The new conjugates of selected bile acids (hyocholic (2), deoxycholic (3), hyodeoxycholic (4) and 12-ketocholic (5) acids) with ethyl 11-aminoundecanoate 7, 8, 11, and 13 were synthesized. The conjugation reaction was carried out in ethyl acetate in the presence of N-ethoxycarbonyl-2-ethoxy-1,2-dihydroquinoline (EEDQ) and triethylamine. Under the same experimental conditions, the conjugation reaction involving ethyl 6-aminohexanoate resulted in formation of a conjugate 9 only in the case of deoxycholic acid (3) in addition to the unexpected ethyl ester 10. In the case of the other bile acids (cholic (1), hyodeoxycholic (4) and 12-ketocholic (5) acids) only an unexpected ester formation took place giving esters 6, 12, and 14. Cytotoxic activity against four tumor cell lines (human breast adenocarcinoma ER-, MDA-MB-231; breast adenocarcinoma ER+, MCF-7; cervix epiteloid carcinoma, HeLa S-3; and prostate cancer, PC-3) was evaluated. Conjugate 8 showed strong activity against HeLa S-3 and conjugate 11 for PC-3. Ethyl ester of 12-ketocholic acid 14 showed very strong antiproliferative activity against MCF-7 and HeLa S-3
The study goal was to provide an overview of antibiotic prescribing practices of Serbian dentists when treating endodontic infections and to disseminate the current ESE (European Society of Endodontology) recommendations to the study participants. A link to an online questionnaire was sent to 628 Serbian dentists whose email addresses were publicly available on the Internet, 158 of whom responded to the survey, resulting in a 25.16% response rate. The significance of possible associations was assessed via the Chi-squared test and Cramer’s V measure of association, with p < 0.05 considered as statistically significant. According to the study findings, 55.7% of respondents prescribed a 5-day antibiotic course. Moreover, Amoxicillin 500 mg was the first-choice antibiotic for 55.1% of the respondents, followed by Clindamycin 600 mg (18.4%). For patients allergic to penicillin, 61.4% of respondents prescribed Clindamycin. Statistically significant differences emerged only in relation to acute apical abscess with systemic involvement, whereby dentists aged 46–55 were least likely to prescribe antibiotics in these clinical situations (p = 0.04). Analyses further revealed that recommendations for safe antibiotic prescribing practices were not always followed, as in certain cases, patients were given antibiotics even when this was not indicated. These findings highlight the need for additional education on responsible antibiotic use to prevent bacterial resistance.
The multistage syntheses of the p-toluenesulphonyloxy esters (1-benzyloxy-4-p-toluenesulphonyloxybutane (3a) 1-benzyloxy-6-p-toluenesulphonyloxyhexane (3b) and 1-benzyloxy-10-p-toluenesulphonyloxydecane (3c)(, alkyl chlorides (1-benzyloxy-4-chlorobutane (4a), 1-benzyloxy-6-chlorohexane (4b) and 1-benzyloxy-10-chlorodecane (4c)(, as well as alkyl iodides (1-benzyloxy-4-iodobutane (5a), 1-benzyloxy-6-iodohexane (5b) and 1-benzyloxy-10-iododecane (5c)( with the terminal O-benzyl groups starting from 1,4-butanediol (1a), 1,6-hexanediol (1b) and 1,10-decanediol (1c) were carried out. The possibilities of formation and addition of the corresponding Grignard reagent to the C-17 carbonyl group of dehydroepiandrosterone were investigated
The aim of this paper is selection and analysis of articles with chemistry content in selected Serbian journals in the second half of the 19th century, which were aimed towards general public, in order to get insight into the level and quality of additional chemistry informing of readers. Two journals were selected, that contained entertaining, literature and scientific content ('Sedmica' and 'Vila'), and two other, with entertainment and literature nature ('Danica' and 'Matica'). The analyzed journals primarily addressed the general public and played an important role in readers' information and education. Historical method was applied in this research. The above-mentioned journals were analyzed separately, with the short historical survey. Complete editions of these journals were analyzed, and the selection of articles was made according to the textual content or the title itself. The chemistry content presented in these journals is of the great variety. Among other things, interesting comments of the chemical schoolbooks are found, as well as lectures on science
In this paper a part of the model of the curriculum, which should improve chemical education in primary schools is presented. The implemented module refers to metals and non-metals in the fields of applied chemistry and chemical industry. Contents of the curriculum from 1974 to 2004 are considered. The quantity and quality of the pupils' knowledge are analyzed. The research showed that the pupils' knowledge is low. The module is implemented for the sake of overcoming the observed drawbacks in the curriculum, which should facilitate further chemical education, especially in the field of chemical technology. Contents of the curriculum, ways of implementation of the contents, and methods for evaluation of the pupils' knowledge are proposed considering the results of the research. For this purpose the method of descriptive analysis and statistical methods are used
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