RESUMEN
Improving the productivity of secondary metabolites is highly beneficial for the utilization of natural products. Here, we found that gene duplication of the goadsporin biosynthetic gene locus resulted in hyper-production. Goadsporin is a linear azole containing peptide that is biosynthesized via a ribosome-mediated pathway in Streptomyces sp. TP-A0584. Recombinant strains containing duplicated or triplicated goadsporin biosynthetic gene clusters produced 1.46- and 2.25-fold more goadsporin than the wild-type strain. In a surrogate host, Streptomyces lividans, chromosomal integration of one or two copies of the gene cluster led to 342.7 and 593.5 mg/L of goadsporin production. Expression of godI, a self-resistance gene, and of godR, a pathway-specific transcriptional regulator, under a constitutive promoter gave 0.79- and 2.12-fold higher goadsporin production than the wild-type strain. Our experiments indicated that a proportional relationship exists between goadsporin production per culture volume and the copy number of the biosynthetic gene cluster.
Asunto(s)
Biosíntesis de Péptidos/genética , Péptidos/genética , Metabolismo Secundario/genética , Streptomyces/metabolismo , Secuencia de Aminoácidos , Duplicación de Gen , Regulación Bacteriana de la Expresión Génica , Péptidos y Proteínas de Señalización Intercelular , Péptidos/metabolismo , Streptomyces/genéticaRESUMEN
Natural products produced by microorganisms are important starting compounds for drug discovery. Secondary metabolites, including antibiotics, have been isolated from different Streptomyces species. The production of these metabolites depends on the culture conditions. Therefore, the development of a new culture method can facilitate the discovery of new natural products. Here, we show that mycolic acid-containing bacteria can influence the biosynthesis of cryptic natural products in Streptomyces species. The production of red pigment by Streptomyces lividans TK23 was induced by coculture with Tsukamurella pulmonis TP-B0596, which is a mycolic acid-containing bacterium. Only living cells induced this pigment production, which was not mediated by any substances. T. pulmonis could induce natural-product synthesis in other Streptomyces strains too: it altered natural-product biosynthesis in 88.4% of the Streptomyces strains isolated from soil. The other mycolic acid-containing bacteria, Rhodococcus erythropolis and Corynebacterium glutamicum, altered biosynthesis in 87.5 and 90.2% of the Streptomyces strains, respectively. The coculture broth of T. pulmonis and Streptomyces endus S-522 contained a novel antibiotic, which we named alchivemycin A. We concluded that the mycolic acid localized in the outer cell layer of the inducer bacterium influences secondary metabolism in Streptomyces, and this activity is a result of the direct interaction between the mycolic acid-containing bacteria and Streptomyces. We used these results to develop a new coculture method, called the combined-culture method, which facilitates the screening of natural products.
Asunto(s)
Productos Biológicos/metabolismo , Ácidos Micólicos/metabolismo , Streptomyces/efectos de los fármacos , Actinomycetales/clasificación , Actinomycetales/aislamiento & purificación , Actinomycetales/metabolismo , Antibacterianos/aislamiento & purificación , Análisis por Conglomerados , Corynebacterium glutamicum/metabolismo , Medios de Cultivo/química , ADN Bacteriano/química , ADN Bacteriano/genética , ADN Ribosómico/química , ADN Ribosómico/genética , Datos de Secuencia Molecular , Filogenia , Pigmentos Biológicos/metabolismo , ARN Ribosómico 16S/genética , Rhodococcus/metabolismo , Análisis de Secuencia de ADN , Microbiología del Suelo , Streptomyces/clasificación , Streptomyces/aislamiento & purificaciónRESUMEN
A new cytotoxic compound, pterocidin, was isolated from the endophytic Streptomyces hygroscopicus TP-A0451, and the structure was determined on the basis of spectroscopic data. Pterocidin showed cytotoxicity against some human cancer cell lines with IC50 values of 2.9-7.1 microM.
Asunto(s)
Antibióticos Antineoplásicos/aislamiento & purificación , Pironas/aislamiento & purificación , Streptomyces/metabolismo , Antibióticos Antineoplásicos/química , Antibióticos Antineoplásicos/farmacología , Línea Celular Tumoral , Humanos , Pironas/química , Pironas/farmacologíaRESUMEN
In the screening of antitumor compounds from microbial secondary metabolites, myxochelin A was isolated from a culture broth of Nonomuraea pusilla TP-A0861. The absolute configuration was determined to be S by synthesizing both enantiomers from an L- or D-lysine derivative and comparing their specific rotations. Both enantiomers of myxochelin A showed remarkable inhibitory effects on the invasion of murine colon 26-L5 carcinoma cells at non-cytotoxic concentrations.
