In order to discover new antibacterial agents, series of 2-salicyloylbenzofuran derivatives were designed, synthesized and evaluated for their antibacterial activities against three Gram-(+) strains (methicillin-sensitive Staphylococcus aureus (MSSA) ATCC 29213, methicillin-resistant Staphylococcus aureus (MRSA) ATCC 43300, and Streptococcus faecalis (S. faecalis) ATCC 29212) and one Gram-(-) s...

BACKGROUND Antibacterial activity of honey is mainly dependent on a combination of its peroxide activity and non-peroxide components. This study aims to investigate antibacterial activity of five varieties of Malaysian honey (three monofloral; acacia, gelam and pineapple, and two polyfloral; kelulut and tualang) against Staphylococcus aureus, Bacillus cereus, Escherichia coli, and Pseudomonas a...

BACKGROUND Staphylococcus aureus is the direct reason of mastitis. Mastitis is a disease characterized by pathological changes in mammary glands as well as physical, chemical, bacteriological changes in milk. This disease causes loses in milk yield and quality. In recent years, it is reported that mastitis pathogens have developed a resistance to antibiotics as a natural consequence of widespre...

In this study, 2-(N-pyrrolidine-alkyl) tanshinones bearing pyrrolidine groups were synthesized and the antibacterial mechanism was explored. These derivatives selectively elicited antibacterial activity against Gram-positive bacteria. Moreover, their antibacterial activities were time-, concentration-dependent and persistent. It appeared that Fenton-mediated hydroxyl radicals were involved, and...

Chitin, chitosan and quaternary chitosan films were prepared, and the mechanical properties and the antibacterial activities of chitosan and quaternary chitosan films were evaluated. The tensile strength of chitin films was 30-40% lower than that of chitosan films, but the crystallinity of the former was much higher than those of the latter. A detailed analysis of the crystallinity and orientat...

Cinnamaldehyde is a natural product with broad spectrum of antibacterial activity. In this work, it was used as a template for design and synthesis of a series of 17 cinnamylideneacetophenones. Phenolic compounds 3 and 4 exhibited MIC (minimum inhibitory concentration) and MBC (minimum bactericidal concentration) values of 77.9 to 312 µM against Staphylococcus aureus, Streptococcus mutans, and ...

Ursolic acid, an important bioactive compound, was isolated from ethanol extract of aerial parts of Sambucus australis. In order to develop bioactive ursolic acid derivatives, two semi-synthetic compounds were obtained through modification at C-3. The antibacterial activity of the ursolic acid and its derivatives was investigated. The microdilution method was used for determination of the minim...

The first phytochemical investigation of the fruits of Angelica lucida has led to the isolation and characterization of five known coumarins (imperatorin, isoimperatorin, heraclenol, oxypeucedanin hydrate and heraclenin). All isolated compounds were identified by means of spectral and literature data. The extracts and the isolated constituents from A. lucida have been also evaluated for their a...

The new compound Z-4-2 was isolated from the fermentation broth of Streptomyces djakartensis NW35, together with the known compound N-acetyltryptamine (Z-9-2) by bioassay-guided fractionation. Its chemical structure was elucidated as (E)-2-methoxy-1,4 naphthoquinone-1-oxime (Z-4-2) mainly by NMR analyses and MS spectral data. Their antibacterial activities against bacteria were evaluated by the...

Three ovine-derived cathelicidins, SMAP29, OaBac5mini, and OaBac7.5mini, were compared with respect to their antibacterial activities and interactions with membranes. SMAP29 was confirmed to be alpha-helical, broad spectrum, and able to disrupt both the outer and the cytoplasmic membranes at relatively low concentrations. In contrast, the two proline- and arginine-rich OaBac peptides had more-m...