Establishment of a fast discriminant model with electronic nose for Polygonati Rhizoma mildew based on odor variation / 中国中药杂志

The odor fingerprint of Pollygonati Rhizoma samples with different mildewing degrees was analyzed and the relationship between the odor variation and the mildewing degree was explored. A fast discriminant model was established according to the response intensity of electronic nose. The α-FOX3000 electronic nose was applied to analyze the odor fingerprint of Pollygonati Rhizoma samples with different mildewing degrees and the radar map was used to analyze the main contributors among the volatile organic compounds. The feature data were processed and analyzed by partial least squares discriminant analysis(PLS-DA), K-nearest neighbor(KNN), sequential minimal optimization(SMO), random forest(RF) and naive Bayes(NB), respectively. According to the radar map of the electronic nose, the response values of three sensors, namely T70/2, T30/1, and P10/2, increased with the mildewing, indicating that the Pollygonati Rhizoma produced alkanes and aromatic compounds after the mildewing. According to PLS-DA model, Pollygonati Rhizoma samples of three mildewing degrees could be well distinguished in three areas. Afterwards, the variable importance analysis of the sensors was carried out and then five sensors that contributed a lot to the classification were screened out: T70/2, T30/1, PA/2, P10/1 and P40/1. The classification accuracy of all the four models(KNN, SMO, RF, and NB) was above 90%, and KNN was most accurate(accuracy: 97.2%). Different volatile organic compounds were produced after the mildewing of Pollygonati Rhizoma, and they could be detected by electronic nose, which laid a foundation for the establishment of a rapid discrimination model for mildewed Pollygonati Rhizoma. This paper shed lights on further research on change pattern and quick detection of volatile organic compounds in moldy Chinese herbal medicines.

Identification and bioinformatics analysis of genes associated with MVA pathway in Magnolia officinalis / 中国中药杂志

Methyl valerate (MVA) pathway is one of the important ways for synthesis of terpenoids. This study was based on data of the transcriptome sequencing of Magnolia officinalis, the associated genes MoACOT, MoHMGS, MoHMGR, MoMK in methyl valerate (MVA) pathway, were completed in detail by using bioinformatics methods. The results of analysis showed that MoACOT and MoMK were stable hydrophobic proteins, MoHMGS and MoHMGR were unstable hydrophobic protein. The secondary structures of all proteins were hybrid architecture,and alpha helical were the major motifs. There were no clear transmembrane domains in MoACOT, MoHMGS and MoMK, but two transmembrane domains were founded in MoHMGR which were from 39-61 aa and 82-104 aa resepectively. The results of evolutionary relationship analysis showed that MoACOT, MoHMGS, MoHMGR and MoMK had relative close relationship to angiosperm or dicotyledonous plants, and accorded with genetic evolution rule. From transcriptome data, transcripted level of MoACOT, MoHMGS, MoHMGR, MoMK in M. officinalis and M. officinalis var. biloba was not significantly different. The result provided theoretical reference for study on Methyl valerate (MVA) pathway of terpenoid of M. officinalis.

Gene cloning and bioinformatics analysis of new gene for chlorogenic acid biosynthesis of Lonicera hypoglauca / 中国中药杂志

To obtain the key genes for chlorogenic acid biosynthesis of Lonicera hypoglauca, four new genes ware obtained from the our dataset of L. hypoglauca. And we also predicted the structure and function of LHPAL4, LHHCT1 , LHHCT2 and LHHCT3 proteins. The phylogenetic tree showed that LHPAL4 was closely related with LHPAL1, LHHCT1 was closely related with LHHCT3, LHHCT2 clustered into a single group. By Real-time PCR to detect the gene expressed level in different organs of L. hypoglauca, we found that the transcripted level of LHPAL4, LHHCT1 and LHHCT3 was the highest in defeat flowers, and the transcripted level of LHHCT2 was the highest in leaves. These result provided a basis to further analysis the mechanism of active ingredients in different organs, as well as the element for in vitro biosynthesis of active ingredients.