Biosynthetic studies on saframycin A, a quinone antitumor antibiotic produced by Streptomyces lavendulae

The biosynthesis of saframycin A, a heterocyclic quinone antitumor antibiotic isolated from Streptomyces lavendulae 314, was studied by feeding experiments with 14C and 13C precursors. Highly increased production of saframycin A and prolongation of the maximum production period of saframycin A were attained by constant pH control of the culture and by addition of chloramphenicol to the culture. The biosynthetic origin of the quinone skeleton common to the saframycin group was confirmed to be two tyrosine molecules which condense to generate the basic ring system of saframycin A. Feeding experiments with [1-13C]tyrosine showed specific labeling of C-11 and C-21 carbons of saframycin A, and the enrichment of the carbons was 40-fold over natural abundance. Two O- and two C-methyl and one N-methyl carbons arose directly from methionine, and alanine and glycine were the precursors for the pyruvoyl amide side chain of saframycin A.

Structure-activity relationships of saframycins

In vitro antitumor activities of 13 saframycins, including the potent antitumor component, saframycin A, were determined with the highly sensitive established cell line of L1210 mouse leukemia to investigate structure-activity relationships. Saframycins which lack the alpha-cyanoamine group or the alpha-carbinolamine group exhibited much lower cytotoxic activity than saframycin A. The modification of active saframycins either at the C-14 position on the basic skeleton or at the C-25 position on the side chain with bulky substituents resulted in a decrease in cytotoxic activity. These structure-activity relationships corroborated the proposed major mechanism of action for the antitumor activity of saframycin A and supported our proposed model for the saframycin A-DNA adduct.

Leucinostatins, peptide mycotoxins produced by Paecilomyces lilacinus and their possible roles in fungal infection

Peptide mycotoxins "leucinostatins" were obtained from the culture strains of Paecilomyces lilacinus, which were isolated both from soil and a case of human oculomycosis. Comparative studies of the symptoms of experimental keratomycosis caused both by the inoculation of P. lilacinus and by direct administration of leucinostatins into the infection model in rabbit suggested the possible role of leucinostatins in the inflammatory response of invaded tissues. Leucinostatin was formerly reported as a single entity. However, in the course of the structural studies, leucinostatin was found to be a complex of two closely related components, and the structures of the both mycotoxins were determined. Both of the mycotoxins possessed high toxicity to experimental animals. The intraperitoneal and oral LD50 values in mice were 1.8 and 5.4 to 6.3 mg/kg by a single administration. Toxicological studies showed that leucinostatins have some potent effects on liver cells after oral administration. It was also found that leucinostatins exhibit strong uncoupling activity on rat liver mitochondrial system.

Prolactin response to thyrotropin-releasing hormone in children with gynecomastia, premature thelarche and idiopathic precocious puberty

Plasma prolactin (PRL) response to synthetic thyrotropin-releasing hormone (TRH) was studied in six patients with pubertal gynecomastia, five patients with premature thelarche and nine female patients with idiopathic precocious puberty. The basal concentration of plasma PRL was higher (p less than 0.01) in pubertal gynecomastia as compared to control, while baseline plasma PRL levels in premature thelarche and idiopathic precocious puberty were similar to those in controls. Plasma PRL level after TRH in patients with pubertal gynecomastia was higher (p less than 0.01) than that in control, while plasma PRL responses to TRH in idiopathic precocious puberty and premature thelarche were comparable to those controls. The TRH-induced PRL release was more enhanced during treatment with cyproterone acetate (CA) than before CA therapy in four of five patients with idiopathic precocious puberty. These data suggest that the enhanced release of PRL may, at least in part, contribute to breast enlargement in pubertal gynecomastia and that seen in idiopathic precocious puberty and premature thelarche may not depend on the PRL secretion. The prolonged administration of CA enhances the PRL responsiveness to TRH.

Studies on defense mechanisms against Candida albicans infection in congenitally athymic nude (nu/nu) mice

The defense mechanisms against Candida albicans infection were studied by using a mouse thigh lesion model in congenitally athymic nude (nu/nu) mice and their normal littermates (nu/+). Nu/nu mice were more resistant to C. albicans infection than nu/+ mice judging from the course of the thigh lesion, the results of CFUs (colony-forming units) of C. albicans in the lesion, and histopathological observations. Histopathological and serological studies revealed that granulocytic cellular infiltration was predominant, and there were few indications of development of cell-mediated immunity to protect Candida infection in Candida-infected nu/nu and nu/+ mice. These results confirmed that lower susceptibility of nu/nu mice to C. albicans infection as compared to nu/+ mice was due to accelerated non-specific defense mechanisms in nu/nu mice, and that cell-mediated or humoral immunity played a minor role in the defense against Candida infection in this experimental model. Furthermore, treatment with high titer of rabbit anti-C. albicans serum was effective to control the number of Candida cells in thigh lesions of BALB/c mice. Above experimental results seem to clearly indicate the great variability of defense manifestation according to the experimental model exployed.

