analysis of diterpenoids in the bark of Pseudolarix kaempferi was performed using high-performance liquid chromatography/ multi-stage mass spectrometry (HPLC-ESI/MSn). The characteristic fragmentation behaviors of the diterpenoids are the cleavages of the lactone ring and C4-O bond. Furthermore, the eliminations of substituent groups at C-18, C-7 and C-8 can also be observed in the MS" (n = 3-4) spectra. For C-4 acetoxy subsititued diterpenoids, [M+Na-60]+ and [M-H-104] are the base peaks of MS2 spectra in the positive and negative ionization modes, respectively. For C-4 hydroxyl subsititued diterpenoids, [M+Na-44]+ and [M-H-62] are the base peaks of MS2 in the positive and negative ionization modes, respectively. For C-18 glucosylated or esterized diterpenoids, [M+Na-44]+ is the base peak of MS2 spectra in positive ionization mode. These fragmentation rules were successfully exploited in the identification of diterpenoids in methanol/water (6:4) extract of P. kaempferi by LC-MS in positive ionization mode. A total of 9 diterpenoids were identified or tentatively characterized, and one of them is reported here for the first time. The described method could be utilized for the sensitive and rapid qualitative analysis of P. kaempferi.

Two new phenolic acids from Drynariae rhizoma / 药学学报

To study the chemical constituents of Drynariae Rhizoma, nine phenolic acids were isolated from a 70% ethanol extract by using a combination of various chromatographic techniques including column chromatography over silica gel, ODS, Sephadex LH-20, and semi-preparative HPLC. By spectroscopic techniques including 1H NMR, 13C NMR, 2D NMR, and HR-ESI-MS, these compounds were identified as 4, 4'-dihydroxy-3, 3'-imino-di-benzoic acid (1), protocatechuic acid (2), gallic acid (3), p-hydroxybenzoic acid (4), (E)-caffeic acid (5), ethyl trans-3, 4-dihydroxycinnamate (6), caffeic acid 4-O-beta-D-glucopyranoside (7), p-coumaric acid 4-O-beta-D-glucopyranoside (8), and 23(S)-12-O-caffeoyl-12-hydroxyllauric acid glycerol ester (9), separately. Among them, 1 and 9 are new compounds, and 3, 4, and 6 were isolated from Drynaria species for the first time.

Biotransformation of podophyllotoxin by cell suspension culture and root culture of Rheum palmatum / 中国中药杂志

<p><b>OBJECTIVE</b>To study the biotransformation of podophyllotoxin by the cell suspension culture and root culture systems of Rheum palmatum.</p><p><b>METHOD</b>Using plant tissue culture technology and HPLC techniques to isolate products. The structures were elucidated by spectroscopic means.</p><p><b>RESULT</b>Cell suspension culture of R. palmatum could convert podophyllotoxin to produce picropodophyllotoxin with the yield of 73.8%, while root culture of R. palmatum could convert podophyllotoxin to produce epipodophyllotoxin and apopodophyllotoxin.</p><p><b>CONCLUSION</b>Podophyllotoxin did not affect the pH value of the media used in tissue cultures. Both cell suspension culture and root culture of R. palmatum can convert podophyllotoxin.</p>

Pharmacognostical studies on Dactylicapnos scandens / 中国中药杂志

<p><b>OBJECTIVE</b>To offer evidences for quality control of medicinal plant of Dactylicapnos scandens.</p><p><b>METHOD</b>Pharmacognostic studies were carried out through field collection, morphological and microscopic characteristics, and TLC.</p><p><b>RESULT</b>Observation and description of the experimentation were made.</p><p><b>CONCLUSION</b>Dactylicapnos scandens can be identified from Genus of Dactylicapnos which has the similar morphological characteristics. The morphological and microscopic characteristics and the results of TLC can be used as evidences for quality control of this medicinal plant.</p>