(1)H and (13)C NMR assignments of eight nitrogen containing compounds from Nocardia alba sp.nov (YIM 30243(T))

An unprecedented new natural product named nocarsin A (1), 5H-4a,6,7a-triazacyclopenta[cd]indene-5,7(6H)-dione (1), together with seven known compounds lumichrome (2), cyclo (L-Leu-L-Tyr) (3), cyclo (L-Ala-L-Ile) (4), cyclo (L-Ala-L-Leu) (5), cyclo (L-Val-L-Ala) (6), 5-methyluracil (7) and uracil (8), was isolated from Nocardia alba sp.nov (YIM 30243(T)), which was isolated from a soil sample collected from Yunnan Province, P. R. China. NMR techniques including COSY, HSQC, ROESY, and HMBC were used to elucidate the structures of these compounds. We report the unambiguous assignments of the (1)H and (13)C NMR spectra of the new compound nocarsin A (1).

Nocardia amamiensis sp. nov., isolated from a sugar-cane field in Japan

An actinomycete, strain TT 00-78T, was isolated from soil from a sugar-cane field on Amami Island in Japan, using an SDS/yeast extract pre-treatment method, and the taxonomy was studied using a polyphasic approach. The chemotaxonomic and morphological characterizations clearly demonstrated that the strain belongs to the genus Nocardia. 16S rRNA gene sequencing studies showed that the strain was closely related to the type strains of Nocardia pneumoniae (98.6 %), Nocardia araoensis (98.1 %), Nocardia arthritidis (97.9 %) and Nocardia beijingensis (97.7 %). However, the results of DNA–DNA hybridization and physiological and biochemical tests showed that strain TT 00-78T could be differentiated from its closest phylogenetic relatives both genotypically and phenotypically. Therefore this strain represents a novel species of the genus Nocardia, for which the name Nocardia amamiensis sp. nov. is proposed. The type strain is TT 00-78T (=NBRC 102102T=DSM 45066T=KCTC 19208T).

Nocardia terpenica sp. nov., isolated from Japanese patients with nocardiosis

Two bacterial strains isolated from different hospitals in Japan were subjected to a polyphasic analysis. Strains IFM 0406 and IFM 0706T, producers of novel terpenoid antibiotics, were found to have morphological, biochemical, physiological and chemotaxonomic properties consistent with their classification in the genus Nocardia, except for the presence of MK-8(H4) as one of the predominant menaquinones in addition to the major menaquinone MK-8(H4ω-cyc). The 16S rRNA gene sequence similarity of strains IFM 0406 and IFM 0706T was 99.9 %, and the closest members of Nocardia to these strains were the type strains of Nocardia nova and Nocardia mexicana, showing similarity of 97.5 and 97.1 %, respectively. Based on their characteristic phenotypic and phylogenetic properties, a novel species of the genus Nocardia, Nocardia terpenica sp. nov. is proposed for the two strains. The type strain is IFM 0706T (=JCM 13033T=DSM 44935T=NBRC 100888T).

Nocardichelins A and B, siderophores from Nocardia strain acta 3026

An actinomycete, strain Acta 3026, isolated from mangrove soil was characterized and found to belong to the genus Nocardia. The strain produces two new cytotoxic metabolites, nocardichelins A (1) and B (2). Each of the compounds strongly inhibited human cell lines from gastric adenocarcinoma, breast carcinoma, and hepatocellular carcinoma with GI50 values in a low micromolar to nanomolar range. The structural characterization of the compounds was performed by mass spectrometry and NMR spectroscopy. The nocardichelins represent a new group of siderophores that combine the structural elements of mycobactin-type siderophores from mycobacteria and hydroxamate-type siderophores (desferrioxamine B) produced by streptomycetes. The chromazurol S assay, characteristic for iron(III) complexation, was positive, confirming the role as a siderophore.

Nocardia acidivorans sp. nov., isolated from soil of the island of Stromboli

A Gram-positive, non-spore-forming bacterium (strain GW4-1778T) was isolated from soil of the Italian island of Stromboli. 16S rRNA gene sequence similarity studies showed that strain GW4-1778T is a member of the genus Nocardia, most closely related to Nocardia pseudobrasiliensis (GenBank accession no. DQ659914; 98.6 %), Nocardia nova (Z36930; 98.6 %), Nocardia niigatensis (AB092563; 98.4 %), Nocardia jiangxiensis (AY639902; 98.0 %), Nocardia uniformis (Z46752; 98.0 %) and Nocardia miyunensis (AY639901; 97.8 %). Strain GW4-1778T could be distinguished from any other established Nocardia species by sequence similarity values of less than 97.5 %. Strain GW4-1778T exhibited a quinone system with the predominant compound MK-8 (H4, ω-cycl) (99.5 %) and traces of MK-8 (H4), characteristic for the genus Nocardia. The polar lipid profile of strain GW4-1778T consisted of the predominant compound diphosphatidylglycerol, moderate amounts of phosphatidylethanolamine, phosphatidylinositol, two phosphatidylinositol mannosides, a unknown polar lipid and trace amounts of two unknown lipids and the major fatty acids were C15 : 0, C16 : 0, C17 : 1 ω8c and 10-methyl C17 : 0. The results of DNA–DNA hybridizations and physiological and biochemical tests allowed genotypic and phenotypic differentiation of strain GW4-1778T from related species with 16S rRNA gene similarities of >97.5 %. Therefore, strain GW4-1778T merits species status, for which the name Nocardia acidivorans sp. nov. is proposed, with the type strain GW4-1778T (=CCUG 53410T=CIP 109315T=DSM 45049T).