The effect of heating on Y-chromosome detection

The effect of heating on Y-chromosome detection was investigated. Heat-treated blood was divided into four groups according to the hemolysis pattern obtained by the coil planet centrifuge system. A significant difference between the Y-positive nuclei of males and females was observed up to group III of the hemolysis pattern, and it was possible to determine the sex of the blood donor in spite of karyolysis and degeneration of blood components. However, sex determination of blood in group IV, indicating complete hemolysis, was impossible because of overlapping between male and female Y-chromosome counts. Practical application of this sex determination method was successful even with severely burned cadavers. However, it was suggested that putrefaction together with heat damage made the identification nearly impossible.

Epidemiologic survey of juvenile-onset insulin dependent diabetes mellitus (IDDM) in Hokkaido, Japan, 1973-1981

An epidemiological survey of juvenile-onset insulin dependent diabetes mellitus (0-15 years) was performed in Hokkaido, Japan, during 1973-1981. The mean annual incidence during the nine year period was 1.26 per 100,000 and showed a significant increasing trend. The prevalence of IDDM at the ages of 0-15 and 6-15 were 7.7 and 11.7 per 100,000 respectively. These figures were much lower than those previously reported in Caucasians. Peaks in incidence were seen from February to April, and a reduction in incidence from July to September. The females showed a bimodal distribution with the peak incidence at 10 to 12 years and with a smaller peak at about 7 years. The males showed a broad single peak at about 10 to 13 years.

Prolactin response to arginine in children with hyperthyroidism and primary hypothyroidism

Plasma prolactin (PRL) response to arginine was examined in 16 prepubertal and 18 pubertal children with constitutional short stature, 5 patients with hyperthyroidism and 4 patients with primary hypothyroidism. The mean basal concentration of plasma PRL was significantly higher (P less than 0.01) in primary hypothyroidism than in other groups. Arginine infusion elicited significant (P less than 0.05) rises in plasma PRL in all groups. The maximal increment of plasma PRL above the baseline level after arginine stimulation was significantly larger (P less than 0.05) in pubertal than in prepubertal females and was significantly smaller (P less than 0.05) in patients with hyperthyroidism than in age- and sex-matched controls. There was no sex difference in arginine-stimulated PRL secretion. These data suggest that arginine produces a significant increase in plasma PRL and the PRL response to arginine was greater in pubertal than in prepubertal children. Plasma PRL response to arginine is suppressed in children with hyperthyroidism and the basal plasma PRL is markedly elevated in primary hypothyroidism.

Diaminopimelic acid profiles of alkalophilic and alkaline-resistant strains of Actinomycetes

Twenty alkalophilic actinomycetes with optimum growth pH of 9.0 to 9.5 were isolated. Although these new isolates morphologically closely resembled conventional streptomycetes containing LL-diaminopimelic acid, nine out of 20 isolated contained meso-diaminopimelic acid. Among 420 International Streptomyces Project (ISP) Streptomyces strains tested for their maximum growth pH, only 6 strains grew at pH 11.5. Of these six strains, three strains, S. caeruleus ISP 5103, A. alborubidus ISP 5465 and S. autotrophicus ISP 5011 contained meso-diaminopimelic acid.

Factors Affecting Yield and Safety of Protein Production from Cassava by Cephalosporium eichhorniae

The properties of Cephalosporium eichhorniae 152 (ATCC 38255) affecting protein production from cassava carbohydrate, for use as an animal feed, were studied. This strain is a true thermophile, showing optimum growth at 45° to 47°C, maximum protein yield at 45°C, and no growth at 25°C. It has an optimum pH of about 3.8 and is obligately acidophilic, being unable to sustain growth at pH 6.0 and above in a liquid medium, or pH 7.0 and above on solid media. The optimum growth conditions of pH 3.8 and 45°C were strongly inhibitive to potential contaminants. It rapidly hydrolyzed cassava starch. It did not utilize sucrose, but some (around 16%) of the small sucrose component of cassava was chemically hydrolyzed during the process. Growth with cassava meal (50 g/liter [circa 45 g/liter, glucose equivalent]) was complete in around 20 h, yielding around 22.5 g/liter (dry biomass), containing 41% crude protein (48 to 50% crude protein in the mycelium) and 31% true protein (7.0 g/liter). Resting and germinating spores (10 6 to 10 8 per animal) injected by various routes into normal and γ-irradiated 6-week-old mice and 7-day-old chickens failed to initiate infections.

