title: Characterization of the constituents and antioxidant activity of Brazilian green tea (Camellia sinensis var. assamica IAC-259 cultivar) extracts.
abstract: Freeze-dried extracts from Camellia sinensis var. assamica IAC-259 cultivar named Brazilian green tea were prepared by hot water and ultrasound-assisted extractions using leaves harvested in spring and summer. Their caffeine and catechin contents were measured by high performance liquid chromatography-diode array detector. The antioxidant activity of the major green tea compounds and Brazilian green tea extracts was evaluated using a 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay. The levels of caffeine were higher in the summer samples (p < 0.05); otherwise, there were no significant variations related to the catechin contents between spring and summer samples. The sonication method using water/acetone as solvent had a high efficiency to extract not only epigallocatechin gallate but also epicatechin gallate (p < 0.05). Antioxidant activities of the Brazilian green tea extracts were not significantly different among seasons and extraction systems. The antioxidant data (IC50) of the Brazilian green tea extracts showed a significant correlation with their epigallocatechin gallate and epicatechin gallate contents (p < 0.05).
authors.affiliation: Faculdade de Farmácia, Universidade Federal do Rio Grande do Sul, Av. Ipiranga 2752, Porto Alegre, RS, 90610-000, Brazil.
authors.forename: Samuel T
authors.initials: ST
authors.lastname: Saito
authors.forename: Grace
authors.initials: G
authors.lastname: Gosmann
authors.forename: Jenifer
authors.initials: J
authors.lastname: Saffi
authors.forename: Márcio
authors.initials: M
authors.lastname: Presser
authors.forename: Marc F
authors.initials: MF
authors.lastname: Richter
authors.forename: Ana M
authors.initials: AM
authors.lastname: Bergold
mesh_terms: D000975:Antioxidants / Q000032:analysis* / Q000494:pharmacology; D001938:Brazil; D028241:Camellia sinensis / Q000737:chemistry*; D002392:Catechin / Q000031:analogs & derivatives / Q000032:analysis; D010936:Plant Extracts / Q000737:chemistry*; D018515:Plant Leaves / Q000737:chemistry*; D012621:Seasons
chemical_list: D000975:Antioxidants; D010936:Plant Extracts; D002392:Catechin; C062669:epicatechin gallate; C045651:epigallocatechin gallate