Sch 486058: a novel cyclic peptide of actinomycete origin.

The structure of a novel cyclic peptide (1) produced by Actinomycete sp. has been assigned on the basis of extensive NMR and mass spectral data.

Carbon-13 nuclear magnetic resonance spectra of D-homoannulated 17-hydroxypregnan-20-ones.

The 13C-NMR spectra of several groups of isomeric D-homoannulated 17 alpha-hydroxypregnan-20-ones have been recorded. The chemical shifts of the various carbon atoms have been correlated with the structures of the different isomers.

An unusual rearrangement product formed during production of mometasone furoate (Sch 32088).

The structure of an unusual rearrangement product obtained during the production of mometasone furoate (Sch 32088) was assigned on the basis of NMR and X-ray crystallography data.

An unusual dienone-phenol rearrangement product formed during the synthesis of mometasone furoate (Sch 32088).

The structure of an unusual dienone-phenol rearrangement product 4 obtained during the synthesis of mometasone furoate (Sch 32088) was assigned on the basis of NMR and x-ray crystallographic data. The mechanism of formation is discussed.

Hydrolysis and subsequent cyclization of etazolate hydrochloride and related compounds in aqueous solutions: application of PMR and mass spectrometry in accelerated stability studies.

The hydrolysis of etazolate hydrochloride, an inhibitor of cyclic nucleotide 3',5'-monophosphate phosphodiesterase that degrades cyclic adenosine 3',5'-monophosphate (cyclic AMP) to adenosine 5'-monophosphate, and related compounds was studied by PMR and mass spectrometry. The compounds underwent reversible acid-catalyzed hydrolysis in aqueous solutions at 60 degrees, followed by cyclization to a major and a minor product formed by independent pathways. Under the experimental conditions, the minor product was stable. The formation rate of the major product, 6-ethyl-1,6-dihydrodipyrazolo [3,4-b:3',4'-d] pyridin-3(2H)-one, was considerably greater than that of the minor component, 3-ethoxy-6-ethyl-1,6-dihydrodipyrazolo [3,4-b:3',4'-d] pyridine. For the 6-methyl analog of etazolate, the rate of methyl deuteration was considerably slower than the rate of cyclization.

Decomposition of alpha-hydroxyaryl ketones and characterization of some unusual products.

Alpha-Hydroxyaryl ketones such as 2-hydroxypropiophenone and 1-(2,4-difluorophenyl)-2-hydroxy-1-propanone, the key intermediates in the preparation of antifungal agents, decompose into oxidized, rearranged, and condensed products. These products were isolated and characterized. The possible mechanisms for the formation of the products are discussed.

Structure elucidation of Sch 20561, a cyclic dehydropeptide lactone--a major component of W-10 antifungal antibiotic.

Antibiotic W-10 is a fermentation complex produced by the bacterium Aeromonas sp. W-10. The cyclic dehydropeptide lactones Sch 20562 (1) and Sch 20561 (2) are the major components of this fermentation complex and are of biological interest in view of their unique structural features and potent antifungal activity. The chemical degradation studies that were utilized in the assignment of structure 2 for Sch 20561 are described here. The structure determination of 2 made use of the ozonolytic cleavage of the dehydropeptide units to form fragments that were sequenced by mass spectrometry. The cyclic dehydropeptide lactone Sch 20561 (2) was found to be the aglycone of Sch 20562 (1) and these two natural products were correlated by a chemical transformation involving the deglucosidation of 1 to form 2.

A family of novel macrocyclic lactones, the saccharocarcins produced by Saccharothrix aerocolonigenes subsp. antibiotica. II. Physico-chemical properties and structure determination.

Six novel tetronic acid analogs were isolated from the fermentation broth of the actinomycete Saccharothrix aerocolongenes subsp. antibiotica SCC1886. The structures of these saccharocarcins were determined by their spectral data, and chemical degradation. All six compounds are derived from two modified tetronic acid homologs which differ from other tetronic acids by having an ethyl or propyl side chain at C-23 and a methyl group at C-16. They are all characterized by a novel sugar-amide at C-17.

A novel tetracycline from Actinomadura brunnea. Fermentation, isolation and structure elucidation.

A novel tetracycline antibiotic, Sch 33256, was isolated from a culture broth of a new species of Actinomadura. The antibiotic was isolated by solvent extraction, Sephadex G-25 column chromatography and crystallization. The structure was determined by comparison of the spectra with that of chlortetracycline. Spectroscopic analysis of the compound yielded 2'-N-methyl-8-methoxychlortetracycline as the proposed structure.

A new tetracycline antibiotic from a Dactylosporangium species. Fermentation, isolation and structure elucidation.

An actinomycete identified as a Dactylosporangium sp. produces a new tetracycline, 4a-hydroxy-8-methoxychlortetracycline (Sch 34164). The addition of magnesium ions to complex fermentation media increased the antibiotic titers. Sch 34164 was isolated by solvent extraction and Sephadex G-25 column chromatography. The novel structure was proposed based on spectroscopic analysis. The shift of C-4a (35 to 77 ppm) and C-8 (140 to 163 ppm) in the 13C NMR as compared to chlortetracycline was indicative of the novel hydroxyl and methoxy substituents, respectively.