Saframycin S, a new saframycin group antibiotic

Saframycin S, structurally the decyano-saframycin A and biosynthetically the precursor of saframycin A, is a new antibiotic and is assumed to be the active principle for the formation of the antibiotic-DNA complex to manifest its activity. In the present study on the biological activity of saframycin S, the antibiotic showed a marked activity against Ehrlich ascites tumor with the doses of 0.5 to 0.75 mg/kg/day for 10 days, and the rate of 40-day survivors was 80 to 90%. However, this antibiotic was less effective against P388 leukemia than saframycin A at the doses tested. Saframycin S also showed the highest antimicrobial activity, in particular against gram-positive bacteria, among the saframycin group antibiotics identified to date. the LD50 of saframycin S was 3.2 mg/kg (i.p.) for ddY mice. The biological activity and toxicity of saframycin S in relation to its structure were described.

Microbial Transformation of β -Ionone and β -Methylionone

Aspergillus niger JTS 191 was selected from many microorganisms tested as capable of converting ionones to other compounds having aromas. The individual transformation products from β -ionone were isolated and identified by comparison with synthetically derived compounds. The major products were ( R )-4-hydroxy- β -ionone and ( S )-2-hydroxy- β -ionone. 2-Oxo-, 4-oxo-, 3,4-dehydro-, 2,3-dehydro-4-oxo-, 3,4-dehydro-2-oxo-, ( S )-2-acetoxy-, ( R )-4-acetoxy-, and 5,6-epoxy- β -ionone and 4-(2,3,6-trimethylphenyl)-but-3-en-2-one were also identified. Analogous transformation products of β -methylionone also were identified. Based on gas-liquid chromatographic analysis during the fermentation, we propose two main oxidative pathways of β -ionone. The results of this study suggest that these transformations of β -ionones may be useful as tobacco-flavoring compounds.

Some chemotherapeutic properties of two new antitumor antibiotics, saframycins A and C

The antitumor activity of saframycin was examined against four different experimental tumor systems in mice. Saframycin A and C inhibited the growth of L1210 cells in suspension culture completely at concentrations of 0.02 microgram/ml and 1.0 microgram/ml, respectively. The LD50's of saframycin A for ddY mice were 4.9 mg/kg (ip) and 3.3 mg/kg (iv), respectively. In C3H/He mice, the LD50's were 10.5 mg/kg (ip) and 9.7 mg/kg (iv), respectively. Saframycin A was highly active against Ehrlich ascites carcinoma and P388 leukemia, and moderately active against L1210 leukemia and B16 melanoma. The antitumor activity of saframycin A was 50 to 100 times greater than that of saframycin C. The survivors cured of Ehrlich ascites carcinoma by treatment with saframycin A developed a resistance to rechallenge with the same tumor. On the other hand, when carbazilquinone and adriamycin were used as reference drugs, the cured mice in these cases did not resist rechallenge with the same tumor. When saframycin A (5 mg/kg) was administered intraperitoneally into mice, the blood concentration of saframycin A was 4.6 microgram/ml after 30 min, and 2.8 microgram/ml after 1 hr, and the total recovery within 3 hr from the urine was 30%. Saframycin A was found to be distributed widely, though to different extents, in various organs when injected intraperitoneally into mice.

Morphological changes in yeasts as a result of the action of 5-fluorocytosine

The mode of action of 5-fluorocytosine on Candida albicans and Saccharomyces cerevisiae was studied with special reference to morphology and ultrastructure. Shortly after contact of yeast cells with 10 mug of 5-fluorocytosine per ml, marked enlargement of the cells occurred. The initial increase in cell size was almost the same with both yeast strains. As incubation proceeded, further increase in cell volume continued with C. albicans, whereas no further change in cell volume was observed with S. cerevisiae. An electron microscope examination of C. albicans cells after exposure to the drug revealed characteristic changes, consisting of an enlarged nucleus and a thin cell wall. The morphological changes were exactly comparable to those reported with inhibitors of deoxyribonucleic acid synthesis in mammalian cells and some bacteria.

Phagocytosis of Candida albicans by rabbit alveolar macrophages and guinea pig neutrophils

Studies of host-parasite relationships at the cellular level, using Candida albicans and rabbit alveolar macrophages or guinea pig neutrophils are presented. Guinea pig neutrophils killed the intracellular candida cells presumed by myeloperoxidase-halide-hydrogen peroxide system. In contrast, rabbit alveolar macrophages did not kill the intracellular candida cells although their phagocytic rate was almost comparable to that of neutrophils. Phagocytizing macrophages were eventually destroyed by the intracellular proliferation of candida cells and formation of germ tubes and pseudomycelia. No significant improvement of candidacidal activity was observed with macrophages from normal and immunized rabbits in immune serum. The mode of phagocytosis by macrophages and neutrophils were also studied under the scanning electron microscope.

