Isochromophilones from an endophytic fungus Diaporthe sp.

Three new azaphilone compounds,isochromophilones X-XII(1-3),together with two known ones sclerotioramine(4)and isochromophilone VI(5)were isolated from the cultures of an endophytic fungus Diaporthe sp.The structures were elucidated by extensive HRESIMS and NMR spectroscopic analyses.All compounds were tested for their cytotoxicities against five human cancer cell lines by MTT method,among which compound 1 showed moderate inhibitory effects on these cell lines.This was the first report of azaphilones isolated from Diaporthe sp.

Nitric Oxide Potentiates Oligosaccharide-induced Artemisinin Production in Artemisia annua Hairy Roots

The purpose of the present study was to characterize the generation of nitric oxide （NO） in Artemisia annua roots induced by an oligosaccharide elicitor （OE） from Fusarium oxysporum mycelium and the potentiation role of NO in the elicitation of artemisinin accumulation. The OE （0.3 mg total sugar/mL） induced a rapid production of NO in cultures, which exhibited a biphasic time course, reaching the first plateau within 1.5 h and the second within 8 h of OE treatment. Artemisinin content in 20-day-old hairy roots was increased from 0.7mg/g dry wt to 1.3 mg/g dry wt by using the OE treatment for 4d. In the absence of OE, the NO donor sodium nitroprusside （SNP） at 10, 50 ~1 and 100 ~1 enhanced the growth of hairy roots, but had no effect on artemisinin synthesis, The combination of SNP with OE increased artemisinin content from 1.2 mg/g drywt to 2.2 mg/g dry wt, whereas the maximum production of artemisinin in cultures was 28.5 mg/L, a twofold increase over the OE treatment alone. The effects of SNP on the OE-induced artemisinin were suppressed strongly by the NO scavenger 2-（4- carboxyphenyl）-4,4,5,5-tetramethylimidazoline-l-oxyl-3-oxide （cPTIO）. The results suggest that NO can strongly potentiate elicitor-induced artemisinin synthesis in A. annua hairy roots.

Verticase:a Fibrinolytic Enzyme Produced by Verticillium sp,Tj33,an Endophyte of Trachelospermum jasminoides

Plant endophytes are among the most important resources of biologically active metabolites. Twenty-three endophyte strains residing in Trachelospermum jasminoides were cultivated in vitro with the cultures assayed for the fibrinolytic substance production. As a result, the culture of VerticUlium sp. Tj33 was shown to be the most active. A fibrinolytic enzyme designated as verticase was subsequently purified from the supernatant of Verticillium sp. culture broth by a combination of DEAE-52, Sephadex G-75 and hydrophobic column chromatographies. Verticase, with its molecular mass of 31 kDa and pl of 8.5, was demonstrated to be homogeneous by sodium dodecyl suIfate-polyacrylamide gel electrophoresis and isoelectric focusing electrophoresis. Verticase is an enzyme that hydrolyzes fibrin directly without activation of plaminogen. It was stable in a broad pH range from 4 through to 11 with the optimal reaction pH value and temperature shown to be around 9-10 and 50-60℃, respectively. The fibrinolytic activity of verticase was severely inhibited by phenylmethylsulfony fluoride, indicating that verticase was a serine protease.

Discovery of daspyromycins A and B,2-aminovinyl-cysteine containing lanthipeptides,through a genomics-based approach

Lanthipeptides are one of the largest groups of ribosomally synthesized and post-translationally modified peptides(RiPPs)and are characterized by the presence of lanthionine(Lan)or methyllanthionine residues(MeLan).Only very few lanthipeptides contain a C-terminal 2-aminovinyl-cysteine(AviCys)motif,but all of them show potent antibacterial activities.Recent advances of genome sequencing led to the rapid accumulation of new biosynthetic gene clusters(BGCs)for lanthipeptides.In this study,through our genome mining strategy,we found the AviCys containing lanthipeptides are widespread in the bacterial kingdom.A lanthipeptide-type biosynthetic gene cluster was identified from public bacterial genome database.Two new lanthipeptides,daspyromycins A and B(1 and 2)containing AviCys motif,along with two degraded products,daspyromycins C and D(3 and 4),were obtained after heterologous expression of the gene cluster in Streptomyces albus J1074.Daspyromycins A and B showed potent antimicrobial activity against a spectrum of Gram-positive and-negative bacteria including methicillin-resistant Staphylococcus aureus(MRSA)and vancomycin-resistant Enterococci(VRE).

Antiosteoporotic Tetrahydroxanthone Dimers from Aspergillus brunneoviolaceus FB-2 Residing in Human Gut

A complex community of human-associated microorganisms plays diversely important roles in maintaining health,and the metabolites help to define whether a particular human-associated microbe is a friend or a foe.This work shows that Aspergillus brunneoviolaceus FB-2,derived from the stool of a healthy individual,produces a family of antiosteoporotic xanthone dinners including penibishexahydroxanthone A(1)and brunneoxanthones A-E(2-6,undescribed previously).The structures of 1-6 were elucidated by MS and NMR spectroscopic analysis,and the absolute configuration of 2 was established by X-ray crystallography.Compounds 4-6 are relatively rare examples of highly oxidized heterodimeric xanthones with an 8-ketone functionality.Finally,the prednisolone-induced osteoporotic zebrafish enabled our demonstration that the antiosteoporotic effects of 1-6 are dose-dependent.