Biologically active labdane-type diterpene glycosides from the root-stalks of Gleichenia japonica.

A glycoside showing a strong growth inhibition of lettuce was isolated from the root-stalks of Gleichenia japonica and its structure was established to be the 3-O-alpha-rhamnopyranosyl-(1----2)-beta-glucopyranoside of 13-O-alpha-rhamnopyranosyl-(+)-3 beta-hydroxymanool. In addition, two related glycosides were also isolated and they were characterized as the 3-O-beta-fucopyranosyl-(1----3)-alpha-rhamnopyranosyl-(1----2)-beta- glucopyranoside of 13-O-alpha-rhamnopyranosyl-(+)-3 beta-hydroxymanool and the 13-O-rhamnopyranoside of the same diterpene alcohol. The diterpene alcohol accelerated the growth of lettuce.

Low-dose-rate effect of tritium beta-rays on transfection activity of phage DNA related to an oxidative species different from .OH, HO2. O2-., and H2O2.

In order to study the low-dose-rate effect of tritium beta-irradiation, we exposed single-stranded DNA of M13 mp10 phage to purified tritiated water. The beta-irradiated DNA was then transfected to E. coli K12 JM101.

The pigments in the dorsal skin of frogs.

The five pigments 1-5 and a colorless substance 6 were present in the dorsal skin of frogs of nine selected species belonging to Rhacophoridae, Ranidae, Hylidae, and Bufonidae and were identified as pterin-6-carboxylic acid, xanthopterin, isoxanthopterin, erythro-biopterin, 6-hydroxymethylpterin, and guanine, respectively. Another pigment 7 was specifically present in the skin of genus Rhacophorus and was deduced to be a pteridine derivative composed of five molecules of pterin-6-carboxylic acid [1].