Myrcia bella Cambess., Myrcia fallax (Rich.) DC. and Myrcia guianensis (Aubl.) DC. (Myrtaceae) are trees found in Brazilian Cerrado. They have been widely used in folk medicine for the treatment of gastrointestinal disorders, hemorrhagic and infectious diseases. Few reports have been found in the literature connecting their phenolic composition and biological activities. In this regard, we have profiled the main phenolic constituents of Myrcia spp. leaves extracts by ESI(−)Q-TOF-MS. The main constituents found were ellagic acid (M. bella), galloyl glucose isomers (M. guianensis) and hexahydroxydiphenic (HHDP) acid derivatives (M. fallax). In addition, quercetin and myricetin derivatives were also found in all Myrcia spp. extracts. The most promising antioxidant activity, measured by 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity, was found for M. fallax extracts (EC₅₀ 8.61 ± 0.22 µg·mL⁻¹), being slightly less active than quercetin and gallic acid (EC₅₀ 2.96 ± 0.17 and 2.03 ± 0.02 µg·mL⁻¹, respectively). For in vitro antiproliferative activity, M. guianensis showed good activity against leukemia (K562 TGI = 7.45 µg·mL⁻¹). The best antimicrobial activity was observed for M. bella and M. fallax to Escherichia coli (300 and 250 µg·mL⁻¹, respectively). In conclusion, the activities found are closely related to the phenolic composition of these plants.

The present study aimed to evaluate the effect of seasonal and diurnal events on the chemical profile of the essential oil obtained from the leaves of Copaifera langsdorffii Desf. This study was performed in a Brazilian savanna named Cerrado. We identified the best harvesting period for obtaining the highest amount of compounds used for commercial and industrial purposes. The chemical profile of the essential oils was evaluated by GC-FID and GC-MS, and the results were assessed through multivariate analyses. The data showed that the time of day and seasonal variations affect the quality of the essential oil obtained. Leaves harvested at the end of the day (5:00 pm) in the dry season resulted in richer essential oils with higher amounts of non-oxygenated sesquiterpenes. To the best of our knowledge, environmental conditions induce metabolic responses in the leaves of C. langsdorffii, which changes the patterns of sesquiterpene production. Therefore, these factors need to be considered to obtain better concentrations of bioactive compounds for pharmacological studies.

Dry and wet seasons present in different formations on the Cerrado domain are capable of promoting alterations in the composition of volatile compounds (terpenes) in the essential oil from copaiba (Copaifera langsdorffi Desf.). Different ecophysiological conditions of regions and climatic change could be important factors in modifying the chemical profile of terpenes and the yields from essential oil. Copaiba plants from semideciduous seasonal forests show differences into the phytochemical profile obtained in dry and wet seasons, with presence of monoterpenes alpha-thujene, o-cymene, (Z)-beta-ocimene, (E)-beta-ocimene, gamma-terpinene and terpinolene in point 1 (in the wet season), while Cerrado strictu sensu did not show significant differences in chemical composition of volatile compounds (only alpha-cadinol and seychellene showed significant differences). Nevertheless, sesquiterpenes trans-caryophyllene, gamma-cadinene, delta-cadinene, germacrene B and the oxygenated sesquiterpene caryophyllene oxide did not shown any significant differences in the essential oil composition among different points, independent of seasonality.

Machaerium hirtum (Vell.) Stellfeld (Fabaceae) known in Brazil as “jacaranda de espinho” or “espinheira santa nativa” is a medicinal plant commonly used in folk medicine to treat ulcers, cough and diarrhea. This study aimed to investigate the anti-inflammatory and antinociceptive effects of hydroalcoholic extracts from M. hirtum twig (HEMh) using in vivo experimental models of nociception through the involvement of transient receptor potential channels, acid-sensing ion channel (ASIC), nitrergic, opioidergic, glutamatergic, and supraspinal pathways. Our results revealed an antinociceptive effect of HEMh mediated by the opioidergic, l-arginine-nitric oxide and glutamate systems, as well as by interactions with TRPA1/ASIC channels. The anti-inflammatory effect of HEMh evaluated with a xylene-induced ear edema and by the involvement of arachidonic acid and prostaglandin E2 (PGE₂) showed involvement of the COX pathway, based on observed decreases in PGE₂ levels. A phytochemical investigation of the HEMh led to the isolation of α-amyrin, β-amyrin, allantoin, apigenin-7-methoxy-6-C-β-d-glucopyranoside, and apigenin-6-C-β-d-glucopyranosyl-8-C-β-d-xylopyranoside. In conclusion, the acute oral administration of HEMh inhibits the nociceptive behavioral response in animals through the nitrergic, opioid, glutamatergic pathways, and by inhibition of the TRPA1 and ASIC channels, without causing locomotor dysfunction. In addition, its anti-inflammatory effect is associated with the COX pathway and decreased PGE₂ levels.