This is the first study to investigate the effect of ethanol concentrations on the phenolic content and biological activities of Sripanya Punica granatum peel extract. Various concentrations of ethanol, (20 to 80% v/v), were used in the maceration process. Extracts were investigated for total phenolic content by the Folin–Ciocalteu method, antioxidant activities by 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2’-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) assay, and anti-tyrosinase activity by a spectrophotometric method. The chemical composition was investigated using high-performance liquid chromatography. The irritation of the extracts was determined by Hen’s egg test–chorioallantoic membrane assay. The results demonstrated that E60, which was extracted using 60% v/v ethanol, had the highest yield (66.23 ± 0.38% w/w), the highest total phenolic content (490.42 ± 7.20 μg GAE/g), and the highest antioxidant and anti-tyrosinase activities. IC50 values on DPPH• and ABTS•+ inhibition were 10.97 ± 0.97 and 6.48 ± 0.06 µg/mL, respectively. The 60% v/v ethanol extract (E60) possessed strong tyrosinase inhibition with an IC50 value of 0.10 ± 0.13 µg/mL, which is more potent than kojic acid. The major constituents were punicalagin (4.05 ± 0.26% w/w) and ellagic acid (0.63 ± 0.04% w/w). E60 was safe for topical application since it did not induce irritation. Therefore, we suggest that E60 is a promising agent for further product development.
18 October 2023 in Journal of the Taiwan Institute of Chemical Engineers
A new composite system, Ba(Zr0.07Ti0.93)O3 (BZT93) ceramic/NiO nanoparticles, was fabricated to investigate the effect of NiO nanoparticles on the properties of these composites. M-H hysteresis loops showed an improvement in the magnetic behavior for higher NiO content samples plus modified ferroelectric properties. However, the 1 vol.% samples showed the optimum ferroelectric and ferromagnetic properties. Examination of the dielectric spectra showed that the NiO additive promoted a diffuse phase transition, and the two phase transition temperatures, as observed for BZT93, merged into a single phase transition temperature for the composite samples.
1 January 2022 in Microporous and Mesoporous Materials
Propolis is the mixture of resins that honeybees collect from plant buds, leaves and exudates. Antimicrobial and antioxidant properties of propolis have been widely studied, however, there have few reports on Thai propolis. To increase the efficient extraction of organic propolis compounds, extraction methods have been developed. We applied the ultrasound technology to reduce extraction time and increase extraction yields of propolis. The propolis was extracted using ultrasound technology for 15-60 minutes and the propolis extracts were examined to compare their biological activities. Antimicrobial activities of the propolis were investigated using the agar well diffusion method. The free radical-scavenging and antioxidant activities of propolis extracts were measured using the DPPH and FolinCiocalteau colorimetric methods. The propolis extracted using ultrasound for 15 and 30 minutes showed inhibitory effects on tested fungi and bacteria as well as antioxidant activities.