Looking for the Physiological Role of Anthocyanins in the Leaves of Coffea arabica

Abstract

The aim of this study was to determine which anthocyanins are related to the purple coloration of young leaves in Coffea arabica var. Purpurascens and assess their impact on photosynthesis as compared to C. arabica var. Catuaí, with green leaves. Two delphinidin glicosides were identified and histological cross-sections showed they were located throughout the adaxial epidermis in young leaves, disappearing as the leaves mature. Regardless the irradiance level, the photosynthetic performance of Purpurascens leaves did not differ from that observed in leaves of the Catuaí variety, providing no evidence that anthocyanins improve photosynthetic performance in coffee plants. To analyze the photoprotective action of anthocyanins, we evaluated the isomerization process for chlorogenic acids (CGAs) in coffee leaves exposed to UV-B radiation. No differences were observed in the total concentration of phenolic compounds in either variety before or after the UV treatment; however, we observed less degradation of CGA isomers in the Purpurascens leaves and a relative increase of cis-5-caffeoylquinic acid, a positional isomer of one of the most abundant form of CQA in coffee leaves, trans-5-caffeoylquinic acid, suggesting a possible protective role for anthocyanins in this purple coffee variety.

Determination of Phenolic Compounds, Procyanidins, and Antioxidant Activity in Processed Coffea arabica L. Leaves

“…Similar results for epicatechin, mangiferin isomangiferin, procyanidin B, rutin, and quercetin glucoside derivatives contents were reported in coffee leaves (Almeida et al, 2014) [7]. In addition, coffee leaf samples in this study contained seven (i.e., caffeine, quercetin glucoside, rutin, mangiferin, isomangiferin, catechin, and epicatechin) bioactive compounds reported in commercial coffee leaves [1,4,5,6].…”

“…Coffee leaf tea has higher antioxidant potential and lower caffeine than traditional tea. The polyphenol content of coffee leaf depends on the maturity, the harvest times (month of harvest), and the coffee species of its leaf and are phytochemically composed of caffeine, trigonelline, adenine-7-glucosyl, theobromine, theophylline, ent -kaurane diterpenpids, 7-methylxanthine, anthocyanins, mangiferin, isomangiferin, catechin, epicatechin, procyanidin B1, chlorogenic acid (5-CQA), glucoside, rutin, isorhamnetin, quercetin, isoquercitrin, kaempferol, histidine, pipecolic acid, sucrose, tannins, caffeic acid, p-coumaric acid, ferulic acid, sinapic acid, neochlorogenic acid (3-CQA), and cryptochlorogenic acid (4-CQA) [1,3,4,5,6,7,8].…”

Significance of bioactive compounds, therapeutic and agronomic potential of non-commercial parts of the Coffea tree

“…The presence of compounds such as anthocyanins in Coffea arabica var. Purpurascens, prevents degradation of isomers of chlorogenic acid exposed to UV radiation (Domingues Júnior et al, 2012). The hydroxycinnamic acids content in C. arabica is higher than in other species such as Coffea sessilifl Bridson, Coffea resinora Hook.…”

Progress in Phytochemical and Bioactivities of Coffea arabica L.

“…Chen et al identified delphinidin 3,5-diglucoside (10) and delphinidin 3-(6"-malonyl-glucoside) (11) in the young leaves of C. arabica L. [6] Besides the above mentioned constituents, flavonoids and their glycosides were also isolated from the leaves of C. arabica L., which were named as cyanidin-3-O-Glu (12), cyanidin-3-O-rutinoside (13), kaempferol (14), kaempferol-3-O-Glc (15), kaempferol-3-O-Glc-Hex-DeHex (16), kaempferol-3-O-Glc-Hex (17), kaempferol-3-O-Glc-(6''-Rha) (18), quercetin (19), quercitrin (20), isoquercitrin (21), rutin (22), hyperoside (23), quercetin-3-O-Glc-Hex-DeHex (24), quercetin-3-O-Glu (25), luteolin (26), patuletin (27), fisetin (28), myricetin (29) and apigenin (30). [6][7][8][9] Their structures are shown in Figure 2.…”