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1.
Chemistry ; 30(12): e202303717, 2024 Feb 26.
Article in English | MEDLINE | ID: mdl-38072903

ABSTRACT

Organic-inorganic hybrid multifunctional materials have shown significant application in lighting and sensor fields, owing to their prominent performance and diversity structures. Herein, we synthesized two multifunctional compounds: (propyl-quinuclidone)2 CdBr4 (1) and (F-butyl-quinuclidone)2 CdBr4 (2). By introducing light-emitting organic cation with flexible long chain, 1 and 2 exhibit excellent transition properties and bright blue-white fluorescence. Then, combine fluorescence lifetime and first-principal calculation, providing evidence for the electron transfer emission. Subsequently, investigated the impact of substituent carbon chain length (methyl to butyl), structural rigidity (C-C to C-F) and halide framework (Cl to I) on the fluorescence properties. Results indicate that Cd⋅⋅⋅Cd distance and structural rigidity play an important role in fluorescence. Overall, our research provides valuable insight and example for chemical modifications enhance compound performance.

2.
Inorg Chem ; 62(27): 10847-10853, 2023 Jul 10.
Article in English | MEDLINE | ID: mdl-37366025

ABSTRACT

Hybrid organic-inorganic perovskites (HOIPs) have attracted much attention due to their excellent properties and easy synthesis. As far as we know, most documented ferroelastics mainly focus on the 3D (three-dimensional) perovskites, the 2D monolayer perovskite ferroelastics are rarely reported before. In this work, we synthesized a 2D lead-based perovskite (C5NH13Br)2PbBr4 (1) (C5NH13Br = 5-bromoamylamine cation) by introducing flexible chain organic cations. The evolution of ferroelastic domains observed by a polarized light microscope confirms that compound 1 undergoes a ferroelastic phase transition at 392/384 K. In addition, its direct band gap is 2.877 eV. Interestingly, the material emits an attractive blue light (quantum yield 5.06%) under UV light. Three structural descriptors are introduced to quantitatively analyze the relationship between structural distortion and the shape of emission peak. This work provides a way to design multifunctional perovskite-type materials.

3.
J Nat Prod ; 86(6): 1512-1519, 2023 06 23.
Article in English | MEDLINE | ID: mdl-37200613

ABSTRACT

One new aromatic polyketide, prealnumycin B (1), and four known aromatic polyketides, K1115A (2), 1,6-dihydroxy-8-propylanthraquinone (DHPA, 3), phaeochromycin B (4), and (R)-7-acetyl-3,6-dihydroxy-8-propyl-3,4dihydronaphthalen-1(2H)-one (5), were isolated from the marine-derived Streptomyces sundarbansensis SCSIO NS01; these compounds represent four sets of aromatic polyketides differing in size and shape. A type II polyketide synthase (PKS) cluster, als, was identified by complete genome sequencing and was shown, by in vivo gene inactivation experiments in the wild-type (WT) NS01 strain and heterologous expression experiments, to encode the biosynthesis of compounds 1-5. Moreover, heterologous expression of the als cluster afforded three additional aromatic polyketides representing two different carbon skeletons, the new phaeochromycin L (6) and two known aromatic polyketides, phaeochromycins D (7) and E (8). These findings expand our knowledge of type II PKS machineries and their versatility in generating structurally diverse aromatic polyketides and highlight the power of type II PKSs in accessing new polyketides via ectopic expression in heterologous hosts.


