Description of Streptomyces siderophoricus sp. nov., a promising nocardamine-producing species isolated from the rhizosphere soil of Mangifera indica.

An actinomycete, designated strain CH9-7T, was isolated from the rhizosphere soil of Mangifera indica. The morphological and chemotaxonomic properties, such as the production of spiral spore chains and the presence of LL-diaminopimelic acid in the peptidoglycan, showed that it belongs to the genus Streptomyces. Based on the 16S rRNA gene analysis, it was confirmed that strain CH9-7T was a member of the genus Streptomyces and revealed 99.9% 16S rRNA gene sequence similarity to its closest relative strains, Streptomyces lydicus NBRC 13058 T and Streptomyces chattanoogensis NBRC 12754 T. Although the strain showed high 16S rRNA gene sequence similarity values, however, genome relatedness indexes exhibited that the average nucleotide identity based on the MUMmer (ANIm) algorithm, the average amino acid identity (AAI), and the digital DNA-DNA hybridization values between strain CH9-7T and its closest phylogenomic relatives were below the threshold values for delineation of a novel species, (ANIm ranging from 87.5 to 88.6, AAI ranging from 80.6 to 84.6, and dDDH ranging from 28.4 to 31.7), respectively. A taxonomic position of strain CH9-7T in the phylogenomic tree showed that the closest relative strain was S. lydicus NBRC 13058 T. The comparative phenotypic studies between strain CH9-7T and its closest relatives revealed that strain CH9-7T could be classified as a novel species of the genus Streptomyces. Thus, the name Streptomyces siderophoricus sp. nov. is proposed for the strain. The type strain is CH9-7T ( = TBRC 17833 T = NBRC 116426 T). The chemical investigation led to the isolation of four known compounds (compounds 1-4). Among these compounds, compound 1 was identified to be nocardamine, a promising bioactive substance.

Pradimicin U, a promising antimicrobial agent isolated from a newly found Nonomuraea composti sp. nov.

Pradimicin U is a new dihydrobenzo[a]naphthacenequinone compound found to be active on a screen designed to investigate compounds with antimicrobial activity, produced by the actinomycete designated strain FMUSA5-5T. The strain was isolated from a bio-fertilizer of Musa spp. collected from Suphanburi province, Thailand. The chemotaxonomic characteristics and 16S rRNA gene analysis revealed that strain FMUSA5-5T is a member of the genus Nonomuraea. Low genome-based taxonomic criteria, average nucleotide identity (ANI) (82.8-88.3%), average amino-acid identity (AAI) (79.4-87.3%), and digital DNA-DNA hybridization (dDDH) (29.5-38.5%) values and several phenotypic differences between strain FMUSA5-5T and its closest type strains of the genus Nonomuraea indicated that strain FMUSA5-5T represents a novel species of the genus Nonomuraea and the name Nonomuraea composti sp. nov. is proposed for the strain. The crude extract from the culture broth of strain FMUSA5-5T displayed promising antimicrobial activity against several pathogens and led to the isolation of a novel secondary metabolite, pradimicin U. Interestingly, this compound displayed a broad spectrum of biological activities such as antimalarial activity against Plasmodium falciparum K1 (IC50 value = 3.65 µg/mL), anti-Mycobacterium tuberculosis H37Ra (MIC value = 25.0 µg/mL), anti-Alternaria brassicicola BCC 42724 (MIC value = 25.0 µg/mL), anti-Bacillus cereus ATCC 11778 and anti-Staphylococcus aureus ATCC 29213 (MIC values = 6.25 and 1.56 µg/mL, respectively). Moreover, the compound possessed strong anti-human small cell lung cancer (NCI-H187) activity with IC50 value of 5.69 µg/mL, while cytotoxicity against human breast cancer (MCF-7) and Vero cells was very weak (IC50 values of 52.49 and 21.84 µg/mL, respectively).

Streptomyces telluris sp. nov., a promising terrestrial actinobacterium with antioxidative potentials.