Sch 37137, a novel antifungal compound produced by a Micromonospora sp. Taxonomy, fermentation, isolation, structure and biological properties.

A new antifungal compound, Sch 37137, was isolated from the cultured broth of a Micromonospora sp., SCC 1792. Sch 37137 is structurally related to A 19009, a dipeptide previously discovered from a Streptomyces sp. The compound was weakly active against species of Candida and dermatophytes (mean MICs greater than or equal to 128 micrograms/ml) in Sabouraud dextrose, yeast-nitrogen and modified Eagles minimum essential media; however activity against Candida sp. (mean MICs greater than or equal to 12 micrograms/ml) and dermatophytes (mean MICs greater than or equal to 0.8 microgram/ml) significantly improved in MA medium.

Neurokinin receptor inhibitors: fermentation, isolation, physico-chemical properties, structure and biological activity.

Seven neurokinin (NK) receptor inhibitors SCH 60059 (1), SCH 60065 (2), SCH 64879 (3), SCH 60061 (4), SCH 60063 (5), SCH 60057 (7), and SCH 64878 (9) and two uncharacterized components 6 and 8, were isolated from the fermentation broth of a fungus taxonomically classified as an Acremonium sp. These compounds were isolated from the fermentation broth by ethyl acetate extraction. Purification and separation of the individual compounds were achieved by NK1 and NK2 assay-guided fractionation using gel filtration, reverse phase chromatography and HPLC. The NK active compounds were identified to be a family of polyhydroxy isoprenoid derivatives, including glycosylated members, by spectroscopic and degradation studies. Compounds 1 approximately 5 and 7 contain nine isoprene units connected in head to tail fashion and compound 9 contains fifteen isoprene units connected in a similar manner. All these compounds showed dual inhibition in NK1 and NK2 assays with IC50 values ranging from 2.5 approximately 11 microM in the NK1 assay and 6.8 approximately 16 microM in the NK2 assay.

A novel phenazine antifungal antibiotic, 1,6-dihydroxy-2-chlorophenazine. Fermentation, isolation, structure and biological properties.

A novel, solvent extractable, antibiotic complex has been purified from the fermentation broth of an unusual member of the genus Streptosporangium. Two of the major components were isolated from the complex by alumina column chromatography. One of the components was identified as a previously reported compound, 1,6-dihydroxyphenazine. The other component was a novel chlorine containing phenazine, 1,6-dihydroxy-2-chlorophenazine, which exhibited broad spectrum antifungal activity in vitro against dermatophytes and Candida.

A novel macrolactam-trisaccharide antifungal antibiotic. Taxonomy, fermentation, isolation, physico-chemical properties, structure elucidation and biological activity.

A novel secondary metabolite SCH 42282 (1), with antifungal activity was isolated from the fermentation broth of a soil actinomycete identified as a Microtetraspora sp. The active compound was separated from the fermentation broth by butanol extraction and purified on a silica gel column and by multi-coil counter current chromatography. The compound was identified as a novel macrolactam trisaccharide related to SCH 38518 (4). The structure was established by hydrolysis of the parent compound and spectroscopic studies of the acetate derivative. The compound is active against Candida spp. (Geometric Mean MIC's. 18 micrograms/ml) but less active SCH 42729 (3). the disaccharide (Geometric Mean MIC's, > or = 10.7 micrograms/ml and SCH 38518 (4), the monosaccharide (Geometric Mean Mic's, 3.8 micrograms/ml.

Novel fungal metabolites as cell wall active antifungals: fermentation, isolation, physico-chemical properties, structure and biological activity.

Two novel antifungal compounds, 1 (SCH 466457), and 2 (SCH 466456), active in a "cell wall" assay, were isolated from the fermentation broth of an unidentified fungus. The active compounds were separated from the broth filtrate by adsorption on a macroreticular resin and were purified on reverse phase HPLC. Detailed mass spectrometric and NMR experiments and degradative studies helped in elucidating the structures of these compounds. The compounds were identified to be peptides containing amino acids such as alanine, aminoisobutyric acid, proline, leucine, valine, glycine and a previously identified beta-keto acid, 2-methyl 3-oxotetradecanoic acid. (5) Both compounds were active against Candida, dermatophytes and Aspergillus (Geometric Mean MIC's, 8.9, 20 and 16 microg/ml, and 64, 128 and 23 microg/ml, respectively for 1 and 2).

A novel macrolactam-disaccharide antifungal antibiotic. Taxonomy, fermentation, isolation, physico-chemical properties, structure elucidation and biological activity.

