A novel quinoline alkaloid possessing a 7-benzyl group from the centipede, Scolopendra subspinipes.

The novel quinoline alkaloid scolopendrine was isolated from the centipede, Scolopendra subspinipes mutilans L. Koch. The structure was determined to be 2-hydroxy-7-[(4-hydroxy-3-methoxyphenyl)methyl]-3-methoxy-8-quinolyl sulfate on the basis of high-resolution electron-spray ionization mass spectroscopy and two-dimensional NMR spectral data. Unlike quinoline alkaloids so far reported, scolopendrine is unique in having a 7-benzyl moiety in the quinoline ring.     

Mean thickness measurement of distributed fine particles by using alpha-ray absorption curves (author's transl)

The mean superficial density of fine particles, such as polystyrene latex particles or ion exchange resin particles, dispersed on a thin supporting film was measured by means of the thickness gauge which used the absorption curves of alpha-rays. The measured absorption curves coincided with the ones calculated from the particle diameter, density, number of particles per unit area and equivalent film thickness to an absorption gas of 1 mmHg. On the other hand, when the particle diameter exceeded a certain limit, the measured mean superficial density which was derived from the pressure displacement of absorption curve considerably differed from the true mean superficial density. This limit can be calculated from the shape of absorption curve, which depends on the alpha-ray spectrum emitted from the source. In the case of the 241Am source used in this study, the limit was about 450 microgram/cm2 for polystyrene latex particles. The mean superficial density of a sample can easily be obtained by measuring the pressure displacement of absorption curve when the maximum thickness difference is below the limit. However, when the maximum thickness difference exceeds the limit, it is necessary to estimate the whole shape of absorption curves.     

Rapid method for detection of restriction endonuclease-producing strains in enteropathogenic bacteria

An improved rapid method is described for the detection of restriction endonucleases in enteropathogenic bacteria including Salmonella and Escherichia coli. With the improved method, at least six restriction endonucleases with different specificity were found in 415 strains tested. Five of them were shown to be isoschizomers of known restriction endonucleases, while one seemed to be novel. Among the isoschizomers, SthI endonuclease (isoschizomer of KpnI) in Salmonella thompson appears to be useful; unlike KpnI, SthI generates DNA fragments with a 5′-protruding end.