Ingestion of High β-Glucan Barley Flour Enhances the Intestinal Immune System of Diet-Induced Obese Mice by Prebiotic Effects

The prebiotic effect of high β-glucan barley (HGB) flour on the innate immune system of high-fat model mice was investigated. C57BL/6J male mice were fed a high-fat diet supplemented with HGB flour for 90 days. Secretory immunoglobulin A (sIgA) in the cecum and serum were analyzed by enzyme-linked immunosorbent assays (ELISA). Real-time PCR was used to determine mRNA expression levels of pro- and anti-inflammatory cytokines such as interleukin (IL)-10 and IL-6 in the ileum as well as the composition of the microbiota in the cecum. Concentrations of short-chain fatty acids (SCFAs) and organic acids were analyzed by GC/MS. Concentrations of sIgA in the cecum and serum were increased in the HGB group compared to the control. Gene expression levels of IL-10 and polymeric immunoglobulin receptor (pIgR) significantly increased in the HGB group. HGB intake increased the bacterial count of microbiota, such as Bifidobacterium and Lactobacillus. Concentrations of propionate and lactate in the cecum were increased in the HGB group, and a positive correlation was found between these organic acids and the IL-10 expression level. Our findings showed that HGB flour enhanced immune function such as IgA secretion and IL-10 expression, even when the immune system was deteriorated by a high-fat diet. Moreover, we found that HGB flour modulated the gut microbiota, which increased the concentration of SCFAs, thereby stimulating the immune system.

Altered expression of topoisomerase IIalpha contributes to cross-resistant to etoposide K562/MX2 cell line by aberrant methylation

KRN 8602 (MX2) is a novel morpholino anthracycline derivative having the chemical structure 3′-deamino-3′-morpholino-13-deoxo-10-hydroxycarminomycin hydrochloride. To investigate the mechanisms of resistance to MX2, we established an MX2-resistant phenotype (K562/MX2) of the human myelogeneous leukaemia cell line (K562/P), by continuously exposing a suspension culture to increasing concentrations of MX2. K562/MX2 cells were more resistant to MX2 than the parent cells, and also showed cross-resistance to etoposide and doxorubicin. Topoisomerase (Topo) IIα protein levels in K562/MX2 cells were lower of those in K562/P cells on immunoblot analysis and decreased expression of Topo IIα mRNA was seen in K562/MX2 cells. Topoisomerase II catalytic activity was also reduced in the nuclear extracts from K562/MX2 cells when compared with K562/P cells. Aberrant methylated CpG of Topo IIα gene was observed in K562/MX2 cells when compared with the parent line on methylation-specific restriction enzyme analysis. To overcome the drug resistance to MX2 and etoposide, we investigated treatment with 5-Aza-2′-deoxycytidine (5AZ), which is a demethylating agent, in K562/MX2 cells. 5-Aza-2′-deoxycytidine treatment increased Topo IIα mRNA expression in K562/MX2 cells, but not in K562/P cells, and increased the cytotoxicity of MX2 and etoposide. Methylated CpG was decreased in K562/MX2 cells after 5AZ treatment. We concluded that the mechanism of drug resistance to MX2 and etoposide in K562/MX2 cells might be the combination of decreased expression of Topo IIα gene and increased methylation, and that 5AZ could prove to be a novel treatment for etoposide-resistant cell lines, such as K562/MX2.

[Proposed mechanism of action of metalloendopeptidase-F in the treatment of patients with chronic hepatitis B or C infection]