Subject(s)
Carbon , Polyketides , Gene Silencing , Multigene Family , Polyketide Synthases/genetics , Skeleton
4.
J Nat Prod ; 85(1): 256-263, 2022 01 28.
Article in English | MEDLINE | ID: mdl-35042332

ABSTRACT

Vicenistatin (1) is a potent polyketide antitumor antibiotic composed of a 20-membered macrolactam core appended to a unique aminosugar, vicenisamine. In this study, vicenistatin was isolated and its biosynthetic gene cluster identified from Monodonata labio-associated Streptomyces parvus SCSIO Mla-L010. A set of five genes, vicC, vicD, vicE, vicF, and vicG, was confirmed to be involved in the biosynthesis of the aminosugar by gene inactivations. VicG was characterized as an N-methyltransferase that catalyzes the methylation of the 4'-amino group in the last step of the aminosugar biosynthetic pathway; the N-demethyl intermediate 4'-N-demethylvicenistatin (2) was isolated from the ΔvicG mutant strain. In addition, vicR1 was characterized as a positive pathway-specific regulatory gene. Notably, N-demethyl compound 2 was found to exert impressive antibacterial activities, with MIC values spanning 0.06-4 µg/mL, against a panel of Gram-positive bacteria including methicillin-resistant Staphylococcus aureus, Gram-negative Helicobacter pylori, and mycobacterium Mycobacterium smegmatis and the fungal pathogen Candida albicans. Compound 2 was also found to display reduced cytotoxicities relative to vicenistatin, especially against noncancerous human cell lines.


Subject(s)
Amino Sugars/metabolism , Aminoglycosides/pharmacology , Gastropoda/microbiology , Genes, Regulator , Lactams/pharmacology , Macrolides/pharmacology , Streptomyces/genetics , Animals , Biosynthetic Pathways/genetics , Cell Line, Tumor , Heterografts , Humans , Mice
5.
J Nat Prod ; 84(8): 2217-2225, 2021 08 27.
Article in English | MEDLINE | ID: mdl-34270246

ABSTRACT

Through precursor-directed biosynthesis, feeding halogenated (F-, Cl-, Br-, I-) or methoxy-substituted 4-methyl-3-hydroxyanthranilic acid (4-MHA) analogues to the acnGHLM-deleted mutant strain of Streptomyces costaricanus SCSIO ZS0073 led to the production of ten new actinomycin analogues (4-13). Several of the actinomycin congeners displayed impressive antimicrobial activities, with MIC values spanning 0.06-64 µg/mL to clinically derived antibiotic resistant pathogens, including Staphylococcus aureus, Enterococcus faecium, and Candida albicans, with low cytotoxicity.


Subject(s)
Anti-Infective Agents/pharmacology , Dactinomycin/analogs & derivatives , Streptomyces/metabolism , Candida albicans/drug effects , Cell Line, Tumor , Enterococcus faecium/drug effects , Halogenation , Humans , Microbial Sensitivity Tests , Molecular Structure , Staphylococcus aureus/drug effects , Streptomyces/genetics
6.
Mar Drugs ; 19(8)2021 Jul 31.
Article in English | MEDLINE | ID: mdl-34436279

ABSTRACT

We have previously shown deep-sea-derived Streptomyces koyangensis SCSIO 5802 to produce two types of active secondary metabolites, abyssomicins and candicidins. Here, we report the complete genome sequence of S. koyangensis SCSIO 5802 employing bioinformatics to highlight its potential to produce at least 21 categories of natural products. In order to mine novel natural products, the production of two polycyclic tetramate macrolactams (PTMs), the known 10-epi-HSAF (1) and a new compound, koyanamide A (2), was stimulated via inactivation of the abyssomicin and candicidin biosynthetic machineries. Detailed bioinformatics analyses revealed a PKS/NRPS gene cluster, containing 6 open reading frames (ORFs) and spanning ~16 kb of contiguous genomic DNA, as the putative PTM biosynthetic gene cluster (BGC) (termed herein sko). We furthermore demonstrate, via gene disruption experiments, that the sko cluster encodes the biosynthesis of 10-epi-HSAF and koyanamide A. Finally, we propose a plausible biosynthetic pathway to 10-epi-HSAF and koyanamide A. In total, this study demonstrates an effective approach to cryptic BGC activation enabling the discovery of new bioactive metabolites; genome mining and metabolic profiling methods play key roles in this strategy.