Asunto(s)
Actinobacteria/química , Antineoplásicos/química , Antineoplásicos/farmacología , Lisina/análogos & derivados , Actinobacteria/metabolismo , Actinobacteria/ultraestructura , Animales , Antineoplásicos/síntesis química , Antineoplásicos/aislamiento & purificación , Adhesión Celular/efectos de los fármacos , Línea Celular Tumoral , Movimiento Celular/efectos de los fármacos , Neoplasias del Colon/tratamiento farmacológico , Neoplasias del Colon/patología , Lisina/síntesis química , Lisina/química , Lisina/aislamiento & purificación , Lisina/farmacología , Ratones , Microscopía Electrónica de Rastreo , Resonancia Magnética Nuclear Biomolecular , Espectrometría de Masa Bombardeada por Átomos Veloces , EstereoisomerismoRESUMEN
In the screening for muscarinic M3 receptor binding inhibitors from microbial secondary metabolites, the extract of Nocardia nova JCM 6044 was found to be highly active. Bioassay-guided isolation led to the identification of three siderophores, nocardimicins G (1), H (2) and I (3). Their chemical structures were determined by spectroscopic analysis using NMR and MS. 1 and 2 inhibited the binding of tritium-labeled N-methylscopolamine to the muscarinic M3 receptor with Ki values of 0.44 microM and 0.37 microM, respectively, whereas 3 showed no inhibition at 10 microM. 1 and 2 also showed weak binding inhibitory activity to the M5 receptor but not to the M1, M2 and M4 receptors at 10 microM.
Asunto(s)
Nocardia/química , Receptor Muscarínico M3/antagonistas & inhibidores , Sideróforos/aislamiento & purificación , Ácidos Hidroxámicos/aislamiento & purificación , Ácidos Hidroxámicos/farmacología , Estructura Molecular , Antagonistas Muscarínicos/química , Antagonistas Muscarínicos/aislamiento & purificación , Antagonistas Muscarínicos/farmacocinética , Antagonistas Muscarínicos/farmacología , Oxazoles/aislamiento & purificación , Oxazoles/farmacología , Receptor Muscarínico M3/metabolismo , Sideróforos/química , Sideróforos/farmacologíaRESUMEN
The structure assigned to the antitumor antibiotic BU-4664L from Micromonospora sp. was revised to 5,10-dihydro-4,6,8-trihydroxy-10-(3,7,11-trimethyl-trans-2,trans-6,10-dodecatrienyl)-11H-dibenzo[b,e] [1,4]-diazepin-11-one based on the NMR analysis.
Asunto(s)
Antibióticos Antineoplásicos/química , Dibenzazepinas/química , Micromonospora/metabolismo , Sesquiterpenos/química , Antibióticos Antineoplásicos/biosíntesis , Espectroscopía de Resonancia Magnética , Conformación MolecularRESUMEN
The anchorage-independence of cells is closely related to their tumorigenicity. In the screening of inhibitors of anchorage-independent growth of tumor cells, anicemycin was isolated from the fermentation broth of an actinomycete strain TP-A0648. The producing strain was isolated from a leaf of Aucuba japonica collected in Toyama, Japan and identified as Streptomyces sp. based on the taxonomic data. The structure of anicemycin was elucidated as a new analog of spicamycin by NMR and MS analysis. Anicemycin inhibited the anchorage-independent growth of the human ovary cancer SKOV-3 cells with an IC50 of 0.015 microM about three times more potently than their anchorage-dependent growth.