Chronic hepatitis B and C virus infections have been characterized by the pathophysiological features with a high incidence of progression to cirrhosis and development of hepatocellular carcinoma. The viral persistence produced by escape mutations from virus-specific cytotoxic T lymphocytes (CTL) response may lead to upregulation of delayed-type hypersensitivity immune response, which causes hepatic tissue damage through non specific macrophage activation and CTL response and promotes pathogenesis of hepatic fibrosis. In a preliminary clinical study, a novel metalloendopeptidase-F (MEP-F) has been shown to be effective in the treatment of patients with either chronic hepatitis B or C infection. Oral administration of MEP-F resulted in a significant reduction of the serum levels of HBs antigen and HCV RNA and improvement in the liver function abnormalities. However, the mechanism of action of MEP-F is not yet well understood. There are accumulating evidences showing an important role of alpha 2-macroglobulin-proteinase complexes in regulatory mechanisms of immune response and repairing within impaired and inflammatory tissues. In this article, reviewing the pharmacological and biological properties of alpha 2-macroglobulin-proteinase complexes, the mechanism of anti-viral effect of MEP-F is examined based on the clinical findings. It is indicated that alpha 2-macroglobulin-MEP-F complexes may induce macrophage/Kuppfer cell activation and proliferation through binding their receptors on the cells and activating signaling cascades, which enhance both anti-viral specific and nonspecific immune responses. alpha 2-Macroglobulin-MEP-F complexes may also augment cellular immunity and hepatic regeneration by neutralizing the immunosuppressive and fibrogenic activities of transforming growth factor-beta.

Successful treatment of radiation cystitis with hyperbaric oxygen therapy: resolution of bleeding event and changes of histopathological findings of the bladder mucosa

To assess the effect of hyperbaric oxygen (HBO) therapy on radiation cystitis, clinical and histopathological characteristics were examined. Three women with radiation cystitis were treated with HBO therapy. Macrohaematuria was arrested in all patients. Cystoscopy demonstrated abnormal telangiectasia and inflammatory mucosa before treatment. After HBO therapy, the inflammatory mucosae were healed. However, abnormal vessels did not completely disappear. Histopathologically, the epithelium was atrophic and dilated lymph vessels and inflammatory cells were seen in the submucosa. These changes improved after treatment. HBO therapy is effective against radiation cystitis. With improvement of the clinical symptoms also the cystoscopic and histopathological findings changed favourably.

Immunosuppressive effects of gallic acid and chebulagic acid on CTL-mediated cytotoxicity

Gallic acid (GA) and chebulagic acid (CA) were isolated from the extract of a herbal medicine, kashi (myrobalans: the fruit of Terminalia chebula) as active principles that blocked the cytotoxic T lymphocyte (CTL)-mediated cytotoxicity. GA and CA inhibited the killing activity of CD8+ CTL clone at IC50 values of 30 microM and 50 microM, respectively. Granule exocytosis in response to anti-CD3 stimulation was also blocked by GA and CA at the equivalent concentrations.

Pseudoxanthomatous lesions with membranocystic changes of collagen fibers in an SLE patient receiving long-term steroid treatment

We report a 50-year-old Japanese woman with a 3-year history of systemic lupus erythematosus treated with prednisolone, who had diffuse plane yellowish macules mainly on the upper arm. The lesion was clinically diagnosed as diffuse plane xanthomatosis. However, the histopathological findings from both the yellowish macules and the normal-appearing skin revealed a heavy degeneration of collagen fibers with membranocystic structure throughout the entire dermis and the collagenous septum of the subcutaneous tissue. Ultrastructurally, the membranocystic structure was not due to the degenerative change of fat cells as seen in membranous lipodystrophy but was caused by the degenerative change of collagen fibers with fat deposit.

Novel blockade of cell surface expression of virus glycoproteins by leucinostatin A

The nonapeptide leucinostatin A (LSA) inhibited syncytium formation without profoundly affecting HN glycoprotein synthesis in Newcastle disease virus (NDV)-infected BHK cells. At similar doses of LSA, cytopathic effect and infectious virus production were suppressed in vesicular stomatitis virus (VSV)-infected BHK cells. Blockade by LSA of cell surface expression of NDV-HN and VSV-G glycoproteins was demonstrated, accompanied by intracellular accumulation of these virus glycoproteins. LSA acts as an inhibitor of mitochondrial F-type H(+)-translocating ATPase, a key enzyme in the generation of ATP, but its action against cell surface expression of virus glycoproteins was independent of the depletion of intracellular ATP. LSA also acts as an ionophore, but its action on intoxication by ricin and diphtheria toxin was different from that of monensin. This novel action of LSA is expected to be useful in investigation of the mechanism of intracellular trafficking of proteins.