Subject(s)
Lactams, Macrocyclic/metabolism , Streptomyces , Aquatic Organisms , Genome , Humans , Multigene Family , Phytotherapy , Whole Genome Sequencing
7.
Mar Drugs ; 19(6)2021 May 24.
Article in English | MEDLINE | ID: mdl-34073984

ABSTRACT

Desotamides A, a cyclohexapeptide produced by the deep-sea-derived Streptomyces scopuliridis SCSIO ZJ46, displays notable antibacterial activities against strains of Streptococcus pnuemoniae, Staphylococcus aureus, and methicillin-resistant Staphylococcus epidermidis (MRSE). In this study, to further explore its antibacterial potential and reveal the antibacterial structure-activity relationship of desotamides, 13 cyclopeptides including 10 new synthetic desotamide A analogues and wollamides B/B1/B2 were synthesized and evaluated for their antibacterial activities against a panel of Gram-positive and -negative pathogens. The bioactivity data reveal that residues at position II and VI greatly impact antibacterial activity. The most potent antibacterial analogues are desotamide A4 (13) and A6 (15) where l-allo-Ile at position II was substituted with l-Ile and Gly at position VI was simultaneously replaced by d-Lys or d-Arg; desotamides A4 (13) and A6 (15) showed a 2-4-fold increase of antibacterial activities against a series of Gram-positive pathogens including the prevalent clinical drug-resistant pathogen methicillin-resistant Staphylococcus aureus (MRSA) with MIC values of 8-32 µg/mL compared to the original desotamide A. The enhanced antibacterial activity, broad antibacterial spectrum of desotamides A4 and A6 highlighted their potential as new antibiotic leads for further development.


Subject(s)
Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/pharmacology , Gram-Positive Bacteria/drug effects , Peptides, Cyclic/chemistry , Peptides, Cyclic/pharmacology , Gram-Positive Bacteria/growth & development , Microbial Sensitivity Tests , Streptomyces , Structure-Activity Relationship
8.
Zhong Nan Da Xue Xue Bao Yi Xue Ban ; 46(12): 1409-1414, 2021 Dec 28.
Article in English, Zh | MEDLINE | ID: mdl-35232912

ABSTRACT

Coronary heart disease and diabetes mellitus are closely related to chronic low-grade inflammation. Interleukin-34 (IL-34) is a new member of the interleukin family discovered in recent years. It is involved in the pathophysiological process of mononuclear phagocyte system mainly via binding to colony stimulating factor-1 receptor, and it is closely related to inflammatory and autoimmune diseases. IL-34 is highly expressed in patients with coronary heart disease or diabetes mellitus. IL-34 induces atherosclerosis and insulin resistance through multiple pro-inflammatory actions, ultimately leading to the occurrence and development of coronary heart disease, type 2 diabetes, and their comorbidities.


Subject(s)
Coronary Disease , Diabetes Mellitus, Type 2 , Insulin Resistance , Coronary Disease/complications , Diabetes Mellitus, Type 2/complications , Humans , Inflammation/complications , Interleukins
9.
Zhong Nan Da Xue Xue Bao Yi Xue Ban ; 46(4): 373-378, 2021 Apr 28.
Article in English, Zh | MEDLINE | ID: mdl-33967083

