Kunio Ando

Unusual concentration of urine and prevention of polydipsia by fungal prenylphenols in doca hypertensive rats

When deoxycorticosterone acetate (DOCA)-loaded uninephrectomized rats were fed on standard laboratory pellet diet and 1% saline for 5 weeks, caloric homeostasis became abnormal resulting in (a) hyperlipidemia, (b) cholesterol deposit in the heart, (c) significant reduction of triglycerides in the aorta, heart and liver and (d) a 60% increase in the cardiac free fatty acids (FFA) on one hand and a 50% reduction of the hepatic FFA on the other. These facts suggest that the hypertension severely reduces hepatic lipogenesis, whereas the cardiovascular system depends much more on FFA as a metabolic fuel than on glucose. This idea is supported by the deficiency in total body potassium (K) and decrease in serum immunoreactive insulin (IRI) which occur in the hypertension. These alterations were attenuated by the fungal prenylphenols, 4-0-methylascochlorin (MAC) and ascofuranone (AF). The protective effect seems to be partly attributable to the counteraction to DOCA. In addition, the agents caused a specific increase of renal water reabsorption. MAC treatment resulted in a particularly marked reduction of saline intake and excretion of unusually thick urine with 2.8 times higher sodium (Na) concentration than in the DOCA/saline control rats.

Isolation of 2.4-Dichlorophenol from a soil fungus and its biological significance

2.4-Dichlorophenol was isolated from the fermented broth of a soil Penicillium. Although some derivatives of 2.4-dichlorophenol were known as synthetic plant hormones, it is the first that 2.4-dichlorophenol was isolated from living world. This fact suggests some derivatives of it are not artifact hormones but growth regulatory hormones of plants as well as gibberellins and cytokinins. The evidence was presented that the fungus produced some derivatives of 2.4-dichlorophenol in addition to stress the biological significance of the isolation.

HOW TO DISCOVER NEW ANTIBIOTICS FOR INSECTICIDAL USE

Abstract Our experience on the research and development of miticidal antibiotic, tetranactin, is described. The macrotetrolide antibiotic, tetranactin, has recently been isolated from the fermented broth of Streptomyces aureus S-3466 using Azukibean weevil as a test insect. The antibiotic is, so far as we know, the first pesticidal antibiotic ever commercialized. It has been in use in Japan as an agricultural miticide since 1973. Our screening procedures, chemical and biological properties of tetranactin are summarized in this paper.

Enhanced excretion of fecal neutral sterols and the hypocholesterolemic property of 4-O-methylascochlorin in mice.

The hypocholesterolemic property of experimental agent 4-O-methylascochlorin (MAC) was examined in male mice. MAC exerted hypocholesterolemic activity without hepatomegaly in mice given MAC mixed in a standard laboratory diet for a week. MAC also significantly reduced plasma total cholesterol (p-TC) in mice when it was administered immediately after meals by gastric intubation in controlled feeding. However, the oral administration through gastric tube was completely ineffective on p-TC in mice with empty stomach. These results suggest a close relationship between hypocholesterolemic efficacy and the timing of diet intake. Hypercholesterolemia also induced by a high fat-cholesterol diet was unaffected by MAC when it was given mixed with the diet.From the isotopic study, three plausible mechanism were proposed for the mode of action: (I) enhanced output of biliary cholesterol, (II) inhibition of intestinal cholesterol absorption followed by an increment of fecal neutral sterols and (III) modulation of chol...

Effect of carbohydrates on induction of bacteriophage lambda

Abstract In our screening for antitumor antibiotics using induction of bacteriophage lambda as an in vitro marker, it was found that a monosaccharide induced the phage from lysogenic Escherichia coli . The phage inducing activity was investigated by an agar diffusion method for nine monosaccharides, five disaccharides, one trisaccharide and three related compounds. A most remarkable activity was shown by mannose, maltose, melibose, trehalose and glucuronolactone.