title: Acylphloroglucinol Derivatives from the South African Helichrysum niveum and Their Biological Activities.
abstract: Phytochemical investigation of aerial parts of Helichrysum niveum (H. niveum) using different chromatographic methods including semi-preparative HPLC afforded three new (1-3) and six known (4-10) acylphloroglucinols alongside a known dialcohol triterpene (11). The structures of the isolated compounds were characterized accordingly as 1-benzoyl-3 (3-methylbut-2-enylacetate)-phloroglucinol (helinivene A, 1), 1-benzoyl-3 (2S-hydroxyl-3-methylbut-3-enyl)-phloroglucinol (helinivene B, 2), 8-(2-methylpropanone)-3S,5,7-trihydroxyl-2,2-dimethoxychromane (helinivene C, 3), 1-(2-methylbutanone)-4-O-prenyl-phloroglucinol (4), 1-(2-methylpropanone)-4-O-prennyl-phloroglucinol (5), 1-(butanone)-3-prenyl-phloroglucinol (6), 1-(2-methylbutanone)-3-prenyl-phloroglucinol (7), 1-butanone-3-(3-methylbut-2-enylacetate)-phloroglucinol (8), 1-(2-methylpropanone)-3-prenylphloroglucinol (9), caespitate (10), and 3β-24-dihydroxyterexer-14-ene (11). Excellent total antioxidant capacities were demonstrated by helinivenes A and B (1 and 2) when measured as oxygen radicals absorbance capacity (ORAC), ferric-ion reducing antioxidant power (FRAP), trolox equivalent absorbance capacity (TEAC) and including the inhibition of Fe(2+)-induced lipid peroxidation (IC50 = 5.12 ± 0.90; 3.55 ± 1.92) µg/mL, while anti-tyrosinase activity at IC50 = 35.63 ± 4.67 and 26.72 ± 5.05 µg/mL were also observed for 1 and 2, respectively. This is the first chemical and in vitro biological study on H. niveum. These findings underpin new perspectives for the exploitation of these natural phenolic compounds in applications such as in the natural cosmeceutical and pharmaceutical sectors.
authors.affiliation: Chemistry Department, University of Western Cape, Private Bag X17, Bellville 7535, South Africa. 3318925@myuwc.ac.za.
authors.forename: Olugbenga K
authors.initials: OK
authors.lastname: Popoola
authors.affiliation: Oxidative Stress Research Centre, Faculty of Health and Wellness Sciences, Cape Peninsula University of Technology, P. O. BOX 1906, Bellville 7535, South Africa. MarnewickJ@cput.ac.za.
authors.forename: Jeanine L
authors.initials: JL
authors.lastname: Marnewick
authors.affiliation: Oxidative Stress Research Centre, Faculty of Health and Wellness Sciences, Cape Peninsula University of Technology, P. O. BOX 1906, Bellville 7535, South Africa. rautenbachf@cput.ac.za.
authors.forename: Fanie
authors.initials: F
authors.lastname: Rautenbach
authors.affiliation: Chemistry Department, University of Western Cape, Private Bag X17, Bellville 7535, South Africa. eiwuoha@uwc.ac.za.
authors.forename: Emmanuel I
authors.initials: EI
authors.lastname: Iwuoha
authors.affiliation: Chemistry Department, University of Western Cape, Private Bag X17, Bellville 7535, South Africa. ahmohammed@uwc.ac.za.
authors.forename: Ahmed A
authors.initials: AA
authors.lastname: Hussein
mesh_terms: D000975:Antioxidants / Q000737:chemistry / Q000494:pharmacology; D036562:Helichrysum / Q000737:chemistry*; D015227:Lipid Peroxidation / Q000187:drug effects; D015394:Molecular Structure; D010696:Phloroglucinol / Q000737:chemistry* / Q000494:pharmacology; D035261:Plant Components, Aerial / Q000737:chemistry; D010936:Plant Extracts / Q000737:chemistry* / Q000494:pharmacology; D013019:South Africa
chemical_list: D000975:Antioxidants; D010936:Plant Extracts; D010696:Phloroglucinol
keywords: Helichrysum niveum; anti-aging; antioxidant; asteraceae; phloroglucinols