ABSTRACT

OBJECTIVES: To investigate the level and significance of serum γ-glutamyl transferase-to-platelet ratio (GPR) and monocyte count to high-density lipoprotein ratio (MHR) in patients with essential hypertension (EH) and unstable angina (UA). METHODS: A total of 218 patients with coronary angiography aged ≥60 years, who were admitted to the EH hospital of the Department of Cardiac Medicine, Affiliated Hospital of Chengde Medical College, were selected from September 2018 to September 2019. They were divided into an EH+UA group (n=113) and an EH group (n=105). In addition, 106 patients with normal coronary angiography who were diagnosed with coronary heart disease were selected as a control group. The general data, blood biochemical indicators, GPR and MHR in each group were compared, and partial correlation analysis and receiver operator characteristic (ROC) curve analysis were performed. RESULTS: Compared with the control group, patients in the EH+UA group and the EH group had higher body mass index (BMI), tyiglyceride (TG), GPR, and MHR, and lower high-density lipoprotein-cholesterol (HDL-C) (all P<0.05); and patients in the EH+UA group had higher white blood cell counts, alanine aminotransferase (ALT), and uric acid (all P<0.05). Compared with the EH group, patients in the EH+UA group had higher GPR and MHR (both P<0.05). Partial correlation analysis showed that after controlling the antihypertensive drugs and lipid-lowering drugs, GPR was found to be positively correlated with BMI, white blood cell count, ALT, TG, and uric acid (r=0.160, 0.111, 0.205, 0.250, 0.154, respectively, all P<0.05), which was negatively correlated with HDL-C (r=-0.238, P<0.05); MHR was positively correlated with BMI, ALT, TG, uric acid, and GPR (r=0.186, 0.307, 0.157, 0.141, 0.223, respectively, all P<0.05), and negatively correlated with HDL-C (r=-0.610, P<0.001). ROC curve analysis showed that GPR had higher specificity and positive predictive value, while MHR had higher sensitivity. When the two indicators were combined, the sensitivity and positive predictive value were higher. CONCLUSIONS: There is a correlation between GPR, MHR and EH combined with UA pectoris, and the combined detection of the two indicators has adjuvant diagnostic value for elderly EH combined with UA.


Subject(s)
Angina, Unstable , Lipoproteins, HDL , Aged , Cholesterol, HDL , Coronary Angiography , Essential Hypertension , Humans , Monocytes
10.
Opt Express ; 28(15): 22287-22296, 2020 Jul 20.
Article in English | MEDLINE | ID: mdl-32752494

ABSTRACT

This work presents a compact LiNbO3 (lithium niobate, LN) electro-optic (EO) Q-switch with a lower driving voltage than the conventional LN Q-switches. By using non-direct cuts of a certain crystallographic orientation, a LN crystal is used both as a quarter-wave plate (QWP) and a pockels cell in a laser cavity. Through theoretical calculations and experiments, we have determined the optimized crystal orientations with low quarter-wave voltages (QWV). A set of compact LN EO Q-switches were prepared and used successfully in the pulse-on mode in a Nd:YAG laser. The Q-switched laser outputs are comparable to those obtained by using a conventional Z-cut LN Q-switch with a QWP. The QWV of the Q-switch with the optimized crystal orientation is 600V lower than that of the Z-cut LN Q-switch.

11.
Appl Microbiol Biotechnol ; 104(6): 2603-2610, 2020 Mar.
Article in English | MEDLINE | ID: mdl-32002605

ABSTRACT

The deep-sea-derived microbe Streptomyces scopuliridis SCSIO ZJ46 produces desotamides A-D. Notably, desotamides A and B display antibacterial activities against pathogenic Gram-positive Streptococcus pneumoniae NCTC 7466, Staphylococcus aureus ATCC 29213, and the methicillin-resistant clinical isolate Staphylococcus epidermidis (MRSE) shhs-E1. The 39-kb desotamide biosynthetic gene cluster (dsa) has previously been identified and heterologously expressed in S. coelicolor M1152 for the purposes of assigning dsa gene functions. In this work, we identified seven genes in the dsa cluster including three regulatory genes (dsaA, dsaM, and dsaN), two transporter genes (dsaK and dsaL), and two other genes, dsaB (annotated as a phosphate synthase) and dsaJ (a PBP-type thioesterase). The DsaA and DsaN were unambiguously shown to be positive regulators of desotamide biosynthesis, and consistent with these roles, inactivation of either gene completely abolished desotamide production. Moreover, overexpression of dsaA or dsaN (independent of each other) was shown to improve desotamide titers. Production of desotamides in M1152/07-6H::dsaA strain was 2.4-fold greater than that in the heterologous dsa expression strain M1152/07-6H whereas desotamide titers from the M1152/07-6H::dsaN strain were about twice that of M1152/07-6H. In addition, inactivation of dsaB and dsaJ (independent of each other) completely abolished desotamide production, indicating their indispensability for desotamide assembly. These studies provide new insights into the functions and combinatorial biosynthetic potentials of seven key genes within the dsa biosynthetic gene cluster. Findings reported here are likely to facilitate further efforts aimed at assessing and developing the desotamides and related analogs for future applications.


