[Metabolic pathway of flavonoids in Blumea balsamifera].

To better understand the biosynthetic pathway of flavonoids in Blumea balsamifera, and to increase the biosynthesis of flavone and flavonol amount, we carried out this research. Basing on transcriptome information, B. balsamifera flavonoids metabolic pathway was analyzed in KEGG data base. The result demonstrated that two metabolic pathways of flavonoids were found in KEGG data base. They were flavonoid biosynthesis pathway (No.ko00941) that contained 32 genes and flavone and flavonol biosynthesis pathway (No.ko00944) that contained 12 genes. Metabolic pathway of flavonoids in B. balsamifera was similar to that in other plants. Chalcone synthase (CHS) and Chalconeisomerase were much likely to be key enzymes on metabolic pathway of flavonoids in B. balsamifera. HCT was much relevant to biosynthesis of favones.

[Analysis of metabolic pathway of terpenoids in Blumea balsamifera].

In order to provide a theoretical basis for the regulation of active ingredient, the terpenoids metabolic pathway and specific enzymes in Blumea balsamifera are investigated. Basing on transcriptome information, B. balsamifera terpenoids metabolic pathway was analyzed in KEGG data base. Four metabolic pathway of terpenoids were found in KEGG data base. They were terpenoid backbone biosynthesis, monoterpenoid biosynthesis, diterpenoid biosynthesis, sesquiterpenoid and triterpenoid biosynthesis, contained 103, 10, 29,59 genes, respectively. Through the analysis of the enzyme and product in the pathway, the result showed that there were 8 kinds of monoterpenes, 3 kinds of diterpenes, 3 kinds of triterpenes and sesquiterpenes. The mainly key enzymes were deoxyxylulose 5-phosphate synthase, HMG-CoA reductase and allyl transferase system. In B. balsamifera, there were relatively few monoterpenes synthetic enzymes, while the type of products was much more than other terpenes. This may be relate to the non-specific catalytic characteristic of monoterpene synthase. It is expected to improve the yield of terpenoids in B. balsamifera by analysis the pathways and regulation the key enzymes.

[Phylogeny and functional divergence of ω-6 and ω-3 fatty acid desaturase families].

The deduced amino acid sequences characteristics, phylogeny, and functional diverge of ω-6 and ω-3 fatty acid desaturase families were analyzed by using Bioinformatics methods. The results showed that all the deduced amino acid sequences shared three highly conserved histidine rich motifs (Hisbox). All the plastidial ω-6 and ω-3 fatty acid desaturases possessed putative N-terminal signal peptide with different amino acids. A relatively conserved hydrophobic region composed of 10 amino-acid residues was found in the middle of signal peptides, which is presumed to be the functional region of the signal peptide of these enzymes. Most of the plant microsomal ω-6 and ω-3 fatty acid desaturases (FAD2 and FAD3) contained a KKXX-like motif of endoplasmic reticulum (ER) retention signal at the C-terminus. However, no such motif was detected in safflower CtFAD2-3, CtFAD2-4, CtFAD2-5, CtFAD2-6, and CtFAD2-7, while an aromatic aa enriched signal (YKNK) was found at their C-terminus which has been reported to be both necessary and sufficient for maintaining localization of the enzymes in the ER. All the amino acid sequences were divided into four categories through phylogenetic analysis. It was suggested that ω-3 fatty acid desaturase originates in a prokaryotic lineage from ω-6 fatty acid desaturase. Both plastidial and microsomal ω-3 fatty acid desaturases could be divided into dicotyledonous and monocotyledonous subgroups, which inferred that functional differentiation of plastidial and microsomal ω-3 fatty acid desaturases had been formed before the divergence of dicotyledonous and monocotyledonous plants. Seed type and housekeeping type FAD2 diverged after the formation of dicotyledonous plants. Except for plant FAD3/plant FAD2, posterior probability values over 0.80 amino acid sites were identified among the functional differentiation subsets, which were mainly distributed at the front and back end of Hisbox I, and the front end of Hisbox II. This indicated that the variations of these amino acid sites played an important role in the size and conformation of protein functional domains and subfamily functional divergence.

New paraconic acids from the endophytic fungus Xylariaceae sp. J4.

Three new paraconic acids, xylariacinics A-C (1-3), were isolated from the endophyte Xylariaceae sp. J4 harbored in the medicinal plant Blumea balsamifera. Their structures were elucidated on the basis of extensive spectroscopic data including HRMS, and NMR. The antibacterial efficacies of compounds 1-3 were evaluated against a panel of bacteria such as Staphylococcus aureus, Bacillus subtilis, Escherichia coli and Pseudomonas aeruginosa. Their antifungal activities were also tested against Colletotrichum gloeosporioides. Unfortunately, all of them were inactive.