ya Li

Bafilomycins and Odoriferous Sesquiterpenoids from Streptomyces albolongus Isolated from Elephas maximus Feces

From a fermentation broth of Streptomyces albolongus obtained from Elephas maximus feces, nine bafilomycins (1-9) and seven odoriferous sesquiterpenoids (10-16) were isolated. The structures of the new compounds, including three bafilomycins, 19-methoxybafilomycin C1 amide (1), 21-deoxybafilomycin A1 (2), and 21-deoxybafilomycin A2 (3), and two sesquiterpenoid degradation products, (1β,4β,4aβ,8aα)-4,8a-dimethyloctahydronaphthalene-1,4a(2H)-diol (10) and (1β,4β,4aβ,7α,8aα)-4,8a-dimethyloctahydronaphthalene-1,4a,7(2H)-triol (11), were elucidated by comprehensive spectroscopic data analysis. The cytotoxicity activity against four human cancer cell lines and antimicrobial activities against a panel of bacteria and fungi of all compounds isolated were evaluated. Compounds 1, 7, and 8 were cytotoxic, with IC50 values ranging from 0.54 to 5.02 μM. Compounds 2, 7, 8, and 10 showed strong antifungal activity against Candida parapsilosis, with MIC values of 3.13, 1.56, 1.56, and 3.13 μg/mL respectively.

Jiangrines A-F and jiangolide from an actinobacterium, Jiangella gansuensis.

Seven new compounds, including five pyrrol-2-aldehyde derivatives, jiangrines A-E (1-5), one indolizine derivative, jiangrine F (7), and one glycolipid, jiangolide (8), along with a known compound, pyrrolezanthine (6), were isolated from the fermentation broth of Jiangella gansuensis, an actinobacterium assigned to a novel family, Jiangellaceae, and a novel order, Jiangellales. The structures were elucidated by detailed spectroscopic analysis and through chemical methods. Compounds 1, 2, 3/4, 5, 6, and 8 demonstrated inhibitory effects on lipopolysaccharide-induced NO production in RAW 264.7 macrophage cells, with IC50 values of 97.8, 60.7, 30.1, 54.9, 58.8, and 61.4 μM, respectively.

Diastaphenazine, a new dimeric phenazine from an endophytic Streptomyces diastaticus subsp. ardesiacus

Diastaphenazine, a new dimeric phenazine from an endophytic Streptomyces diastaticus subsp. ardesiacus

A unique macrolactam derivative via a [4+6]-cycloaddition from Streptomyces niveus

One new macrolactam derivative, nivelactam (1) and one new polyenoic acid derivative, niveamide (2), along with two other known 20-atom macrolactams (3 and 4) were isolated from the fermentation broth of Streptomyces niveus, which obtained from the forest soil in northeastern China. The structures of 1 and 2 were elucidated on the basis of HRESIMS, IR, and NMR spectroscopic data analyses. Compound 1 was proposed as an intramolecular [4+6]-cycloaddition product of 3 by S. niveus, and displayed moderate cytotoxic activity against a panel of human tumor cell lines in vitro, with IC50 values ranging from 3.76 ± 0.58 to 15.02 ± 2.81 μM.

New Derivatives of Nonactic and Homononactic Acids from Bacillus pumilus Derived from Breynia fruticosa

Six new nonactic and homononactic acid derivatives, ethyl homononactate (1), ethyl nonactate (2), homononactyl homononactate (6), ethyl homononactyl nonactate (7), ethyl homononactyl homononactate (8), and ethyl nonactyl nonactate (9), as well as four known compounds, homononactic acid (3), nonactic acid (4), homononactyl nonactate (5), and bishomononactic acid (10), were isolated from culture broth of Bacillus pumilus derived from Breynia fruticosa. The structures of new compounds were elucidated by spectroscopic analysis and chemical methods. The optical purities of 1–6 were determined by HPLC/MS after treatment with L‐phenylalanine methyl ester. The dimeric compounds 5–9 showed weak cytotoxic activities against five human cancer cell lines (IC50 19–100 μg/ml).

Structure determination of two new nerolidol-type sesquiterpenoids from the soil actinomycete Streptomyces scopuliridis

Two new nerolidol-type sesquiterpenes were isolated from the culture broth of Streptomyces scopuliridis, and identified based on 1D and 2D NMR spectroscopic data analyses.