Inhibitory effect of a spicamycin derivative, KRN5500, on the growth of hepatic metastasis of human colon cancer-producing tissue polypeptide antigen

The inhibitory effect of KRN5500, a spicamycin derivative, on the growth of hepatic metastasis of the tissue polypeptide antigen (TPA)-producing human colon cancer COL-1 was examined in severe combined immunodeficient (SCID) mice. Prior to this chemotherapeutic study, we confirmed the high correlation coefficient (r = 0.86, P < 0.01) between plasma TPA levels in athymic nude mice bearing COL-1 and tumor volume. In the chemotherapy of experimental hepatic metastasis induced by intrasplenic injection of COL-1 cells, KRN5500 at 12 mg/kg per day was administered i.v. three times at 4-day intervals. From the start of chemotherapy (day 1), plasma TPA levels in the mice were significantly decreased from 8332 U/l to a minimum of 494 U/l on day 16 and were within the range for intact SCID mice (409-634 U/l). The mean tumor weight was 4.87 g in the liver of untreated mice on day 19 and 0.74 g, in the liver of KRN5500-treated mice, a significant difference, representing a tumor growth inhibition rate of 85%. These results suggest the usefulness of TPA as a tumor marker in an experimental xenograft model. The chemotherapeutic efficacy of KRN5500 against experimental hepatic metastasis indicates that it may be a useful drug for the treatment of patients with hepatic metastases of colon cancer.

Structure-antitumor activity relationship of semi-synthetic Spicamycin derivatives

New derivatives of spicamycin modified at the fatty acid moieties of the molecule were synthesized and their structure-activity relationships were examined. The antitumor activity was greatly influenced by modification of the fatty acid moieties to tetradecadienoyl or dodecadienoyl analogues exhibiting better antitumor activity against COL-1 human colon cancer xenograft than SPM VIII.

Costunolide and dehydrocostus lactone as inhibitors of killing function of cytotoxic T lymphocytes

Costunolide and dehydrocostus lactone were isolated from an extract of mokko (Saussurea lappa Clarke) as inhibitors of killing activity of cytotoxic T lymphocytes (CTL). Mokko lactone was also isolated as an inactive compound from the extract. The structure-activity relationship indicated that alpha-methylene-gamma-butyrolactone is required for the inhibitory effect. Costunolide markedly inhibited the granule exocytosis and the production of inositol phosphates in response to anti-CD3 monoclonal antibody (mAb) stimulation at a concentration that did not affect the binding of anti-CD3 mAb. Tyrosine phosphorylation induced by crosslinking of CD3 molecules was significantly inhibited by costunolide in a dose-dependent manner. These results suggest that costunolide inhibits the killing activity of CTL through preventing the increase in tyrosine phosphorylation in response to the crosslinking of T-cell receptors.

Synthesis and antitumor activities of glycine-exchanged analogs of spicamycin

A series of SPM VIII analogs were synthesized to investigate the effect of the amino acid moiety on the antitumor activity. The L-threonine analog and the glycylglycine analog of SPM VIII showed much higher cytotoxicity to P388 murine leukemia cells (IC50 5.8 nM and 0.11 nM, respectively) than SPM VIII (IC50 25nM). However, replacement of the glycine moiety with other amino acids greatly reduced the antitumor activity against COL-1 human colon cancer xenograft model. This study indicated that the glycine moiety of SPM VIII is crucial for the antitumor effect.

