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Three chromomycin derivatives, chromomycins A 3 ( 1, CA 3 ), A 5 ( 2, CA 5 ), and monodeacetylchromomycin A 3 ( 3, MDA-CA 3 ), were identified from the soil-derived Streptomyces sp. CGMCC 26516. A reinvestigation of the structure of CA 5 is reported, of which the absolute configuration was unambiguously determined for the first time to be identical with that of CA 3 based on nuclear magnetic resonance (NMR) data analysis as well as NMR and electronic circular dichroism calculations. Compounds 1-3 showed potent cytotoxicity against the non-small-cell lung cancer (NSCLC) cells (A549, H460, H157-c-FLIP, and H157-LacZ) and down-regulated the protein expression of c-FLIP in A549 cells. The IC 50 values of chromomycins in H157-c-FLIP were higher than that in H157-LacZ. Furthermore, si-c-FLIP promoted anti-proliferation effect of chromomycins in NSCLC cells. In nude mice xenograft model, 1 and 2 both showed more potent inhibition on the growth of H157-lacZ xenografts than that of H157-c-FLIP xenografts. These results verify that c-FLIP mediates the anticancer effects of chromomycins in NSCLC.

Two new furoquinoline alkaloids, named 1'-oxo-isoplatydesmine ( 1 ) and demethoxyacrophylline ( 2 ), as well as 11 known alkaloids ( 3 - 13 ) were isolated from the root bark of Dictamnus dasycarpus Turcz. The structures of 1 and 2 were established by detailed spectroscopic elucidation, such as 1 D & 2 D NMR and HRMS, etc. The unexpected autoracemization of 1 was discussed based on the stereochemistry of reported dihydrofuroquinolines. Compounds 3-5 exhibited moderate inhibitory activities against Bacillus subtilis , Candida albicans , and Pseudomonas aeruginosa with MICs 32-64 μg/ml, revealing the active principles of D. dasycarpus for treating skin diseases in its traditional usage.

Circular RNA (circRNA) is a type of closed circular RNA molecules formed by reverse splicing, which exists widely in organisms and has become a research hotspot in non-coding RNAs in recent years. Skeletal muscle plays the role of coordinating movement and maintaining normal metabolism and endocrine in organisms. With the development of sequencing and bioinformatics analysis technology, the functions and regulation mechanisms of circRNAs in skeletal muscle development have been gradually revealed. In this review, we summarize the types of molecular regulatory mechanisms, the classical research ideas and the functional research methods of circRNAs, and the research progress of circRNAs involved in normal development of skeletal muscle and regulation of skeletal muscle disease, in order to provide a reference to further study of the genetic mechanisms of circRNAs in the regulation of skeletal muscle development.

Mycobacterium tuberculosis biofilms harbour drug-tolerant bacteria. Identification of drugs that inhibit biofilm formation could enable the dramatic shortening of tuberculosis treatments using standard antibiotics. Arisaema sinii Krause is used to treat pulmonary and lymphatic tuberculosis by Dong People of China. Current study was aimed to purify the active components against M. tuberculosis biofilms from Arisaema sinii extract by using bioassay-guided isolation. (E)-2-(methyl (phenyl) amino) ethyl 2-(2-hydroxyundecanamido)-7, 11-dimethyl-3-oxotetradec-4-enoate, compound 1, was identified as the active component. It could inhibit mycobacterial biofilm formation, disperse the preformed biofilms, and disrupt the mature biofilms at concentration of 4, 8, and 32 μg/ml, respectively. At the dose of 32 μg/ml, it could potentiate the bactericidal activity of isoniazid against M. tuberculosis in mature biofilms. The results of this study indicate that compound 1 might be a novel lead compound against mycobacterial biofilm formation., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

