Current Issue : January - March Volume : 2018 Issue Number : 1 Articles : 5 Articles
Moringa oleifera trees grow well in Jamaica and their parts are popularly used locally for\nvarious purposes and ailments. Antioxidant activities in Moringa oleifera samples from different parts\nof the world have different ranges. This study was initiated to determine the antioxidant activity of\nMoringa oleifera grown in Jamaica. Dried and milled Moringa oleifera leaves were extracted with\nethanol/water (4:1) followed by a series of liquidââ?¬â??liquid extractions. The antioxidant capacities of all\nfractions were tested using a 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay. IC50 values (the amount of\nantioxidant needed to reduce 50% of DPPH) were then determined and values for the extracts ranged\nfrom 177 to 4458 g/mL. Extracts prepared using polar solvents had significantly higher antioxidant\ncapacities than others and may have clinical applications in any disease characterized by a chronic\nstate of oxidative stress, such as sickle cell anemia. Further work will involve the assessment of these\nextracts in a sickle cell model of oxidative stress....
Traditional medicine and ecological cues can both help to reveal bioactive natural\ncompounds. Indigenous Australians have long used kino from trunks of the eucalypt tree,\nCorymbia citriodora, in traditional medicine. A closely related eucalypt, C. torelliana, produces\na fruit resin with antimicrobial properties that is highly attractive to stingless bees. We tested\nthe antimicrobial activity of extracts from kino of C. citriodora, C. torelliana C. citriodora, and\nC. torelliana against three Gram-negative and two Gram-positive bacteria and the unicellular fungus,\nCandida albicans. All extracts were active against all microbes, with the highest activity observed\nagainst P. aeruginosa. We tested the activity of seven flavonoids from the kino of C. torelliana against\nP. aeruginosa and S. aureus. All flavonoids were active against P. aeruginosa, and one compound,\n(+)-(2S)-40,5,7-trihydroxy-6-methylflavanone, was active against S. aureus. Another compound,\n40,5,7-trihydroxy-6,8-dimethylflavanone, greatly increased biofilm formation by both P. aeruginosa\nand S. aureus. The presence or absence of methyl groups at positions 6 and 8 in the flavonoid A ring\ndetermined their anti-Staphylococcus and biofilm-stimulating activity. One of the most abundant and\nactive compounds, 3,40,5,7-tetrahydroxyflavanone, was tested further against P. aeruginosa and was\nfound to be bacteriostatic at its minimum inhibitory concentration of 200 g/mL. This flavanonol\nreduced adhesion of P. aeruginosa cells while inducing no cytotoxic effects in Vero cells. This study\ndemonstrated the antimicrobial properties of flavonoids in eucalypt kino and highlighted that\ntraditional medicinal knowledge and ecological cues can reveal valuable natural compounds....
Phytochemical investigation of Ficus hirta Vahl. (Moraceae) fruits led to isolate two\ncarboline alkaloids (1 and 2), five sesquiterpenoids/norsesquiterpenoids (3ââ?¬â??7), three flavonoids\n(8ââ?¬â??10), and one phenylpropane-1,2-diol (11). Their structures were elucidated by the analysis of\ntheir 1D and 2D NMR, and HR-ESI-MS data. All of the isolates were isolated from this species\nfor the first time, while compounds 2, 4ââ?¬â??6, and 8ââ?¬â??11 were firstly reported from the genus Ficus.\nAntifungal assay revealed that compound 8 (namely pinocembrin-7-O--D-glucoside), a major\nflavonoid compound present in the ethanol extract of F. hirta fruits, showed good antifungal activity\nagainst Penicillium italicum, the phytopathogen of citrus blue mold caused the majority rotten of\ncitrus fruits....
There are concerns about using synthetic phenolic antioxidants such as butylated\nhydroxytoluene (BHT) and butylated hydroxyanisole (BHA) as food additives because of the reported\nnegative effects on human health. Thus, a replacement of these synthetics by antioxidant extractions\nfrom various foods has been proposed. More than 8000 different phenolic compounds have been\ncharacterized; fruits and vegetables are the prime sources of natural antioxidants. In order to extract,\nmeasure, and identify bioactive compounds from a wide variety of fruits and vegetables, researchers\nuse multiple techniques and methods. This review includes a brief description of a wide range\nof different assays. The antioxidant, antimicrobial, and anticancer properties of phenolic natural\nproducts from fruits and vegetables are also discussed....
The phenolic composition of aerial parts from Petiveria alliaceae L., Phyllanthus niruri L.\nand Senna reticulata Willd., species commonly used in Costa Rica as traditional medicines, was\nstudied using UPLC-ESI-TQ-MS on enriched-phenolic extracts. Comparatively, higher values of total\nphenolic content (TPC), as measured by the Folin-Ciocalteau method, were observed for P. niruri\nextracts (328.8 gallic acid equivalents/g) than for S. reticulata (79.30 gallic acid equivalents/g) whereas\nP. alliaceae extract showed the lowest value (13.45 gallic acid equivalents/g). A total of 20 phenolic\nacids and proanthocyanidins were identified in the extracts, including hydroxybenzoic acids (benzoic,\n4-hydroxybenzoic, gallic, prochatechuic, salicylic, syringic and vanillic acids); hydroxycinnamic acids\n(caffeic, ferulic, and p-coumaric acids); and flavan-3-ols monomers [(+)-catechin and (...
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