[Clinical analysis of ureteral injuries]

Six cases of ureteral injuries were analyzed. Two cases were male and 4 cases were female. The right side was affected in 1 case and the left in 5 cases. The affected portion was the uretero-pelvic junction in 1 case and lower iliac vessels in the other cases. Five cases were iatrogenic injuries in surgical or gynecological pelvic operation, and the other was due to blunt trauma. Intraoperative diagnosis was made in 4 cases. Drain leakage led to diagnosis in one case and pyelonephritis in another. Ureteroureterostomy was performed in 2 cases, pyeloureterostomy in 1 case, ureteroneocystostomy with psoas hitch in 1 case, Boari bladder flap in 1 case and simple suture in 1 case. 4-0 or 5-0 Dexon with an atraumatic needle was used for all anastomoses. Except for case 1, who died of the recurrence of carcinosarcoma, renal functions were preserved in all patients during the follow-up period ranging from 5 months to 7 years 8 months.

Antitumor activity of SPM VIII, a derivative of the nucleoside antibiotic spicamycin, against human tumor xenografts

The antitumor activity of spicamycin analogue SPM VIII against human stomach, breast, lung, colon and esophageal cancers was compared to that of mitomycin C (MMC) in the human tumor-nude mice xenograft model. Comparative studies of SPM VIII given i.v. at 6 mg/kg/day daily for 5 days and MMC given i.v. at 6.7 mg/kg on day 1 revealed that the antitumor spectrum of SPM VIII showed a different pattern from that of MMC and that SPM VIII caused tumor mass reductions in more tumors than did MMC in colon cancers (4/12 versus 1/11). In addition to this study, a comparative study of SPM VIII given i.v. at 12 mg/kg/day 8 times at 3- or 4-day intervals and 5'-deoxy-5-fluorouridine (5'-DFUR) given po at 185 mg/kg/day 5 days per week for 4 weeks showed that SPM VIII had the highest effect on SC-9 human stomach cancer and COL-1 human colon cancer among the 3 compounds, resulting in a significant reduction of tumor mass. Although other pharmacological studies are in progress, these results suggest that SPM VIII might be a novel antitumor compound effective for human cancers including cancer of the digestive organs.

Structure-antitumor activity relationship of semi-synthetic spicamycin analogues

Spicamycin, a nucleoside antibiotic containing fatty acids with a variety of chain lengths (C12-C18), showed potent antitumor activity against human gastric cancer SC-9 and human breast cancer MX-1 in a xenograft model. We have made several semi-synthetic spicamycin analogues (SPMs) which differed in the chain length of the fatty acid moiety, and examined their structure-antitumor activity relationship. The cytotoxic activities of SPMs depended on the chain length of the fatty acid moiety, with dodecanoyl, tetradecanoyl, hexadecanoyl and icosanoyl analogues (SPM VIII, SPM X, SPM XII and SPM XVI) exhibiting the most potent cytotoxic activity against P388 murine leukemia cells. SPM VIII showed the most activity against SC-9 in the human tumor xenograft model with the highest therapeutic index among SPMs. The antitumor activity of SPM VIII was superior to that of mitomycin C.

Cryosurgery and topical fluorouracil: a treatment method for widespread basal cell epithelioma in basal cell nevus syndrome

A 58-year-old man with basal cell nevus syndrome had variously sized basal cell epitheliomas (BCEs), mostly of the superficial type, on his chest, back, and lumbar areas. BCEs on the lumbar area were treated with 5-fluorouracil (5-FU) cream which was applied daily under occlusive dressings (ODT). Complete erosion occurred in the center, but not at the periphery of the lesions. In the latter regions, BCE remained. Then cryosurgery (cryo) followed by topical 5-FU (cryo + 5-FU) was tried to treat the peripheral, non-eroded lesions; this caused complete erosions. Biopsy specimens obtained 6 months after epithelization did not show any evidence of recurrence. We also tried either cryo alone or cryo + 5-FU on the chest lesions, and either 5-FU alone or cryo + 5-FU on the abdominal lesions. Cryo alone or 5-FU alone could not clear BCE, but cryo + 5-FU could. These results suggest that the cryo + 5-FU was the most effective of these therapies.

