Mechanisms of MYB-bHLH-WD40 Complex in the Regulation of Anthocyanin Biosynthesis in Plants

Anthocyanins are main coloring substances in plants with various functions such as antioxidant , preventing cardiovascular diseases , and inhibiting oncogenesis. The regulation of transcriptional levels plays a decisive role in the biosynthesis of anthocyanins. Studies have shown that the transcriptional levels of an- thocyanins are mainly regulated by MYB-bHLH-WD40 ternary complex. This paper summarized the structure characteristics of MYB-bHLH-WD40 ternary complex and its regulatory role in anthocyanin biosynthesis pathway, focusing on the regulation mechanism of several important model plants by MYB-bHIM-WD40 complex.

Optimization of Fermentation Process for Hyaluronic Acid Production by Streptococcus zooepidemicus

Hyaluronic acid （HA） is a high molecular weight glycosaminoglycan consisting of alternating D-glucuronic acid and N-acetylglueasamine and plays ex- tremely important roles in many biological processes. In this study, we optimized fermentation process for the production of HA by Streptococcus zooepidemicus ATCC35246, including fermentation broth composition and various fermentation parameters. The experimental results showed that the optimal fermentation broth composition was： glucose 45 g/L, yeast extract 10 g/L, tryptone 12 g/L, KH2PO4 2 g/L, K2HPO4 . 3H20 2 g/L, MgSO4 · 7H2O 2 g/L, and （NH4 ）2SO4 0.4 g/L. The optimal parameters involved in fermentation was： liquid volume 20%, pH 6. 0, rotation speed 180 r/min, fermentation temperature 35 ℃, fermentation duration 18 h, CTAB concentration 25 mg/L. Under the optimized conditions, the yield of HA was 0. 305 g/L, which was dramatically improved by 43.87% compared to that of 0. 212 g/L before optimization.

Three new alkaloids isolated from the stem tuber of Pinellia pedatisecta

The present study was designed to determine the chemical constituents of the stem tuber of Pinellia pedatisecta. The chemical constituents were isolated and purified by various chromatographic techniques, and their structures were elucidated on the basis of physicochemical properties and spectral data. Three new alkaloids(compounds 1, 2, and 3) were obtained and identified as 9-((5-methoxypyridin-2-yl)methyl)-9 H-purin-6-amine(1), 4-(2-(2, 5-dioxopyrrolidin-1-yl)ethyl)phenyl acetate(2), and N-(9-((5-methoxypyridin-2-yl)methyl)-9 H-purin-6-yl)acetamide(3). These compounds were evaluated for their cytotoxicity against human cervical cancer He La cells. Compounds 1 and 3 significantly inhibited the proliferation of He La cells with IC_(50) values being 3.02 ± 0.54 and 7.16 ± 0.62 μmol·L^(-1), respectively.