| The Chinese materia medica preparation Shiqiwaigan Granula is widely used to prevent influenza in the Lingnan region. It is made up of five Chinese crude drugs and the Clerodendrum chinensis is one of the main raw materials. According to different provinces’ flora of China, The Clerodendrum chinensis is probable derived from the plants C. fragrans auct.Non.Vent, C. philippinum Schauer Var.philippinum, C. lindleyi Decne.ex Planch and Clerodendrum bungei. This four plants belong to the same genus and have similar morphological characters, so they are often confused in the clinic. In order to explore the effective components of C. lindleyi as therapeutic agent in folk medicine, distinguish it from adulterant and ensure prescription safe and effective, we systematically investigated the chemical constituents and antioxidant activity of C. lindleyi. The main contents of this study are summarized as follows:Objective To study the chemical constituents of the roots, stems and leaves of C. lindleyi from Verbenaceae, respectively and assess their DPPH radical scavenging effect in vitro. Thereby, to reveal the main potential chemical markers (clusters) for the identification and antioxidant activiy of C. lindleyi. Thus, to provided scientific references for further studies of therapeutic basis of C. lindleyi.Methods The main compounds of C. lindleyi were isolated and purified by various chromatographic techniques such as silica gel, macroporous resin, sephadex, HPLC and so on. Their chemical structures were then elucidated on the basis of analysis of UV, IR, MS and NMR spectroscopic data and by their physico-chemical properties. Free radical scavenging activity of the isolated compounds was tested in vitro by DPPH assay.Results The chemical compositions were isolated and identified by systematical separation techniques and their antioxidant activities were tested, the main research results was as follows:1. Seventeen compounds were isolated from the roots and stems of C lindleyi, they were identified as follows:(1) betulinic acid (1)(2) monoacetylmartinoside (3"-O-acetylmartynoside) (2)(3) 4"-Oacetylmartynoside (3)(4) clerodenoside A (4)(5) 3",4"-O-acetylmartynoside (acetylmartynoside B) (5)(6) acteoside (6)(7) friedelin (7)(8) glutinol (8)(9) taraxerol (9)(10) uncinatone (10)(11) mandarone E (11)(12) (24S)-24-ethylcholesta-5,22,25-trien-3β-ol (12)(13) hedyotol C 4"-O-β-D-glucopyranoside (13)(14) martynoside (14)(15)dibutyl phthalate(15)(16) 2"-O-acetylmartynoside (16)(17)isoacteoside (17)Compounds 1-6,17 were obtained from the roots. Compounds 1,2,4,6,7-16 were obtained from the stems. Both the root and stem contain compounds 1,2, 4 and 6. This seventeen compounds contained eight phenylethanoid glycosides, two diterpenoids, four triterpenoids, one sterol, one lignan and one ester. Compounds 1-17 were all obtained from C. lindleyi for the first time. Compound 13 were obtained from Clerodendrum Linn. for the first time.2. Forty-three compounds from the leaves SD extract of C. lindleyi were identified by GC-MS. Five main compounds which account for 58.8% of the total oil were identified as follows:(1) 1-octen-3-ol(2) 3,7-dimethy1-I,6-octadien-3-ol(3) 3-octanol(4) 3,4,4a,5,6,7-hexahydro-1,1,4a-trimethyl-2 (1H)-Naphthalenone(5) 3,4,4α,5,6,8α-hexahydro-2,5,5,8α-tetramethyl-(2a,4a,8a)-2H-I-Benzopyran3. Bioassay showed that compounds 1-12 have different free radical scavenging capacity.The phenylethanoid glycosides 4"-O-acetylmartynoside (IC50=25 μmol/L), monoacetylmartinoside (IC50=37 μmol/L) and actioside (IC50=60μmol/L) of them exhibited significant DPPH radical scavenging activity, but the diterpenoids, triterpenoids and sterol showed weak activity.Conclusion The main conclusions from the results were showed as follows:1. The systematic phytochemical studies revealed phenylethanoid glycosides may be used as the main potential chemical markers (clusters) for the roots and stems of C. lindleyi. 1-octen-3-ol,3-octanol and 3,7-dimethyl-1,6-octadien-3-ol may be used as the main potential chemical markers (clusters) for the leaves of C. lindleyi.2. The DPPH radical-scavenging test in vitro indicated phenylethanoid glycosides may be the main active constitutent for DPPH radical-scavenging of C. lindleyi, which may be used to explain its effectiveness as therapeutic agent in folk medicine. So they may provide scientific basis for the further studies of Shiqiwaigan Granules.3. The results of the systematic phytochemical studies may become the chemical proofs for further distinguishing C. lindleyi from adulterant. |
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