[Agenesis of internal carotid artery associated with aneurysm of anterior communicating artery (author's transl)]

A case of agenesis of the left internal carotid artery with an aneurysm of the anterior communicating artery was reported in detail. The patient was a 48-year-old man who had an episode of subarachnoid hemorrhage about 10 years ago. This time left heminumbness and motor weakness of the left lower extremity occured and he was brought our hospital. Right common carotid angiography, left retrograde brachial serial angiography and aortography demonstrated an agenesis of the left internal carotid artery, an aneurysm of the anterior communicating artery, tortuous megadolic hobasilar artery and anomalies on the circle of Willis such as absence of supra optic portion of the right anterior cerebral artery, and large left posterior communicating artery. We confirmed latter findings by operation. After successful neck clipping of the aneurysm, his clinical findings were remarkably improved.

Isolation and characterization of satellite antibiotics, mimosamycin and chlorocarcins from Streptomyces lavendulae, streptothricin source

Under novel conditions of culture, Streptomyces lavendulae No. 314 was found to produce new antibiotics, chlorocarcins and mimosamycin in addition to streptothricin. The antibiotics are extracted from culture filtrate with organic solvents and further purified by silica gel chromatography. Chlorocarcins A, B and C are closely related basic antibiotics which are active against gram-positive bacteria, EHRLICH carcinoma and L 1210 leukemia of mice. Mimosamycin is a neutral antibiotic which is mainly active against mycobacteria. Production, isolation and physicochemical properties of the antibiotics are described.

Identification of producer and biological activities of new antibiotics, mimosamycin and chlorocarcins

A strain of Streptomyces, No. 314 identified as a Streptomyces lavendulae produced under a novel condition of culture, four new antibiotics, mimosamycin and chlorocarcins A, B, and C. Among the components of chlorocarcin complex, chlorocarcin A was found to be most biologically active. This antibiotic inhibited the growth of Staphylococcus aureus FDA 209P and Corynebacterium diphtheriae at the concentrations of 0.1 and 0.003 mcg/ml, respectively. Chlorocarcin A also exhibited antitumor activity on EHRLICH carcinoma, ascitic and solid forms, and mouse leukemia L1210. Mimosamycin proved to be mainly active on Mycobacterium tuberculosis and inactive on the experimental murine tumors.

Chromogenesis mirabilis in Streptomyces griseus

A number of chromogenic Streptomyces, producing diffusible melanoid pigment on complex organic media, fail to form melanin pigment on conventionally used synthetic tyrosine agar. By means of our new melanin formation test, almost all the chromogenic streptomyces can now be detected in chemically defined medium. In contrast to ordinary chromogenic streptomyces, two streptomyces species of the International Streptomyces Project, S. griseus ISP 5236 and S. ornatus ISP 5307, produce melanin pigment only on synthetic tyrosine agar, without showing chromogenicity on complex organic media. From the results obtained with S. griseus ISP 5236 and S. phaeochromogenes ISP 5073, it was revealed that melanin formation by Streptomyces, in general, is inhibited by L-cysteine present in organic nitrogen sources incorporated into natural media. Most chromogenic species of streptomyces produce a higher level of tyrosinase and rapidly utilize L-cysteine in the culture media which result in the manifestation of good chromogenicity on natural media. Peculiarity of chromogenicity of S. griseus and S. ornatus might be due to the lower ability to produce tyrosinase and to utilize L-cysteine in the culture medium.

Chromogenicity of Streptomyces

A simplified technique to detect polyphenol oxidase and melanin formation by Streptomyces culture filtrates was developed. The procedure involves the direct assay of pigment formation by the culture filtrate with 3-(3,4-dihydroxyphenyl)-L-alanine (L-dopa) as a substrate. Among cultures of the International Streptomyces Project, 34 failed to produce a diffusible dark brown pigment on peptone-yeast extract-iron-agar and synthetic tyrosine-agar and gave a negative reaction to the melanin formation test. Sixteen cultures produced a diffusible dark brown pigment on both peptone-yeast extract-iron-agar and synthetic tyrosine-agar and gave positive reactions to the test with either L-tyrosine or L-dopa as substrate. Twenty-one cultures produced a diffusible dark brown pigment on peptone-yeast extract-iron-agar, but failed to do so on synthetic tyrosine-agar. Most of these cultures gave a positive reaction to the test when L-dopa was used as the substrate. The correlation between chromogenicity on complex organic media and melanin formation was more clearly established with L-dopa as substrate than with synthetic tyrosine-agar in the present test. The melanin formation test by the present technique, instead of chromogenicity on complex organic media, is recommended as a key feature for the classification of Streptomyces.