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Flavor Development during Roasting
Published in Hii Ching Lik, Borém Flávio Meira, Drying and Roasting of Cocoa and Coffee, 2019
The lipids fraction also contains diterpenes in proportions of up to 20% of the total lipid fraction (Cavin et al., 2002; Köling-Speer and Speer, 2005; Speer and Köling-Speer, 2006; Farah, 2012; Toci et al., 2013). The diterpens cafestol and kahweol are pentacyclic alcohols based on the kaurane skeleton. Methylated forms of cafestol and kahweol have been identified in Robusta seeds (Köling-Speer and Speer, 2005) and 16-o-methylcafestol has been proposed as a tool for species differentiation. Additionally, the amount of kahweol in C. canephora is negligible compared to C. arabica (Czech et al., 2016). Cafestol is the primary constituent of the unsaponifiable fraction of coffee oil, accounting for approximately 0.2 to 0.6% of coffee weight. Kahweol is more sensitive to heat, oxygen, light and acids and is therefore less abundant (Flament, 2002). Higher levels of diterpenes are found in C. arabica compared to C. canephora. Other identified components are coffeadiol and arabiol I, which have structures similar to the diterpenes cafestol and kahweol, respectively, but with different substitutions in the furan ring (Speer and Köling-Speer, 2006).
Antigenotoxicity properties of Copaifera multijuga oleoresin and its chemical marker, the diterpene (−)-copalic acid
Published in Journal of Toxicology and Environmental Health, Part A, 2018
Jacqueline Morais Alves, Luís Fernando Leandro, Juliana Marques Senedese, Pâmela Tinti de Castro, Daiane Eleutério Pereira, Flávia Aparecida Resende, Débora Leite Campos, Jonas Joaquim Mangabeira da Silva, Eliana Aparecida Varanda, Jairo Kenupp Bastos, Sérgio Ricardo Ambrósio, Denise Crispim Tavares
There are few apparent studies available regarding CA, and this is the first to investigate its antigenotoxic potential using in vivo and in vitro assays. However, a number of investigators evaluated the protective effects of other diterpenes. Cavin et al. (2001) demonstrated the antigenotoxic properties of the coffee diterpenes, cafestol, and kahweol, against AFB1 genotoxicity in rat and human cells. These coffee diterpenoids also exhibited protective effects against carcinogens present in the human diet in human-derived hepatoma (HepG2) cells (Majer et al. 2005). In both cases, the antigenotoxic effects were attributed to inhibition of activating enzymes (cytochrome P450; sulfotransferase) and to induction of detoxifying enzymes. Nicolella et al. (2014) noted that manool, a labdane-type diterpene like CA, exerted a protective effect against chromosome damage induced by MMS in HepG2 cells, but not V79 cells. The differential effect of manool in V79 and HepG2 cells may be due, at least in part, to its ability to induce drug-metabolizing enzymes that are present to some extent in HepG2 cells (Nicolella et al. 2014).
Non-heme iron coordination complexes for alkane oxidation using hydrogen peroxide (H2O2) as powerful oxidant
Published in Journal of Coordination Chemistry, 2022
Using substrate-based catalyst reactivity models, the theoretically calculated selectivities are consistent with the observed ones. This interesting protocol was eventually applied to another naturally occurring complex molecule (−)-triacetoxytricalysiolide B, a putative metabolite of the diterpene cafestol found in coffee. In the case of Fe(CF3-PDP) site selectivity observed was opposite to that of Fe(PDP), again confirming the previously delineated steric, electronic, and stereoelectronic rules that determine this selectivity. It is significant to note that Fe(PDP) and Fe(CF3-PDP) are chiral catalysts and both (R,R) and (S,S) versions were evaluated and a promising example of chirality-based oxidation is the protocol described below (Scheme 5).