Chemical transformation of gilvocarcin V. Modification of the side-chain

Gilvocarcin V was chemically transformed to alter its biological activities as well as its solubility by mainly focusing on the vinyl side chain. The oxirane and oxime derivatives showed slightly decreased in vivo antitumor activity, while the aminoethylmorpholine derivative turned out to be soluble in some organic solvents.

Eruptive lichen planus

We herein report a case of a rare variety of the acute eruptive form of lichen planus. The patient was a 51-year-old male who developed an intensely pruritic eruption on the lower legs which spread rapidly to all four extremities and trunk within a few months. The papulosquamous lesions were more than ten thousand in number. Topical steroid, cyclosporine, and systemic griseofulvin treatments were ineffective. However, there was a dramatic response to oral etretinate.

Synthesis and antitumor activity of 4'-O-acylanthracyclines

4'-O-Acyl derivatives of doxorubicin, daunorubicin, 13-deoxocarminomycin, 13-deoxo-10-hydroxycarminomycin, 13-deoxo-11-deoxycarminomycin were synthesized through the formation and mild acid hydrolysis of 2-oxazoline intermediates. The antitumor activity of these 4'-O-acyl derivatives against P388 leukemia was similar to or more effective than the parent anthracyclines.

Determination of the new morpholino anthracycline MX2.HCl and its metabolites in biological samples by high-performance liquid chromatography

Methods for determining concentrations of a new morpholino anthracycline MX2.HCl and its metabolites in biological samples using reversed-phase high-performance liquid chromatography and fluorescence detection are described. The limits of detection were less than 1 ng/ml for all compounds after extraction from 0.5 ml of plasma using C18 Sep-Pak cartridges and consecutive solvent extraction. The recoveries from rat plasma ranged from 72.0 to 89.3%. The peak-height ratio of the fluorescence intensities of these compounds versus internal standard showed a linear correlation for concentrations up to at least 500 ng/ml in the plasma (correlation coefficient r greater than 0.999). The within-day and between-day precisions of this assay were in the range 0.8-8.7% (n = 5) and 2.0-3.5% (n = 5), respectively. The concentrations of these compounds in the blood and urine can be also determined by a slight modification of the extraction procedure.

Cellular pharmacology of MX2, a new morpholino anthracycline, in human pleiotropic drug-resistant cells

We previously reported that MX2, a new morpholino anthracycline, showed marked effects on pleiotropic drug-resistant sublines of murine P388 leukemia in vivo as well as in vitro. In this study we examine the in vitro cytotoxicity against pleiotropic drug-resistant sublines of human tumor cell lines. MX2 was effective against multidrug-resistant sublines of four human tumor cell lines; these cells, having a 4.8- to 200-fold cross-resistance to Adriamycin (ADM) showed only a 0.7- to 2.3-fold resistance to MX2 compared with the sensitive cells. To elucidate the mechanism by which MX2 overcomes multidrug resistance, the intracellular pharmacology of MX2 in human myelogenous leukemia K562 and its ADM-resistant subline (K562/ADM) was examined. Both K562 and K562/ADM cells accumulated MX2 more easily than ADM, and the intracellular accumulation of MX2 attained a steady state in both cell lines within 30 min of incubation at 37 degrees C. The amount of MX2 that accumulated in K562/ADM at a steady state was only 1.3 times lower than that in K562. However, ADM was accumulated slowly in both cell lines compared with MX2, and the intercellular concentration reached a steady state in K562/ADM after 90 min of incubation and in K562 after more than 120 min. K562/ADM cells accumulated a 3.3-fold lower concentration of ADM than K562 after 120 min of exposure. The steady-state concentration of ADM in K562/ADM was 8.3 times lower than that of MX2. In addition, greater than 70% of MX2 was retained in both cell lines after 150 min of incubation in the absence of this drug. Verapamil, a calcium antagonist, hardly augmented the cytotoxicity of MX2 against K562/ADM, and no distinct effect of this drug on both the time course and the maximal level of accumulation of MX2 was observed. Interestingly, MX2 effectively inhibited ATP/Mg2(+)-dependent [3H]vincristine binding to K562/ADM membrane preparations, indicating that MX2 could be transported outside the cell by an active efflux pump. The high intracellular accumulation and retention of MX2 in K562/ADM through the rapid influx of the drug into the cells may be one of the reasons why MX2 circumvents pleiotropic drug resistance.