Asunto(s)
Antibióticos Antineoplásicos/farmacología , Nucleósidos de Purina/farmacología , Streptomyces/metabolismo , Antibióticos Antineoplásicos/biosíntesis , Antibióticos Antineoplásicos/química , Proliferación Celular/efectos de los fármacos , Fenómenos Químicos , Química Física , Ensayos de Selección de Medicamentos Antitumorales , Fermentación , Humanos , Espectroscopía de Resonancia Magnética , Espectrometría de Masas , Microscopía Electrónica de Rastreo , Modelos Moleculares , Hojas de la Planta/microbiología , Nucleósidos de Purina/biosíntesis , Nucleósidos de Purina/química , Espectrofotometría Ultravioleta , Streptomyces/clasificación , Streptomyces/ultraestructura , Relación Estructura-Actividad , Células Tumorales CultivadasRESUMEN
An antifungal pentaene macrolide TPU-0043 was isolated from Streptomyces sp. TP-A0625. The absolute configuration of TPU-0043 was determined to be 2R-(n-butyl)-16-methyl-3S,5S,7S,9R,11R,13R,15S,26S, 27R-nonahydroxyoctacosa-16,18,20,22,24-pentaenoic acid, 27-lactone, by X-ray crystallography of its 13-p-bromobenzenesulfonyl derivative.
Asunto(s)
Antifúngicos/química , Macrólidos/química , Streptomyces/química , Antifúngicos/aislamiento & purificación , Macrólidos/aislamiento & purificación , Macrólidos/farmacología , Espectroscopía de Resonancia Magnética , PoliaminasRESUMEN
The cytoskeletal proteins, actin and myosin, play a central role in pollen tube growth. The pollen tube growth is inhibited by cytochalasin, which interferes with actin polymerization. In the screening of pollen tube growth inhibitors, clethramycin was found from the fermentation broth of an actinomycete strain TP-A0623. The producing strain was isolated from a root of Clethra barbinervis collected in Toyama, Japan and identified as Streptomyces hygroscopicus based on the taxonomic study. Clethramycin showed in vitro antifungal activity against yeast such as Candida albicans and C. glabrata with the MIC of 0.5 approximately 8 microg/ml, but weak activity against Gram-positive and negative bacteria (MIC > or = 64 microg/ml). Cytotoxicity of clethramycin was moderate and the IC50 was 57 microg/ml against HeLa cells and 120 microg/ml against WI-38 cells.
Asunto(s)
Antifúngicos , Flores , Animales , Antifúngicos/química , Antifúngicos/aislamiento & purificación , Antifúngicos/farmacología , Ácidos Grasos Insaturados/química , Ácidos Grasos Insaturados/aislamiento & purificación , Ácidos Grasos Insaturados/farmacología , Fermentación , Flores/efectos de los fármacos , Flores/crecimiento & desarrollo , Masculino , Ratones , Ratones Endogámicos ICR , Pruebas de Sensibilidad Microbiana , Streptomyces , Ésteres del Ácido Sulfúrico/química , Ésteres del Ácido Sulfúrico/aislamiento & purificación , Ésteres del Ácido Sulfúrico/farmacologíaRESUMEN
Two novel antibiotics, watasemycins A and B, were isolated from the fermentation broth of an actinomycete strain. The producing strain TP-A0597 was isolated from the seawater sample collected in Toyama Bay, Japan and identified as Streptomyces sp. based on the taxonomic study. The new antibiotics were obtained by solvent extraction and chromatographic purification and spectroscopic analyses identified that they were new analogs of thiazostatins. Watasemycin possesses a methyl group at 5'-position of thiazostatin instead of a hydrogen atom. Watasemycins showed antibiotic activity against Gram-positive and negative bacteria and yeast.
Asunto(s)
Antibacterianos/química , Streptomyces/metabolismo , Tiazoles/química , Antibacterianos/aislamiento & purificación , Antibacterianos/farmacología , Bacterias Gramnegativas/efectos de los fármacos , Bacterias Grampositivas/efectos de los fármacos , Espectroscopía de Resonancia Magnética , Pruebas de Sensibilidad Microbiana , Microscopía Electrónica de Rastreo , Agua de Mar/microbiología , Streptomyces/clasificación , Streptomyces/ultraestructura , Tiazoles/aislamiento & purificación , Tiazoles/farmacología , Tiazolidinas , Levaduras/efectos de los fármacosRESUMEN
A quinocycline antibiotic, kosinostatin, was isolated from the culture broth of Micromonospora sp. TP-A0468 along with isoquinocycline B. Structure of kosinostatin was determined to be the stereoisomer of isoquinocycline B regarding to the stereochemistry at the C-2' spiro carbon by NMR analysis. Kosinostatin isomerizes to isoquinocycline B through the inversion of the stereocenter at C-2'. Comparison of physico-chemical properties indicated that kosinostatin is presumably identical with quinocycline B isolated by CELMER et al. from Streptomyces aureofaciens.
