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1.
Journal of Zhejiang University. Science. B ; (12): 285-292, 2018.
Artigo em Inglês | WPRIM | ID: wpr-1010388

RESUMO

(R)-2-hydroxy-3-phenylpropionic acid (PLA) is an ideal antimicrobial compound with broad-spectrum activity against a wide range of Gram-positive bacteria, some Gram-negative bacteria, and fungi. We studied the bioconversion of phenylpyruvate (PPA) to PLA using whole recombinant Escherichia coli cells in a series of buffer/organic solvent systems. Octane was found to be the best organic solvent. The optimum volume ratio of the water phase to the n-octane phase, conversion temperature, substrate concentration, and cell concentration were 6:4, 40 °C, 12.5 g/L, and 30 g/L wet cells, respectively. Under the optimized conditions, the average PLA productivity in the aqueous/ n-octane system was 30.69% higher than that in the aqueous system, and 32.31 g/L PLA was obtained with the use of a stirred reactor (2-L scale). Taken together, our findings indicated that PLA biosynthesis was more efficient in an aqueous/n-octane biphasic system than in a monophasic aqueous system. The proposed biphasic system is an effective strategy for enhancing PLA yield and the biosynthesis of its analogues.


Assuntos
Soluções Tampão , Escherichia coli/metabolismo , L-Lactato Desidrogenase/metabolismo , Microrganismos Geneticamente Modificados , Octanos/química , Fenilpropionatos/química , Proteínas Recombinantes/química , Solventes/química , Estresse Mecânico , Temperatura
2.
Safety and Health at Work ; : 192-200, 2010.
Artigo em Inglês | WPRIM | ID: wpr-177403

RESUMO

OBJECTIVES: We have investigated the toxic effects of the inhalation of subchronic and acute levels of n-octane. METHODS: The rats were exposed to n-octane of 0, 2.34, 11.68 and 23.36 mg/L (n = 5 rats/group/gender) in an acute inhalation test (Organization for Economic Co-operation and Development (OECD) TG 403), or to 0, 0.93, 2.62 and 7.48 mg/L (n = 10 rats/group/gender) for a subchronic inhalation test (OECE TG 413), to establish a national chemical management system consistent with the Globally Harmonized Classification System (GHS). RESULTS: Acutely-exposed rats became lethargic but recovered following discontinuation of inhalation. Other clinical symptoms such as change of body weight and autopsy finds were absent. The LC50 for the acute inhalation toxicity of n-octane was determined to exceed 23.36 mg/L and the GHS category was 'not grouping'. Subchronically-treated rats displayed no significant clinical and histopathological differences from untreated controls; also, target organs were affected hematologically, biochemically and pathologically. Therefore, the no observable adverse effect level was indicated as exceeding 7.48 mg/L and the GHS category was 'not grouping' for the specific target organ toxicity upon repeated exposure. CONCLUSION: However, n-octane exposure should be controlled to be below the American Conference of Industrial Hygienists recommendation (300 ppm) to prevent inhalation-related adverse health effects of workers.


Assuntos
Animais , Ratos , Autopsia , Peso Corporal , Inalação , Octanos
3.
Artigo em Inglês | IMSEAR | ID: sea-111674

RESUMO

Biological activity of saturated diethers viz. 1-benzyloxy/phenoxy-8-alkoxy and 1-alkoxy-8-benzyloxy-3,7-dimethyl-1, 8-octanes (IIa-IIq) prepared from Geraniol, were studied on three mosquito species and the bug Dysdercus koenigii. These diethers exhibited oviposition deterrent and developmental inhibition activities of greater magnitudes than the compounds based on citronellol reported in Part I of this paper. Some of these new compounds inhibit development of mosquitoes at 0.05 ppm and deter oviposition at 0.05 per cent doses. Tests were extended to field simulated conditions in selected cases.


Assuntos
Animais , Culicidae/classificação , Estudos de Avaliação como Assunto , Feminino , Insetos Vetores/classificação , Masculino , Octanos/farmacologia , Oviposição/efeitos dos fármacos , Éteres Fenílicos/farmacologia , Terpenos/química
4.
Egyptian Journal of Pharmaceutical Sciences. 1987; 28 (1-4): 149-61
em Inglês | IMEMR | ID: emr-8706

RESUMO

Ten esters derived from 3-hydroxy-8-methyl-8-azabicycle [3.2.1] octane and the corresponding methiodin salts were synthesised. The novel compounds were evaluated for anti-cholinergic activity using rabbit duodenum assay. Among these compounds, 8-methyl-8-azabicycle [3.2.1.] loct-3-y1-3-carbisobutoxy-3- phenyl-propionate [12] was found to be the most effective antispasmodic, comparable in potency to atropine


Assuntos
Octanos , Parassimpatolíticos
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