The toxicity of cochliodinol, an antibiotic metabolite of Chaetomium spp

Cochliodinol is a phenol of unknown structure and a metabolite of Chaetomium cochliodes and C. globosum. It inhibited the growth of some species of several genera of microfungi at concentrations of 1–10 μg/ml. The germination of spores of Botrytis allii and Fusarium moniliforme was also inhibited, at similar concentrations. Cochliodinol forms stable, insoluble salts with strong bases but the triethanolamine salt is appreciably soluble in water. Solutions of this salt inhibit the growth of many species of bacteria. The growth of several strains of Pseudomonas aeruginosa isolated from the local general hospital was inhibited at 30 μg/ml. Cytopathological effects were not observed in cultures of HeLa cells at 5 μg/ml and preliminary toxicity tests in young turkeys and rats did not reveal symptoms of acute toxicity.

Identification of an intermediate of phloroglucinol degradation by mass spectroscopic analysis

The product of enzymatic reduction of phloroglucinol was tentatively identified as a dihydrophloroglucinol based on thin-layer chromatography and ultraviolet spectrum. Confirmatory evidence of its identity is presented by mass spectroscopic analysis.

Monosomy for a G autosome

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The production of cochliodinol and a related metabolite by Chaetomium species

A purple pigment, named cochliodinol, C32H32N2O4, has been isolated from three isolates of Chaetomium cochliodes and from two isolates of Chaetomium globosum. The pigment is produced intracellularly on a wide range of media in quantities up to 0.45 mg/ml. The rate of production for a given isolate is proportional to its growth but such proportionality is not observed when one isolate is compared to another. A second, fluorescent pigment, C32 H28N2O4, is produced by those isolates that produce cochliodinol but in 1/500 of the yield.

Chemical and biological properties of some oxindolidyl-3-methines

Several 1-methyloxindohdyl-3-methines have been synthesized, either by condensation of 1-methyloxindole with an aldehyde, or by a Wittig reaction of a chloromethylene compound with a 1-methylisatin When examined m the mass spectrometer the expected ion reactions were observed and, in addition, a reaction involving expulsion of the carbonyl group of the oxindole moiety and rearrangement of the residual fragment, to give a 1-methylbenzo[b]azepinium ion was observed. The anions of the oxindolidyluracilmethines 4 and 5, (R = Me, R′ = OH) had an absorption band near 380 mμ but the corresponding neutral molecules absorbed at 325–350 mμ. The 5-nitrofuran derivatives 3 were the only compounds that inhibited the growth of Bacillus subtilis.

The biological properties of 3,6-epidithiadiketopiperazines. Degradation of gliotoxin-B by Bacillus subtilis (HLX 373)

Like sporidesmin, gliotoxin catalyzes the decomposition of azide in the presence of iodine, and this catalysis can be used for its estimation. The presence of respiring cells of Bacillus subtilis does not interfere with the estimation. Thus it was possible to show that the concentration of gliotoxin decreased when solutions of the antibiotic were incubated with respiring cells. The rate of the decomposition was independent of the gliotoxin concentration in the range 2–25 μg/ml, but was dependent on the number of cells, the pH, and the available nitrogen in the suspending medium. Loss of gliotoxin was most rapid at pH 5.5 and continued when the supernatant was reincubated after centrifugal removal of the cells. No loss of gliotoxin occurred when solutions were incubated in the absence of cells at pH 5.5. By contrast, chemical degradation at pH 8.0 was inhibited in the presence of cells. These results are consistent with the hypothesis that B. subtilis secretes an enzyme which degrades the disulfide group in gliotoxin.

The growth of Bacillus subtilis in media containing chetomin, sporidesmin, and gliotoxin

Sporidesmin, gliotoxin, and chetomin increase the lag phase of growth of Bacillus subtilis. By daily subculture of the organism in media that contained one of the antibiotics in sufficient concentration to increase the lag phase of growth by 300%, organisms were obtained whose lag phase of growth was the same as that of the parent strain (HLX 373). Repetition of this process has made it possible to obtain cultures which have a lag phase of growth of 300 ± 20 min in the presence of chetomin (0.15 μg/ml), gliotoxin (3.0 μg/ml), or sporidesmin (30 μg/ml). The culture which could grow in the presence of gliotoxin lost this ability on subcultivation in the absence of the antibiotic. Sufficient cross resistance was shown to indicate the possibility that these three antibiotics had a similar mode of action.

The biological properties of 3,6-epidithiadiketopiperazines. Inhibition of growth of Bacillus subtilis by gliotoxins, sporidesmins, and chetomin

The ability of chetomin and the sporidesmin and gliotoxin groups of fungal metabolites to inhibit the growth of Bacillus subtilis (HLX 373) has been examined. With the exception of gliotoxin dibenzoate, compounds having the 3,6-epidithiadiketopiperazine structure, when added to the culture medium before inoculation, increased the lag phase of growth; this increase was influenced by the number of organisms in the inoculum and the concentration of the metabolite. When the disulfide bridge was eliminated chemically, the resulting degradation products were biologically inactive.

Approach of domestic chicks to stationary objects of different texture

Two experiments were designed to compare the attractiveness to 3-day-old chicks of rough-lined and smooth-lined objects. In Exp. I chicks were reared individually in a pen containing a small open-ended box which was either rough-lined or smooth-lined. Chicks returned to the box after separation more often when reared with the smooth-lined box than when reared with the rough-lined box. In Exp. II chicks were reared in pens containing two boxes, one smooth-lined and one rough-lined. After separation most chicks showed a preference for the smooth-lined box. The significance of these findings is discussed in relation to studies of ‘contact comfort’ and of imprinting.

Chemical and biological properties of an extracellular lipopolysaccharide from Escherichia coli grown under lysine-limiting conditions

Lipopolysaccharide was prepared from the extracellular lipoglycopeptide produced by the lysine-requiring mutant Escherichia coli A.T.C.C. 12408 grown under lysine-limiting conditions. The lipid moiety, containing glucosamine phosphate and four fatty acids (lauric acid, myristic acid, beta-hydroxymyristic acid and palmitic acid) corresponded in composition to lipid A of known bacterial lipopolysaccharides. The components of the polysaccharide moiety were d-glucose, d-galactose, l-glycero-d-manno-heptose, 3-deoxy-2-oxo-octonic acid, ethanolamine and phosphate. These are the constituents of the polysaccharide of the cell-wall antigens from rough strains of E. coli. Lipopolysaccharides were also prepared from whole cells of E. coli 12408 grown with excess or limited amounts of lysine; they were identical in carbohydrate composition with the extracellular lipopolysaccharide. The biological properties of this material also resembled those of known lipopolysaccharides; it was antigenic, pyrogenic, toxic and had adjuvant activity.