Thiols in nitric oxide synthase-containing Nocardia sp. strain NRRL 5646

Mycothiol (MSH) [1-D-myo-inosityl-2-(N-acetyl-l-cysteinyl)amido-2-deoxy-alpha-D-glucopyranoside], isolated as the bimane derivative, was established to be the major thiol in Nocardia sp. strain NRRL 5646, a species most closely related to Nocardia brasiliensis strain DSM 43758(T). Thiol formation and detection of MSH-dependent formaldehyde dehydrogenase activity in cell extracts are relevant to the possible modulation of nitric oxide toxicity generated by strain NRRL 5646.

Isolation and identification of 2alpha,25-dihydroxyvitamin D3, a new metabolite from Pseudonocardia autotrophica 100U-19 cells incubated with Vitamin D3

Pseudonocardia autotrophica converted Vitamin D(3) to 25-hydroxyvitamin D(3) and 1alpha,25-dihydroxyvitamin D(3). The hydroxylation of Vitamin D(3) with P. autotrophica was enhanced by the addition of cyclodextrin. In this microbial hydroxylation, a new Vitamin D(3) metabolite was observed in the reaction mixture of P. autotrophica and Vitamin D(3), and was isolated in a pure form by several steps of chromatography. The structure of the new metabolite was determined to be 2alpha,25-dihydroxyvitamin D(3) by UV, NMR and mass spectroscopic analyses. Biological evaluation of the new metabolite was conducted by means of several experiments.

Stability study on the nitrile hydratase of Nocardia sp. 108: from resting cell to crude enzyme preparation

In recent years, nitrile hydratases (NHases) have drawn increasing attentions due to their critical roles in organic synthesis. In present paper, extensive investigation on the stability and activity of the NHase from Nocardia sp. 108, which is succeed in the industrial application in China, were conducted by the bioconversion of acrylonitrile to acrylamide in a batch manner. Cultivation study demonstrated that biosynthesis of NHase changed significantly with culture time, and the optimal NHase biosynthesis phase was 45 h after inoculation with NHase activity of 1209.8 U/g of biomass. Stability study indicated that crude enzyme preparation both exhibit a good stability when exposed to the pH 7.2 tris-HCl buffer at 4 degrees C for 4 h.

[Peculiarities of cell wall ultrastructure of Nocardia dassonvilei]

Peculiarities of cell wall building and chemical content of Nocardia dassonvilei have been studied in conditions of culture growth and development. It has been established that according to the phases of actinomyces a mass of cell wall changes. In particular, it is maximal in logarithmic phase and minimal - in stationary phase. In the phase of dying an insignificant increase of cell wall is noted. It appears to be a result of the increase of amino acid content in peptic fraction of peptide-glycane in this phase. At the same time it has been established that according to the growth phases, in cell wall of the studied actynomyces the amount of teihoic acid appears to be a changeable value. In particular, it decreases from logarithmic to the phase of dying. The content of cell wall free polysaccharides also changes; their synthesis begins in logarithmic phase, reaches to maximum in stationary phase and is minimal in the phase of dying. According to the results of our investigations it has been established that chemical content of Nocardia dassonvilei cell wall is qualitatively stable in the dynamics of culture growth.

Nocardimicins G, H and I, siderophores with muscarinic M3 receptor binding inhibitory activity from Nocardia nova JCM 6044

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.

Nocardimicins A, B, C, D, E, and F, siderophores with muscarinic M3 receptor inhibiting activity from Nocardia sp. TP-A0674

In the screening for muscarinic M3 receptor binding inhibitors from microbial secondary metabolites, the extract of Nocardia sp. TP-A0674 was found to be highly active. Bioassay-guided fractionation of it led to the isolation of six new siderophores, nocardimicins A (1), B (2), C (3), D (4), E (5), and F (6), as active principles. Their chemical structures were determined by spectroscopic and degradation analysis. Of these congeners, nocardimicin B (2) inhibited the binding of tritium-labeled N-methylscopolamine to the muscarinic M3 receptor most potently with a Ki value of 0.13 microM. Compound 2 showed more selective activity to M3 and M4 receptors than other subtypes.