Subject(s)
Gene Expression Regulation, Bacterial , Genes, Regulator , Peptides, Cyclic/biosynthesis , Streptomyces/genetics , Bacterial Proteins/genetics , Biosynthetic Pathways , Multigene Family
12.
Proc Natl Acad Sci U S A ; 114(19): 4948-4953, 2017 05 09.
Article in English | MEDLINE | ID: mdl-28438999

ABSTRACT

Galactose, a monosaccharide capable of assuming two possible configurational isomers (d-/l-), can exist as a six-membered ring, galactopyranose (Galp), or as a five-membered ring, galactofuranose (Galf). UDP-galactopyranose mutase (UGM) mediates the conversion of pyranose to furanose thereby providing a precursor for d-Galf Moreover, UGM is critical to the virulence of numerous eukaryotic and prokaryotic human pathogens and thus represents an excellent antimicrobial drug target. However, the biosynthetic mechanism and relevant enzymes that drive l-Galf production have not yet been characterized. Herein we report that efforts to decipher the sugar biosynthetic pathway and tailoring steps en route to nucleoside antibiotic A201A led to the discovery of a GDP-l-galactose mutase, MtdL. Systematic inactivation of 18 of the 33 biosynthetic genes in the A201A cluster and elucidation of 10 congeners, coupled with feeding and in vitro biochemical experiments, enabled us to: (i) decipher the unique enzyme, GDP-l-galactose mutase associated with production of two unique d-mannose-derived sugars, and (ii) assign two glycosyltransferases, four methyltransferases, and one desaturase that regiospecifically tailor the A201A scaffold and display relaxed substrate specificities. Taken together, these data provide important insight into the origin of l-Galf-containing natural product biosynthetic pathways with likely ramifications in other organisms and possible antimicrobial drug targeting strategies.


Subject(s)
Actinobacteria/metabolism , Aminoglycosides/biosynthesis , Bacterial Proteins/metabolism , Guanosine Diphosphate Sugars/metabolism , Intramolecular Transferases/metabolism , Actinobacteria/genetics , Aminoglycosides/genetics , Bacterial Proteins/genetics , Guanosine Diphosphate Sugars/genetics , Intramolecular Transferases/genetics
13.
Org Biomol Chem ; 17(15): 3760-3764, 2019 04 10.
Article in English | MEDLINE | ID: mdl-30702740

ABSTRACT

The antimicrobial nucleoside antibiotic A201A is produced by the deep-sea derived Marinactinospora thermotolerans SCSIO 00652. Bioinformatics analysis revealed that mtdV, downstream within the A201A biosynthetic gene cluster, encodes a protein with low homology to a group of chorismate pyruvate-lyases. To explore the role of mtdV in A201A biosynthesis, mtdV was inactivated and HPLC analysis revealed that the resulting ΔmtdV mutant failed to produce A201A; production was partially restored by adding exogenous 4-hydroxybenzoic acid (4HB) to the fermentation. In vitro biochemical assays showed that MtdV catalyzes the conversion of chorismate into 4HB, thereby firmly demonstrating that MtdV is a chorismate lyase involved in A201A biosynthesis. In addition, supplementation of the ΔmtdV mutant with various 4HB analogs enabled production of seven new A201A analogs. Antimicrobial assays showed that the purified A201A analogs 3'-F-A201A and 3'-Cl-A201A were just as active as A201A against the test strains with MIC values of 1-8 µg mL-1.