Asunto(s)
Aminoglicósidos , Antibacterianos/química , Espectroscopía de Resonancia Magnética , Estructura Molecular , EstereoisomerismoRESUMEN
Pradimicin A (PRM), a mannose-binding antifungal antibiotic, induced the apotosis-like cell death in Saccharomyces cerevisiae. The nuclear breakage and DNA fragmentation were observed in yeast cells by DAPI and TUNEL staining after the treatment with PRM. Accumulation of reactive oxygen species (ROS) was also detected in PRM-treated yeast cells by staining with dichlorodihydrofluorescein diacetate. PRM-induced cell death and the accumulation of ROS were prevented by pretreating the yeast cells with a radical scavenger, N-acetylcysteine. These results indicate that PRM induces the apoptosis-like cell death in yeast through the generation of ROS.
Asunto(s)
Antraciclinas/farmacología , Antifúngicos/farmacología , Apoptosis , Saccharomyces cerevisiae/efectos de los fármacos , Antraciclinas/química , Antifúngicos/química , Fragmentación del ADN , Etiquetado Corte-Fin in Situ , Indoles , Lectina de Unión a Manosa/farmacología , Estructura Molecular , Especies Reactivas de Oxígeno/metabolismo , Saccharomyces cerevisiae/metabolismoRESUMEN
Kosinostatin, a quinocycline antibiotic was isolated from the culture broth of an actinomycete strain TP-A0468 along with isoquinocycline B. The producing strain was isolated from the seawater sample collected in Toyama Bay and identified as Micromonospora sp. based on the taxonomic study. Kosinostatin was obtained from the culture fluid by solvent extraction and ODS column chromatography. Kosinostatin inhibited the growth of Gram-positive bacteria strongly (MIC=0.039 microg/ml) and Gram-negative bacteria and yeasts moderately (MIC= 1.56 approximately 12.5 microg/ml). It showed cytotoxicity against various cancer cell lines with the IC50 of 0.02 approximately 0.6 microm and inhibited human DNA topoisomerase Ila with the IC50 of 3 approximately 10 microM.
Asunto(s)
Aminoglicósidos , Antibacterianos/aislamiento & purificación , Antibacterianos/farmacología , Antibióticos Antineoplásicos/aislamiento & purificación , Antibióticos Antineoplásicos/farmacología , Bacterias/efectos de los fármacos , Fermentación , Humanos , Pruebas de Sensibilidad Microbiana , Estereoisomerismo , Células Tumorales Cultivadas/efectos de los fármacosRESUMEN
Staurosporine is a representative member of indolocarbazole antibiotics. The entire staurosporine biosynthetic and regulatory gene cluster spanning 20-kb was cloned from Streptomyces sp. TP-A0274 and sequenced. The gene cluster consists of 14 ORFs and the amino acid sequence homology search revealed that it contains three genes, staO, staD, and staP, coding for the enzymes involved in the indolocarbazole aglycone biosynthesis, two genes, staG and staN, for the bond formation between the aglycone and deoxysugar, eight genes, staA, staB, staE, staJ, staI, staK, staMA, and staMB, for the deoxysugar biosynthesis and one gene, staR is a transcriptional regulator. Heterologous gene expression of a 38-kb fragment containing a complete set of the biosynthetic genes for staurosporine cloned into pTOYAMAcos confirmed its role in staurosporine biosynthesis. Moreover, the distribution of the gene for chromopyrrolic acid synthase, the key enzyme for the biosynthesis of indolocarbazole aglycone, in actinomycetes was investigated, and rebD homologs were shown to exist only in the strains producing indolocarbazole antibiotics.
Asunto(s)
Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Familia de Multigenes , Estaurosporina/biosíntesis , Streptomyces/genética , Streptomyces/metabolismo , Secuencia de Aminoácidos , Clonación Molecular , Regulación Bacteriana de la Expresión Génica , Datos de Secuencia Molecular , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismoRESUMEN
A novel shuttle integration cosmid vector (pTOYAMAcos), based on pKU402, and shuttle integration vectors (pTYM18 and pTYM19) were constructed for the cloning of actinomycete DNA and its heterologous expression. These vectors contain oriT of an IncP transmissible plasmid in order to transfer genes by conjugation from Escherichia coli to actinomycetes, and they also contain int derived from actinophage phiC31 in order to integrate site-specifically into the chromosomal DNA. pTOYAMAcos contains the lambdacos site to promote packaging of vectors containing 35 to approximately 45-kb DNA fragments into lambda particles. pTYM18 and pTYM19 contain kanamaycin and thiostrepton resistance genes, respectively, and have multiple cloning sites including EcoRI and HindIII sites, which are available for blue/white screening in E. coli. To demonstrate the utility of these vectors, we expressed the entire gene cluster for rebeccamycin biosynthesis from Lechevalieria aerocolonigenes using pTOYAMAcos and detected rebeccamycin production in transformed S. lividans. In addition, we demonstrated the utility of pTYM 19 in a gene-disruption complementation test. L. aerocolonigenes deltarebC strain, which is defective in rebeccamycin production because of a rebC deletion, was restored to rebeccamycin production by complemention by rebC cloned in pTYM 19.
