Enzyme inhibition and antibacterial potential of 4-Hydroxycoumarin derivatives

The 4-Hydroxycoumarin derivatives are known to show a broad spectrum of pharmacological applications. In this paper we are reporting the synthesis of a new series of 4-Hydroxycoumarin derivatives synthesized through Knovenegal condensation; they were characterized by using UV-Vis, FT-IR, NMR spectroscopies. The synthesized compounds were evaluated for antibacterial activity against Staphylococcus aureus and Salmonella typhimurium strains. The compounds (2), (3) and (8) showed favorable antibacterial activity with zone of inhibitions 26.5± 0.84, 26.0 ± 0.56 and 26.0 ± 0.26 against Staphylococcus aureus (Gram-positive) respectively. However, the compounds (5) and (9) were found more active with 19.5 ± 0.59 and 19.5 ± 0.32 zone of inhibitions against Salmonella typhimurium (Gram-negative). Whereas, in urease inhibition assay, none of the synthesized derivatives showed significant anti-urease activity; although, in carbonic anhydrase-II inhibition assay, the compound (2) and (6) showed enzyme inhibition activity with IC50 values 263±0.3 and 456±0.1, respectively.

The in vitro and in vivo investigation of biological activities and phenolic analysis of Helichrysum plicatum subsp. plicatum

In Turkey, Helichrysum genus is represented by 26 taxa belonging to 20 species in Turkish flora of which 14 ones are endemic to Turkey. The aerial parts of Helichrysum plicatum subsp. plicatum are used kidney stones, kidney and stomach ailments. The extraction procedures and solvents are important step in processing of bioactive constituents from the plant materials. Therefore, the aim of this study was to evaluate in vitro antioxidant, antimicrobial, anti-urease, anticholinesterase and in vivo anti-inflammatory activities of Helichrysum plicatum subsp. plicatum different extracts. In addition, the phenolic characterization of the Soxhlet and maceration methanol extracts which showed significant antioxidant, anti-urease, antimicrobial, anti-inflammatory and anticholinesterase activities were performed by HPLC-DAD and LC-MS/MS. In the present study, the Soxhlet methanol extract exhibited strong antioxidant, antimicrobial and anticholinesterase activities than other extracts. The maceration methanol extract showed the strongest anti-urease activity. The Soxhlet methanol and maceration methanol extracts showed in vivo anti-inflammatory activities very close to each other. As a result of this study, chlorogenic acid, dicaffeoylquinic acid, luteolin, luteolin-7-O-glucoside, naringenin-O-hexoside and isoquercitrin compounds were analysed in plant. Therefore, it is thought that methanol extracts can be used as a natural source in the future for food and pharmaceutical industries.