Nocardia elegans sp. nov., a member of the Nocardia vaccinii clade isolated from sputum

Two bacterial isolates from the sputa of a patient with a pulmonary infection were subjected to a polyphasic taxonomic study. Chemotaxonomic investigations revealed the presence of cell-wall chemotype IV and mycolic acids consistent with the profile for the genus Nocardia. Comparative 16S rRNA gene sequencing showed that these isolates constitute a distinct subline within the genus Nocardia, displaying 99·6–95·5 % sequence similarities with established species. However, DNA–DNA hybridization studies demonstrated unambiguously that the isolates are genealogically distinct from closely related species, namely Nocardia veterana and Nocardia africana, which show high levels of 16S rRNA sequence similarity (99·2 and 99·6 % sequence similarity, respectively). On the basis of both phenotypic and phylogenetic evidence, it is proposed that these isolates be classified as a novel species of the genus Nocardia, for which the name Nocardia elegans sp. nov. is proposed. The type strain is IMMIB N-402T (=CCUG 50200T=CIP 108553T).

Nocardia polyresistens sp. nov

A novel actinomycete strain YIM 33361T was isolated from a soil sample collected from Yunnan, China. Comparative 16S rRNA gene sequencing showed that the strain constituted a distinct subclade within the genus Nocardia, displaying more than 3 % sequence divergence from established species. Based on its morphological, chemotaxonomic, phenotypic and genotypic characteristics, strain YIM 33361T (=CCTCC AA 204004T=KCTC 19027T) is proposed as the type strain of a novel species, Nocardia polyresistens sp. nov.

Nocardia shimofusensis sp. nov., isolated from soil, and Nocardia higoensis sp. nov., isolated from a patient with lung nocardiosis in Japan

Three actinomycete strains isolated from soils and one strain isolated from a patient with lung nocardiosis in 1999 and 2001 in Japan have been provisionally assigned to the genus Nocardia on the basis of morphological criteria. These isolates were further investigated to determine their specific taxonomic status. Detailed chemotaxonomic characterization and 16S rRNA gene sequence analysis of these isolates confirmed that they belong to the genus Nocardia. The 16S rRNA gene sequences of the four strains were most similar to that of Nocardia farcinica. However, the sequence similarity values between these four strains and N. farcinica were <98.9 %. These four strains were susceptible to 5-fluorouracil, and they have the ability to decompose urea, which is a very characteristic trait. Furthermore, DNA-DNA relatedness data revealed that IFM 10311(T), IFM 10312 and IFM 10313 comprise a single novel species of Nocardia, that IFM 10084(T) represents another novel species of Nocardia and that these two novel species could be distinguished from N. farcinica. The names Nocardia shimofusensis sp. nov. and Nocardia higoensis sp. nov. are proposed, with IFM 10311(T) (=NBRC 100134(T)=JCM 12122(T)=DSM 44733(T)) and IFM 10084(T) (=NBRC 100133(T)=JCM 12121(T)=DSM 44732(T)) as the respective type strains.

NMR spectroscopic analysis of new spiro-piperidylrifamycins

New spiro-piperidylrifamycin derivatives are presented. These compounds were synthesized from the reaction of 3-amino-4-iminorifamycin S and enantiomerically pure 4-piperidones, which generate diasteroisomeric rifabutin analogues with a new stereocentre at the spiranic carbon. The (1)H and (13)C NMR spectra of these new compounds, and also the configuration of the new stereogenic centres, were assigned using 2D NMR spectroscopic techniques. A preliminary study of the (1)H and (13)C NMR spectra of the starting compounds rifamycin S, 3-amino-4-iminorifamycin S and the related rifabutin was also carried out and as a result, their previously published (13)C NMR data were corrected.

Nocardia aobensis Sp. Nov., isolated from patients in Japan

Five clinical isolates, strains IFM 0137, 0372(T), 0496, 0556, and 0952, were provisionally assigned to the genus Nocardia based on morphological criteria. Nearly complete 16S rDNA sequences were determined for these strains. These data showed that they are most similar to that of Nocardia africana, Nocardia cerradoensis and Nocardia veterana. However, DNA-DNA relatedness data showed that the five strains were of a single species and were distinguishable from N. africana, N. cerradoensis and N. veterana. Therefore, these strains represent a new species within the genus Nocardia. The designation of these five strains is Nocardia aobensis sp. nov. The type strain is IFM 0372(T) (=NBRC 100429(T)=JCM 12352(T)=DSM 44805(T)).

Brasilibactin A, a cytotoxic compound from actinomycete Nocardia brasiliensis

A new cytotoxic compound, brasilibactin A (1), has been isolated from the actinomycete Nocardia brasiliensis IFM 0995, and the structure was elucidated on the basis of spectroscopic data and chemical means.

