A reliable validated high-performance liquid chromatography-photodiode array detection method for quantification of terpenes in Copaifera pubiflora, Copaifera trapezifolia, and Copaifera langsdorffii oleoresins

The Copaifera oleoresins are widely used in folk medicine to treat various diseases. The goal of this study was to develop a validated reverse-phase high-performance liquid chromatography method with photodiode array detection (RP-HPLC-PDA) to quantify eight terpenes: ent-hardwickiic acid, ent-copalic acid, ent-7α-acetoxy hardwickiic acid, ent-16-hydroxy-3,13-clerodadiene-15,18-dioic acid, ent-5,13-labdadiene-15-oic acid, junenol, ent-kaurenoic acid, and 13E-ent-labda-7,13-dien-15-oic acid in the oleoresins of Copaifera pubiflora L. (OCP), Copaifera trapezifolia L. (OCT) and Copaifera langsdorffii L. (OCL). The linearity of the method was confirmed in the range of 20.00-500 µg.mL-1 (r2 > 0.999). The limit of quantification was between 1,05 and 16.89 µg.mL-1. Precision and accuracy ranges were found to be %RSD <0.2 and 96% to 110%, respectively. Based on the obtained results, the developed analytical method is rapid, precise, accurate, and sensitive for quantifying these terpenes in Copaifera's oleoresins.

Electrospray ionization tandem mass spectrometry of labdane-type acid diterpenes

Copaifera (Leguminoseae) species produce a commercially interesting oleoresin that displays several biological activities, including antimicrobial and anti-inflammatory properties. Labdane-type diterpenes are the main chemical constituents of these oleoresins, and copalic acid is the only compound that has been detected in all Copaifera oleoresins. In this study, we investigate some aspects of the gas-phase fragmentation reactions involved in the formation of the product ions from the deprotonated compounds (-)-ent-copalic acid (1), (-)-ent-3β-hydroxy-copalic acid (2), (-)-ent-3β-acetoxy-copalic acid (3), and (-)-ent-agathic acid (4) by electrospray ionization tandem mass spectrometry (ESI-MS/MS) and multiple stage mass spectrometry (MSⁿ ). Our results reveal that the product ion with m/z 99 is common to all the analyzed compounds, whereas the product ion with m/z 217 is diagnostic for compounds 2 and 3. Moreover, only compound 4 undergoes CO₂ (44 u) and acetic acid (60 u) elimination from the precursor ion. Thermochemical data obtained by computational chemistry at the B3LYP/6-31G(d) level of theory support the proposed ion structures. These data helped us to identify these compounds in a crude commercial Copaifera langsdorffii oleoresin by selective multiple reaction monitoring (MRM). Finally, a precursor ion scan (PIS) strategy aided screening of labdane-type acid diterpenes other than 1 to 4 in the same Copaifera oleoresin sample and led us to propose the structures of 8,17-dihydro-ent-agathic acid (5) and 3-keto-ent-copalic acid (6), which have not been previously reported in Copaifera oleoresins.

Copaifera duckei Oleoresin and Its Main Nonvolatile Terpenes: In Vitro Schistosomicidal Properties

In this article, the in vitro schistosomicidal effects of three Brazilian Copaifera oleoresins (C. duckei, C. langsdorffii, and C. reticulata) are reported. From these botanical sources, the oleoresin of C. duckei (OCd) demonstrated to be the most promising, displaying LC₅₀ values of 75.8, 50.6, and 47.2 μg/ml at 24, 48, and 72 h of incubation, respectively, against adult worms of Schistosoma mansoni, with a selectivity index of 10.26. Therefore, the major compounds from OCd were isolated, and the diterpene, (-)-polyalthic acid (PA), showed to be active (LC₅₀ values of 41.7, 36.2, and 33.4 μg/ml, respectively, at 24, 48, and 72 h of incubation). Moreover, OCd and PA affected the production and development of eggs, and OCd modified the functionality of the tegument of S. mansoni. Possible synergistic and/or additive effects of this balsam were also verified when a mixture of the two of its main compounds (PA and ent-labd-8(17)-en-15,18-dioic acid) in the specific proportion of 3:1 (w/w) was tested. The obtained results indicate that PA should be considered for further investigations against S. mansoni, such as, synergistic (combination with praziquantel (PZQ)) and in vivo studies. It also shows that diterpenes are an important class of natural compounds for the investigation of agents capable of fighting the parasite responsible for human schistosomiasis.

Immunomodulatory action of Copaifera spp oleoresins on cytokine production by human monocytes

Copaifera spp oleoresins have been used in folk medicine for centuries; nevertheless, its immunomodulatory action has not been investigated. Thus, the goal of this study was to characterize different oleoresins and to verify their action on human monocytes regarding pro- and anti-inflammatory cytokine production (TNF-α and IL-10, respectively). The chemical composition of Brazilian Copaifera reticulata, Copaifera duckey and Copaifera multijuga oleoresins was analyzed by HPLC-MS. Cell viability was assessed by MTT method after incubation of cells with Copaifera spp. Noncytotoxic concentrations of oleoresins were incubated with human monocytes from healthy donors, and cytokine production was determined by ELISA. HPLC-MS analysis for terpenes allowed the identification of six diterpene acids and one sesquiterpene acid. Oleoresins exerted no cytotoxic effects on human monocytes. All oleoresins had a similar profile: LPS-induced TNF-α production was maintained by oleoresins, while a significant inhibitory action on IL-10 production was seen. Copaifera oleoresins seemed to exert an activator profile on human monocytes without affecting cell viability. Such effect may be due to the presence of either diterpene or sesquiterpene acids; however, further studies are necessary to determine the involvement of such compounds in Copaifera immunomodulatory effects.