A series of new pleuromutilins derivatives were designed and synthesized through coupling 2-aminothiazole ring of WL001 with different nitrogen-containing substituted heterocycles in the side chain. Their biological activities were evaluated against both Gram-positive and Gram-negative clinical bacteria in vitro Most new compounds displayed specificity to certain strain of bacteria. Particularly, compounds with saturated nitrogen-containing heterocycles exhibited significant antibacterial activities (0.062 5-8 µg · mL(-1)) superior or similar to those of amoxicillin, tiamulin and levofloxcin. Furthermore, treatment with 15a and 15b having piperidine or morpholine residues also could effectively inhibit Gram-negative bacteria. Therefore, our novel findings may provide a new insight into the design of novel pleuromutilin derivatives and lay the basis for further studies on the treatment of drug-resistance of pathogenic bacteria.
The aim of this study is to investigate the anti-inflammatory effect of the adenosine derivative N6-(3-hydroxylaniline) adenosine (WS070117M1) on cigarette smoke plus LPS (lipopolysaccharide)-induced chronic obstructive pulmonary disease (COPD) in mice and its mechanism. COPD model was established by exposing male BALB/c mice to cigarette smoke and challenged with LPS inhalation. Supernatants of bronchoalveolar lavage fluid (BALF) were harvested and IL-1β, IL-6, IL-8 and TGF-β1 levels were measured by ELISA (enzyme-linked immunesorbent assay). The number of total white blood cells and neutrophils in bronchoalveolar lavage fluid was counted separately. Lung tissue was stained with Mayer 's hematoxylin and eosin for histopathologic examination. pAMPKa protein expression and distribution of lung tissue were analyzed by immunohistochemistry method. In vitro, levels of AMPKα phosphorylation in phorbol-12- myristate-13-acetate (PMA) differentiated THP-1 cells was detected by immunohistochemistry, IL-8 level in supernatants of cigarette smoke condensate stimulating PMA differentiated THP-1 cells was measured by ELISA. The results showed that WS070117M1 treatment significantly activated AMPKa in the lung tissue. It also resulted in down regulation of IL-1β, IL-6, IL-8 and TGF-β1 levels in bronchoalveolar lavage fluid and IL-8 level in cigarette smoke condensate stimulating PMA differentiated THP-1 cells. In addition, WS070117M1 could inhibit the recruitment of total white blood cells and neutrophils. These results suggest that WS070117M1 may alleviate the airway inflammation by activating AMPK in the lung tissue.
To study the chemical constituents of the traditional Chinese herb Baeckea Frutescens L., a new flavonol glycoside, named 6, 8-dimethylkaempferol-3-O-alpha-L-rhamnoside (1), together with seven known compounds: quercetin (2), quercetin-3-O-alpha-L-rhamnoside (3), myricetin (4), myricetin-3-O-alpha-L-rhamnoside (5), gallic acid (6), ursolic acid (7) and 1,3-dihydroxy-2-(2'-methoxylpropionyl)-5-methoxy-6-methylbenzene (8) were isolated by using silica gel column chromatography, polyamide column chromatography and recrytallization. Their structures were identified on the basis of physicochemical properties and spectroscopic analysis. Among them, compounds 2-7 were isolated from this plant for the first time and compound 8 was first isolated from plant.
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