Monofloral honey samples (Coffea robusta) from Vietnam were determined for their chemical compositions. This is the first report on the chemical composition and antioxidant activity of coffee honey from Vietnam. These samples were characterized by their high contents of total and reducing sugars, total phenolic contents, and total flavonoid contents. The contents of seven phenolic acids (PAs) were quantified by high performance liquid chromatography (HPLC) and analyzed with the assistance of principle component analysis (PCA) to differentiate the honey samples into groups. The hydroxymethylfurfural (HMF) (0.048–2.933 mg/kg) and free acid contents (20.326–31.163 meq/kg) of coffee honey were lower in Nepal, which reflected the freshness of the honey when conducting this survey. The coffee honey had total sugar and reducing sugar contents 831.711 g/kg and 697.903 g/kg, respectively. The high level of total phenolic (0.642 mg GAE/g) and flavonoid (0.0341 mg GE/g) contents of coffee honey contributed to their antioxidant activity of this honey sample. Among the coffee honey tested, the IC50 of DPPH radical-scavenging activities value was 1.134–17.031 mg/mL, while the IC50 of ABTS radical-scavenging activities value was 115.381–213.769 mg/mL. The phenolic acids composition analysis displayed that gallic acid appeared in high concentrations in all studied honey samples, ranging from 0.037–1.015 mg/kg, and ferulic acid content ranged from 0.193 to 0.276 mg/kg. The content of trigonelline and caffeine in coffee honey samples ranged from 0.314–2.399 mg/kg and 8.946–37.977 mg/kg. The data in this article highlight the relevance of coffee honey as a healthy substance.
Ginger, a commonly used spice and medicinal herb, is an abundant source of bioactive compounds. However, the utilization of ginger in the pharmaceutical industry is still moderate and not commensurate with the potential of the Vietnamese horticulture industry, mainly due to a lack of information about the quality of input materials. In this study, we compared the volatile compounds of gingers collected from 13 provinces of Vietnam using GC/MS and GC-FID analysis to provide a basis for selecting and standardizing input materials. Furthermore, ginger essential oil from Ben Tre province of Vietnam exhibited significant antibacterial activity particularly in inhibiting Gram-positive bacteria, including S. aureus and S. epidermidis, with inhibition zones of 30.00 ± 1.41 and 24.67 ± 3.30 mm, respectively. However, no significant inhibition was observed against Gram-negative bacteria P. aeruginosa and E. coli. We also isolated 5 non-volatile compounds from ginger extract, namely 6-shogaol (1), quercetin (2), rutin (3), beta-sitosterol (4) and beta-sitosterol-3-O-beta-D-glucopyranoside (5). Among them, compounds 1–3 displayed cytotoxicity against Hep3B, SK-LU-1, MCF-7, SK-LU-1, SW480 and HepG2 tumour cell lines, with an IC50 values ranging between 62.7 ± 2.1 and 97.6 ± 1.1 µM, using Ellipticine as a positive control. Compounds 4 and 5 showed cytotoxicity against Hep3B and HepG2 tumor cells, with the IC50 values ranging between 21.5 ± 5.1 and 46.9 ± 3.7 µM but did not exhibit any significant cytotoxicity against SW480 and SK-LU-1 cells. Compound 4 also demonstrated middling cytotoxicity against the MCF7 cell line, with an IC50 value of 43.6 ± 5.1 µM. These findings suggest further applications of Vietnamese ginger for the treatment of infectious and cancer-related diseases.
27 December 2024 in Proceedings of universities. Applied chemistry and biotechnology
This study evaluated the antifungal and antioxidant activities of earthworm (Perionyx excavatus) powder extracts using different solvents including 80% ethanol, 50% ethanol, and distilled water. The extraction efficiencies ranged from 18.5 to 21.2%, while total protein contents ranged from 64.8 to 67.5%. Notably, the aqueous extract exhibited the highest values in both extraction efficiency and total protein content. Thin-layer chromatography analysis revealed the presence of amino acids and peptides with Rf values ranging from 0.42 to 0.65. Fourier-transform infrared spectroscopy spectra displayed characteristic peaks associated with protein structures. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis indicated protein compositions primarily below 50 kDa molecular weight in the extracts, particularly with the 80% ethanol extract predominantly consisting of proteins below 30 kDa. Antifungal tests against Candida albicans demonstrated the highest efficacy with 80% ethanol extract, exhibiting an inhibition zone diameter of 13.3 mm and a minimum inhibitory concentration of 75 mg/mL. Additionally, the extracts showed DPPH and ABTS radical scavenging activities, with 80% ethanol extract displaying the highest antioxidant potential with IC50 values of 231.3 μg/mL for DPPH assay and 208.9 μg/mL for ABTS assay. In conclusion, earthworm powder extracts exhibited significant biological activities, rendering them promising candidates for pharmaceutical and cosmetic applications.
17 November 2021 in Chemistry of Natural Compounds