Ji-Dong Wang

Nonomuraea solani sp. nov., an actinomycete isolated from eggplant root (Solanum melongena L.)

A novel actinomycete, designated strain NEAU-Z6(T), was isolated from eggplant (Solanum melongena L.) root. Phylogenetic analysis based on the 16S rRNA gene sequence showed that strain NEAU-Z6(T) belonged to the genus Nonomuraea, with highest sequence similarity to Nonomuraea monospora PT 708(T) (98.83 %), Nonomuraea rosea GW 12687(T) (98.55 %) and Nonomuraea rhizophila YIM 67092(T) (98.02 %). Sequence similarities between strain NEAU-Z6(T) and other species of the genus Nonomuraea ranged from 97.94 % (Nonomuraea candida HMC10(T)) to 96.30 % (Nonomuraea wenchangensis 210417(T)). Key morphological, physiological and chemotaxonomic characteristics of strain NEAU-Z6(T) were congruent with the description of the genus Nonomuraea. The G+C content of the genomic DNA was 64.51 mol%. DNA-DNA relatedness and comparative analysis of physiological, biochemical and chemotaxonomic data allowed genotypic and phenotypic differentiation of strain NEAU-Z6(T) from closely related species. Thus, strain NEAU-Z6(T) represents a novel species of the genus Nonomuraea, for which the name Nonomuraea solani sp. nov. is proposed. The type strain is NEAU-Z6(T) ( = CGMCC 4.7037(T) = DSM 45729(T)).

Gene Replacement for the Generation of Designed Novel Avermectin Derivatives with Enhanced Acaricidal and Nematicidal Activities.

ABSTRACT Avermectin (AVM) and ivermectin (IVM) are potent pesticides and acaricides which have been widely used during the past 30 years. As insect resistance to AVM and IVM is greatly increasing, alternatives are urgently needed. Here, we report two novel AVM derivatives, tenvermectin A (TVM A) and TVM B, which are considered a potential new generation of agricultural and veterinary drugs. The molecules of the TVMs were designed based on structure and pharmacological property comparisons among AVM, IVM, and milbemycin (MBM). To produce TVMs, a genetically engineered strain, MHJ1011, was constructed from Streptomyces avermitilis G8-17, an AVM industrial strain. In MHJ1011, the native aveA1 gene was seamlessly replaced with milA1 from Streptomyces hygroscopicus. The total titer of the two TVMs produced by MHJ1011 reached 3,400 mg/liter. Insecticidal tests proved that TVM had enhanced activities against Tetranychus cinnabarinus and Bursaphelenchus xylophilus, as desired. This study provides a typical example of exploration for novel active compounds through a new method of polyketide synthase (PKS) reassembly for gene replacement. The results of the insecticidal tests may be of use in elucidating the structure-activity relationship of AVMs and MBMs.

A new prenylated indole derivative from endophytic actinobacteria Streptomyces sp. neau-D50

A new prenylated indole derivative 3-acetonylidene-7-prenylindolin-2-one (1) was isolated from the endophytic actinobacterium Streptomyces sp. neau-D50, together with four known hybrid isoprenoids, 7-isoprenylindole-3-carboxylic acid (2), 3-cyanomethyl-6-prenylindole (3), 6-isoprenylindole-3-carboxylic acid (4) and 7,4′-dihydroxy-5-methoxy-8-(γ,γ-dimethylallyl)-flavanone (5). The structures of these compounds were elucidated on the basis of extensive spectroscopic analysis and comparison with data from the literature. Compounds 1 and 2 demonstrated strong cytotoxic activities against human lung adenocarcinoma cell line A549 with an IC50 of 3.3 and 5.1 μg mL− 1, respectively, which are comparable to that of the positive control doxorubicin (4.2 μg mL− 1). Furthermore, compounds 1–4 exhibited potent antifungal activity against phytopathogenic fungi Colletotrichum orbiculare, Phytophthora capsici, Corynespora cassiicola and Fusarium oxysporum.

