Natural polyphenols are important dietary antioxidants that significantly benefit human health. Coffee and tea have been shown to largely contribute to the dietary intake of these antioxidants in several populations. More recently, the use of coffee leaves to produce tea has become a potential commercial target, therefore prompting studies on the quantification of polyphenols in coffee leaves. In this study a variety of coffee leaf species, at different development stages, were analyzed using ultra-high pressure liquid chromatography. The results demonstrate that both the botanical origin of the samples and their maturity influence significantly the concentration of the antioxidants; for total chlorogenic acids a two-fold difference was found between different species and up to a three-fold variation was observed between young and mature leaves. Furthermore, the range of concentrations of chlorogenic acids in young leaves (35.7–80.8 mg/g of dry matter) were found to be comparable to the one reported for green coffee beans. The results provide important data from which potential new commercial products can be developed.

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Quantitative analyses of mono-p-coumaroylquinic acids (pCoQAs) and total chlorogenic acids (CGAs) in green coffee commercial lots of C. arabica C. canephora and C. liberica from different geographic origins and eight wild Coffea species were carried out. Among the commercial lots, pCoQAs average content of C. arabica (0.67 mg/g) is higher than that of C. canephora (0.40 mg/g) being C. liberica intermediate (0.58 mg/g). As far as the analyzed wild Coffea species is concerned, C. pseudozanguebariae is characterized by the lower pCoQAs content (0.12 mg/g) whereas C. sessiliflora is by far the richest source of pCoQAs (2.18 mg/g). Effect of the roasting process on the mono-p-coumaroylquinic acids profile was evaluated for the economically exploited species C. arabica and C. canephora. For the first time distribution of mono-p-coumaroylquinic acid isomers

Tri‐3,4‐dimethoxycinnamoyl‐1,5‐γ‐quinide was synthesized and fully characterized by a direct synthesis from quinic acid and a large excess of 3,4‐dimethoxycinnamoyl chloride. Mono‐ and di‐3,4‐dimethoxycinnamoyl‐1,5‐γ‐quinides were also obtained from the direct coupling of 1,5‐γ‐quinide and 3,4‐dimethoxycinnamoyl chloride in different molar ratios. Moreover, a hypothetical mechanism of the direct lactonization is proposed.

To determine the botanical origin of Coffea honey, a new method using proton nuclear magnetic resonance ((1)H NMR) is proposed. Integration of the aromatic region of the NMR spectrum of Coffea honey diluted in deuterated water allowed us to simultaneously quantify caffeine, theobromine, and trigonelline, as well as other compounds. The amounts of the three markers listed are significantly higher than those previously reported for Citrus spp. honey: caffeine ranged from 15 to 98 mg/kg, theobromine from 25 to 160 mg/kg, and trigonelline from 23 to 86 mg/kg. The concurrent presence of these three substances is proposed as an indicator of the botanical origin of Coffea honey. Excellent correlation was found between these markers and the relative amounts of Coffea pollen measured in the same samples.