Subject(s)
Actinobacteria/enzymology , Aminoglycosides/biosynthesis , Oxo-Acid-Lyases/metabolism , Aminoglycosides/chemistry , Biocatalysis , Computational Biology , Molecular Structure , Mutation , Oxo-Acid-Lyases/genetics
14.
Mar Drugs ; 17(2)2019 Feb 21.
Article in English | MEDLINE | ID: mdl-30795576

ABSTRACT

Aborycin is a ribosomally synthesized member of the type I lasso peptide natural products. In the present study, aborycin was isolated and identified from the deep-sea-derived microbe Streptomyces sp. SCSIO ZS0098. The aborycin biosynthetic gene cluster (abo) was identified on the basis of genome sequence analyses and then heterologously expressed in Streptomyces coelicolor M1152 to effectively produce aborycin. Aborycin generated in this fashion exhibited moderate antibacterial activity against 13 Staphylococcus aureus strains from various sources with minimum inhibitory concentrations MICs = 8.0~128 µg/mL, against Enterococcus faecalis ATCC 29212 with an MIC = 8.0 µg/mL, and against Bacillus thuringiensis with MIC = 2.0 µg/mL. Additionally, aborycin displayed potent antibacterial activity (MIC = 0.5 µg/mL) against the poultry pathogen Enterococcus gallinarum 5F52C. The reported abo cluster clearly has the potential to provide a means of expanding the repertoire of anti-infective type I lasso peptides.


Subject(s)
Peptides/pharmacology , Streptomyces/genetics , Amino Acid Sequence , Anti-Infective Agents/chemistry , Anti-Infective Agents/isolation & purification , Anti-Infective Agents/pharmacology , Bacillus thuringiensis/drug effects , Bacterial Proteins/biosynthesis , Bacterial Proteins/chemistry , Bacterial Proteins/genetics , Bacterial Proteins/pharmacology , Biological Products/chemistry , Biological Products/isolation & purification , Biological Products/pharmacology , Enterococcus/drug effects , Enterococcus faecalis/drug effects , Enterococcus faecalis/metabolism , Multigene Family , Peptides/chemistry , Peptides/genetics , Peptides/isolation & purification , Staphylococcus aureus/drug effects , Staphylococcus aureus/metabolism , Streptomyces/metabolism , Streptomyces coelicolor/drug effects , Streptomyces coelicolor/metabolism
15.
Mikrochim Acta ; 187(1): 45, 2019 12 13.
Article in English | MEDLINE | ID: mdl-31836912

ABSTRACT

A foam consisting of reduced graphene oxide was synthesized by a one-pot hydrothermal method. The foam was used to prepare a nanocomposite with hemin which is formed via π-interactions. The nanocomposite was incorporated via a Nafion film and then placed on a glassy carbon electrode (GCE). The modified GCE displays outstanding catalytic activity towards H2O2. It is assumed that this is due to (a) the redox-active center [Fe(III/II)] of hemin, and (b) the crosslinked macroporous structure of the foam. Both improve the electron transfer rate and electrochemical signals. Under the optimum experimental conditions and a working voltage of typically -0.41 mV (vs. SCE), the sensor has a 2.8 nM H2O2 detection limit, and the analytically useful range extends from 5 nM to 5 mM with a sensitivity of 50.5 µA µM-1 cm-2. The modified GCE has high sensitivity and fast response. It was utilized to quantify H2O2 in spiked environmental water samples. Graphical abstractSchematic representation of the electrochemical sensor based on a nanocomposite prepared from hemin and reduced graphene oxide foam, which can be applied to the determination of hydrogen peroxide in serum.


Subject(s)
Electrochemical Techniques , Graphite/chemistry , Hemin/chemistry , Hydrogen Peroxide/analysis , Nanocomposites/chemistry , Water Pollutants, Chemical/analysis , Graphite/chemical synthesis , Particle Size , Surface Properties
16.
Microb Cell Fact ; 17(1): 28, 2018 Feb 20.
Article in English | MEDLINE | ID: mdl-29463238

