Bioactive Compounds of Fruit Parts of Three Eugenia uniflora Biotypes in Four Ripening Stages

Abstract

Variability of secondary metabolites in edible (peel and pulp) and inedible (seeds) parts of three pitanga varieties, red, red-orange and purple, was investigated during the maturation process. Hydrolysable tannins, anthocyanins, and flavonoids were quantified by HPLC/DAD and carotenoids by absorbance. Peel/pulp showed greater complexity of constituents (carotenoids, anthocyanins, flavonoids, and hydrolysable tannins), while only tannins were identified in seeds, but in quantities of 10 to 100 times greater. The red-orange variety showed the highest levels of phenolic compounds in seeds and peel/pulp, except anthocyanins. The analysis of the principal response curves showed that the pitanga biotype has greater influence on metabolite variation than ripening stages. During peel/pulp maturation, a reduction in the levels of flavonoids and tannins contrasted with an increase in carotenoids and cyanidin-3-O-glucoside in all varieties, whereas in the seeds oenothein B, the major tannin, increased up to 1.32 g/100 g fresh weight. Such marked differences between fruit parts demonstrate that the seeds in stages E3 and E4 are a source of hydrolysable tannins, compounds known for their antitumor activity, while peel/pulp of all varieties in the ripe stage provide natural antioxidants, such as carotenoids and flavonoids. Lastly, the purple biotype can be a rich source of the cyanidin-3-O-glucoside pigment a potent bioactive compound.

New Hydrolyzable Tannin with Potent Antioxidant and α-Glucosidase Inhibitory Activity from Black Tea Produced from Camellia taliensis

“…The EtOAc extract was further isolated by various CC on Diaion HP20SS, RP-18, Toyopearl HW-40F, MCI-gel CHP20P, and Sephadex LH-20, to yield 32 compounds, including one undescribed hydrolyzable tannin ( 1 ) and one new natural product ( 24 ). The compounds, which had were in advance, were recognized as seven hydrolyzable tannins ( 2 − 8 ) including 4- O -(6′- O -galloyl- β -D-glucopyranosyl)- cis - p -coumaric acid ( 2 ) [ 21 ], 2- O -galloyl-4,6- O -( S )-hexahydroxydiphenoyl- β -D-glucopyranose ( 3 ) [ 22 ], 1- O -galloyl-4,6- O -( S )-hexahydroxydiphenoyl- β -D-glucopyranose ( 4 ) [ 23 ], 1,2-di- O -galloyl-4,6- O -( S )-hexahydroxydiphenoyl- β -D-glucopyranose ( 5 ) [ 24 ], 1,6-di- O -galloyl- β -D-glucopyranose ( 6 ) [ 25 ], 1,2,6-tri- O -galloy- β -D-glucopyranose ( 7 ) [ 26 ], and 1,4,6-tri- O -galloyl- β -D-glucopyranose ( 8 ) [ 27 ], 10 flavonol and its glycosides ( 9 − 18 ) including kaempferol 3- O - β -D-glucopyranoside ( 9 ) [ 28 ], kaempferol 3- O -(6″- trans - p -coumaroyl)- β -D-glucopyranoside ( 10 ) [ 29 ], quercetin 3- O - β -D-glucopyranoside ( 11 ) [ 30 ], kaempferol 3- O -rutinoside ( 12 ) [ 23 ], rutin ( 13 ) [ 31 ], kaempferol 3- O - β -D-galactopyranoside ( 14 ) [ 32 ], kaempferol 3- O - α -L-rhamnopyranoside ( 15 ) [ 33 ], quercetin ( 16 ) [ 34 ], quercetin 3-(2″- β -D-glucosyl)- α -L-rhamnopyranoside ( 17 ) [ 35 ], and kaempferol 3-(2″- β -D-glucosyl)- α -L-rhamnopyranoside ( 18 ) [ 35 ], and 14 simple phenolics ( 19 − 32 ) including gallic acid ( 19 ) [ 36 ], 3,4-dihydroxybenzoic acid ( 20 ) [ 37 ], p -hydroxybenzoic acid ( 21 ) [ 38 ], m -hydroxybenzoic acid ( 22 ) [ 39 ], methyl gallate ( 23 ) […”

“…taliensis, with similar chemical constituents to the extensively cultivated tea plants, C. sinensis and its variety assamica, is the earliest, most used and widely distributed wild tea tree, whose leaves were utilized by the locals of its growing regions to manufacture various types of tea. A comprehensive chemical study of black tea from C. taliensis resulted in the separation and recognition of one new hydrolyzable tannin, 1-O-galloyl-4,6-tetrahydroxydibenzofurandicarboxyl-β-D-glucopyranose (1), together with 31 known compounds, comprising seven hydrolyzable tannins (2-8), 10 flavonols and their glycosides (9)(10)(11)(12)(13)(14)(15)(16)(17)(18), and 14 simple phenolics (19)(20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30)(31)(32) with 24 as a new natural product. It is noted that 15 compounds (2, 3, 15, 17, 18, 21, 22, 24, 26-32) were obtained from C. taliensis and 20 compounds (2, 3, 6, 7, 8, 15, 17, 18, 20-22, 24-32) were isolated from black tea for the first time.…”

“…The EtOAc extract was further isolated by various CC on Diaion HP20SS, RP-18, Toyopearl HW-40F, MCI-gel CHP20P, and Sephadex LH-20, to yield 32 compounds, including one undescribed hydrolyzable tannin (1) and one new natural product (24). The compounds, which had were in advance, were recognized as seven hydrolyzable tannins ( 2 (10) [29], quercetin 3-O-β-D-glucopyranoside (11) [30], kaempferol 3-O-rutinoside (12) [23], rutin (13) [31], kaempferol 3-O-β-D-galactopyranoside ( 14) [32], kaempferol 3-O-α-L-rhamnopyranoside (15) [33], quercetin ( 16) [34], quercetin 3-(2 -β-Dglucosyl)-α-L-rhamnopyranoside (17) [35], and kaempferol 3-(2 -β-D-glucosyl)-α-L-rhamnopy ranoside (18) [35], and 14 simple phenolics (19−32) including gallic acid (19) [36], 3,4dihydroxybenzoic acid (20) [37], p-hydroxybenzoic acid ( 21) [38], m-hydroxybenzoic acid (22) [39], methyl gallate ( 23) [40], 3-(2-methoxy-2-oxoethyl) benzoic acid (24) [41], chlorogenic acid (25) [42], 5-O-(E)-p-coumaroylquinic acid (26) [43], 5-O-caffeoylshikimic acid (27) [44], caffeic acid (28) [45], E-p-hydroxycinnamic acid (29) [46], 1-(3 ,4 -dihydroxycinnamoyl) cyclopenta ne-2,3-diol (30) [47], 3,4,8,9,10-pentahydroxydibenzo[b,d]pyran-6-one (31) [48], and (3R)...…”

“…The HPLC-MS combined with electrospray ionization (HPLC-ESI-MS) analysis indicated the rich presence of polyphenols. Further comprehensive chemical study on its EtOAc extract resulted in the separation and recognition of 32 phenolic compounds, which were 8 hydrolyzable tannins (1)(2)(3)(4)(5)(6)(7)(8) with one new tannin (1), 10 flavonols and its glycosides (9)(10)(11)(12)(13)(14)(15)(16)(17)(18), and 14 simple phenolics (19)(20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30)(31)(32) with one new natural product (24). The antioxidant activity on the DPPH and ABTS + assays of most isolates and α-glucosidase inhibitory activity of all hydrolyzable tannins were tested.…”