A novel macrolide compound from Streptomyces bingchenggensis: fermentation, isolation, structure elucidation and biological properties

A novel macrolide compound from Streptomyces bingchenggensis : fermentation, isolation, structure elucidation and biological properties

A new quinoline derivative with cytotoxic activity from Streptomyces sp. neau50

A new quinoline derivative, methyl 8-(3-methoxy-3-methylbutyl)-2-methylquinoline-4-carboxylate (1), was isolated from the endophytic strain Streptomyces sp. neau50, and the structure was elucidated by extensive spectroscopic analysis. Compound 1 showed cytotoxicity against human lung adenocarcinoma cell line A549 with an IC(50) value of 29.3 μg mL(-1).

Isolation and Identification of Novel Macrocyclic Lactones from Streptomyces avermitilis NEAU1069 with Acaricidal and Nematocidal Activity

Bioactivity-guided fractionation of Streptomyces avermitilis NEAU1069 fermentation broth was used to isolate and determine the chemical identity of bioactive constituents with acaricidal and nemotocidal activity. The structures of novel compounds 1 and 2 were determined on the basis of spectroscopic analysis, including 1D and 2D NMR as well as HRESI-MS, ESI-MS of spectrometry analysis, UV and IR spectroscopic analyses, and comparison with data from the literature. The acaricidal activities of the isolated compounds against adult mites and mite eggs were evaluated by mortality and unhatched eggs. The nematocidal activity of the isolated compounds against Caenorhabditis elegans was calculated according to the immobilized rates against the total number of tested nematodes. The results indicated that compounds 1 and 2 exhibited potent acaricidal activity against adult mites, with a mortality of >90% at a concentration of 30 microg/mL. However, compounds 1 and 2 showed only weak acaricidal activity against mite eggs, with unhatched mite egg rates of <60% at a concentration of 100 microg/mL. Compound 2, a hydroxylated derivative at C-23 of 1, possessed a high nematocidal activity against C. elegans, with an immobility of >90% at a concentration of 10 microg/mL. These results demonstrate that compounds 1 and 2, especially compound 2, have potential as pesticides with acaricidal and nematocidal activity.

Three new milbemycin derivatives from Streptomyces bingchenggensis.

In the continuing study of the chemical compositions of the strain Streptomyces bingchenggensis, three new milbemycin derivatives, milbemycin α31 (1), secomilbemycins C (2), and D (3), were isolated. Their structures were established on the basis of extensive spectroscopic analysis.

A novel macrocyclic lactone with insecticidal bioactivity from Streptomyces microflavus neau3.

A novel macrocyclic lactone (1) was isolated from the fermentation broth of Streptomycesmicroflavus neau3, and the structure was elucidated by extensive spectroscopic analysis. Compound 1 showed high acaricidal activity against adult mites (IC(50)=11.1 μg mL(-1)), and nematocidal activity against Caenorhabditis elegans (IC(50)=17.4 μg mL(-1)), especially the acaricidal activity against mite eggs with an IC(50) of 37.1 μg mL(-1), which was relative higher than that of the commercial acaricide and nematocide milbemycins A(3)/A(4).

Xiangella phaseoli gen. nov., sp. nov., a member of the family Micromonosporaceae

A novel endophytic actinomycete, designated strain NEAU-J5(T) was isolated from roots of snap bean (Phaseolus vulgaris L.). Comparative analysis of the 16S rRNA gene sequence indicated that NEAU-J5(T) is phylogenetically related to members of the family Micromonosporaceae. The whole-cell sugars were galactose, mannose and glucose. The predominant menaquinones were MK-9(H4) and MK-9(H6). The major fatty acids were C16:0, C18:0, C17:1ω7c, iso-C15:0 and C17:0. The phospholipids were phosphatidylmethylethanolamine, phosphatidylethanolamine, phosphatidylcholine, phosphatidylinositol and phosphatidylinositol mannoside. The DNA G+C content was 72.2 mol%. On the basis of the morphological and chemotaxonomic characteristics, phylogenetic analysis and characteristic patterns of 16S rRNA gene signature nucleotides, strain NEAU-J5(T) represents a novel species of a new genus within the family Micromonosporaceae, for which the name Xiangella phaseoli gen. nov., sp. nov. is proposed. The type strain of Xiangella phaseoli is strain NEAU-J5(T) (=CGMCC 4.7038(T)=DSM 45730(T)).

New β-class milbemycin compound from Streptomyces avermitilis NEAU1069 : fermentation, isolation and structure elucidation

New β-class milbemycin compound from Streptomyces avermitilis NEAU1069: fermentation, isolation and structure elucidation