Ocotea (Quinet and Andreata, 2002)

Antonio, Ananda S., Veiga-Junior, Valdir F. & Wiedemann, Larissa Silveira Moreira, 2020, Ocotea complex: A metabolomic analysis of a Lauraceae genus, Phytochemistry (112314) 173, pp. 1-8 : 5-6

2.3. Flavonoids profile in Ocotea

Existing data about flavonoid profiles in Ocotea are scarce and describe the composition of only 3.4% of Ocotea species, with an occurrence number of 66, distributed within 37 distinct chemical structures (Supplementary Table 4). Due to the limited available data regarding the flavonoid profile of Ocotea , it was not possible to apply chemometric analysis and therefore the analysis was based on the evolutionary indices of flavonoids and their descriptive occurrence. It is worth mention that flavonoids biosynthesis specialization analysis can give in sight in plants evolutionary pattern, as their diversification within botanic species is related to modification in gene sequences related to plants evolutional and adaptative process ( Sakakibara et al., 2019).

Flavonoids described in Ocotea are mainly glycosylate derivates of catechin, epicatechin, quercetin and kaempferol, of which 45.5% are O - glycosylated and only one is O -alkylated. This pattern confirms that Ocotea could either a basal or intermediate genus in the evolutionary lineage of Lauraceae . Additionally, Ocotea presents a flavone:flavonol rate of 0.05, reinforcing the ancestralism within Lauraceae family postulated by phylogenetics approaches. It is worth mentioning that the evolutionary advancement indices become more precise and accurate when a larger set of species is evaluated, as demonstrated in previous studies with other botanic groups ( Santos and Salatino, 2000; Brant et al., 2001; Murai et al., 2008).

The absence of O -alkylated flavonoids in Ocotea also indicates that this genus is older than Aniba , which is characterized by the occurrence of these types of flavonoids in greater number when compared to O - glycosylated flavonoids ( Brant et al., 2001; Gottlieb, 1972; Santos and Salatino, 2000). Additionally, regarding the presence of specific biomarkers within this chemical class, only O. vellosiana and O. lancifolia have specialized flavonoids with low occurrence number within Lauraceae , the myricetin-3-O-glucoside and isohramnetin-3-O-flucoside-7- O-ramnoside, respectively ( da Silva et al., 2017; Garcez et al., 1995). As it is a chemical class of large occurrence within flowering plants, their usage in identification thought metabolomics can only be performed in untargeted approaches and, ideally, also applying the evolutionary advancement indices as variables.