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Curcumae Rhizoma (Ezhu in Chinese) is a multi-origin herbal medicine with excellent clinical efficacy. For fast discrimination and quantification analysis of Ezhu from three botanical origins (Curcuma kwangsiensis, Curcuma phaeocaulis, and Curcuma wenyujin), ultra-violet (UV) spectroscopy and high performance liquid chromatography (HPLC) combined with chemometric tools were employed in this study. Firstly, the analysis method for the simultaneous determination of eleven compounds in Ezhu was developed by HPLC, and the UV spectra of thirty-eight batches of Ezhu were acquired. Then, principal component analysis (PCA), an unsupervised pattern recognition method, was applied on the HPLC and UV spectral data. PCA did not show a clear separation between C. phaeocaulis and C. wenyujin samples with HPLC data. By contrast, the supervised techniques, decision tree (DT) and linear discriminant analysis (LDA), achieved the complete discrimination for the three species of Ezhu with 100 % correct classification rate (CCR), showing excellent performance. Based on UV spectral data, PCA presented good performance for discriminating the three species of Ezhu. LDA, support vector machine (SVM) and k-nearest neighbors (KNN) models provided 96.3 % CCR for the calibration set and 100 % CCR for the validation set. Moreover, the partial least squares (PLS) and back propagation-artificial neural network (BP-ANN) quantitative models established on UV spectral data were satisfactory in predicting the contents of zederone, curdione and 3,5-dihydroxy-1-(3,4-dihydroxyphenyl)-7-(4-hydroxyphenyl)-heptane. The residual predictive deviation (RPD) for zederone, curdione and 3,5-dihydroxy-1-(3,4-dihydroxyphenyl)-7-(4-hydroxyphenyl)-heptane of PLS models were 3.169, 1.502 and 1.735, and that of BP-ANN models were 3.467, 2.481 and 2.370, respectively. The present work proposed a rapid and reliable method for the discrimination of Ezhu from three botanical origins and the prediction of zederone, curdione and 3,5-dihydroxy-1-(3,4-dihydroxyphenyl)-7-(4-hydroxyphenyl)-heptane contents in Ezhu, which will help a lot in the quality control of Ezhu and other multi-origin herbal medicines.

The anti-rheumatic fraction (ARF), is responsible for the anti-inflammatory and analgesic effects of Dianbaizhu derived from the aerial part of Gaultheria leucocarpa var. yunnanensis (Ericaceae). The gastrointestinal metabolism of ARF was investigated in vitro through simulating a series of models-gastric juice, intestinal juice, and human intestinal bacteria, analyzed by HPLC-DAD and UPLC-LTQ-Orbitrap-MSn. ARF includes three categories: methyl salicylate glycosides, organic acids and the others. The primordial and metabolic components of ARF bio-transformed by simulated gastric fluid (36 and 13), intestinal fluid (29 and 7) and two human fecal bacteria (34 and 34, 40 and 25) were characterized, respectively. The methyl salicylate glycosides, MSTG-B, MSTG-A and gaultherin, with terminal-xylosyl-moiety in sugar chain were always being found in the whole gastrointestinal incubation processing. The metabolites were formed through hydrolysis of ester and glucosidic bond, as well as methylation, hydroxylation, acetylation, sulfation, reduction, decarboxylation, deglycosylation and glucuronidation. The metabolic conversion effect of the four index compounds, MSTG-B, MSTG-A, gaultherin, and chlorogenic acid by human intestinal bacteria exhibited much stronger. Those markers' variation in content-time curve in volunteer A gut flora were faster than that in volunteer B's. These results indicate that ARF is relatively stable in the gastrointestinal tract.