Intermolecular stacking of gilvocarcin V tetraacetate as evidenced by nuclear magnetic resonance studies

The temperature-dependent and concentration-dependent 1H NMR studies as well as 13C-relaxation experiments on gilvocarcin V tetraacetate strongly suggest intermolecular stacking of the antibiotic solution.

Molecular cloning and characterization of the gene conferring curromycin resistance on a curromycin non-producing mutant derived from Streptomyces hygroscopicus 358AV2

We cloned six different DNA fragments from a curromycin producing strain, Streptomyces hygroscopicus 358AV2, which confer curromycin-resistance on a curromycin non-producing and sensitive strain, S. hygroscopicus Rgll, a protoplast regenerant of the strain 358AV2. We studied the plasmid pSHR2 carrying one of the DNA fragments. By Southern blot analysis, the cloned DNA sequence in pSHR2 was found to be deleted in the Rgll genome. From the Rgll strain, a curromycin producing revertant A-4 was obtained, indicating that the structural genes for the curromycin biosynthesis and resistance are retained in the Rgll genome. Based on the existence of A-4 and the deletion of the DNA region corresponding to the cloned DNA sequence in the Rgll genome, we conclude that the cloned DNA sequence carries a regulatory gene governing curromycin-resistance but not the resistance gene itself. The smallest DNA region in pSHR2 conferring curromycin-resistance was sequenced, and it was found that there were two small open reading frames (ORF) on each strand of the cloned DNA. In-frame fusion of ORFs to the reporter gene lacZ revealed that one ORF designated cre was indeed translated in vivo. The putative gene product deduced from the cre ORF is a basic and hydrophilic protein having a calculated molecular weight of 6 kdaltons.

Effects of a new calcium channel blocker, TA 3090, on serum lipoprotein levels in mild to moderate essential hypertension

The 25 hypertensive patients received 20 to 40 mg of TA 3090 daily for 12 weeks. Blood pressures declined significantly during treatment, from a mean of 162/98 to 145/88 mmHg. There were no significant changes in levels of total or very low-density lipoprotein cholesterol or triglyceride, in levels of low-density lipoprotein cholesterol, high-density lipoprotein (HDL) cholesterol, HDL2 cholesterol, HDL3 cholesterol, or in levels of apolipoprotein (apo) B, C-II, C-III, or E. Apo A-I and A-II levels increased significantly from 130 and 29.2 mg/dl before treatment to 152 and 31.4 mg/dl at 12 weeks. Mean serum creatinine levels decreased significantly from 0.92 to 0.80 mg/dl. No other drug-related changes in laboratory test results or side effects were noted. It is concluded that TA 3090 is a safe and effective treatment for mild to moderate hypertension.

Microbial conversion of anthracyclinones to carminomycins by a blocked mutant of Actinomadura roseoviolacea

New anthracycline antibiotics, 1-hydroxy-11-deoxycarminomycin II and 11-deoxycarminomycin II were produced by a blocked mutant MuW1 of Actinomadura roseoviolacea from epsilon-pyrromycinone and aklavinone, respectively. We found that the enzyme catalyzing hydroxylation at the C-11 position was not lost but was down regulated in the strain MuW1.

Role of DNA-binding in the cytotoxicity of an anthracycline, R20X2 and its morpholino analog, MX2

3'-Deamino-3'-morpholino-13-deoxo-10-hydroxycarminomycin (MX2), a morpholino anthracycline derived from 13-deoxo-10-hydroxycarminomycin (R20X2) was 16 times less cytotoxic than R20X2 against cultured P388 leukemia cells. The reduced cytotoxicity of MX2 was not explainable by intracellular or intranuclear concentration of the drug or by its DNA-intercalating activity. Binding of MX2 and R20X2 to DNA was measured, after isolating the DNA fraction from an incubation mixture of the drugs with P388 cells or with calf thymus DNA. The amount of R20X2 bound to the DNA was obviously larger than that of MX2, and was dependent on incubation time. These data suggest that the poor binding activity of MX2 to DNA contributes to its reduced cytotoxicity.

