ABSTRACT
Objective To investigate the anti-tumor activity of triterpenoids from Ganoderma lucidum on different tumor cells . Methods The MTT assay was adopted to detect the in vitro inhibition effect on 5 kinds of tumor cells .The inhibiting curve was drawn ,IC50 was calculated for reflecting the compound′s cytotoxic activity .Results The in vitro experiments demonstrated that three kinds of triterpenoids compound monomer showed different degrees of inhibition effect ,in which the inhibitory effect of gano-derenic acid Y was stronger ,its IC50 on H460 lung cancer cells was 22 .4 μmol/L ,followed by 7-oxo-ganoderic acid Z2 ,its IC50 was 43 .1 μmol/L .Conclusion Ganoderenic acid Y shows a strong inhibitory activity on H 460 lung cancer cells ,7-oxo-ganoderic acid Z2 shows a certain inhibitory activity on H 460 lung cancer cells ,moreover the inhibitory activity is dose dependent .The three com-pounds of ganoderenic acid Y ,7-oxo-ganoderic acid Z2 and ganoderon B have no activity or very weak activity to the other detected cell lines .The anti-lung cancer activity of ganoderenic acid Y and 7-oxo-ganoderic acid Z2 needs to be further deeply studied .
ABSTRACT
Objective To identify energy metabolism-proteins of mice midbrain by using the proteomic technique,and to investi-gate the relationship between these proteins and neural diseases.Methods Two-dimensional gel electrophoresis was used to sepa-rate totally soluble proteins extracted from mice midbrain.Some protein spots on two-dimensional gel electrophoresis gels were ana-lyzed by using matrix assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS).Results 24 protein spots related with energy metabolism were separated by two-dimensional gel electrophoresis and identified by using MALDI-TOF MS successfully.Conclusion The establishment of energy metabolism-related proteins map of mice midbrain lays a foundation for the research on the involvement of these proteins in neural disease pathogenesis.
ABSTRACT
Traditional herbal medicines, Panax ginseng, Panax quinquefolium and Panax notoginseng, attract our attention for their extensive and powerful pharmacological activities. Ginsenosides are the main active constituents of these medicinal herbs. The related glycosyltransferases involved in ginsenoside biosynthesis are the key enzymes which catalyze the last important step. Modification of ginsenoside aglycones by glycosyltransferases produces the complexity and diversity of ginsenosides, which have more extensive pharmacological activity. At present, ginsenoside aglycones and compound K have been obtained by synthetic biology. As the last step of ginsenoside biosynthesis, glycosylation of ginsenoside aglycones has been studied intensively in recent years. This review summarizes the basic strategies and research advances in studies on glycosyltransferases involved in ginsenoside biosynthesis, which is expected to lay the theoretical foundation for the in-depth research of biosynthetic pathway of ginsenosides and their production by synthetic biology.
ABSTRACT
The cyclization of 2,3-oxidosqualene is the key branch point of ergosterol and triterpenoid biosynthesis. Downregulation of 2,3-oxidosqualene metabolic flux to ergosterol in Saccharomyces cerevisiae may redirect the metabolic flux toward the triterpenoid synthetic pathway. In our study, primers were designed according to erg7 gene sequence of S. cerevisiae. Three fragments including 5' long fragment, 5' short fragment and erg7 coding region fragment were amplified by PCR. 5' long fragment consists of the promoter and a part of erg7 coding region sequence. 5' short fragment consists of a part of promoter and a part of erg7 coding region sequence. These fragments were inserted reversely into pESC-URA to construct antisense expression plasmids. The recombinant plasmids were transformed into S. cerevisiae INVSc1 and recombinant strains were screened on the nutritional deficient medium SD-URA. The erg7 expression level of recombinant strains, which harbored antisense expression plasmid of erg7 coding region, was similar to that of INVScl by semi-quantitative PCR detection. But erg7 expression level of recombinant strains, which harbored 5' long antisense fragment and 5' short antisense fragment, was significantly lower than that of the control. The results of TLC and HPLC showed that the ergosterol content of recombinant strains, which harbored 5' long antisense fragment, decreased obviously. The ergosterol contents of the others were almost equal to that of INVSc1. Lanosterol synthase gene expression was downregulated by antisense RNA technology in S. cerevisiae, which lays a foundation for reconstructing triterpenoid metabolic pathway in S. cerevisiae by synthetic biology technology.
ABSTRACT
The cyclotides are a family of cyclic "mini" proteins that occur in Violaceae, Rubiaceae and Cucurbitaceae plant families and contain a head-to-tail cyclic backbone and a cystine knot arranged by three disulfide bonds. To study the natural cyclotides of V tianshanica, dried herb was extracted with 50% ethanol, and the concentrated aqueous extract was subjected to a solvent-solvent partitioning between water and hexane, ethyl acetate and n-butanol, separately. The n-butanol extract containing cyclotides was subjected to column chromatography over Sephadex LH-20, eluted with 30% methanol. The subfractions were directly reduced by DTT and analyzed by reverse-phase HPLC. The peaks with different retention times were shown on the profile of RP-HPLC and collected. The cyclotides were speculated based on masses range from 3 000 to 3 500 Da. The purified cyclotides were reduced with DTT, alkylated with iodoacetamide, and then were cleaved with endoproteinase Glu-C, endoproteinase Lys-C and Trypsin, separately. The digested peptides were purified on RP-HPLC and analyzed on MALDI TOF/TOF analyzer. A new cyclotide, cycloviolacin T1 and a reported cyclotide varv E were systemically determined using MALDI TOF/TOF system. So the method for the isolation and characterization of cyclotides was quickly built up in succession.