| Pharmacological activity of Alpinia officinarum Hance is clear as an edible herb.Originally,its main origin is Xuwen Country of Guangdong Province.In recent years,the cultivated area of A.officinarum in Hainan has increased gradually with the rubber interval planted,but there is no investigation on the chemical compositions produced in Hainan.Galangin,the main active ingredient from A.officinarum,has a variety of pharmacological activities.However,it mainly existed in the form of phaseⅡ metabolism in vivo through the study of pharmacokinetics.Pharmacodynamic substance bases whether galangin or its metabolites have not been studied.Therefore,our objectives are to separate the chemical constituents of A.officinarum in Hainan,and to clarify the activity of representative diarylheptanes on adipocytes.Furthermore,the effects of galangin and its metabolites on the expression of lipids,cholesterol and triglycerides in Hep G2 cells were investigated by the isolation and structure identification of galangin metabolites and the activity study of galangin and its metabolites on Hep G2 cells.In this study,the chemical constituents of A.officinarum in Hainan were separated by multiple column chromatography and a total of 16 chemical constituents were isolated and identified including 13 diarylheptanoids,5-ethoxy-1,7-diphenyl-3-heptanone(1),5-methoxy-1,7-diphenyl-3-heptanone(2),5-hydroxyl-1,7-diphenyl-3-heptanone(3),6-hydroxyl-7-(4″-hydroxyl-3″-methoxyphenyl)-1-phenyl-4-en-3-one(4),6-hydroxyl-1,7-diphenyl-4-en-3-one(5),3,6-furan-7-(4″-hydroxyl-3″-methoxyphenyl)-1-phenylheptane(6),7-(4″-hydroxyl-3″-methoxyphenyl)-1-phenyl-4-en-3-one(7),5-methoxy-7-(4″-hydroxyl-3″-methoxyphenyl)-1-phenyl-3-heptanone(8),5-hydroxyl-7-(4″-hydroxyl-3″-methoxyphenyl)-1-phenyl-3-heptanone(9),1,7-diphenyl-4-en-3-one(10),trans-(4R,5S)-epoxy-1,7-diphenyl-3-heptanone(11),7-(4″-hydroxy-3″-methoxyphenyl)-1-phenyl-hepta-4E,6E-dien-3-one(12),1,7-diphenyl-3-heptanone(13);one lactone,atractylenolideⅠ(14);two flavonoids,galangin(15)and kaempferide(16).Among them,compound 11 was a new compound,and 12 was a new natural product.Furthermore,13 and 14 were isolated from A.officinarum for the first time.Simultaneously,diarylheptanoids(1-12)isolated from A.Officinarum were tested the effects for the proliferation and differentiation of 3T3-L1 adipocytes.The result showed that twelve diarylheptanes promoted adipogenesis dosedependently.Moreover,MTT experiment showed that diarylheptanes had no effect on the growth of 3T3-L1 preadipocytes with low dosage but significantly promoted the proliferation of adipocytes at high dosage.Two metabolites of galangin were isolated from urine sample using preparative HPLC and their structures were identified as galangin-3-O-β-D-glucuronic acid and galangin-7-O-β-D-glucuronic acid by spectral data.They can reduce oleic acid-induced lipid accumulation in a dose-dependent manner,and decrease the contents of intracellular triglyceride and total cholesterol in Hep G2 cells.Real-time q PCR showed that two metabolites significantly decreased the expression of lipogenic genes such as SREBP-1a,SREBP-1c,and SREBP-2transcription factors and its downstream genes such as FAS,ACC,and HMGR.Furthermore,the inhibitory efficiency of two metabolites was higher than galangin.Hypolipidemic activity of galangin in vivo may be played by its metabolites.In this paper,the chemical constituents of A.officinarum in Hainan were systematically separated and analyzed,and the chemical composition was clarified.Furthermore,The effects of diarylheptanoids on the proliferation and differentiation of adipocytes were also screened as well as lipid-lowering activity of galangin and its metabolites.These work laid the foundation for the rational use of A.officinarum and further pharmacological research. |
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