Neue Molekülverbindungen des β-1,2,3,4,5,6-Hexachlorcyclohexans

Eight new molecular compounds between -1,2,3,4,5,6-hexachlorocyclohexane (-HCH) and some heterocyclic salts (hydrochlorides of - and -picoline, 2,4,6-collidine, ,-bipyridine, isoquinoline, acridine, 9-phenylacridine, and 2,4,6-triphenylpyrylium perchlorate), with the molecular ratio 12, were synthesised and described by means of spectroscopic (IR, UV, NMR) and X-ray-diffraction methods. Some of the molecular compounds may be used for quantitative separation of the heterocyclic salts from complex mixtures.

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Lehrstuhl für Mineralogie.     

Energy transfer evidence for in vitro and in vivo complexes of Vibrio harveyi flavin reductase P and luciferase

Conservation of energetically "expensive" metabolites is facilitated by enzymatic intra- and intermolecular channeling mechanisms. Our previous in vitro kinetic studies indicate that Vibrio harveyi reduced nicotinamide adenine dinucleotide phosphate-flavin mononucleotide (NADPH-FMN) oxidoreductase flavin reductase P (FRP) can transfer reduced riboflavin 5'-phosphate (FMNH2) to bacterial luciferase by direct channeling. However, no evidence has ever been reported for such an FMNH2 channeling between these two enzymes in vivo. The formation of a donor-acceptor enzyme complex, stable or transient, is mandatory for direct metabolite channeling between two enzymes regardless of details of the transfer mechanisms. In this study, we have obtained direct evidence of in vitro and in vivo FRP-luciferase complexes that are functionally active. The approach used is a variation of a technique previously described as Bioluminescence Resonance Energy Transfer. Yellow fluorescence protein (YFP) was fused to FRP to generate an active FRP-YFP fusion enzyme, which emits fluorescence peaking at 530 nm. In comparison with the normal 490 nm bioluminescence, an additional 530 nm component was observed in both the in vitro bioluminescence from the coupled reaction of luciferase and FRP-YFP and the in vivo bioluminescence from frp gene-negative V. harveyi cells that expressed FRP-YFP. This 530 nm bioluminescence component was not detected in a control in which a much higher level of YFP was present but not fused to FRP. Such findings indicate an energy transfer from the exited emitter of luciferase to the FRP component of the luciferase-FRP-YFP complex. Hence, the formation of an active complex of luciferase and FRP-YFP was detected both in vitro and in vivo.     

Synthesis of functionally substituted cyanoacetates

Some new cyanoacetates were synthesized and characterized. They are precursors for -cyanoacrylates used as rapidly polymerized, cold-hardening adhesives.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 523–525, March, 1993.     

FLAVIN-SENSITIZED PHOTODYNAMIC MODIFICATION OF MULTISUBUNIT PROTEINS

Abstract— Riboflavin 5'-phosphate (FMN)-sensitized photodynamic modifications of multisubunit alcohol dchydrogenase, bacterial luciferase. L-glutamate dehydrogenase, and catalase all lead to significant formation of crosslinked species. On the contrary, irradiation of monomeric lysozyme, trypsin inhibitor, trypsin, and bovine serum albumin in the presence of FMN yields either no or only trace amounts of polymerized molecules. Photodynamic modifications thus appear to be much more efficient in crosslinking proteins with quaternary structures in their native forms. While no photodegradations of other proteins were found, FMN-sensitized modifications of the nonidentical dimeric (αß) bacterial luciferase resulted in the formation of two degraded fragments as well as two polymerized species. Singlet oxygen is shown to be involved in the photopolymerization of luciferase but it is unclear whether singlet oxygen is the sole species active in initiating the crosslinking reaction(s). FMN also sensitizes effective inactivations of luciferase which can be attributed to actions of singlet oxygen, triplet FMN, H₂O₂. and superoxide anion. Photodynamic inactivation of luciferase proceeds faster than photopolymerization; these processes are thus not coupled.     

Synthesis and Stereochemistry of Some New 1,3-Dioxane Derivatives of 1,4-Diacetylbenzene

 The synthesis and stereochemistry of new 1,3-dioxane derivatives of 1,4-diacetylbenzene are reported. The anancomeric structure of these compounds, the axial orientation of the aryl group for both 1,3-dioxane rings, and the cis and trans isomerism of some of these compounds is discussed considering data of conformational analysis, NMR investigations, and single crystal X-ray diffractometry.