Search Results (5)

The aim of this work was to assess the chemical composition and physico-chemical, techno-functional, and in vitro antioxidant properties of flours obtained from the peel and flesh of pitahaya (Hylocereus ocamponis) to determine their potential for use as ingredients for food enrichment. The chemical composition, including total betalains, mineral content, and polyphenolic profile, was determined. The techno-functional properties (water holding, oil holding, and swelling capacities) were also evaluated. For the antioxidant capacity, four different methodologies, namely ferrous ion-chelating ability assay, ferric-reducing antioxidant power assay; 1,1-Diphenyl-2-picrylhydrazyl radical scavenging ability assay, and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) radical assay, were used. Pitahaya-peel flour had higher values for protein (6.72 g/100 g), ash (11.63 g/100 g), and dietary fiber 56.56 g/100 g) than pitahaya-flesh flour, with values of 6.06, 3.63, and 8.22 g/100 g for protein, ash, and dietary fiber, respectively. In the same way, pitahaya peel showed a higher content of minerals, betalains, and polyphenolic compounds than pitahaya-flesh flour, with potassium (4.43 g/100 g), catechin (25.85 mg/g), quercetin-3-rhamnoside (11.66 mg/g) and myricetrin (12.10 mg/g) as principal compounds found in the peel. Again, pitahaya-peel flour showed better techno-functional and antioxidant properties than pitahaya-flesh flour. The results obtained suggest that the flours obtained from the peel and pulp of pitahaya (H. ocamponis) constitute a potential material to be utilized as an ingredient in the food industry due to the high content of bioactive compounds such as betalains, phenolic acids, and flavonoids, with notable antioxidant capacity. Full article

Myrica rubra (Lour.) Siebold & Zucc bark is a traditional natural medicine used by the people of the Dong minority in western Hunan in China. In this study, the main compounds in Myrica rubra bark including epigallocatechin gallate, myricetrin, myricetin, taraxerol, myricanol, and 11-O-acetylmyricanol were separated using both silica gel column chromatography and high-speed countercurrent chromatography (HSCCC). Notably, it is the first report of discovering 11-O-acetylmyricanol from Myrica rubra bark. The results of the bioactivity studies suggested that epigallocatechin gallate showed the highest α-glucosidase inhibitory activity, while myricetin exhibited the highest reactive oxygen species (ROS) scavenging ability in zebrafish embryos. Intriguingly, myricanol exhibited strong apoptosis-inducing activity on HepG2 cells, and further studies revealed that myricanol was capable of promoting the cleavage of caspase 3, 8, and 9, then resulting in the apoptosis in HepG2 cells. The findings of the present study have important implications for the separation of the main compounds in Myrica rubra and will provide credence to the ethnomedicinal application of the isolated compounds against cardiovascular disease and cancer. Full article

Two new lactones, named Ardisicreolides A–B (1–2), together with four known flavonoids, Quercetin (3), Myricetrin (4), Quercitrin (5), Tamarixetin 3-O-rhamnoside (6), were isolated from the ethyl acetate portion of 70% ethanol extracts of dried leaves from Ardisia crenata Sims. These compounds were identified from Ardisia crenata Sims for the first time. The structures of 1–6 were elucidated according to 1D and 2D-NMR methods and together with the published literature. All of the isolated compounds were evaluated for in vitro anti-microbial effect against Escherichia coli, Pseudomonas aeuroginosa, Enterococcus faecalis, Proteus vulgaris, Staphylococcus aureus, and Bacillus subtilis. In addition, compounds 1–2 were assessed for anti-inflammatory activity by acting on LPS-induced RAW 264.7 macrophage cells in vitro. The results showed that only compound 2 exhibited moderate antibacterial activity on Bacillus subtilis. Moreover, compounds 1 and 2 were found to significantly inhibit the production of nitric oxide (NO) and reduce the release of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), interleukin-4 (IL-4), and interleukin-10 (IL-10) in LPS-induced RAW 264.7 macrophage cells. The present data suggest that lactones from the leaves of A. crenata Sims might be used as a potential source of natural anti-inflammatory agents. Full article

The chemical profile of Myrica rubra (a native species in China) leaf extract was investigated by UPLC-PDA-HRMS, and the neuroprotective activity of two characteristic constituents, myricanol and myricetrin, was evaluated with N2a cells using H₂O₂-inducedoxidative challenge through a series of methods, e.g., MTT assay, ROS assay and [Ca²⁺]i assay. Among the 188 constituents detected in the extract of Myrica rubra leaf, 116 were identified definitely or tentatively by the comprehensive utilization of precise molecular weight and abundant multistage fragmentation information obtained by quadrupole orbitrap mass spectrometry. In addition, 14 potential new compounds were reported for the first time. This work established an example for the research of microconstituents in a complex analyte and revealed that suppression of H₂O₂-induced cytotoxicity in N2a cells was achieved by the pretreatment with myricanol. The evidence suggested myricanol may potentially serve as a remedy for prevention and therapy of neurodegenerative diseases induced by oxidative stress. Full article

Croton species are used in folk medicine in the management of infections, inflammation and oxidative stress-related diseases. In order to isolate, characterize and evaluate the bioactive constituents of Croton menyharthii Pax leaf extracts, repeated column fractionation of the ethyl acetate fraction from a 20% aqueous methanol crude extract afforded three flavonols identified by NMR (1D and 2D) spectroscopic methods as myricetrin-3-O-rhamnoside (myricetrin, 1), quercetin-3-O-rhamnoside (2) and quercetin (3) along with an indole alkaloid, (E)-N-(4-hydroxycinnamoyl)-5-hydroxytryptamine, [trans-N-(p-coumaroyl) serotonin, 4]. All the compounds are reported from the leaf extract of this plant for the first time. The crude extracts, four solvent fractions (hexane, DCM, ethyl acetate and butanol) and isolated compounds obtained from the leaves were evaluated for their inhibitory effects on selected bacteria, a fungus (Candida albicans), cyclooxygenase (COX-2), α-glucosidase and acetylcholinesterase (AChE). Amongst the compounds, quercetin (3) was the most active against Bacillus subtilis and Candida albicans while myricetrin-3-O-rhamnoside (1) and trans-N-(p-coumaroyl) serotonin (4) were the most active compounds against Escherichia coli, Klebsiella pneumonia and Staphylococcus aureus. The inhibitory activity of myricetrin-3-O-rhamnoside (1) against COX-2 was insignificant while that of the other three compounds 2–4 was low. The AChE inhibitory activity of the alkaloid, trans-N-(p-coumaroyl) serotonin was high, with a percentage inhibitory activity of 72.6% and an IC₅₀ value of 15.0 µg/mL. The rest of the compounds only had moderate activity. Croton menyharthii leaf extracts and isolated compounds inhibit α-glucosidase at very low IC₅₀ values compared to the synthetic drug acarbose. Structure activity relationship of the isolated flavonols 1–3 is briefly outlined. Compounds 1–4 and the leaf extracts exhibited a broad spectrum of activities. This validates the ethnomedicinal use of the plant in folk medicine. Full article