Chemical prospection and antioxidant activity of Humiria balsamifera (Aubl.) A. St. Hil. AND Hymenaea courbaril L.

Abstract The objective of this study was to conduct chemical analyses of bioactive compounds found in the bark and leaves of Humiria balsamifera (Aubl.) A. St. Hil. and Hymenaea courbaril L. Chemical screening was performed to detect the presence of secondary metabolites. Quantification of the concentrations of phenolic compounds, anthocyanins, flavonoids, and antioxidants was performed by ultraviolet spectrophotometry through recommended methodologies. Extracts of the leaves of Humiria balsamifera (Aubl.) A. St. Hil. were found to have high concentrations of flobabénic tannins. Tannins, flavonoids, flavonols, flavonones, flavanonols, xanthones, steroids, and saponins were also found in bark extracts of the same species. The plant species Humiria balsamifera (Aubl.) A. St. Hil. and Hymenaea courbaril L. showed potential for antioxidant activity and for use in the pharmacological and food industries. Graphical Abstract


Introduction
Brazil has a long history of the accumulation of knowledge about traditional technologies, with a vast collection of reports on the uses and management of medicinal plants (Brasil 2006).Investigations into the diversity of plant species in Brazil may enable the production of new drugs that are targeted at pathologies currently without effective therapies (duTRA, R. C. et al. 2016).The World Health Organization (WHO 1998) recognised that the majority of Brazil's population relies on traditional medicine for primary care.
Thus, research aimed at discovering new active ingredients originating from Brazilian flora is gaining impetus.This study focuses on plants from the Maranhão State area, with emphasis on the Humiria balsamifera (Aubl.) A. St. Hil, which is a member of the Humiraceae family and Humiria genus and exists in many varieties.The Humiriaceae family includes both woody and medium-sized bushy plants (Herrera et al. 2014).The second species studied here is the Hymenaea courbaril L., an arboreal species belonging to the Hymenaea genus, Fabaceae, which can be found throughout the entire American continent.In addition to medicinal use, it is also known for its logging activity, which makes it a highly exploited species (Fernandes, 2006).
The discovery of new natural pharmaceuticals has led to increased worldwide research of the flora of Brazil.Some of these studies have shown that the high antioxidant content in plants is associated with a lower incidence of chronic disease deaths because they can mitigate the effects of oxidative stress in cells (Silva et al. 2012).Phenolic compounds contribute to human health due to their anticarcinogenic and antimutagenic activities (Vieira et al. 2011;dall'antonia and Archela, 2013).This study undertook the phytochemical screening these plants were screened to identify any bioactive compounds present in bark, fruit and leaves, and to quantify their antioxidant activity, which may make feeding and pharmaceutical bioproducts.

Chemical screening of the species Humiria balsamifera (Aubl.) A. St. Hil. and Hymenaea courbaril L.
Phytochemical screening revealed that the leaves of Humiria balsamifera had the highest concentration of flobabénic tannins, followed by pyrogallic tannins, leucoanthocyanins, flavonols, flavones, flavonols, and xanthones.The bark contained the compounds found in the leaves, along with steroids and saponins (Table S1).
For Hymenaea courbaril species, the leaf presented the larger amounts of the flavonones metabolite groups, followed by phenols and catechins.In contrast, a larger number of metabolite groups was observed in the bark, such as flavonols, flavonones, flavononols, xanthones and leucoanthocyanidins (Table S1).As the Humiria balsamifera bark and Hymenaea courbaril leaves and bark had large amounts of flavones, it may be possible to isolate them in future studies and develop new sources of flavorings.

Phenolic compounds, anthocyanins, and flavonoids in Humiria balsamifera (Aubl.) A. St. Hil. and Hymenaea courbaril L.
Chemical screening of Humiria balsamifera showed that the leaves contained a high concentration of phenolic compounds.The values obtained for the bark in water extracts were higher than those in ether (Table S2).
The concentrations of phenolic compounds, anthocyanins and flavonoids in Hymenaea courbaril showed differences in concentrations when compared to leaves and bark.Higher amounts of phenolic compounds appeared in the fruits in the aqueous and ether extracts in relation to the peel, but the peel had higher levels of anthocyanins and flavonoids, showing that the polarity of the samples and the solvent influence the extraction of secondary metabolites.
According to Vencato et al. (2016) who isolated secondary metabolites in Hymenaea courbaril L., the major components were observed in the flavonoid rutin and in the phenolic compound ellagic acid, in addition to presenting hydrolyzed tannins.

Antioxidant properties of Humiria balsamifera (Aubl.) A. St. Hil. and Hymenaea courbaril L.
The results for antioxidant activity were different for the leaves and the bark.The free radical-scavenging potential of the bark was similar for both the water and ether extracts.However, this potential at leaves was much higher in ether than in the water extracts (Table S3).Therefore, the extraction method was found to influence the antioxidant properties of the leaves.For Hymenaea courbaril L, the analysis showed high antioxidant activity for both fruits and bark (Table S3).This is consistent with values found in this species (Saha and Verma 2015).The ether extract showed a greater potential for radical inhibition than the aqueous extract.Furthermore, higher values were observed for the leaves of Humiria balsamifera and the fruit of Hymenaea courbaril L., 91.7 ± 0.005 and 95, 7 ± 0.082, respectively, as found in similar studies (Sousa et al. 2007).According to Carminate et al. (2014), the presence of tannins is related to microbial activity in Humiria balsamifera leaf extracts.The tannins are capable to protect plants against pathogens and in animal pasture (Rocha et al. 2011).A recent study that determined the leaf extracts successfully inhibited S. aureus and L. monocytogenes (dias et al. 2021) Flavones, flavonoids, and xanthones participate in co-pigmentation and plant uV radiation protection (Brito et al. 2008).Flavonones were also found by Vencato et al. (2016) when investigating Hymeneae courbaril L. bark extracts.Fernandes et al. (2015) reported that the traditional use of the bark is related to its chemical composition and antioxidant properties.
The presence of saponins in the bark of Humiria balsamifera may be related to its medicinal use because of the hemolytic, anthelmintic, spermicidal, and antifungal properties of these compounds (Santiago et al. 2005).These features indicate the importance of these compounds in the adaptation of plants to ensure their survival (Marques et al. 2017).Chemical screening of Humiria balsamifera and Hymenaea courbaril species has shown that there is potential to use parts of these plants as medicines, mainly the bark.
Flavonoids, tannins, chalcones, coumarin, and phenolic acid are linked to health-promoting effects in humans, such as the prevention of cancer, heart diseases, and age-related health issues (Giada and Mancini Filho 2006).