An actinomycete strain, AA8T, which produced a long straight chain of spores (verticillati type), was isolated from the rhizosphere soil of Mangifera indica in Bangkok, Thailand. A polyphasic taxonomic study was carried out to establish the taxonomic position of the strain. Strain AA8T formed a tight taxonomic position in the 16S rRNA gene tree with Streptomyces roseifaciens MBT76T. In contrast, the genome-based taxonomic analysis showed that strain AA8T shared low average nucleotide identity-BLAST (94.1%), the digital DNA-DNA hybridization (58.2%), and the average amino acid identity (93.6%) values with S. roseifaciens MBT76T. Moreover, a combination of physiological and biochemical properties indicated that strain AA8T was distinguished from all Streptomyces species with effectively published names. Strain AA8T, therefore, represents a novel species of Streptomyces, and the name Streptomyces telluris is proposed for the strain. The type strain is AA8T (= TBRC 8483T = NBRC 113461T). The chemical investigation led to the isolation of nine known compounds (compounds 1-9). Among these compounds, compound 7 (3,4-dihydroxybenzaldehyde) possesses strong antioxidant activity equal to ascorbic acid, a powerful antioxidative agent.

New insights into the neuroprotective and beta-secretase1 inhibitor profiles of tirandamycin B isolated from a newly found Streptomyces composti sp. nov.

Tirandamycin (TAM B) is a tetramic acid antibiotic discovered to be active on a screen designed to find compounds with neuroprotective activity. The producing strain, SBST2-5T, is an actinobacterium that was isolated from wastewater treatment bio-sludge compost collected from Suphanburi province, Thailand. Taxonomic characterization based on a polyphasic approach indicates that strain SBST2-5T is a member of the genus Streptomyces and shows low average nucleotide identity (ANI) (81.7%), average amino-acid identity (AAI) (78.5%), and digital DNA-DNA hybridization (dDDH) (25.9%) values to its closest relative, Streptomyces thermoviolaceus NBRC 13905T, values that are significantly below the suggested cut-off values for the species delineation, indicating that strain SBST2-5T could be considered to represent a novel species of the genus Streptomyces. The analysis of secondary metabolites biosynthetic gene clusters (smBGCs) in its genome and chemical investigation led to the isolation of TAM B. Interestingly, TAM B at 20 µg/mL displayed a suppressive effect on beta-secretase 1 (BACE1) with 68.69 ± 8.84% inhibition. Molecular docking simulation reveals the interaction mechanism between TAM B and BACE1 that TAM B was buried in the pocket of BACE-1 by interacting with amino acids Thr231, Asp 228, Gln73, Lys 107 via hydrogen bond and Leu30, Tyr71, Phe108, Ile118 via hydrophobic interaction, indicating that TAM B represents a potential active BACE1 inhibitor. Moreover, TAM B can protect the neuron cells significantly (% neuron viability = 83.10 ± 9.83% and 112.72 ± 6.83%) from oxidative stress induced by serum deprivation and Aß1-42 administration models at 1 ng/mL, respectively, without neurotoxicity on murine P19-derived neuron cells nor cytotoxicity against Vero cells. This study was reportedly the first study to show the neuroprotective and BACE1 inhibitory activities of TAM B.

Development of Jelly Loaded with Nanogel Containing Natural L-Dopa from Mucuna pruriens Seed Extract for Neuroprotection in Parkinson's Disease.

The first line therapy of patients with Parkinson's disease, a neurodegenerative disorder caused by the degeneration of dopaminergic neurons, is levodopa (L-dopa) given orally. Recently, the presence of natural L-dopa in the seed of Mucuna pruriens, a tropical legume in the Fabaceae family, was reported and it showed superior efficiency compared with synthetic L-dopa. Therefore, this study aimed to examine the phytochemical compounds, particularly for natural L-dopa, in M. pruriens seed extract and subsequently prepare a nanogel containing the extract prior to incorporation into a jelly formulation for use as a functional food in elderly patients with Parkinson's disease. The results show that M. pruriens seed extract contains phenolic compounds, flavonoids, tannins, alkaloids, terpenoids, and saponins. The quantitative analysis performed by the HPLC method revealed that spray-dried M. pruriens seed extract contained 5.59 ± 0.21% L-dopa. M. pruriens seed extract possesses a ferric-reducing antioxidant power and shows free-radical scavenging activity, determined by DPPH and ABTS methods, suggesting a distinctive antioxidant ability of the extract. M. pruriens seed extract at 10 ng/mL did not show cytotoxicity against a neuronal cell line (SH-SY5Y cells), kidney cells (HEK293 cells), or Caco-2 cells. Nanogel of M. pruriens seed extract prepared by ionic gelation had the hydrodynamic diameter, polydispersity index and zeta potential value of 384.53 ± 11.24 nm, 0.38 ± 0.05, and -11.23 ± 1.15 mV, respectively. The transepithelial transport of L-dopa in M. pruriens seed-extract nanogel through Caco-2 cells was measured. Nanogel containing M. pruriens seed extract at the concentration of 10 ng/mL exhibited neuroprotective activity. A jelly formulation containing M. pruriens seed-extract nanogel was successfully developed. The prepared jelly exhibited the acceptable physical and microbiological stabilities upon 6 months of the stability test. The half-life of natural L-dopa in jelly were 3.2, 0.9, and 0.6 years for storage conditions at 4, 30, and 40 °C, respectively, indicating the thermal degradation of natural L-dopa. The prepared jelly containing natural L-dopa from M. pruriens seed extract with the prominent antioxidant activity is a promising option for elderly patients suffering from Parkinson's disease.

