Influence of different pretreatments and drying methods on the chemical compositions and bioactivities of Smilacis Glabrae Rhizoma.

BACKGROUND: The processing of medicinal plant materials is one of the important factors influencing the components and biological activities of TCMs. Smilax glabra Roxb. is an herbal vine widely distributed in China, and its dried rhizome (Smilacis Glabrae Rhizoma, SGR) is often used in traditional medicines and functional foods. The processing methods of fresh cutting for SGR slices have been included in ancient Chinese herbal works, some local standards of TCMs, and the current Chinese Pharmacopoeia. Nevertheless, to date, the scientific basis for the processing of fresh medicinal materials for SGR slices has not been revealed. METHODS: To optimize the processing method for preparing SGR slices from the fresh rhizomes, the chemical compositions of the un-pretreated and pretreated (boiling, steaming) samples before and after drying (sun-drying, shade-drying, oven-drying), and the contents of astilbin isomers in dried SGR were analyzed by UHPLC-Q-TOF-MS/MS and UHPLC-DAD methods, respectively. Then, the antioxidant, anti-inflammatory, xanthine oxidase and α-glucosidase inhibitory activities of the prepared SGR slices were investigated by biological assays. RESULTS: A total of fifty-two compounds were identified from the un-pretreated and pretreated samples and a total of forty-nine compounds were identified from the subsequently dried samples. After pretreated by boiling and steaming, the contents of neoastilbin, neoisoastilbin, and isoastilbin in the prepared samples all increased. As a quality marker of SGR, the content of astilbin was unchanged or decreased slightly compared with that in the un-pretreated samples. During the drying process, the contents of the four astilbin stereoisomers in the un-pretreated samples increased significantly, while those in the pretreated samples had a slight increase or decrease. The effects of different processing methods were sorted according to the bioactivities of the prepared SGR. As a result, SGR slices prepared with no pretreatment followed by a sun-drying process have a higher astilbin content, better bioactivities and more energy savings, representing the optimum processing method for SGR slices. CONCLUSIONS: This study reveals the scientific basis for the processing of fresh medicinal materials for SGR slices. The results provide scientific information for the quality control of SGR and its rational applications in herbal medicines and functional foods.

An integrated study of Violae Herba (Viola philippica) and five adulterants by morphology, chemical compositions and chloroplast genomes: insights into its certified plant origin.

BACKGROUND: Viola philippica Cav. is the only original plant for Violae Herba, as described in the Chinese Pharmacopoeia. The quality of this crude drug is affected by several adulterants from congeneric Viola species, and the authentic plant origin of Violae Herba is still controversial. Genome-based identification offers abundant genetic information and potential molecular markers that can be used for the authentication of closely related species. This study aims to investigate the certified origin of Violae Herba and to develop more effective markers for these easily confused species at the genetic level. METHODS: We compared the morphology and chemical composition of 18 batches of commercial samples and six widespread medicinal Viola plants used as Violae Herba or its substitutes by TLC and HPLC-Triple-TOF-MS/MS analyses. The complete chloroplast genomes of these species were sequenced and analyzed, including the general features, repeat sequences, mutational hotspots and phylogeny. The complete chloroplast genomes used as superbarcodes and some specific barcodes screened from mutational hotspots were tested for their ability to distinguish Viola species. RESULTS: A comparative study showed that Violae Herba is a multi-origin traditional Chinese medicine. Commercial decoction pieces and the standard reference drug were mainly derived from V. prionantha, clashing with the record in the Chinese Pharmacopoeia. Chloroplast genome analyses of V. philippica and five adulterants indicated that sequence divergence was relatively low within Viola species. By tree-based approaches, the complete chloroplast genomes showed a better discrimination ability and phylogenetic resolution for each Viola species. These results indicate that the whole chloroplast genomes can be used as superbarcodes to differentiate Viola medicinal plants. More specific DNA barcodes could be further developed from the Viola chloroplast genomes for more efficient and rapid identification of commercial Violae Herba and its adulterants. CONCLUSIONS: This study has implications for chloroplast genome-based phylogenetic analysis and the authentication of multiple Viola species used as Violae Herba. The legal origin recorded in the Chinese Pharmacopoeia should be further revised to V. prionantha, in line with the commercial Violae Herba in the TCM markets.

The complete chloroplast genome sequence of Gynostemma yixingense and comparative analysis with congeneric species.

Gynostemma yixingense, an important medicinal member of the Cucurbitaceae family, is an endemic herbaceous species distributed in East China. It is morphologically similar to the plants in the same genus, which resulted in some confusion in identification and application. Meanwhile, there are still some controversies in taxonomy. Herein, the complete chloroplast genome sequence of G. yixingense was obtained by Illumina paired-end sequencing technology and compared to other chloroplast genome sequences of congeneric species. The complete chloroplast genome of G. yixingense is 157,910 bp in length with 36.94% GC content and contains a large single-copy (LSC) region of 86,791 bp, a small single-copy (SSC) region of 18,635 bp and a pair of inverted repeat (IR) regions of 26,242 bp. The whole genome contains 133 unique genes, including 87 protein-coding genes, 37 tRNA genes, eight rRNA genes and one pseudogene. In addition, 74 simple sequence repeats (SSRs) were identified, most of which were A/T rich. The phylogenetic analysis indicated that G. yixingense had the closest relationship to G. laxiflorum. The result of this study provided an important theoretical basis for chloroplast genome and phylogenetic analysis of G. yixingense.

[Identification of six species of medicinal Diospyros plants based on leaf macro- and micro-morphology].

To establish a method for the identification of five species and one variety of medicinal plants from Diospyros, their leaf veins, epidermis, anatomic and powder characters were observed and compared with macro-morphological and microscopic methods. The results indicated the differences of secondary and tertiary veins among those Diospyros species. The single cell non-glandular hair and glandular hair exist in most species' epidermis while stone cells were only found in the leaf powders of two species. Through the study, the main differences of leaf macro- and micro-morphology of these species were obtained and practical keys were also established, which can provide scientific base not only for identification of these species during their vegetative stages, but also for accuracy authentication of the source of Kaki Folium.