No abstract

No abstract

The investigation of the metabolites from different cocultures of Nigrospora oryzae and Irpex lacteus in solid medium revealed two new squalenes (1 and 2); one new azaphilone (3); two new tremulane sesquiterpenes (4 and 5); and three known compounds, conocenol B (6), conocenol C (7), and 4-(4-dihydroxymethylphenoxy)benzaldehyde (8). The antagonistic relationship was examined by studying metabolite production. The production of compounds 6 and 8 by I. lacteus after the induction of coculture indicated significant selectivity for antifungal activity against phytopathogenic N. oryzae, with MICs of 16 μg/mL; compounds 6 and 8 also exhibited antifungal activities in vivo against Cerasus cerasoides infected by N. oryzae at concentrations of 100 μg/mL. New compounds 2 and 4 showed antifungal activities against Colletotrichum gloeosporioides, with MICs of 8 μg/mL, and compound 4 showed antifungal activity against Didymella glomerata with an MIC of 1 μg/mL. These results indicate that the mutually antagonistic relationship in the coculture of the phytopathogen and the endophyte can result in antibiotics that inhibit the phytopathogen and downregulate the production of phytotoxins by phytopathogenic N. oryzae. New compound 5 from I. lacteus showed weak activity against acetylcholinesterase (AChE), with an inhibition ratio of 16% at a concentration of 50 μM.

Streptomyces are Gram-positive bacteria known for their production of an enormous variety of biologically active secondary metabolites, including antibiotics, immunosuppressants, and anticancer agents.1) Streptomyces sp. (YIM 56130) was a plant endophyte from Drymaria diandra. Through the bioactivity screening, this strain was found to show cytotoxicity to HL-60, P388D1 and A549, and show antibacterial activity to Escherichia coli. As a part of our ongoing search for new and potent antitumor natural products from actinomycetes, the chemical investigation on the yeast of this bacterium was carried out. Three new sesquiterpenes (1-3) have been isolated, and their structures were elucidated by two-dimensional (2D)-NMR and high-resolution (HR)-MS as caryolane-1,7a-diol (1), 1,6,11-eudesmanetriol; (1a,6b)-form (2), 11-eudesmene-1,6-diol; (1a,6b)-form (3). Nine known compounds were also isolated and elucidated as caryolane-1,9a-diol (4), 2) 2-methyl-5-nonanol (5), 3) soyasaponin I (6), 4) cyclo (Ala-Leu) (7), 5) homononatinic acid (8), 6) bsitosteryl glucoside-3Ј-O-heptadecoicate (9), 7) 2Ј-deoxythymidine (10), 8) 2Ј-deoxyuridine (11), 9) trehalose (12). 10) Results and DiscussionCompound 1 was isolated as a minor compound. The molecular formula C 15 H 26 O 2 of 1 was determined from the HRelectrospray ionization (ESI)-MS together with the 13 C-NMR data, which indicated the presence of three degrees of unsaturation. Its IR spectrum suggested the presence of hydroxyl groups. The 1 H-NMR spectrum of 1 in CDC1 3 exhibited signals due to one oxygenated methine at d 3.31, two methines at d 1.6 and d 2.1, six methylenes, and three singlet methyls. The 13 C-NMR and distortionless enhancement by polarization transfer (DEPT) spectra of 1 showed 15 carbon signals for three methyls, six methylenes, three methines (one bearing hydroxyl), and three quaternary carbons (one bearing hydroxyl). But no sp 2 carbon signals. Therefore, this compound might be a saturated tricarbocyclic sesquiterpene diol. After an intensive survey of the reported structures and data of NMR of caryolane-1,9a-diol (4) and caryolane-1,9b-diol, 2) we noticed that skeleton structure of 1 was similar to 4 except for the position of one hydroxyl group. The 1 H-1 H correlation spectroscopy (COSY) correlations between H-7 and H-6 then to H-5, and the heteronuclear multiple-bond correlation (HMBC) correlations from H-15 to C-7 and H-5 to C-7, indicated that the position of the hydroxyl was at C-7 (Fig. 1). The signals of carbons and protons were assigned by the heteronuclear single quantum coherence (HSQC), HMBC, Three new sesquiterpenes were isolated from the fermentation broth of Streptomyces sp. and their structures were determined as caryolane-1,7a a-diol (1), 1,6,11-eudesmanetriol; (1a a,6b b)-form (2), 11-eudesmene-1,6-diol; (1a a,6b b)-form (3), together with nine known compounds as caryolane-1,9a a-diol (4), 2-methyl-5-nonanol (5), soyasaponin I (6), cyclo (Ala-Leu) (7), homononatinic acid (8), b b-sitosteryl glucoside-3 -O-heptadecoicate (9), 2 -deoxythym...

Two new oxidation products-related aureonitol and cytochalasan were isolated from Chaetomium globosum fermented in Chinese yam (Dioscorea opposita) and determined as 10,11-dihydroxyl- aureonitol (1) and yamchaetoglobosin A (2). Compound 2 indicated significant inhibitory effect on nitric oxide production in LPS-activated macrophages, anti-acetylcholinesterase activity with the inhibition ratios of 92.5, 38.2% at 50 μM, and cytotoxicity to HL-60, A-549, SMMC-7721, MCF-7 and SW480 with the range of inhibition ratio at 51-96% for a concentration of 40 μM. Compounds 1, 2 showed weak anticoagulant activity with PT at 16.8 s. Few work was reported on the anti-acetylcholinesterase, and anticoagulant activities of aureonitol, and cytochalasan derivatives. The preliminary structure-activity relationship stated that the oxidation ring-opening in yamchaetoglobosin A can retain the inhibitory effect against NO production and tumor cell.