Mucuna pruriens Seed Aqueous Extract Improved Neuroprotective and Acetylcholinesterase Inhibitory Effects Compared with Synthetic L-Dopa.

L-dopa, a dopaminergic agonist, is the gold standard for the treatment of Parkinson's disease. However, due to the long-term toxicity and adverse effects of using L-dopa as the first-line therapy for Parkinson's disease, a search for alternative medications is an important current challenge. Traditional Ayurvedic medicine has suggested the use of Mucuna pruriens Linn. (Fabaceae) as an anti-Parkinson's agent. The present study aimed to quantify the amount of L-dopa in M. pruriens seed extract by HPLC analysis. The cytotoxicity and neuroprotective properties of M. pruriens aqueous extract were investigated by two in vitro models including the serum deprivation method and co-administration of hydrogen peroxide assay. The results showed the significant neuroprotective activities of M. pruriens seed extracts at a concentration of 10 ng/mL. In addition, the effects of L-dopa and M. pruriens seed extract on in vitro acetylcholinesterase activities were studied. M. pruriens seed extract demonstrated acetylcholinesterase inhibitory activity, while synthetic L-dopa enhanced the activity of the enzyme. It can be concluded that the administration of M. pruriens seed might be effective in protecting the brain against neurodegenerative disorders such as Parkinson's and Alzheimer's diseases. M. prurience seed extract containing L-dopa has shown less acetylcholinesterase activity stimulation compared with L-dopa, suggesting that the extract might have a superior benefit for use in the treatment of Parkinson's disease.

Streptomyces epipremni sp. nov., an endophytic actinomycete isolated from the root of Epipremnum aureum.

An endophytic Streptomyces-like micro-organism, designated strain PRB2-1T was isolated from root tissue of Epipremnum aureum (Linden and André) G.S. Bunting. The typical morphological and chemotaxonomic characteristics, i.e. the ability to produce straight spore chains directly on aerial mycelium and the presence of ll-diaminopimelic acid in cell-wall peptidoglycan, were consistent with its assignment to the genus Streptomyces. 16S rRNA gene analysis showed that strain PRB2-1T is a member of the genus Streptomyces with the highest similarity to Streptomyces bryophytorum DSM 42183T (98.4 %). Moreover, the draft genome sequence of strain PRB2-1T exhibited low average nucleotide identity by blast (79.9-83.8 %) and digital DNA-DNA hybridization (24.9-28.3 %) values to the reference strains, which were well below the species circumscription threshold. The DNA G+C content of genomic DNA was 73.6 mol%. Comparison of phenotypic characteristics and whole-genome sequence between strain PRB2-1T and its close relatives indicated that strain PRB2-1T could be classified as a novel species of the genus Streptomyces. Thus the name, Streptomyces epipremni sp. nov. is proposed for the strain. The type strain is PRB2-1T (=TBRC 7642T=NBRC 113169T).

Streptomyces endocoffeicus sp. nov., an endophytic actinomycete isolated from Coffea arabica (L.).

