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Biomedical subjects

R Masuma

Publications and source records attributed to R Masuma.

At least 37 records · Page 2Linked to original sources
PubMed1996

New isochromophilones VII and VIII produced by Penicillium sp. FO-4164.

New isochromophilones VII and VIII were isolated from the culture broth of Penicillium sp. FO-4164. The structures were elucidated as 6H-2-benzopyran-6,8(7H)-dione, 5-chloro-3-(3',5'-dimethyl-1',3'-heptadienyl)-1,7,8a-trihydro-7, 8a-dihydroxy-7-methyl-7-acetate for isochromophilone VII and 6H-2-benzopyran-6-one,5-chloro-3-(3',5'-dimethyl-1', 3'-heptadienyl)-1,7,8,8a-tetrahydro-7,8-dihydroxy-7-methyl-8-acetate for isochromophilone VIII. Isochromophilones VII and VIII inhibited diacylglycerol acyltransferase activity with IC50 values of 20.0 and 127 microM and acyl-CoA: cholesterol acyltransferase activity with IC50 values of 24.5 and 47.0 microM, respectively.

Acyltransferases↗
PubMed1996

Andrastins A-C, new protein farnesyltransferase inhibitors produced by Penicillium sp. FO-3929. I. Producing strain, fermentation, isolation, and biological activities.

New protein farnesyltransferase inhibitors, andrastins A-C, have been discovered in the cultured broth of Penicillium sp. FO-3929. Andrastins extracted from broth supernatant were purified by silica gel chromatography, ODS chromatography and HPLC. The IC50 of andrastins A, B, and C against protein farnesyltransferase were 24.9, 47.1, and 13.3 microM, respectively.

Alkyl and Aryl Transferases↗
PubMed1996

Herquline B, a new platelet aggregation inhibitor produced by Penicillium herquei Fg-372.

A new herquline analog, herquline B was isolated from the culture broth of Penicillium herquei Fg372. Herquline B contains one piperazine and two cyclohexenones. The pyrrolidine ring of herquline A was cleaved to yield herquline B. The IC50 value of herquline B against platelet aggregation induced by ADP and platelet-activating factor were 1.6 and 5.0 microM, respectively.

Alkaloids↗
PubMed1996

Chlovalicin, a new cytocidal antibiotic produced by Sporothrix sp. FO-4649. I. Taxonomy, fermentation, isolation and biological activities.

Selective growth inhibition against IL-6 dependent cells was detected in fermentation extracts of a fungal strain FO-4649 which was characterized as Sporothrix species. An active metabolite (1) termed chlovalicin was isolated together with ovalicin and two other ovalicin derivatives (compounds 3 and 4). Chlovalicin, a ovalicin derivative with a chlorinated methylene moiety at the C-1 position of the cyclohexane ring, dose-dependently inhibited the growth of IL-6 dependent MH60 cells (IC50, 7.5 microM) in the presence of 0.2 U/ml IL-6 and, to a lesser extent, the growth of B16 melanoma cells (IC50, 38 microM). Among the other three compounds, only ovalicin showed inhibitory activity (IC50, 27 microM) against MH60 cells. These four compounds did not show any antimicrobial activity at a concentration of 1000 micrograms/ml.

Animals↗
PubMed1995

Terpendoles, novel ACAT inhibitors produced by Albophoma yamanashiensis. I. Production, isolation and biological properties.

A series of new acyl-CoA: cholesterol acyltransferase (ACAT) inhibitors termed terpendoles were isolated from the culture broth of a fungal strain FO-2546 which was proposed to belong to a new genus designated as Albophoma yamanashiensis. Among four structurally related terpendoles, terpendole C showed the most potent ACAT inhibitory activity with an IC50 value of 2.1 microM in an in vitro enzyme assay, followed by terpendoles D (IC50: 3.2 microM), A (15.1 microM) and B (26.8 microM). Evaluation of their ACAT inhibition in the cell assay using J774 macrophages indicated that terpendole D exhibited the highest specificity (cytotoxicity vs. ACAT inhibition) among microbial ACAT inhibitors we discovered so far.

Animals↗
PubMed1995

Phenopyrrozin, a new radical scavenger produced by Penicillium sp. FO-2047.

A new radical scavenger, named phenopyrrozin, was isolated from the culture broth of Penicillium sp. FO-2047. Phenopyrrozin was purified from whole broth solvent extraction, silica gel chromatography, and HPLC. The structure of phenopyrrozin was elucidated as 5,6,7,7a-tetrahydro-2-hydroxy-1-phenyl-3H-pyrrolizin-3-one. The IC50 of phenopyrrozin against lipid peroxidation induced by Cr2K2O7 was 73 micrograms/ml. Phenopyrrozin also reduced chromosomal aberrations induced by paraquat.

