RESUMO
Sequential formation of distant bonds in organic molecules was achieved for the palladium-catalyzed hydrosilylation/cyclization of various 1,n-dienes by chain walking of the metal catalyst. The reaction was applicable to various 1,n-dienes, including a 1,13-diene, to form a cyclopentane ring as well as a carbon-silicon bond at a remote site. The use of "nondissociative" chain walking provides a fascinating strategy in organic synthesis to functionalize distant parts of organic molecules, in a particular order, within a catalytic cycle by effectively moving the reactive center from a remote position.
RESUMO
Vibrio spp. are natural inhabitants of marine and estuarine environments. Vibrio cholerae, Vibrio parahaemolyticus, and Vibrio vulnificus are the major infectious agents for humans. Their densities are affected by environmental factors such as water temperature and salinity. The detailed contribution of each factor still remains to be elucidated. Here we conducted multi-coastal study in a 21-month period to examine relationships between environmental factors and V. cholerae, V. parahaemolyticus and V. vulnificus densities in sea surface water in eight coastal sites of four prefectures in Japan. Vibrio densities were measured by a most-probable-number with PCR method which is highly sensitive and quantitative (3/100 ml of detection limit). Vibrio densities were analyzed with environmental factors including water temperature, salinity, total dissolved substance, and pH, and their quadratics. A linear regression model suited best for prediction of V. cholerae density. A novel double-quadratic model suited best for the prediction of V. parahaemolyticus and V. vulnificus densities.
Assuntos
Água do Mar/microbiologia , Vibrio cholerae/isolamento & purificação , Vibrio parahaemolyticus/isolamento & purificação , Vibrio vulnificus/isolamento & purificação , Algoritmos , Carga Bacteriana/métodos , Microbiologia Ambiental , Humanos , Japão , Modelos Teóricos , Reação em Cadeia da Polimerase , Salinidade , Água do Mar/química , Temperatura , Vibrio cholerae/classificação , Vibrio cholerae/genética , Vibrio parahaemolyticus/classificação , Vibrio parahaemolyticus/genética , Vibrio vulnificus/classificação , Vibrio vulnificus/genéticaRESUMO
Short syntheses of 4-deoxycarbazomycin B and sorazolon E were established through the condensation of cyclohexanone and commercially available 4-methoxy-2,3-dimethylaniline, followed by PdII -catalyzed dehydrogenative aromatization/intramolecular C-C bond coupling and deprotection. A chiral dinuclear vanadium complex (Ra ,S,S)-6 mediated the enantioselective oxidative coupling of sorazolon E, affording (+)-sorazolon E2 in good enantioselectivity.
Assuntos
Carbazóis/síntese química , Carbazóis/química , Estrutura Molecular , EstereoisomerismoRESUMO
Sarcocystis fayeri (S. fayeri) is a newly identified causative agent of foodborne disease that is associated with the consumption of raw horse meat. The testing methods prescribed by the Ministry of Health, Labour and Welfare of Japan are time consuming and require the use of expensive equipment and a high level of technical expertise. Accordingly, these methods are not suitable for use in the routine sanitary control setting to prevent outbreaks of foodborne disease. In order to solve these problems, we have developed a new, rapid and simple testing method using LAMP, which takes only 1 hour to perform and which does not involve the use of any expensive equipment or expert techniques. For the validation of this method, an inter-laboratory study was performed among 5 institutes using 10 samples infected with various concentrations of S. fayeri. The results of the inter-laboratory study demonstrated that our LAMP method could detect S. fayeri at concentrations greater than 10(4) copies/g. Thus, this new method could be useful in screening for S. fayeri as a routine sanitary control procedure.