Nocardia pigrifrangens sp. nov., a novel actinomycete isolated from a contaminated agar plate

A polyphasic study was undertaken to establish the taxonomic position of an actinomycete strain isolated from a contaminated agar plate. The strain, designated 7031T, had morphological and chemotaxonomic properties typical of the genus Nocardia. An almost-complete 16S rRNA gene sequence determined for the strain was aligned with available sequences for nocardiae, and phylogenetic trees were inferred using three tree-generating algorithms. Strain 7031T clustered with the type strains of Nocardia carnea and Nocardia flavorosea, showing low 16S rRNA gene sequence similarities to these species (97.2 and 97.5 %, respectively). The strain was also distinguished from the closest species by a range of phenotypic properties. It is proposed that the strain be recognized as a novel species of Nocardia, Nocardia pigrifrangens sp. nov., the type strain of which is 7031T (= AS 4.1808T = JCM 11884T).

Brasilicardins B–D, new tricyclic terpernoids from actinomycete Nocardia brasiliensis

Three new tricyclic terpenoids, brasilicardins B-D (2-4), were isolated together with brasilicardin A (1), a potent immunosuppressive compound, from the cultured broth of a pathogenic actinomycete Nocardia brasiliensis IFM0406, and the structures and stereochemistry were determined by spectroscopic data and a single crystal X-ray diffraction analysis. The immunosuppressive and cytotoxic activities of 2-4 were examined in the comparison with 1.

Transvalencin A, a Thiazolidine Zinc Complex Antibiotic Produced by a Clinical Isolate of Nocardia transvalensis: II.Structure Elucidation

A novel antifungal antibiotic, transvalencin A, is produced by Nocardia transvalensis IFM 10065 isolated from a patient with actinomycotic mycetoma in Japan. The antibiotic structure was elucidated using NMR, mass spectrometric investigations, and X-ray crystallographic analysis. Transvalencin A is a 1:1 complex of a zinc and an organic acid with a phenolic substituent. Transvalencin A is comprised of o-substituted p-chlorophenol, tetrasubstituted oxazoline, disubstituted thiazolyl-N-methylthiazolidine and monosubstituted N-methylthiazolidine.

Kribbella antibiotica sp. nov., a Novel Nocardioform Actinomycete Strain Isolated from Soil in Yunnan, China

A novel nocardioform actinomycete strain YIM 31530T was isolated from a soil in Yunnan, China. Based on the results of phenotypic characteristics, phylogenetic studies and DNA-DNA hybridization results, strain YIM 31530T should be assigned to a new species of the genus Kribbella, for which the name Kribbella antibiotica sp. nov. is proposed. The type strain is YIM 31530T(= CCTCC AA001021T = DSM 15501T). The GenBank accession number for the sequence reported in this paper is AY082063.

Transvalencin A, a Thiazolidine Zinc Complex Antibiotic Produced by a Clinical Isolate of Nocardia transvalensis: I.Taxonomy, Fermentation, Isolation and Biological Activities

A new thiazolidine-type antibiotic with zinc in its structure, designated transvalencin A, was isolated from Nocardia sp. IFM 10065, a clinical isolate from a patient with actinomycotic mycetoma. The strain was identified as Nocardia transvalensis based on its morphological, phenotypic and phylogenetic characteristics. Transvalencin A showed antimicrobial activity against fungi such as Trichophyton mentagrophytes and Cryptococcus neoformans. The antibiotic is also active against Gram-positive bacteria such as Micrococcus luteus. We observed higher activity for fungi in an acidic medium than in a neutral medium.

Nocathiacins, new thiazolyl peptide antibiotics from Nocardia sp. I. Taxonomy, fermentation and biological activities

Thiazolyl peptide antibiotics, nocathiacin I, II and III, were identified in a culture of Nocardia sp. WW-12651 (ATCC 202099). They exhibit potent in vitro activity (ng/ml) against a wide spectrum of gram-positive bacteria, including multiple-drug resistant pathogens such as methicillin-resistant Staphylococcus aureus (MRSA), multi-drug resistant Enterococcus faecium (MREF) and fully penicillin-resistant Streptococcus pneumoniae (PRSP), and demonstrate excellent in vivo efficacy in a systemic Staphylococcus aureus infection mice model.

Nocathiacins, new thiazolyl peptide antibiotics from Nocardia sp. II. Isolation, characterization, and structure determination

A new group of thiazolyl peptide antibiotics, the nocathiacins, was isolated from cultured broth of Nocardia sp. The major analogs nocathiacins I-III (1-3) were purified using silica gel and Sephadex LH-20 chromatography techniques. The structures of nocathiacins I-III were determined by spectroscopic (2D-NMR, MSn) methods, and share structural similarities to glycothiohexide-alpha (4).