Culture broth of an actinomycete isolate, Nocardia sp. CS682 showed specifically higher antibacterial activity against methicillin resistant Staphylococcus aureus (MRSA). Purified substance from the organism, CS-682, which is active against MRSA and Micrococcus leuteus, is a C(28)H(37)NO(8) (M+H(+), observed: 516.83) and identified as an unusual macrolide antibiotic, nargenicin. The chemical structure of CS-682 was identified by FT-IR, (1)H-NMR, (13)C-NMR, and ((1)H-(1)H and (1)H-(13)H) COSY. The anti-MRSA activity of CS-682 was stronger than that of oxacillin, vancomycin, monensin, erythromycin, and spiramycin. Phylogenetic analysis showed that strain CS682 is closely related to Nocardia tenerifensis DSM 44704(T) (98.7% sequence similarity), followed by N. brasiliensis ATCC 19296(T) (98.4% sequence similarity). The ability of Nocardia sp. CS682 to produce nargenicin was unique.
Camellia japonica L. is a plant of which the seeds are used as a folk medicine, and it is native to South Korea, Japan and China. In previous study, triterpenes, flavonoids, tannins and fatty acids which have antiviral, antioxidant and anti inflammatory activity were reported from C. japonica leaf and flower. In Korea, the seed from this plant is used as a traditional medicine and in folk remedies for the treatment of bleeding and inflammation. However, the major issue associated with the use of the seed as a medicinal and/or functional food ingredient is its application to the pharmaceutical and food industry. First, the productivity of seed extract is very much less than that of the leaf. Second, the beneficial usage of the seed extract as an alternative medicine and functional source is not yet clear. Thus, in this study, we focused on another part of the plant, the leaf, and found that the extract of Camellia japonica leaf has a high concentration of vitamin E, rutin and other biologically active compounds related to hyperuricemia. We aimed to investigate the biological activities, namely the antioxidant activities, xanthine oxidase (XO) inhibitory activity and anti‑hyperuricemic effects of extract from C. japonica leaf and the phytochemicals contained therein. Ethanol extracts of C. japonica leaf (ECJL) were prepared, and the extract was used with respect to antioxidant activities, total phenolic contents and XO inhibitory activity. The in vivo XO inhibitory activity and anti‑hyperuricemic effects of the extract were evaluated in mice with potassium oxonate‑induced hyperuricemia. To clarify the marker compounds that are responsible for the anti‑hyperuricemic effects, several key constituents were identified using gas chromatography‑mass spectrometry (GC‑MS) and and liquid chromatography-mass spectrometry (LC-MS). ECJL was found to have strong antioxidant activities, and in vitro XO inhibitory activity. The results of the in vivo experiments using mice demonstrated that ECJL at the doses of 100 and 300 mg/kg inhibited hepatic XO activity and significantly attenuated hyperuricemia. To the best of our knowledge, the present study is the first report on the XO inhibitory and anti-hyperuricemic effects of ECJL, which can be therapeutically applied in the treatment of hyperuricemia and gout.
The present study was performed to evaluate the antibacterial activities of an antimicrobial peptide (CSpK14) and the synergies thereof with β-lactams against vancomycin-resistant Staphylococcus aureus (VRSA) and Enterococci (VRE). Our strain was isolated from fermented food (kimchi), which is 99.79 % homologous with Bacillus amyloliquefaciens subsp. plantarum FZB42(T). CSpK14 was purified to homogeneity by diammonium sulfate precipitation, concentration, dialysis, and followed by two-stage chromatographic separation, i.e., Sepharose Cl-6B and Sephadex G-25 chromatography, and had a molar mass of ~4.6 kDa via Tricine SDS-PAGE and in situ examination. It was stable at pH 6.0-11.5 and temperature up to 80 °C. In addition, it was also stable with various metal ions, solvents, and proteases. The N-terminal amino acid sequence was H-Y-D-P-G-D-D-S-G-N-T-G and did not show any significant homology with reported peptides. However, it shows some degrees of identity with alpha-2-macroglobulin and ligand-gated channel protein from different microorganisms. CSpK14 significantly reduced the minimum inhibitory concentrations (MICs) of β-lactams and had no effect on non-β-lactams against VRSA and VRE. MICs of CSpK14/oxacillin and CSpK14/ampicillin were reduced by 8- to 64-fold and 2- to 16-fold, respectively. The time killing assay between CSpK14/oxacillin (2.29-2.37 ΔlogCFU/mL at 24 h) and CSpK14/ampicillin (2.30-2.38 ΔlogCFU/mL at 24 h) being >2-fold and fractional inhibitory concentration index ˂0.5 revealed synergy. Furthermore, the biofilms formed by VRSA and VRE were reduced completely. CSpK14 was simple to purify, had low molecular mass, was stable over a wide pH range or tested chemicals, had broad inhibitory spectrum, and possessed potent synergistic antimicrobial-antibiofilm properties. CSpK14 synergistically enhanced the efficacy of β-lactams and is therefore suitable for combination therapy.
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