An aerobic, non-motile, Gram-stain positive actinomycete, designated strain CA3R110T, was isolated from the surface-sterilised root of Coffea arabica L. collected from Lampang Province, Thailand. 16S rRNA gene sequence analysis indicated that strain CA3R110T was a member of the genus Streptomyces and showed the closest similarities to Streptomyces buecherae AC541T (99.2%), followed by Streptomyces rapamycinicus NRRL B-5491T (99.1%), Streptomyces luteoverticillatus NBRC 3840T (99.1%), Streptomyces coerulescens NBRC 12758T (99.1%), and Streptomyces iranensis HM 35T (99.0%). Strain CA3R110T contained LL-diaminopimelic acid in cell peptidoglycan, MK-9(H6), and MK-9(H8) as major menaquinone, iso-C16:0, iso-C15:0, C16:0 as major fatty acids. Diphosphatidylglycerol, phosphatidylethanolamine, hydroxy-phosphatidylethanolamine, phosphatidylglycerol, phosphatidylinositol, phosphatidylinositolmannoside were detected in the cell. The chemotaxonomic characteristics possessed the typical properties of the genus Streptomyces. A low digital DNA-DNA hybridization (< 55.7%) and average nucleotide identity-blast (ANIb) (< 92.2%) values revealed that strain CA3R110T could be distinguished from any known Streptomyces species. With the differences in phenotypic and genotypic data, strain CA3R110T represents a novel species of genus Streptomyces, for which the name Streptomyces endocoffeicus sp. nov. is proposed. The type strain is CA3R110T (= TBRC 11245T = NBRC 114296T).

Streptomyces musisoli sp. nov., an actinomycete isolated from soil.

An actinobacterium, strain CH5-8T, which formed spiral chains of spore arising from the aerial mycelium, was isolated from rhizosphere soil of Musa spp. The organism exhibited vivid greenish yellow substrate mycelium and easily produced the medium grey aerial spore mass on ISP2 medium. The typical chemotaxonomic properties of members of the genus Streptomyces were observed for strain CH5-8T, e.g. ll-diaminopimelic acid in cell peptidoglycan, MK-9(H8), MK-9(H6), and MK-9(H4) as major menaquinones and anteiso-C15 : 0, iso-C16 : 0, and anteiso-C17 : 0 as major fatty acids. Diphosphatidylglycerol, phosphatidylethanolamine, hydroxyphosphatidylethanolamine, phosphatidylglycerol, phosphatidylinositol and phosphatidylinositol mannoside were detected in the cells. A combination of morphological and chemotaxonomic data supported the assignment to the genus Streptomyces. The analysis result obtained for the 16S rRNA gene sequence confirmed the taxonomic affiliation at the genus level of this strain. The novel strain CH5-8T showed the highest 16S rRNA gene sequence values to Streptomyces echinatus NBRC 12763T (98.9 %), followed by Streptomyces actinomycinicus RCU-197T (98.9 %). The average nucleotide identity by blast (ANIb) and digital DNA-DNA hybridization values between CH5-8T and its closest relatives, S. echinatus CECT 3313T and S. actinomycinicus RCU-197T, were ≤91.6 % and ≤47.4 %, respectively. The digital DNA G+C content of genomic DNA was 72.1 mol%. On the basis of these phenotypic and genotypic data, strain CH5-8T represents a novel species, for which the name Streptomyces musisoli sp. nov. is proposed. The type strain is CH5-8T (=TBRC 9950T=NBRC 113997T).

Streptomyces coffeae sp. nov., an endophytic actinomycete isolated from the root of Coffea arabica (L.).

An endophytic actinobacterium, designated strain CA1R205T, was isolated from the surface-sterilized root of Coffea arabica L. collected from Ratchaburi province, Thailand. The taxonomic position of this strain was evaluated using a polyphasic approach. The strain produced light yellowish brown to dark brownish black substrate mycelium and greyish white aerial mycelium. The spiral spore chains were produced directly on aerial mycelium. CA1R205T was found to have ll-diaminopimelic acid in the cell peptidoglycan, galactose, glucose, mannose and ribose as whole-cell reducing sugars, MK-10(H4), MK-9(H6), MK-10(H2), MK-9(H4), MK-10(H6) and MK-10(H8) as menaquinones and iso-C15 : 0, anteiso-C15 : 0, iso-C16 : 0 and C16 : 0 as major fatty acids. Diphosphatidylglycerol, phosphatidylethanolamine, hydroxyphosphatidylethanolamine, phosphatidylglycerol and phosphatidylinositol were detected in the cells. These characteristics were consistent the typical chemotaxonomic properties of members the genus Streptomyces. The taxonomic affiliation at the genus level of this strain could be confirmed using its 16S rRNA gene sequence data. CA1R205T showed the highest 16S rRNA gene sequence similarity value to Streptomyces rapamycinicus NRRL B-5491T (98.9 %), followed by Streptomyces iranensis HM 35T (98.8 %). Digital DNA-DNA hybridization and average nucleotide identity-by blast (ANIb) values between CA1R205T and S. rapamycinicus NRRL B-5491T were 27.2 and 81.5 %, respectively. The DNA G+C content of genomic DNA was 70.7 mol%. Due to the differences in physiological, biochemical and genotypic data, CA1R205T could be discriminated from its closest neighbour. Thus, CA1R205T should be recognized as representing a novel species of the genus Streptomyces, for which the name Streptomyces coffeae sp. nov. is proposed. The type strain is CA1R205T (=TBRC 11244T=NBRC 114295T).

