ABSTRACT
Objective: Poria cocos and Polyporus umbellatus are similar medicinal fungi in traditional Chinese medicines. A method for fingerprint analysis of monosaccharide composition of polysaccharides by HPLC combined with chemometrics methods has been developed for characterization and discrimination of them in this research. Methods: The polysaccharides were extracted by decocting in water, and then completely hydrolyzed with hydrochloride. Monosaccharides in the hydrolyzates were derivatized with 1-phenyl-3-methyl-5-pyrazolone (PMP) for HPLC analysis. More than 20 batches of P. cocos and P. umbellatus from different regions were analyzed. Results: The fingerprints of P. cocos showed five common characteristic peaks, which were identified by comparing with the reference substances. The five peaks corresponded to the derivatives of mannose, ribose, glucose, galactose, and fucose. At the same time, the fingerprints of P. umbellatus showed eight common characteristic peaks, of which seven were identified as the derivatives of mannose, ribose, rhamnose, glucose, galactose, xylose, and fucose. Moreover, the similarity of their fingerprints was respectively calculated by the Similarity Evaluation System for Chromatographic Fingerprint of TCM published by China Pharmacopoeia Committee (Version 2004A). And the data were further processed by hierarchical cluster analysis (HCA) and principal component analysis (PCA). The similarity evaluation and HCA indicated that there were no significant difference in P. cocos or P. umbellatus samples from different geographical regions, but PCA was performed to characterize the difference in monosaccharide constituents between P. cocos and P. umbellatus, and linear discriminant analysis (LDA) showed the overall correct classification rate was 100%. Conclusion: The fingerprint analysis method of monosaccharide composition of water-soluble polysaccharides can distinguish P. cocos and P. umbellatus, and can be applied for the authentication or quality control for P. cocos and P. umbellatus.
ABSTRACT
Objective: To clone the Bax inhibitor-1 (BI-1) gene from Polyporus umbellatus and perform the bioinformatics and expression mode analysis. Methods: To clone the full-length cDNA of BI-1 using RACE technology. The characteristics of physiochemical properties, conserved domains, and transmembrane domain of the predicted BI-1 protein were determined using bioinformatic tools. Results: The full-length cDNA of BI-1 gene was 1 091 bp in length and encoded a 334-aa protein with a molecular weight of 36170 and an isoelectric point (pI) of 10.51. The polypeptide chain was a hydrophobin with five hydrophobic regions. The PuBI-1 belonged to basidiomycete group according to the phylogenetic analysis. Real time quantitative PCR (RT-qPCR) analysis revealed that the transcription level of PuBI-1 gene was significantly higher in the beginning and developing stages of sclerotial formation with 3.8 and 7.497 fold over those in the mycelium, but the transcripts decreased sharply with the sclerotial development. Conclusion: Molecular characterization and expression patten of PuBI-1 gene will be useful for the further functional determination of the gene during the development of P. umbellatus sclerotium.