Advances in the biosynthesis of natamycin and its regulatory mechanisms / 生物工程学报

Natamycin is a polyene macrolide antibiotics with strong and broad spectrum antifungal activity. It not only effectively inhibits the growth and reproduction of fungi, but also prevents the formation of some mycotoxins. Consequently, it has been approved for use as an antifungal food preservative in most countries, and is also widely used in agriculture and healthcare. Streptomyces natalensis and Streptomyces chatanoogensis are the main producers of natamycin. This review summarizes the biosynthesis and regulatory mechanism of natamycin, as well as the strategies for improving natamycin production. Moreover, the future perspectives on natamycin research are discussed.

Identification of a novel antibiotic from myxobacterium stigmatella eracta WXNXJ-B and evaluation of its antitumor effects In-vitro

This work was to isolate and identify the bioactive secondary metabolite which was produced by myxobacteriumStigmatella eracta WXNXJ-B, and to evaluate its antitumor and apoptosis-inducing effects. The results showed that one novel compound [molecular formula C29H25NO3] was isolated, purified by Sephadex LH-20 column chromatography and preparative RP-HPLC, and identified as 5-[6-benzyl-quinolin-3-ylmethyl]-6- phenyl-3,7-dioxa- bicycle [4.1.0] heptan-3-one [named as quinoxalone] according to its UV, IR, HRMS and NMR spectra. The compound showed strong antitumor activity on B16, HepG2, MCF-7, SGC-7901, MDA-MB231 and CT-26 six tumor cell lines in vitro. Nevertheless, it showed less cytotoxic to the mouse normal spleen cells [IC50 was 836.27 +/- 13.02 mg mL-1]. The cytotoxic study on HepG2 cellsin-vitro showed that quinoxalone could induce the change of cell nuclear and arrested the cell division in the S and G2/M phase. Our results suggest that quinoxalone could be a potential anti-cancer agent

Influence of Bioethics in Medical Education / 中国医学伦理学

Higher medical education should bring the superiority of the course into play,and develop the bioethics education effectively.We should arouse medical undergraduate's respect and enthusiasm for bioethics,help them reevaluate their value concept and learn to use basic theory of bioethics to guide the medical service.Thus medical science can develop in a healthy way.

THE ANTI-OXIDATIVE EFFECT OF PERSIMMON LEAF FLAVONOID IN VITRO / 营养学报

Objective: To study the anti oxidative effects of PLF. Methods: The ?OH scavenging effect was measured by salicylic acid method, the content of MDA in liver mitochondria and microsome was measured by TBA assay; hemolysis of RBC and the swelling of mitochondria were detected by spectrophotometric methods. Results: PLF can scavenge ?OH, inhibit production of MDA, swelling of mitochondria and hemolysis of RBC. Conclusion: PLF has anti oxidation effects invitro.