Novel Multifunctional Ascorbic Triazole Derivatives for Amyloidogenic Pathway Inhibition, Anti-Inflammation, and Neuroprotection.

Alzheimer's disease (AD) is a common neurodegenerative disorder. The number of patients with AD is projected to reach 152 million by 2050. Donepezil, rivastigmine, galantamine, and memantine are the only four drugs currently approved by the United States Food and Drug Administration for AD treatment. However, these drugs can only alleviate AD symptoms. Thus, this research focuses on the discovery of novel lead compounds that possess multitarget regulation of AD etiopathology relating to amyloid cascade. The ascorbic acid structure has been designated as a core functional domain due to several characteristics, including antioxidant activities, amyloid aggregation inhibition, and the ability to be transported to the brain and neurons. Multifunctional ascorbic derivatives were synthesized by copper (I)-catalyzed azide-alkyne cycloaddition reaction (click chemistry). The in vitro and cell-based assays showed that compounds 2c and 5c exhibited prominent multifunctional activities as beta-secretase 1 inhibitors, amyloid aggregation inhibitors, and antioxidant, neuroprotectant, and anti-inflammatory agents. Significant changes in activities promoting neuroprotection and anti-inflammation were observed at a considerably low concentration at a nanomolar level. Moreover, an in silico study showed that compounds 2c and 5c were capable of being permeated across the blood-brain barrier by sodium-dependent vitamin C transporter-2.

Effects of Quercetin and Curcumin Combination on Antibacterial, Antioxidant, In Vitro Wound Healing and Migration of Human Dermal Fibroblast Cells.

Wound healing impairment due to a postponed, incomplete, or uncoordinated healing process has been a challenging clinical problem. Much research has focused on wound care, particularly on discovery of new therapeutic approaches for acute and chronic wounds. This study aims to evaluate the effect of the combination of quercetin and curcuminoids at three different ratios on the antimicrobial, antioxidant, cell migration and wound healing properties. The antioxidant activities of quercetin, curcuminoids and the mixtures were tested by DPPH and ABTS free radical scavenging assays. The disc diffusion method was performed to determine the antibacterial activities of quercetin, curcuminoids and the mixtures against S. aureus and P. aeruginosa. The cytotoxicity and cell migratory enhancing effects of quercetin, curcuminoids and the mixtures against human dermal fibroblasts were investigated by MTT assay, scratch assay and Transwell migration assay, respectively. The results showed the synergism of the quercetin and curcuminoid combination to inhibit the growth of S. aureus and P. aeruginosa, with the inhibition zone ranging from 7.06 ± 0.25 to 8.78 ± 0.38 mm, respectively. The DPPH free radical scavenging assay demonstrated that the combination of quercetin and curcuminoids yielded lower IC50 values (15.38-23.70 µg/mL) than curcuminoids alone (25.75 µg/mL). Quercetin and a 3:1 quercetin/curcuminoid mixture at non-toxic concentrations showed the ability to stimulate the migration of fibroblasts across the matrix, whereas only quercetin alone accelerated the wound closure of fibroblasts. In conclusion, the mixture of quercetin and curcuminoids at a 3:1 ratio was the best formulations for use in wound healing due to the antimicrobial, antioxidant and cell-migration-enhancing activities.

Neuroprotective potential of new chromones isolated from the soil actinomycete Microbispora sp. TBRC6027.