ABSTRACT

BACKGROUND: The deep-sea-derived microbe Streptomyces koyangensis SCSIO 5802 produces neoabyssomicins A-B (1-2) and abyssomicins 2 (3) and 4 (4). Neoabyssomicin A (1) augments human immunodeficiency virus-1 (HIV-1) replication whereas abyssomicin 2 (3) selectively reactivates latent HIV and is also active against Gram-positive pathogens including methicillin-resistant Staphylococcus aureus (MRSA). Structurally, neoabyssomicins A-B constitute a new subtype within the abyssomicin family and feature unique structural traits characteristic of extremely interesting biosynthetic transformations. RESULTS: In this work, the biosynthetic gene cluster (BGC) for the neoabyssomicins and abyssomicins, composed of 28 opening reading frames, was identified in S. koyangensis SCSIO 5802, and its role in neoabyssomicin/abyssomicin biosynthesis was confirmed via gene inactivation and heterologous expression experiments. Bioinformatics and genomics analyses enabled us to propose a biosynthetic pathway for neoabyssomicin/abyssomicin biosynthesis. Similarly, a protective export system by which both types of compounds are secreted from the S. koyangensis producer was identified, as was a four-component ABC transporter-based import system central to neoabyssomicin/abyssomicin biosynthesis. Furthermore, two regulatory genes, abmI and abmH, were unambiguously shown to be positive regulators of neoabyssomicin/abyssomicin biosynthesis. Consistent with their roles as positive regulatory genes, the overexpression of abmI and abmH (independent of each other) was shown to improve neoabyssomicin/abyssomicin titers. CONCLUSIONS: These studies provide new insight into the biosynthesis of the abyssomicin class of natural products, and highlight important exploitable features of its BGC for future efforts. Elucidation of the neoabyssomicin/abyssomicin BGC now enables combinatorial biosynthetic initiatives aimed at improving both the titers and pharmaceutical properties of these important natural products-based drug leads.


Subject(s)
Biosynthetic Pathways/genetics , Genes, Regulator/genetics , Multigene Family/genetics , Streptomyces/genetics
17.
Bioorg Med Chem ; 26(8): 1488-1494, 2018 05 01.
Article in English | MEDLINE | ID: mdl-29452840

ABSTRACT

Borrelidin A (1) is produced by several species of Streptomyces and within its bioactive scaffold, the vinylic nitrile moiety is essential for activity. We report herein newly discovered members of the borrelidin family, borrelidin F (2), borrelidin G (3), borrelidin H (4) and borrelidin I (5); all were isolated from Streptomyces rochei SCSIO ZJ89 originating from a mangrove-derived sediment sample. These structurally diverse metabolites enabled a number of new structure-activity relationships (SARs) to be identified, especially with respect to the different configurations at the C11-OH and C12-C15 double bonds for which the absolute configurations were determined using spectroscopic methods. Importantly, borrelidin H (4) was found to have a therapeutic window superior to that of borrelidin A (1) in vitro and could inhibit migration of cancer cells.


Subject(s)
Antineoplastic Agents/pharmacology , Streptomyces/chemistry , Antineoplastic Agents/chemistry , Antineoplastic Agents/isolation & purification , Cell Line , Cell Movement/drug effects , Dose-Response Relationship, Drug , Drug Screening Assays, Antitumor , Fatty Alcohols/chemistry , Fatty Alcohols/isolation & purification , Fatty Alcohols/pharmacology , Humans , Molecular Structure , Structure-Activity Relationship , Wound Healing/drug effects
18.
J Nat Prod ; 81(7): 1570-1577, 2018 07 27.
Article in English | MEDLINE | ID: mdl-30015485