Animals↗
PubMed1995

Macrosphelide, a novel inhibitor of cell-cell adhesion molecule. I. Taxonomy, fermentation, isolation and biological activities.

Potent anti-adherent activity was detected in fermentation extracts of microbial strain FO-5050. Active compounds designated macrosphelide A and B were isolated and the structure was determined to be 16-membered macrolide antibiotics possessing three ester bonds in the ring structure. Macrosphelide A dose-dependently inhibited the adhesion of HL-60 cells to LPS-activated HUVEC monolayer (IC50, 3.5 microM); macrophelide B also inhibited HL-60 adhesion but to a lesser extent (IL50, 36 microM). Macrosphelide A did not show any antimicrobial and cytocidal activities at the concentration of 1000 micrograms/ml and 100 micrograms/ml, respectively.

Anti-Bacterial Agents↗
PubMed1995

Fudecalone, a new anticoccidial agent produced by Penicillium sp. FO-2030.

Penicillium sp. FO-2030, a soil isolate, was found to produce a new anticoccidial compound. The active compound, designated fudecalone, was isolated from the fermentation broth of the producing strain by solvent extraction, silica gel column chromatography and preparative HPLC. The structure of fudecalone was elucidated to be 3,3a,6,6a,7,8,9,10-octahydro-1-hydroxy-4,7,7-trimethyl-1H-naphtho[1,8a- c]furan-6-one mainly by spectroscopic studies including various NMR measurements. The anticoccidial activity using cell systems indicated that schizont formation of monensin-resistant Eimeria tenella was completely inhibited by fudecalone at concentrations more than 16 microM.

Animals↗
PubMed1995

Isochromophilones III-VI, inhibitors of acyl-CoA:cholesterol acyltransferase produced by Penicillium multicolor FO-3216.

New azaphilones named isochromophilones III-VI were isolated from the culture broth of Penicillium multicolor FO-3216 as inhibitors of acyl-CoA: cholesterol acyltransferase (ACAT). Their structures were elucidated by NMR and other spectroscopic analyses. The IC50 values of isochromophilones III, IV, V and VI for ACAT activity in an enzyme assay using rat liver microsomes were calculated to be 110, 50, 50 and 120 microM, respectively.

Animals↗
PubMed1995

Isochromophilones I and II, novel inhibitors against gp120-CD4 binding produced by Penicillium multicolor FO-2338. I. Screening, taxonomy, fermentation, isolation and biological activity.

Isochromophilones I and II, the first novel gp120-CD4 binding inhibitors of microbial origin, were isolated from a cultured broth of a soil fungus designated as Penicillium multicolor FO-2338. These compounds were obtained as yellow powders from the cultured broth together with the known related compounds sclerotiorin, ochrephilone and rubrorotiorin. Isochromophilones I and II (C23H25O5Cl and C22H27O4Cl, respectively) have an azaphilone skeleton and a chlorine atom. Isochromophilones strongly inhibited gp120-CD4 binding (IC50: 6.6 and 3.9 microM, respectively), but the other related compounds did not. Isochromophilone II inhibited significantly HIV replication in peripheral human lymphocytes at 25 microM.

Antiviral Agents↗
PubMed1995

Amidepsines, inhibitors of diacylglycerol acyltransferase produced by Humicola sp. FO-2942. I. Production, isolation and biological properties.

Humicola sp. FO-2942, a soil isolate, was found to produce a series of new inhibitors of diacylglycerol acyltransferase (DGAT). Three active compounds, designated amidepsines A, B and C, were isolated from the fermentation broth of the producing strain by solvent extraction, silica gel column chromatography, ODS column chromatography and HPLC. Amidepsines inhibit DGAT activity with IC50 values of 10.2 approximately 51.6 microM in an enzyme assay system using rat liver microsomes. Amidepsines also showed specific inhibition of triacylglycerol formation in intact Raji cells, indicating that they inhibit DGAT activity in living cells.

Acyltransferases↗
PubMed1994

Pyripyropenes, novel inhibitors of acyl-CoA:cholesterol acyltransferase produced by Aspergillus fumigatus. I. Production, isolation, and biological properties.

Aspergillus fumigatus FO-1289, a soil isolate, was found to produce a series of novel inhibitors of acyl-CoA:cholesterol acyltransferase (ACAT). Four active compounds, named pyripyropenes A, B, C and D, were isolated from the fermentation broth of the producing strain by solvent extraction, silica gel column chromatography, ODS column chromatography and preparative HPLC. Pyripyropenes A, B, C and D show very potent ACAT inhibitory activity in an enzyme assay system using rat liver microsomes with IC50 values of 58, 117, 53 and 268 nM, respectively.

Animals↗