Nine new chromone analogs (1-9) were isolated from the soil actinomycete Microbispora sp. TBRC6027. The chemical structures were determined based upon NMR spectroscopic methods. These compounds were evaluated in vitro by using P19-derived neurons for neuroprotective activity against oxidative stress induced by serum deprivation and showed % viability of neurons at the concentration of 1 ng/mL varied from 43.51% to 52.99% without significant neurotoxicity for P19-derived neurons at the same concentration. Moreover, all tested compounds were inactive for antibacterial activity against both Gram-positive and Gram-negative bacteria and for cytotoxicity against MCF-7 (human breast cancer) and Vero cells at maximum tested concentration 50 µg/mL. However, compounds 4, 6, and 7 displayed weak cytotoxicity against NCI-H187 (human small-cell lung cancer) cells with IC50 in a range of 87.99-91.57 µM.

A novel diterpene agent isolated from Microbispora hainanensis strain CSR-4 and its in vitro and in silico inhibition effects on acetylcholine esterase enzyme.

An actinomycete strain CSR-4 was isolated from the rhizosphere soil of Zingiber montanum. Taxonomic characterization revealed strain CSR-4 was a member of the genus Microbispora. Whole-genome sequence analysis exhibited the highest average nucleotide identity (ANI) value (95.34%) and digital DNA-DNA hybridization (DDH) value (74.7%) between strain CSR-4 and the closest relative M. hainanensis DSM 45428T, which was in line with the assignment to same species. In addition, a new diterpene compound, 2α-hydroxy-8(14), 15-pimaradien-17, 18-dioic acid, and nine known compounds were isolated from the ethyl acetate crude extract of fermentation broth. Interestingly, a new diterpene displayed the suppressive effect on the recombinant human acetylcholinesterase (rhAChE) enzymes (IC50 96.87 ± 2.31 µg/ml). In silico studies based on molecular docking and molecular dynamics (MD) simulations were performed to predict a binding mode of the new compound into the binding pocket of the rhAChE enzyme and revealed that some amino acids in the peripheral anions site (PAS), anionic subsite, oxyanion site and catalytic active site (CAS) of the rhAChE have interacted with the compound. Therefore, our new compound could be proposed as a potential active human AChE inhibitor. Moreover, the new compound can protect significantly the neuron cells (% neuron viability = 88.56 ± 5.19%) from oxidative stress induced by serum deprivation method at 1 ng/ml without both neurotoxicities on murine P19-derived neuron cells and cytotoxicity against Vero cells.

Antibacterial, antitubercular, antimalarial and cytotoxic substances from the endophytic Streptomyces sp. TBRC7642.

Eight previously undescribed naturally-occurring compounds, including abyssomycins Y - Z, methyl aeruginoate, desferri-ferrithocin-4-hydroxyphenethylester, streptomethiocins A - B, furaquinocin I, and streptolactone, along with eleven known compounds were isolated from the endophytic Streptomyces sp. TBRC7642. The chemical structures were determined based on spectroscopic means including 1D, 2D NMR spectroscopy and mass spectrometry. The absolute configurations were assigned by relying on CD spectra and their optical rotations. In addition, the isolated compounds were evaluated for biological activity, such as antimalarial, antitubercular, antibacterial (both Gram-positive and Gram-negative bacteria), as well as for cytotoxicity against MCF-7, NCI-H187, and Vero cells.

Jiangella endophytica sp. nov., an endophytic actinomycete isolated from the rhizome of Kaempferia elegans.

An endophytic actinobacterium, designated strain KE2-3T, was isolated from surface-sterilised rhizome of Kaempferia elegans. The polyphasic approach was used for evaluating the taxonomic position of this strain. The taxonomic affiliation of this strain at genus level could be confirmed by its chemotaxonomic characteristic, i.e. the presence of ll-diaminopimelic acid in the cell peptidoglycan, MK-9(H4) as the major menaquinone, iso-C16 : 0, anteiso-C15 : 0, iso-C14 : 0 and iso-C15 : 0 as the predominant fatty acids in cells, and the presence of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol and phosphatidylinositol mannoside in its membranes. Based on 16S rRNA gene sequence analysis, strain KE2-3T was identified as a member of the genus Jiangella and showed the highest similarities to Jiangella muralis DSM 45357T (99.3 %) followed by Jiangella albaDSM 45237T (99.2 %), Jiangella alkaliphilia DSM 45079T (99.0 %), Jiangella gansuensisDSM 44835T (98.8 %) and Jiangella mangrovi3SM4-07T (98.6 %). However, the draft genome sequence of strain KE2-3T exhibited low average nucleotide identity values to the reference strains (85.5-90.2 %), which were well below the 95-96 % species circumscription threshold. The DNA G+C content of genomic DNA was 72.3 mol%. With the differences of physiological, biochemical and genotypic data, strain KE2-3T could be discriminated from its closest neighbour. Thus, strain KE2-3T should be recognised as a novel species of genus Jiangella, for which the name Jiangellaendophytica sp. nov. is proposed. The type strain is KE2-3T (=BCC 66359T=NBRC 110004T).