ABSTRACT

Four known compounds, rishirilide B (1), rishirilide C (2), lupinacidin A (3), and galvaquinone B (4), representing two anthracene scaffolds typical of aromatic polyketides, were isolated from a culture of the deep-sea-derived Streptomyces olivaceus SCSIO T05. From the S. olivaceus producer was cloned and sequenced the rsd biosynthetic gene cluster (BGC) that drives rishirilide biosynthesis. The structural gene rsdK2 inactivation and heterologous expression of the rsd BGC confirmed the single rsd BGC encodes construction of 1-4 and, thus, accounts for two anthracene scaffolds. Precursor incubation experiments with 13C-labeled acetate revealed that a Baeyer-Villiger-type rearrangement plays a central role in construction of 1-4. Two luciferase monooxygenase components, along with a reductase component, are presumably involved in the Baeyer-Villiger-type rearrangement reaction enabling access to the two anthracene scaffold variants. Engineering of the rsd BGC unveiled three SARP family transcriptional regulators, enhancing anthracene production. Inactivation of rsdR4, a MarR family transcriptional regulator, failed to impact production of 1-4, although production of 3 was slightly improved; most importantly rsdR4 inactivation led to the new adduct 6 in high titer. Notably, inactivation of rsdH, a putative amidohydrolase, substantially improved the overall titers of 1-4 by more than 4-fold.


Subject(s)
Anthracenes/isolation & purification , Genes, Bacterial , Multigene Family , Streptomyces/genetics , Anthracenes/metabolism , Gene Rearrangement , Oceans and Seas , Water Microbiology
19.
J Nat Prod ; 81(8): 1892-1898, 2018 08 24.
Article in English | MEDLINE | ID: mdl-30070834

ABSTRACT

Three new abyssomicin monomers designated neoabyssomicins D (1), E (2), and A2 (3) and the two dimeric neoabyssomicins F (4) and G (5) were discovered from the marine-derived Streptomyces koyangensis SCSIO 5802, and their structures rigorously elucidated. Neoabyssomicin D (1) possesses an unprecedented 8/5/5/7 ring skeleton, the biosynthesis of which (as well as 2) is proposed herein. Additionally, dimeric agents 4 and 5 were found to be active against methicillin-resistant Staphylococcus aureus and vesicular stomatitis virus, respectively.


Subject(s)
Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/pharmacology , Streptomyces/chemistry , Bacteria/drug effects , Humans , Methicillin-Resistant Staphylococcus aureus/drug effects , Microbial Sensitivity Tests , Molecular Structure , Vesiculovirus/drug effects
20.
AAPS PharmSciTech ; 19(3): 1141-1151, 2018 Apr.
Article in English | MEDLINE | ID: mdl-29218581

ABSTRACT

Dissolving microneedles (MNs) offered a simple, minimally invasive method for meloxicam (MX) delivery to the skin. However, the fabrication of dissolving MNs still faced some challenges, such as significant time consumption, loss of drug activity, and difficulty in regulating MN drug loading. To address these issues, we developed the tip-dissolving (TD) MNs. Several kinds of drugs were encapsulated successfully, and the quantity of MX ranged from 37.23 ± 8.40 to 332.53 ± 13.37 µg was precisely controlled. The effects of fabrication process on biomacromolecules stability were studied, and it was found that tyrosinase kept 90.4% activity during the fabrication process. The whole process for the fabrication of MNs only takes approximately 1 h. In order to further evaluate the potential of the TD MNs, MX TD MNs were prepared for in vitro release experiments, in vivo release experiments, safety evaluation, pharmacokinetic studies, and pharmacodynamic studies. The results demonstrated that MX TD MNs offered several advantages, including rapid release of the encapsulated drug (91.72% within 30 min), efficient drug delivery to skin (79.18%), no obvious skin irritation, decent relative bioavailability (122.3%), and strong anti-inflammatory and analgesic effects. Based on these results, we envisage that the TD MNs have promising potential for transdermal drug delivery of MX.


Subject(s)
Thiazines/administration & dosage , Thiazoles/administration & dosage , Administration, Cutaneous , Animals , Biological Availability , Drug Delivery Systems/instrumentation , Drug Liberation , Female , Humans , Male , Meloxicam , Mice , Needles , Rats , Skin/metabolism , Thiazines/pharmacokinetics , Thiazines/pharmacology , Thiazines/toxicity , Thiazoles/pharmacokinetics , Thiazoles/pharmacology , Thiazoles/toxicity
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