Akira Matsumoto

Gilvocarcin V (GV) is an antitumor antibiotic with a coumarin-based aromatic structure that promotes protein-DNA cross-linking when photoactivated by near-UV light. We have now identified several proteins that are selectively cross-linked to DNA in human fibroblasts by photoactivated GV, using NH2-terminal amino acid sequencing and Western blot analysis of the purified cross-linked proteins. The selectively cross-linked proteins are histone H3 and GRP78, a heat shock protein belonging to the hea

Unlike bis(diethylamino)organosilylboranes, bis(diisopropylamino)organosilylboranes, which have UV absorption at longer wavelength than 300 nm, undergo photolysis to afford pairs of an organosilyl radical and a bis(diisopropylamino)boryl radical by homolytic scission of the silicon-boron bonds. Generation of organosilyl radical and organoboryl radical was confirmed by trapping experiments using TEMPO (2,2,6,6-tetramethylpiperidine N-oxyl). The organosilyl radical thus generated induces not only

L-cell cultures were infected with elementary bodies (EB) of meningopneumonitis organisms. Cell walls were prepared from reticulate bodies (RB), which are the intracellular developmental forms into which EB are converted, and from EB at appropriate times after infection. When fragmented EB cell walls were shadowcast with platinum palladium alloy, about one-half of the fragments were seen to be composed of hexagonally arrayed structures on the inner side of the cell wall. When EB cell walls were

A series of hydrogen-atom transfer (HAT) catalysts based on the readily available and tunable 1,4-diazabicyclo[2.2.2]octane (DABCO) structure was designed, and their photoinduced HAT catalysis ability was demonstrated. The combination of our HAT catalyst with an acridinium-based organophotoredox catalyst enables efficient and site-selective C–H alkylation of substrates ranging from unactivated hydrocarbons to complex molecules. Notably, a HAT catalyst with additional substituents adjacent to a n

Abstract Radical polymerization studies on diallyl oxalate (DAO), diallyl malonate (DAM), diallyl succinate (DASu), diallyl adipate (DAA), and diallyl sebacate (DAS) have been conducted kinetically from the standpoint of cyclopolymerization. Benzoyl peroxide was employed as the initiator. The initial overall rate of polymerization, R p was not proportional to the square root or the first power of the initiator concentration, [I]. But R p /[I] 1/2 and [I] 1/2 bore a linear relationship, provided

The eigenfunctions in discrete and continuum states for the Morse potentials are discussed. The orthogonality relations of the eigenfunctions in the discrete and continuum states are proved. The generalised matrix elements are given by analytic expressions. The phaseshift for l=0(s wave) for the Morse potential is obtained exactly. In addition, analytic evaluations of integrals related to the confluent hypergeometric functions and the Laguerre polynomials are given in the appendix.

Human lactoferrin contains 2 asparagine-linked sugar chains in 1 molecule. These sugar chains were released as oligosaccharides by hydrazinolysis from two lactoferrin samples of different races. The two oligosaccharide fractions gave exactly the same fractionation pattern upon paper electrophoresis and Bio-Gel P-4 column chromatography after sialidase digestion. A structural study of the oligosaccharides obtained from the two samples by sequential exoglycosidase digestion in combination with met

Abstract Radical cyclopolymerization of allyl methacrylate (AMA) was investigated in detail, especially under the specified conditions; that is, above the ceiling temperature for a head‐to‐tail propagation (Δ G ht ≥ 0) in the polymerization of methacrylate. Thus the structure of the polymer obtained was examined by 1 H‐ and 13 C‐NMR and infrared (IR) spectroscopy; no existence of unreacted pendant methacrylyl groups was observed, which suggests that, as a cyclopolymerization mechanism of AMA, in

New vitamin E was isolated and purified from palm and rice bran oils by column chromatography and preparative HPLC.Structural determination was made by UV, MS and 1-H-NMR spectroscopy as 2, 5, 7, 8- tetramethy1-2- (4', 8', 12'-trimethyltrideca-11'-enyl) -6-chromanol.

Abstract Studies on gelation in the radical polymerization of diallyl dicarboxylates have been conducted by Simpson, 9,11 Gordon, 10 and Oiwa. 13 However, the results obtained have not always been consistent and are still far from full elucidations. In this paper, the gel point in the polymerization of diallyl aromatic dicarboxylates, including diallyl phthalate (DAP), diallyl isophthalate (DAI), and diallyl terephthalate (DAT) is experimentally reexamined in detail and discussed according to Go

The cell walls of Chlamydia psittaci (meningopneumonitis strain) were examined by the freeze-etching and negative staining techniques. It was observed that the cleaved convex surface of the developmental, reticulate body was covered with numerous non-etchable particles 9 to 10 nm in diameter, these particles being rarely seen on the concave surface. Similarly, the convex surface of the mature, elementary body (EB) was covered with many particles but the concavity lacked these particles. After et