Phenolic Antioxidants from the Leaves of Camellia pachyandra Hu.

Abstract

Camellia pachyandra Hu. is a species in Camellia sect. Heterogenea (Theaceae), whose leaves have been used for making tea and consumed by the local people living in Yunnan province, China. This is the first investigation of the chemical constituents in the leaves of C. pachyandra, from which 22 phenolic compounds including nine hydrolyzable tannins (1-9), 11 flavonol glycosides (10-20), and two simple phenolics (21, 22) were isolated. It was noted that the leaves of the title plant contained no caffeine and no catechin, whereas hydrolyzable tannins were found to be the major constituents, of which the content of ellagitannin 5 reached to 3.7%. All the isolates were evaluated for their antioxidant activities by DPPH radical scavenging and tyrosinase inhibitory assays. Though the secondary metabolites without caffeine and catechins are different from the commonly consumed tea plants, the results suggested that the leaves of C. pachyandra, rich in hydrolyzable tannins as potent antioxidants, could be developed as an ideal resource for a natural beverage without caffeine.

Phytochemical Study of Tapirira guianensis Leaves Guided by Vasodilatory and Antioxidant Activities

“…MET and EAF showed a potent in vitro ability to scavenge the free radical DPPH, that could be attributed to the phenolic compounds identified. 1,4,6-tri- O -galloyl-β- d -glucose (EA1), quercetin 3- O -(6″- O -galloy)-β- d -galactopyranoside (EA2), quercetin (EA3) and myricitrin have already been shown to have antioxidant activity [ 37 , 38 , 39 , 40 ]. In addition, antioxidant effect of quercetin and its metabolites was described in vascular smooth muscle cells from normotensive and spontaneously hypertensive rats, by inhibiting the membrane NADPH oxidase activity [ 41 ].…”

Evaluation of the anti-osteoporosis and antioxidant activities of phenolic compounds from Euphorbia maculata

“…1). Comparison of the NMR data of isolated compounds with those reported previously led to the identification of known compounds including astragalin 2'',3''-O-digallate (1) (Ercil et al, 2005), astragalin 2''-Ogallate (2) (Isobe et al, 1980), isoquercitin 2''-O-gallate (3) (Gao et al, 2010), quercitrin 2''-O-gallate (4) (Isobe et al, 1981), quercetin (5) (Ternai and Markham, 1976), hyperin (6) (Kang et al, 2012), isoquercitrin (7) (Kang et al, 2012), rutin (8) , isomyricitrin (9) (Kazuma et al, 2003), nicotiflorin (10) (Park et al, 2008), astragalin (11) (Kim et al, 2004), phlorizin (12) (Rui-Lin et al, 1982), corilagin (13) (Sudjaroen et al, 2012), 1,3,4,6-tetra-O-galloyl-β-D-glucopyranoside (14) (Lim et al, 1997), protocatechuic acid (15) (Zhang et al, 1998), methyl gallate (16) (Wei et al, 2005), brevifolin carboxylic acid (17) (Tanaka et al, 1990), methyl brevifolin carboxylate (18) (Zheng et al, 2009), and ellagic acid (19) (Li et al, 1999).…”

Secondary Metabolites

“…Camellia sinensis and some other species from the genus Camellia have also been used for making tea and are consumed widely (Gao et al, 2010). More than 96 phenolic compounds were identified in C. sinensis tea.…”

“…Repeated silica gel, sephadex-LH20, RP-18, RP-8, MCI-gel, diaion and toyopearl chromatography columns have been used to fractionate simple phenolics, flavonoids and tannins from kernels and nuts Karamac, 2009), fruits such as apples, Morus nigra, Punica granatum (Lee et al, 2010;Pawlowska et al, 2008); olive oil (Khanal et al, 2011), tea (Gao et al, 2010;Liu et al, 2009), seeds such as lentils (Amarowicz & Karamac 2003), medicinal species, including Ulmus davidiana and Tridax procumbens (Jung et al, 2008;Agrawal, 2011); and aromatic plants, including mint and sage (She et al, 2010;Wang et al, 1998).…”

“…Phenolic compounds were also isolated from the leaves of C. pachysandra. The ethyl acetate and aqueous fractions were separately subjected to repeated CC over Diaion HP-20SS, Sephadex LH-20, MCI-gel CHP20P, and Toyopearl HW-40F to give 22 phenolic compounds, including nine hydrolyzable tannins, 11 flavonol glycosides and two simple phenols, without caffein or catechin (Gao et al, 2010).…”