Asunto(s)
Actinobacteria/genética , Clonación Molecular/métodos , Cósmidos/genética , Vectores Genéticos , Cromatografía Líquida de Alta Presión , Conjugación Genética , Escherichia coli/enzimología , Expresión Génica , Técnicas de Transferencia de Gen , Genes Bacterianos , Familia de Multigenes/genética , Plásmidos , Mapeo Restrictivo , Transformación BacterianaRESUMEN
Pradimicin is an antifungal antibiotic which induces apoptosis like cell death in the yeast Saccharomyces cerevisiae. Pradimicin-resistant mutants were isolated from the S. cerevisiae and the mutation points were analyzed. A point mutation of YPD1 that led to a substitution of the 74th glycine (Gly74) to cysteine (Cys) was identified in a mutant strain NH1. In S. cerevisiae, Ypd1 transfers a phosphoryl group from the sensor kinase Slnl to the response regulator Sskl which regulates a downstream MAP kinase in response to hyperosmotic stress. Gly74 is located in a three-residue reverse turn domain that connects two alpha-helices, one of which contains a histidine residue which is phosphorylated. In the reverse turn, glycine (relative position +10 to the active-site histidine) is highly conserved in Ypd1 and other histidine-containing phosphotransfer proteins. It was therefore suggested that the substitution of Gly74 to Cys altered the Ypd1 structure, which resulted in the resistance to pradimicin.
Asunto(s)
Antraciclinas/farmacología , Proteínas de Unión al ADN/genética , Mutación Puntual , Proteínas de Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/efectos de los fármacos , Antraciclinas/química , Secuencia de Bases , Cartilla de ADN , Farmacorresistencia Fúngica , Péptidos y Proteínas de Señalización Intracelular , Proteínas QuinasasRESUMEN
In the screening of novel antifungal compounds, yatakemycin was found in the culture broth of Streptomyces sp. TP-A0356. Yatakemycin was obtained by solvent extraction of the fermentation broth and chromatographic purification using ODS column and preparative HPLC. The structure of yatakemycin was elucidated by NMR and CID-MS/MS experiments as a novel antibiotic belonging to a family of CC-1065 and duocarmycins known to be DNA alkylating agents. Yatakemycin inhibited the growth of pathogenic fungi such as Aspergillus fumigatus and Candida albicans with the MIC values of 0.01-0.03 microg/ml, more potent than amphotericin B (MIC: 0.1-0.5 microg/ml) or itraconazole (MIC: 0.03-0.2 microg/ml). It also showed potent cytotoxicity against cancer cell lines with the IC50 of 0.01-0.3 microg/ml.
Asunto(s)
Antifúngicos/química , Indoles/química , Pirroles/química , Pirrolidinonas/química , Streptomyces/química , Antifúngicos/biosíntesis , Antifúngicos/aislamiento & purificación , Antifúngicos/farmacología , Aspergillus fumigatus/efectos de los fármacos , Candida albicans/efectos de los fármacos , Cromatografía en Gel , Cromatografía Líquida de Alta Presión , Duocarmicinas , Fermentación , Indoles/aislamiento & purificación , Indoles/farmacología , Pruebas de Sensibilidad Microbiana , Microscopía Electrónica de Rastreo , Estructura Molecular , Peso Molecular , Resonancia Magnética Nuclear Biomolecular , Pirroles/aislamiento & purificación , Pirroles/farmacología , Pirrolidinonas/aislamiento & purificación , Pirrolidinonas/farmacología , Espectrometría de Masa Bombardeada por Átomos Veloces , Espectrofotometría Infrarroja , Espectrofotometría Ultravioleta , Streptomyces/clasificación , Streptomyces/metabolismoRESUMEN
Aspergillus fumigatus TP-F0196 produces pseurotin A, synerazol and gliotoxin. Phenylalanine is a common biosynthetic precursor of these antibiotics. Feeding fluorophenylalanine to the culture induced the production of novel fluorinated analogs. These fluorinated antibiotics were obtained from the culture broth by solvent extraction and purified by chromatographies, and their antimicrobial and antitumor activities were investigated. Among the novel fluorinated analogs, 19- and 20-fluorosynerazols exhibited potent anti-angiogenic activity in the chorioallantoic membrane assay. In addition, 19-fluorosynerazol showed more potent cytocidal activity against several cancer cell lines than synerazol.
