草苁蓉中2个单萜苷类化合物的NMR研究

从草苁蓉75%乙醇提取物中分离得到了2个单萜苷类化合物,结合其理化性质,并通过1DNMR(1 H NMR,13 C NMR)及1 H-1 H COSY、HSQC、HMBC、NOESY等多种波谱学方法进行结构鉴定,鉴定2个化合物分别为β-D-glucopyranose 1-(3,7-dimethyl-2-trans-6-octa-dienoate)(化合物1)和6,7-dihydrofoliamenthoic acid diglucoside(化合物2),其中化合物1为新化合物,化合物2为第1次从列当科植物中获得.

Discovery of human pancreatic lipase inhibitors from root of Rhodiola crenulata via integrating bioactivity-guided fractionation,chemical profiling and biochemical assay

Although herbal medicines(HMs)are widely used in the prevention and treatment of obesity and obesity-associated disorders,the key constituents exhibiting anti-obesity activity and their molecular mechanisms are poorly understood.Recently,we assessed the inhibitory potentials of several HMs against human pancreatic lipase(hPL,a key therapeutic target for human obesity),among which the root-extract of Rhodiola crenulata(ERC)showed the most potent anti-hPL activity.In this study,we adopted an integrated strategy,involving bioactivity-guided fractionation techniques,chemical profiling,and biochemical assays,to identify the key anti-hPL constituents in ERC.Nine ERC fractions(retention time=12.5e35 min),obtained using reverse-phase liquid chromatography,showed strong anti-hPL activity,while the major constituents in these bioactive fractions were subsequently identified using liquid chromatography-quadrupole time-of-flight mass spectrometry(LC-Q-TOF-MS/MS).Among the identified ERC constituents,1,2,3,4,6-penta-O-galloyl-β-D-glucopyranose(PGG)and catechin gallate(CG)showed the most potent anti-hPL activity,with pIC50 values of 7.59±0.03 and 7.68±0.23,respectively.Further investigations revealed that PGG and CG potently inhibited hPL in a non-competitive manner,with inhibition constant(Ki)values of 0.012 and 0.082 mM,respectively.Collectively,our integrative analyses enabled us to efficiently identify and characterize the key anti-obesity constituents in ERC,as well as to elucidate their anti-hPL mechanisms.These findings provide convincing evidence in support of the anti-obesity and lipid-lowering properties of ERC.

Metabolite characterization of Penta-O-galloyl-β-D-glucose in rat biofluids by HPLC-QTOF-MS

Objective： To understand the in vivo metabolic fate of 1,2,3,4,6-Penta-O-galloyl-β-d-glucose（PGG）naturally existed in many medicinal herbs and food plants such as Rhus chinensis,Paeonia suffruticosa,Paeonia lactiflora and Mango.Methods： The metabolites of PGG in rat biofluids were characterized using high performance liquid chromatography combined with quadrupole time-of-flight tandem mass spectrometry（HPLC-QTOF-MS）.Results： Ten metabolites in urine,five metabolites in feces and two metabolites in plasma,were observed when the rats were administrated with a single intravenous injection of PGG（20 mg/kg）.Conclusion： PGG is firstly metabolized to gallic acid,then gallic acid undergoes sulfation,glucuronidation and methylation by rat liver.The determination of metabolites and the proposed metabolic pathway of PGG in vivo will be benefit to gain deeper insights into its pharmacological activities.