Mechanism and stereochemistry of the biosynthesis of 2-deoxystreptamine and neosamine C

Feeding experiments with D-[6,6-2H2]-, D-(6R)-[6-2H1]- and D-(6S)-[6-2H1]glucose in the fermentation of Streptomyces ribosidificus, followed by field desorption MS and 2H NMR analyses of the resulting labeled ribostamycin samples, clearly demonstrated that 1) both hydrogens of the C-6 hydroxymethyl group of D-glucose are stereospecifically incorporated into the C-2 position of 2-deoxystreptamine and 2) the pro S hydrogen of the C-6 position of D-glucose is stereospecifically removed during the elaboration of neosamine C in the biosynthesis of ribostamycin. A plausible mechanism of formation of the deoxy-scyllo-inosose, an early precursor to 2-deoxystreptamine, is suggested to be analogous to the dehydroquinate synthesis in the shikimate pathway and the conversion of the C-6 hydroxymethyl group of D-glucose into the aminomethyl group of neosamine C is likely to involve a dehydrogenation step to a formyl group.

Studies on the biosynthesis of bialaphos (SF-1293). 8. Purification and characterization of 2-phosphinomethylmalic acid synthase from Streptomyces hygroscopicus SF-1293

2-Phosphinomethylmalic acid (PMM) synthase catalyzes the condensation of phosphinopyruvic acid (PPA), an analog of oxalacetic acid, and acetyl-CoA to form PMM. The enzyme was purified approximately 700-fold from a cell-free extract of Streptomyces hygroscopicus SF-1293, a bialaphos producing organism, to an electrophoretically homogeneous state. The purified PMM synthase has a subunit molecular weight of 48,000 by SDS-polyacrylamide gel electrophoresis and a native molecular weight of 90,000 approximately 98,000 by gel filtration. PMM synthase was relatively unstable, showed maximum activity at pH 8.0 and 30 degrees C, and was inhibited strongly by p-chloromercuribenzoate, iodoacetamide and EDTA. Enzyme activity suppressed by EDTA was completely restored by adding Co++ or Mn++ and partially restored by addition of Ca++, Fe++ or Mg++. The specific substrates of this enzyme are PPA or oxalacetic acid in addition to acetyl-CoA. The enzyme does not catalyze the liberation of CoA from acetyl-CoA in the presence of alpha-keto acids, such as pyruvate, alpha-ketoglutarate, deamino-alpha-ketodemethylphosphinothricin or phosphonopyruvate. The condensation reaction did not take place when propionyl-CoA or butyryl-CoA was used as a substrate in place of acetyl-CoA. The Km values of the enzyme were 0.05 mM for acetyl-CoA, 0.39 mM for PPA and 0.13 mM for oxalacetate. PMM synthase is very similar to (R)-citrate synthase of Clostridium in the inhibition pattern by sulfhydryl compounds, its metal ion requirement and stereospecificity; unlike (R)-citrate synthase PMM synthase was not inhibited by oxygen.

[The structure and antitumor activity of antitumor antibiotics--recent progress]

Effort looking for new antitumor antibiotics useful for the treatment of curing cancer resulted to the discovery of a number of new compounds with newer action mechanism as well as newer structural feature. The antibiotics which have been discovered since 1984 are discussed under classifications of action mechanism and structural feature, as well. The first group, which belong to a novel class of antibiotics containing a bicyclodiynene carbon skeleton in the molecules exhibited the most strong anti-tumor activity comparing with the antitumor antibiotics so far discovered. The action mechanism of this was explained by the diradical formation of diynene-cyclization, which led to the scission of double strand DNA. Amongst, esperamicin A seems of great interest in view of the therapeutic development. Moreover, elsamicin A, a member of chatarin antibiotics, and FR-900482 compound, an antibiotic having a polycyclic alkalodal skeleton are under development for the new chemotherapeutic agents. Rhizoxin, the metabolite of Rhizopus chinensis is also a promising candidate as anticancer agent. Its action mechanism was classified as an inhibitor of mitosis by binding to the microtibline proteins. Rhizoxin A shows no cross resistance with vincristine. MX2 (KRN 8602), the morpholino derivative of 13-deoxo-10-hydroxy-carminomycin, shows anticancer activity against tumor cells resistant to P388/ADM as well as low cardial toxicity. Miscellaneous compounds whose action mechanism are unknown are described.