Microbispora soli sp. nov., isolated from soil of a hot spring.

A novel actinomycete, strain RTBAU4-9T, which produced longitudinally paired spores on aerial mycelia, was isolated from a soil sample of a hot spring area. This strain exhibited chemotaxonomic and genotypic properties typical of the genus Microbispora, such as meso-diaminopimelic acid in the cell-wall peptidoglycan, glucose, ribose and trace amount of madurose as the characteristic whole-cell sugars, phosphatidylethanolamine, diphosphatidylglycerol and phosphoglycolipids as the membrane phospholipids, MK-9(H4), MK-9(H2) and MK-9(H0) as the characteristic menaquinones, and iso-C16 : 0 and anteiso-C17 : 0 as the main fatty acids. The G+C content of the genomic DNA was 70.2 mol%. The result of 16S rRNA gene sequence analysis revealed the strain was a member of the genus Microbispora and was most closely related to Microbispora hainanensis 211020T (98.3 % 16S rRNA gene sequence similarity). In addition, the low percentage of DNA-DNA relatedness (<28.1±1.2 %) and several phenotypic differences confirmed that strain RTBAU4-9T should be considered as representing a novel species of the genus Microbispora, for which the name Microbispora soli sp. nov. is proposed. The type strain is RTBAU4-9T (=TBRC 7648T=NBRC 113147T).

Jishengella zingiberis sp. nov., isolated from root tissue of Zingiber montanum.

A novel actinomycete, strain PLAI 1-1T, which formed spiny single spore directly on substrate mycelium was isolated from root tissue of Zingiber montanum. The isolate contained meso-diaminopimelic acid and 3-hydroxydiaminopimelic acid in the cell-wall peptidoglycan. The acyl type of the cell-wall muramic acid was glycolyl. The whole-cell sugars of strain PLAI 1-1T were glucose, arabinose, xylose, ribose and a trace amount of mannose. The membrane phospholipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylserine and phosphatidylinositol. The major menaquinone was MK-9 (H4). The main cellular fatty acids were iso-C15 : 0 and C17 : 1ω8c. The G+C content of the genomic DNA was 70.6 mol%. 16S rRNA gene sequence analysis revealed that strain PLAI 1-1T was a member of the genus Jishengella and had the highest 16S rRNA gene sequence similarity to Jishengella endophytica DSM 45430T (99.2 %). Based on the data of physiological and biochemical tests, including the result of DNA-DNA hybridization, strain PLAI 1-1T represents a novel species of the genus Jishengella, for which the name Jishengellazingiberis sp. nov. is proposed. The type strain is PLAI 1-1T (=TBRC 7644T=NBRC 113144T).

Semisynthesis and biological evaluation of prenylated resveratrol derivatives as multi-targeted agents for Alzheimer's disease.

A series of prenylated resveratrol derivatives were designed, semisynthesized and biologically evaluated for inhibition of ß-secretase (BACE1) and amyloid-ß (Aß) aggregation as well as free radical scavenging and neuroprotective and neuritogenic activities, as potential novel multifunctional agents against Alzheimer's disease (AD). The results showed that compound 4b exhibited good anti-Aß aggregation (IC50 = 4.78 µM) and antioxidant activity (IC50 = 41.22 µM) and moderate anti-BACE1 inhibitory activity (23.70% at 50 µM), and could be a lead compound. Moreover, this compound showed no neurotoxicity along with a greater ability to inhibit oxidative stress on P19-derived neuronal cells (50.59% cell viability at 1 nM). The neuritogenic activity presented more branching numbers (9.33) and longer neurites (109.74 µm) than the control, and was comparable to the quercetin positive control. Taken together, these results suggest compound 4b had the greatest multifunctional activities and might be a very promising lead compound for the further development of drugs for AD.