A novel natural product (1), with antifungal activity was isolated from the culture broth of an actinomadurae. The active compound was separated from broth by n-butanol extraction and purified by silica gel and multicoil counter current chromatography. Physico-chemical data suggested the structure of this compound to be a novel macrolactam disaccharide related to Sch 38518 (3). The structure was determined by spectroscopic studies on the acetate derivative. It was active against Candida spp. (MIC's, 4 approximately 64 micrograms/ml) but less than the monosaccharide, Sch 38518 (MIC's, 1 approximately 16 micrograms/ml).

SCH 45752--an inhibitor of calmodulin-sensitive cyclic nucleotide phosphodiesterase activity.

A highly potent inhibitor of calmodulin-sensitive phosphodiesterase (PDE) activity was isolated from the culture broth of an unidentified fungal isolate, SCF-125. A chemically defined medium was developed for production of this compound. The PDE inhibitor was isolated from the fermentation filtrate by adsorption on a macro-reticular resin and further purified by gel filtration chromatography and reverse-phase HPLC. The major PDE inhibitor was identified as cephalochromin, a bis-naphthopyrone, by spectral data analysis. The compound, SCH 45752, inhibited calmodulin-sensitive PDE activities with IC50 values of 40-47 nM. It inhibited the activities of calmodulin-independent PDE and various protein kinases with higher IC50 values (2-40 microM). SCH 45752 does not appear to be a calmodulin antagonist. Furthermore, SCH 45752 affects smooth muscle contraction at a concentration of 30 microM; it potentiated the relaxing effect of sodium nitroprusside on carotid artery media contracted by histamine. Thus SCH 45752 is one of the most potent inhibitors of calmodulin-sensitive PDE activity known, and it is capable of exerting a pharmacological effect in at least one intact tissue model.

Inhibition of c-fos proto-oncogene induction by Sch 52900 and Sch 52901, novel diketopiperazine produced by Gliocladium sp.

Sch 52900 (1) and Sch 52901 (2), two new inhibitors of c-fos proto-oncogene induction, have been isolated from the fermentation of broth of the fungal culture (SCF-1168), Gliocladium sp. Along with compounds 1 and 2, a known compound verticillin A (3) was also obtained from the culture. Structure elucidation of 1 and 2, accomplished by analysis of spectral data in comparison with the data of 3, revealed both 1 and 2 were found to be closely related to the verticillin family of diketopiperazines. All three compounds prevented serum-stimulated transcription of the human c-fos promoter, using a fos/lac Z reporter gene assay, with IC50 values of 1.5, 18 and 0.5 microM of 1, 2 and 3, respectively. Northern analysis revealed the exposure of cells to compound 3 causes inhibition of both phorbol ester-induced c-fos induction of serum-induced JE induction in the absence of inhibiting RNA synthesis, as measured by [3H]uridine incorporation. There results suggest that this class of compounds exerts antitumor activity by blocking a signal transduction pathway that is common to and necessary for the induction of at least a subset of immediate early genes involved in cell proliferation.

A novel class of platelet activating factor antagonists from Phoma sp.

Four novel platelet activating factor (PAF) antagonists, Sch 47918, Sch 49026, Sch 49027 and Sch 49028, were isolated from the fermentation broth of the fungal culture, Phoma sp. (ATCC 74077). The structures of these compounds were elucidated by spectroscopic methods. The structure and stereochemistry of the first isolated component, Sch 47918, were confirmed by single crystal X-ray diffraction analysis. Sch 49028, the most active component, was found to inhibit PAF-induced human platelet aggregation in vitro with an IC50 of 1.26 microM. However, this compound was inactive in vivo at 5 mg/kg, iv against PAF-induced bronchospasm in guinea pigs.

A family of depsi-peptide fungal metabolites, as selective and competitive human tachykinin receptor (NK2) antagonists: fermentation, isolation, physico-chemical properties, and biological activity.

Four tachykinin (NK2) receptor inhibitors, SCH 378161 (1), SCH 217048 (2), SCH 378199 (3), and SCH 378167 (4) were isolated from the fermentation broth of a taxonomically unidentified fungus. These compounds were separated from the fermentation broth by ethyl acetate extraction. Purification and separation of the individual compounds were achieved by NK2 assay-guided fractionation using gel filtration, reverse phase chromatography and HPLC. They were identified to be a family of depsipeptides by spectroscopic and degradation studies. Compounds 1 and 3 contain proline and differ as an amide and acid whereas 2 and 4 contain pipecolic acid and differ in being an amide and acid. All of these compounds contain an identical hydroxy acid. They are selective NK2 inhibitors with Ki values ranging from 27-982 nM and demonstrate no activity at 10 microM in the NK1 and NK3 assays. In addition, compounds 1 and 2 inhibited NKA-induced increases in the concentration of intracellular Ca2+, [Ca2+]i, in a CHO cell expressing the human NK2 receptor; this inhibition was competitive in nature with pA2 values of 7.2 and 7.5, respectively. These data demonstrate that these natural products are selective and competitive receptor antagonists of the human NK2 receptor.