Enzyme production by growing cells of acinetobacter in presence of sophoroselipid and triton X-100

The effects of an extracellular microbial glycolipid, the interfacial active lactonic sophoroselipid, and of Triton X-100 on strains of Acinetobacter calcoaceticus are compared. Sophoroselipid diminished growth rates on n-heptadecane. Both surfactants led to the excretion of enzyme activities into the culture medium. Sophoroselipid increased the release of cytoplasmic malate dehydrogenase whereas in presence of Triton X-100 the quinoprotein glucose dehydrogenase was also excreted in large amounts.     

Preservation of Coombs' serum in liquid nitrogen

Experiments with Coombs-sera as raw and usable sera having different levels of titre were carried out in order to examine their stability in fluid nitrogen. Therewith, significant differences concerning the storing stability did not appear. Generally seen two third of the sera retained their initial titres at the end of one year in store.     

A 15N nuclear magnetic resonance study of the biosynthesis of quinoxaline antibiotics

Uniformly ¹⁵N-labelled triostin A and echinomycin have been prepared by growing the producing organisms on enriched media and their ¹⁵N nuclear magnetic resonance spectra partially assigned by a combination of nuclear Overhauser effect and scalar coupling constant measurements. Selective feeding experiments using unlabelled L-tryptophan-supplemented media have shown that N-1 and N-4 of the quinoxaline rings have their origins in the indole and amino groups of tryptophan, respectively.     

Effects of Suanzaorentang on behavior changes and central monoamines

Previously, it was found that the ancient Chinese remedy of Suanzaorentang could be a promising anxiolytic drug (Chen and Hsieh, 1985a, Chen and Hsieh, 1985b). To understand the mechanism of the action of Suanzaorentang, the effects of Suanzaorentang on behavior changes and central monoamines and their metabolites were studied in rats. It was found that Suanzaorentang significantly (1) prolonged the period from the onset of clonic to tonic convulsions induced by pentylenetetrazol or picrotoxin, (2) prolonged the sleep duration induced by hexobarbital, (3) reduced locomotor activity, (4) enhanced the hypomotility induced by alpha-MT, (5) reduced the locomotor stimulation produced by levodopa plus benserazide, and (6) reduced central HVA, VMA, and 5-HIAA, but had no significant effects on central DA, NA, and 5-HT. These facts implied that Suanzaorentang decreased the turnover rate of central monoamines and central catecholaminergic activity.     

Antioxidant effect of diethyldithiocarbamate on microsomal lipid peroxidation assessed by low-level chemiluminescence and alkane production

Different thiol-containing compounds, such as diethyldithiocarbamate (DDC), glutathione, penicillamine, and dithioerythritol have been chosen to study their effect on ascorbate/Fe-ADP-induced lipid peroxidation, detected by low-level chemiluminescence and alkane production. In the concentration range used, these thiols exerted a temporary protection against lipid peroxidation by lengthening the induction period; after overcoming this induction period, no substantial inhibition of either chemiluminescence or alkane production was observed. DDC was effective in protecting against lipid peroxidation in the nanomolar range, whereas the group of other thiol-containing molecules operated in the millimolar range.