Reaktionen von o-Chinonen mit Aminen und Proteinen. 4. Mitteilung. 7a-Methyl-5,6-dioxo-5,6,7,7a-tetrahydroindol-Derivate aus 4-Methylbrenzcatechin und Enaminen

Reactions of o-Quinones with Amines and Proteins. 7a-Methyl-5,6,7,7a-tetrahysroindole Derivatives from 4-Methylcatechol and Enamines Methyl l-[2′-(methoxycarbonyl)ethyl]-7a-methyl-5,6-dioxo-5.6.7,7a-tetrahydro-indole-3-carboxylate ( 1 ) was isolated after the oxidation of 4-methylcatechol with silver ( 1 ) oxide in the presence of b?-alanine methyl ester in glacial acetic acid. The formation of 1 requires in situ dehydrogenation of the b?-aminocarboxylate and addition of the resulting enamine to 4-methyl-1,2-benzoquinone. Reaction of ethyl 3-(phenylamino)crotonate with 4-methyl-1,2-benzoquinone afforded ethyl 2,7a-dimethyl-5,6-dioxo-1-phenyl-5,6,7,7a-tetrahydroindole-3-carboxylate ( 6 ). Despite the fact that the yields are low, the addition of enamines to o-quinones represents an interesting novel extension of the Nenitzescu-reaction which is well known in the p-quinone series. Compound 1 may be considered as a novel model for the crosslinking of proteins by o-quinones. Formation of 1 was, however, not observed under physiological conditions.     

Rapid enzyme-linked immunoassay for detection of Salmonella in food and feed products: performance testing program

The BIOLINE Salmonella ELISA Test for Salmonella spp., which is a rapid, easy, and convenient assay was evaluated for use in detecting Salmonella in foods and feeds. Each food matrix or feed was artificially contaminated with low levels of Salmonella. Twenty different matrixes were studied and 20 different Salmonella strains from a broad variety of serogroups (B, C, D, E, F, G, H, I, M, O, P, and U) were used. The EUSA Test kit detected levels as low as 1 cfu/25 g sample with at least 4 of the 20 matrixes tested. The test kit is applicable to all sample types tested. The BIOLINE Salmonella ELISA Test kit has been granted AOAC-RI performance tested status.     

The Prospect of Dimensionality in Porous Semiconductors

With the advent of silicon-based semiconductors, a plethora of previously unknown technologies became possible. The development of lightweight low-dimensional organic semiconductors followed soon after. However, the efficient charge/electron transfers enabled by the non-porous 3D structure of silicon is rather challenging to be realized by their (metal-)organic counterparts. Nevertheless, the demand for lighter, more efficient semiconductors is steadily increasing resulting in a growing interest in (metal-)organic semiconductors. These novel materials are faced with a variety of challenges originating from their chemical design, their packing and crystallinity. Although the effect of molecular design is quite well understood, the influence of dimensionality and the associated change in properties (porosity, packing, conjugation) is still an uncharted area in (metal-)organic semiconductors, yet highly important for their practical utilization. In this Minireview, an overview on the design and synthesis of porous semiconductors, with a particular emphasis on organic semiconductors, is presented and the influence of dimensionality is discussed.     

Molekulare Verbände

Ohne Zusammenfassung Alwin Korselt, geb. 17. März 1864, zum Geburtstag.     

Über Verbände mit einer weiteren assoziativen und kommutativen Elementverknüpfung

Ohne Zusammenfassung     

Ma?analytische Fluorbestimmung mittels Zirkon-Alizarin-Farblackes

Zusammenfassung Eine neue titrimetrische Art der Fluorbestimmung wurde beschrieben und eine allgemeine Arbeitsvorschrift gegeben.Die Methode ist für Fluor-Ionen jeder Art, sowohl für ionogen als auch für komplex gebundene, anwendbar und eignet sich vor allem als Betriebs-Schnellverfahren und für Reihenanalysen.