Arugomycin, a new anthracycline antibiotic. I. Taxonomy, fermentation, isolation and physico-chemical properties

Arugomycin (AGM) is a new anthracycline antibiotic produced by strain No. 1098-AV2 which was identified as Streptomyces violaceochromogenes. AGM was isolated by solvent extraction, silicic acid chromatography and Sephadex LH-20 column chromatography. Acid treatment of AGM gave the chromophore, named arugorol, which was identified as 4'-epi-nogalarol, and sugar moieties. AGM inhibited the growth of Gram-positive bacteria and showed antitumor activity against sarcoma S-180 and Ehrlich ascites tumors.

Arugomycin, a new anthracycline antibiotic. II. Structural elucidation

The structure of arugomycin was determined by chemical degradation, and NMR and mass spectral analyses to be a new anthracycline antibiotic with arugorol (4'-epi-nogalarol) as the chromophore and two sugar chains comprising diginosyl-decilonitrosyl-2-deoxyfucose, and (4-O-fumaryl-diginosyl)-diginosyl-2-deoxyfucosyl -diginose.

Arugomycin, a new anthracycline antibiotic. III. Biological activities of arugomycin and its analogues obtained by chemical degradation and modification

Biological activities of arugomycin and its analogues obtained by chemical degradation and modification were evaluated. Differences in the sugar moieties affected their biological activities including induction of differentiation of mouse Friend erythroleukemia cells and mouse myeloid leukemia cells, antitumor activities against sarcoma S-180, Ehrlich ascites carcinoma and P388 leukemia, and cytotoxicity against murine leukemia cells. Some relationships were found between the sugar moieties and biological activities.

Induction of antibiotic production with ethidium bromide in Streptomyces hygroscopicus

Protoplast regeneration carried out in a carriomycin producing organism, Streptomyces hygroscopicus 358 AV2, lose carriomycin productivity without loss of carriomycin-resistance and the ability of formation of aerial mycelium. Ethidium bromide treatment on the 358 AV2 strain generated a bald mutant that produced carriomycin and a new antibiotic curromycin. In some other media, however, the parent strain produced curromycin, indicating that the ethidium bromide treatment altered the regulation of antibiotic production. Ethidium bromide treatment on a protoplast-regenerated strain derived from the parent strain resulted in derivatives capable of producing carriomycin and curromycin. These strains were unstable and tended to lose the recovered antibiotic productivity easily.

Capuramycin, a new nucleoside antibiotic. Taxonomy, fermentation, isolation and characterization

A new antibiotic capuramycin was isolated from the culture filtrate of Streptomyces griseus 446-S3 by adsorption and partition column chromatography. Based on its chemical structure being an uracil nucleoside with a caprolactam substituent, this substance was named as capuramycin. This paper describes the taxonomy of a producing organism, fermentation, isolation, characterization and biological properties of capuramycin.

A novel macrolide antibiotic, notonesomycin A

Fermentation of Streptomyces aminophilus subsp. notonesogenes 647-AV1 produced a mixture of antifungal antibiotics. Notonesomycin A, the main component has been characterized as a new macrolide antibiotic containing a sulfate group, a malonate moiety, two deoxysugars and a 1,3,4-trisubstituted benzene system in the molecule. It was active against some fungi and Gram-positive bacteria in vitro and effective against the sheath blight disease of rice plant in a green house test.