RESUMO
A new alkaloid was isolated from the ethyl acetate extract of the culture of a termite-associated Streptomyces koyangensis BY-4. The structure of 1 was elucidated by using MS, NMR, electronic circular dichroism data, and computational approaches. Compound 1 showed weak antimicrobial activities against a panel of test microbes.
Assuntos
Alcaloides/isolamento & purificação , Indolizinas/isolamento & purificação , Isópteros/microbiologia , Streptomyces/química , Alcaloides/química , Alcaloides/farmacologia , Animais , Aspergillus niger/efeitos dos fármacos , Bacillus subtilis/efeitos dos fármacos , Candida albicans/efeitos dos fármacos , Dicroísmo Circular , Cryptococcus neoformans/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Indolizinas/química , Indolizinas/farmacologia , Testes de Sensibilidade Microbiana , Micrococcus luteus/efeitos dos fármacos , Estrutura Molecular , Ressonância Magnética Nuclear Biomolecular , Pseudomonas aeruginosa/efeitos dos fármacos , Staphylococcus aureus/efeitos dos fármacos , Streptococcus pyogenes/efeitos dos fármacosRESUMO
OBJECTIVE: To analyze the chemical constituents of volatile oil from flowers of Rhododendron mucronatum. METHODS: The volatile oil was extracted by water-steam distillation and analyzed by GC-MS. RESULTS: Forty-nine compounds, which occupied 79.55% of total constituents, were identified. The major constituents were linalool, beta-eudesmene, phytol, benzyl benzoate, benzyl salicylate and nonyl aldehyde. CONCLUSION: The chemical constituents of volatile oil, which contain many bioactive constituents, are mainly composed of terpenes, esters, and alkanes.
Assuntos
Flores/química , Óleos Voláteis/química , Rhododendron/química , Terpenos/análise , Alcanos/análise , Benzoatos/análise , Cromatografia Gasosa-Espectrometria de Massas , Temperatura Alta , Estrutura Molecular , Óleos Voláteis/isolamento & purificação , Fitol/análise , VaporRESUMO
Streptoseomycin (1), which is a rare macrodilactone with potent activities against microaerophilic bacteria, featuring a pentacyclic 5/14/10/6/6 ring system together with an ether bridge, was characterized by a combination of spectroscopic method and X-ray analysis from a marine Streptomyces seoulensis. Sequencing and characterization of a â¼76-kb biosynthetic gene cluster led to the proposition of the biosynthetic pathway of 1. Heterologous expression of the gene cluster using a BAC vector in Streptomyces chartreusis 1018 led to the successful production of 1.
Assuntos
Lactonas/síntese química , Clonagem Molecular , Estrutura Molecular , Família Multigênica , StreptomycesRESUMO
The chemical composition and antioxidant activities of the essential oil from Nandina domestica fruits were studied for the first time. Twenty-two compounds, representing 82.79% of the oil, were identified from the oil. The major compounds were 3-hexen-1-ol (12.9%), linalool (12.3%), 2-methoxy-4-vinylphenol (9.9%), oleic acid (8.0%), furfural (5.8%) and 2,6-di-tert-butyl-4-methylphenol (5.7%). The antioxidant activities of the oil were evaluated using reducing power, metal chelating ability and scavenging capacity against 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2'-azinobis-3-ethylbenzthiazoline-6-sulfonate (ABTS) and superoxide anion free radical. The oil exhibited significant antioxidant activities.
Assuntos
Antioxidantes/química , Antioxidantes/farmacologia , Berberidaceae/química , Óleos Voláteis/química , Óleos Voláteis/farmacologia , Monoterpenos Acíclicos , Compostos de Bifenilo/química , Avaliação Pré-Clínica de Medicamentos/métodos , Frutas/química , Guaiacol/análogos & derivados , Guaiacol/isolamento & purificação , Hexanóis/isolamento & purificação , Concentração Inibidora 50 , Monoterpenos/isolamento & purificação , Picratos/química , Superóxidos/química , Compostos de Vinila/isolamento & purificaçãoRESUMO
The conversion from triene- to diene-typed ansamycins is clarified step by step in Streptomyces seoulensis IFB-A01. Such an intertype convertibility is adopted to establish for the first time the simultaneous mutasynthesis of both types of C17-benzene ansamycins (C17BAs). Three of the newly generated unnatural compounds showed potent cytotoxicity.
Assuntos
Antineoplásicos/síntese química , Antineoplásicos/farmacologia , Rifabutina/análogos & derivados , Rifabutina/síntese química , Streptomyces/química , Antineoplásicos/química , Ensaios de Seleção de Medicamentos Antitumorais , Células Hep G2 , Humanos , Lactamas Macrocíclicas/química , Células MCF-7 , Estrutura Molecular , Rifabutina/química , Rifabutina/farmacologiaRESUMO
Two new compounds, named 2-formylpyrrole-4-acrylamide (1) and dihydrostreptazolin (2) were isolated from the fermentation broth of BY-4, an actinomycetes residing in the gut of Odontotermes formosanus. The structures of 1 and 2 were elucidated by extensive spectral analysis (1H, 13C, 2D NMR, and HR-ESIMS). The isolated compounds were assayed for cytotoxic and antimicrobial activities.