MiR-222-3р has been implicated in tumor cell proliferation and has an important role in the differentiation and maturation of myogenic cells. However, its role in skeletal myoblast proliferation is still unclear. In this study, we found that miR-222-3р expression increases initially and then decreases during C2C12 myoblast proliferation. Using synthetic miRNA mimics and inhibitors in gain- or loss-of-function experiments, we snowed that miR-222-3р overexpression in C2C12 cells promotes myoblast proliferation and represses myofiber formation, while miR-222-3р downregulation has the opposite effect. Using a prediction program, BTG2 was identified as a possible target gene of miR-222-3р. During myogenesis, miR-222-3р mimics repress BTG2 expression, while miR-222-3р inhibitors promote BTG2 expression. Using dual-luciferase reporter assay, we further demonstrated that miR-222-3р specifically targets BTG2. Additionally, we show that siRNA-mediated downregulation of BTG2 expression in C2C12 myoblasts promotes the proliferation and suppresses differentiation. In conclusion, we provide a novel insight into the mechanism by which miR-222-3р regulates the proliferation and differentiation of C2C12 myoblasts by targeting BTG2. This information contributes to our understanding of the role of miRNAs in skeletal muscle development.

Objective: To determine the transmission characteristics of Cysticercuscellulose infections from a social network perspective in Tibetan school children in Sichuan., Methods: A cluster sampling strategy was adopted to select two primary schools with high level of Cysticercuscellulose infections in the Tibetan agriculture areas of Liangshan prefecture, Sichuan province. All of the students from the selected schools were enrolled in the study. Their social network data, including classroom seating, dormitory roommates, best playmates, and those who shared meals and snacks etc, were collected by trained investigators. Stool and blood samples of the students were collected for parasite detection. The transmission network of Cysticercuscellulose infections and the overall social network of school children were analysed., Results: A total of 644 children participated in the study. Taenia solium were found in 6.11% of the stool samples and 13.25% blood samples returned with seropositive. The transmission was centered around the sources of infections: dormitory-clustering in the boarding school and playmate-clustering in the day school. The overall social network analysis revealed "core people" (more relationships), "information disseminators" (closer to other nodes) and "information hubs" (between two nodes) in both schools., Conclusion: Close contacts in dormitories and playgrounds are the main sources of transmission of cysticercosis in the Tibetan schools. The "core people" "information disseminators" and "information hubs" are critical for the prevention and control of cysticercosis in the future., (Copyright© by Editorial Board of Journal of Sichuan University (Medical Science Edition).)

Using a combination of various chromatographic techniques including column chromatography over silica gel, Sephadex LH-20, macroporous adsorbent resin, and reversed-phase HPLC, 115 compounds including diterpenes, sesquiterpenes, treterpenes, coumarins, lignans, fatty acid derivatives, and simple aromatic derivatives were isolated from an ethanol extract of branch of Fraxinus sieboldiana (Oleaceaue), and their structures of the compounds were elucidated by spectroscopic methods including 1 D, 2D NMR and MS techniques. Among them, 41 compounds were new. In previous reports, we have been described the isolation, structure elucidation, and bioactivities of the 41 new compounds and 22 known orii including 8 coumarins, 4 phenolic and 12 phenylethanoidal glycosides. As a consequence, we herein reported the isolation and structure elucidation of the remaining 50 known compounds including 8- hydroxy-12-oxoabieta-9(11),13-dien-20-oic 8, 20-lactone(1), 6beta-hydroxyfcrruginol(2),(+)-pisiferic acid(3), (+)-pisiferal(4),(+)-7-dehydroabiet6none(5), 1-oxomiltirone(6), subdigitatone(7), linarionoside B(8), (9S)-linarionoside B(9), (3R,9R)-3-hydroxy-7,8-dihydro-beta-ionol 9-O-beta-D-apiofuranosyl-(1-->6)-beta-D-glucopyranoside(10), ursolic acid(11), betulinic acid(12), euscaphic acid(13), (+)-syringaresinol(14), (+)-fraxiresinol(15), (+)-1-hydroxysyringaresinol(16), pinoresinol(17), medioresinol(18), 8-acetoxypinoresinol(19), epipinoresinol(20), (-)-olivil(21), (+)-cyclo-olivil(22), 3,3'-dimethoxy-4,4',9-trihydroxy-7,9'-epoxylignan-7'-one(23),(+)-1-hydroxypinoresinol 4'-O-beta-D-glucopyranoside (24), (+)-1-hydroxypinoresinol 4"-O-beta-D-glucopyranoside(25),(+)-syringaresinol O-beta-D-glucopyranoside (26), liriodendrin (27), ehletianol D(28), icariside E5(29) (-)-(7R, 8R)-threo-1-C-syringylglycerol(30),(-)-(7R, 8S)-erythro-guaiacylglycerol (31),(-)-(7R, 8R)-threo-guaiacylglycerol(32), 3-(4-beta-D-glucopyranosyloxy-3-methoxy)-phenyl-2E-propenol(33),2,3-dihydroxy-l-(4-hydroxy-3,5-dimethoxyphenyl)-1-propanone(34), 2,3-dihydroxy-1-(4-hydroxy-3-methoxyphenyl)-1-propanone (35), 3-hydroxy-l-(4-hydroxy-3,5-dimethoxyphenyl)-1-propanone(36), omega-hydroxypropioguaiacone(37), sinapyladehyde(38), trans-p-hydroxycinnamaldehyde(39), syringic acid(40), vanilic acid(41), vanillin(42), 4-hydroxy-benzaldehyde (43), (24R)-24-ethyl-5alpha-cholestane-3beta,5,6beta-triol(44), beta-sitosterol(45), daucosterol(46), 2,6-dimethoxy-I,4-benzoquinone(47), 2,6-dimethoxy-pyran-4-one(48), 1-(beta-D-ribofuranosyl)uracil(49), and mannitol(50). Compouds 1-7,12,18,28-37,44 and 48 were obtained from the genus Fraxinus for the first time.