Asunto(s)
Antifúngicos/biosíntesis , Aspergillus fumigatus/metabolismo , Fluoruros/metabolismo , Gliotoxina/biosíntesis , Inmunosupresores/metabolismo , Inhibidores de la Angiogénesis/farmacología , Antifúngicos/farmacología , Bacterias/efectos de los fármacos , Línea Celular Tumoral , Cromatografía Líquida de Alta Presión , Ensayos de Selección de Medicamentos Antitumorales , Fermentación , Fluoruros/química , Gliotoxina/farmacología , Humanos , Inmunosupresores/farmacología , Espectroscopía de Resonancia Magnética , Espectrometría de Masas , Pruebas de Sensibilidad Microbiana , Pirrolidinonas/farmacologíaRESUMEN
A novel inhibitor for anchorage-independent growth of tumor cells was isolated from the culture broth of a fungal strain. The producing strain TP-F0213 was identified as Penicillium aurantiogriseum Dierckx based on the taxonomic study. The compound designated anicequol was obtained by solvent extraction, HP-20 and silica gel chromatographies and recrystallization. The planar structure was elucidated by NMR analysis to be 16-acetoxy-3,7,11-trihydroxyergost-22-en-6-one. The absolute configuration was determined by the X-ray analysis of 3,7-bis-p-bromobenzoyl derivative. The carbon skeleton of anicequol has the same absolute configuration as ergostane and the configurations of substituents are 3beta, 5alpha, 7beta, 11beta, 16beta and 24S. Anicequol inhibited the anchorage-independent growth of human colon cancer DLD-1 cells with the IC50 of 1.2 microM whereas the IC50 against anchorage-dependent growth was 40 microM.
Asunto(s)
Antibióticos Antineoplásicos , Penicillium/metabolismo , Antibióticos Antineoplásicos/biosíntesis , Antibióticos Antineoplásicos/química , Antibióticos Antineoplásicos/aislamiento & purificación , Antibióticos Antineoplásicos/farmacología , Adhesión Celular/fisiología , Neoplasias del Colon , Medios de Cultivo , Ergosterol/análogos & derivados , Ergosterol/biosíntesis , Ergosterol/química , Ergosterol/aislamiento & purificación , Ergosterol/farmacología , Fermentación , Humanos , Espectroscopía de Resonancia Magnética , Penicillium/clasificación , Penicillium/crecimiento & desarrollo , Células Tumorales Cultivadas/efectos de los fármacos , Células Tumorales Cultivadas/fisiologíaRESUMEN
We studied the effects of hibarimicins and hibarimicin-related compounds produced by Microbispora rosea subsp. hibaria [glycosides (hibarimicins A, B, C, D, E, G, H and I) and aglycon (hibarimicinone)] or compounds produced by its mutants [glycosides (HMP-P4 and -Y6), aglycons (HMP-P1 and -Y1) and shunt products (HMP-M1, M2, M3 and -M4)] on v-Src tyrosine kinase and growth and differentiation of human myeloid leukemia HL-60 cells. Among them, hibarimicin B was a strong and the most selective v-Src kinase inhibitor with differentiation inducing activity of HL-60 cells. Hibarimicin E similarly induced HL-60 cell differentiation but had no v-Src kinase inhibitory activity. Hibarimicinone was the most potent v-Src kinase inhibitor, although less selective, and did not induce differentiation of HL-60 cells. Hibarimicin B competitively inhibited ATP binding to the v-Src kinase, but hibarimicinone showed noncompetitive inhibition. These two compounds, however, showed similar mixed types of inhibition against a Src substrate binding to the v-Src kinase. Altogether, these results suggest that signaling molecules other than Src might be more important in the differentiation induction of HL-60 cells.