Radioactive Phosphorylation of Alcohols to Monitor Biocatalytic Diels-Alder Reactions

Nature has efficiently adopted phosphorylation for numerous biological key processes, spanning from cell signaling to energy storage and transmission. For the bioorganic chemist the number of possible ways to attach a single phosphate for radioactive labeling is surprisingly small. Here we describe a very simple and fast one-pot synthesis to phosphorylate an alcohol with phosphoric acid using trichloroacetonitrile as activating agent. Using this procedure, we efficiently attached the radioactive phosphorus isotope 32P to an anthracene diene, which is a substrate for the Diels-Alderase ribozyme—an RNA sequence that catalyzes the eponymous reaction. We used the 32P-substrate for the measurement of RNA-catalyzed reaction kinetics of several dye-labeled ribozyme variants for which precise optical activity determination (UV/vis, fluorescence) failed due to interference of the attached dyes. The reaction kinetics were analyzed by thin-layer chromatographic separation of the 32P-labeled reaction components and densitometric analysis of the substrate and product radioactivities, thereby allowing iterative optimization of the dye positions for future single-molecule studies. The phosphorylation strategy with trichloroacetonitrile may be applicable for labeling numerous other compounds that contain alcoholic hydroxyl groups

On the proposed conservation of the specific name of Cnemidophorus neomexicanus Lowe & Zweifel, 1952 (Reptilia, Squamata)

Volume: 55Start Page: 39End Page: 4

Cruzamentos entre Arachis hypogaea e as espécies A. diogoi e A. spp (30006, 30035) Interspecific crosses between Arachis hypogaea and the species A. diogoi and A. spp (30006, 30035)

<abstract language="eng">Artificial crosses were made between A. hypogaea, using lines of 'Tatu', 'Roxo', Tatuí x Roxo 80-1 and the cultivar Tatuí as female parents and introduced plants of items 30001 and 30005 reported as belonging to A. diogoi and of 30006 and 30035 of A. spp, under greenhouse conditions. From the pollinated flowers of A. hypogaea x A. diogoi, 53.4 and 45.2% gave rise to pegs and fruits with normal seeds, respectively. The amount of viable pollen grains ranged from 4.8 to 13.4 with an average of 8.3% in this cross compared to 97.2 and 95.7% observed for A. hypogaea and A. diogoi. In the crosses A. hypogaea x A. sp. 30006 and A. hypogaea x A. sp. 30035, 13 and 9 normal fruits with 22 and 15 viable seeds were obtained, respectively. The pollen viability varied from 3.5 to 15 with mean of 10% in the former cross and was around 9.9% in the latter, compared with 97.8 and 98.2% noted for A. sp. 30006 and for A. sp. 30035. These results showed that plants previously classified as A. diogoi belong to another species. They also demonstrated the possibilities of using A. diogoi, A. sp. 30006 and A. sp. 30035 in the peanut genetic improvement