The crude extracts of the fermentation broth from a marine sediment-derived actinomycete strain, Saccharothrix sp. 10-10, showed significant antibacterial activities against drug-resistant pathogens. A genome-mining PCR-based experiment targeting the genes encoding key enzymes involved in the biosynthesis of secondary metabolites indicated that the strain 10-10 showed the potential to produce tetracenomycin-like compounds. Further chemical investigation of the cultures of this strain led to the identification of two antibiotics, including a tetracenomycin (Tcm) analogs, Tcm X (1), and a tomaymycin derivative, oxotomaymycin (2). Their structures were identified by spectroscopic data analysis, including UV, 1D-NMR, 2D-NMR and MS spectra. Tcm X (1) showed moderate antibacterial activities against a number of drug-resistant pathogens, including methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococci (VRE) pathogens, with the MIC values in the range of 32-64 microg x mL(-1). In addition, 1 also displayed significant cytotoxic activities against human cancer cell lines, including HL60 (leukemia), HepG2 (liver), and MCF-7 (breast) with the IC 50 values of 5.1, 9.7 and 18.0 micromol x L(-1), respectively. Guided by the PCR-based gene sequence analysis, Tcm X (1) and oxotomaymycin (2) were identified from the genus of Saccharothrix and their 13C NMR data were correctly assigned on the basis of 2D NMR spectroscopic data analysis for the first time.

In the last decade, along with the development of taxonomy research in marine-derived actinobacteria, more and more halogenated natural products were discovered from marine actinobacteria. Most of them showed good biological activity and unique structure compared to those from land. The special halogenation mechanism in some compounds' biosynthesis has drawn great attention. So in this review, we focus on the halogenated natural products from marine actinobacteria and their halogenation mechanisms.

Six new butanolide derivatives with long aliphatic side chains (1-6), together with 23 known lipophilic constituents, were isolated from the bark of Machilus yaoshansis. Their structures were elucidated by spectroscopic and chemical methods. All the isolates were evaluated for cytotoxic and anti-inflammatory activities.

Nine new fatty acid derivatives, including seven methoxylated (1, 2, and 4-8) and two hydroxylated (3 and 9) fatty acids, have been isolated from the ethanol extract of the stem bark of Fraxinus sieboldiana. Their structures were determined by spectroscopic methods including IR, MS, 1D, and 2D NMR experiments. The 3- or 9-methoxylated fatty acids are reported for the first time in nature.