Copalic Acid Research Articles

Structural characterization of extracellular polysaccharides from Phellinus igniarius SH-1 and their therapeutic effects on DSS induced colitis in mice

Phellinus igniarius is a valuable medicinal and edible mushroom, and its polysaccharides exhibit excellent anti-inflammatory activity. During liquid fermentation to produce P. igniarius mycelia, the fermentation liquid is often discarded, but it contains extracellular polysaccharides. To better utilize these resources, P. igniarius SH-1 was fermented in a 100 L fermenter, and PIPS-2 was isolated and purified from the fermentation broth. The structural characteristics and anti-inflammatory activity of PIPS-2 were determined. PIPS-2 had a molecular weight of 22.855 kDa and was composed of galactose and mannose in a molar ratio of 0.38:0.62. Structural analysis revealed that the main chain of PIPS-2 involved →2)-α-D-Manp-(1 → 3)-β-D-Galf-(1→, and the side chains involved α-D-Manp-(1 → 6)-α-D-Manp-(1→, α-D-Manp-(1 → 3)-α-D-Manp-(1→, and α-D-Manp-(1. PIPS-2 alleviated the symptoms of dextran sodium sulfate (DSS)-induced colitis in mice, improved the imbalance of inflammatory factors and antioxidant enzymes, and increased short-chain fatty acid contents. Combining the intestinal flora and metabolite results, PIPS-2 was found to regulate the abundance of Firmicutes, Lachnospiraceae_NK4A136_group, Proteobacteria, Bacteroides, and many serum metabolites including hexadecenal, copalic acid, 8-hydroxyeicosatetraenoic acid, artepillin C, and uric acid, thereby ameliorating metabolite related disorders in mice with colitis. In summary, PIPS-2 may improve colitis in mice by regulating the gut microbiota and metabolites.

The effect of extraction methods on the yields, chemical composition and antifungal activity of sawdust Cedrus atlantica Manetti essential oils

The aim of this work is to determine the effect of the extraction method on the yield, the chemical composition, and the antifungal activity of cedarwood essential oils (EOs) from sawdust of Moroccan Cedrus atlantica (C. atlantica). EOs were extracted by different methods: hydrodistillation, soxhlet, maceration, and ultrasound. The chemical composition was determined using gas chromatography mass spectrometry (GC-MS) analysis. The yields of EOs were 5.60%, 11.68%, 4.82% and 9.33% for hydrodistillation, soxhlet, maceration and ultrasound, respectively. GC-MS revealed a diversity of chemical compounds depending on extraction methods. Indeed, the main compound of EOs obtained by soxhlet, maceration, and ultrasound was copalic acid methyl ester by a rate of 28.41%, 20.24%, and 24.17%, respectively. However, -himachalene (21.32%) followed by -himachalene (9.40%), β-Copaen-4α-ol (7.71%) and longifolene (6.74%) are the main compounds of EO extracted by hydrodistillation. The antifungal activity of cedarwood EO was tested in vitro on two pathogenic fungi: Fusarium culmorum (F. Culmorum) and Botrytis cineria (B. Cinerea). The minimum inhibitory concentration (MIC) was determined by successive dilutions of the stock solutions. The extracted EOs by soxhlet, maceration and ultrasound showed the important inhibitory effect against B. cinerea (MIC=1.25 mL/L). However, F. culmorum showed resistance towards all tested EOs. The finding of this study showed clearly that the volatile composition of EOs can be variable according to extraction. methods. Moreover, antifungal effects are depending on chemical composition of EOs but also to tested staris.

CHEMICAL AND PHARMACOLOGICAL PROPERTIES OF THE GENUS COPAIFERA IN THE TREATMENT OF INJURIES/WOUNDS: INTEGRATIVE REVIEW

Objective: To identify chemical and pharmacological properties of Copaifera in the treatment of injuries and wounds. Method: Integrative literature review conducted in the LILACS, MEDLINE, PubMed, Taylor & Francis and Scopus databases in January 2022, using the search strategy: “Chemical Properties” AND “Copaifera” AND “Wounds and Injuries” and “Pharmacology” AND “Copaifera” AND “Wounds and Injuries.” Original articles, full text, identified according to level of evidence, written in Portuguese, English or Spanish, were included. Results: In the primary search 261 articles were found. After systematized selection, 12 studies were selected for qualitative analysis. Species of the genus Copaifera have pharmacological properties favorable for wound treatment: control of inflammatory pain, reduction of inflammatory reaction, tissue reepithelialization and repair, angiogenesis, wound retraction and scar remodeling. Among the chemical properties associated with the treatment of injuries, the presence of bioactive compounds stand out: diterpenes, 3-hydroxy-copalic, sesquiterpenes, kolavic-15-methyl ester. Among the tested diterpenes, kaurenoic and copalic acids showed significant hemolytic activities. Only copalic acid and hardwickiic acid inhibited nitric oxide production in lipopolysaccharide-activated macrophages. Conclusion: Plants of the genus Copaifera have chemical and pharmacological properties favorable for the treatment of injuries and wounds.

Fractionation of sesquiterpenes and diterpenic acids from copaiba (Copaifera officinalis) oleoresin using supercritical adsorption

Copaifera officinalis (known as ‘copaiba’) has shown potential application in food and pharmaceutical industries, where biological activities of terpenes are highlighted in the literature. However, clean technologies to fractionate these value-added compounds are still unexplored in literature. This work aimed to separate terpenes from copaiba oleoresin with supercritical CO2 adsorption (SFA), using three adsorbents (zeolite 13X, aluminum oxide, and silicon oxide) at pressures of 9–29 MPa and temperature of 50 ºC. At 9 MPa, zeolite 13X retained β-caryophyllene, achieving concentration factors (CFβ-C) below 0.48, despite good purification efficacy, with the purification factor (PFβ-C) = 1.25. Aluminum and silicon oxides were selective to β-caryophyllene, achieving CFβ-C > 1. Therefore, a two-step adsorption-desorption process could obtain highly concentrated β-caryophyllene fractions. Copalic acid remained adsorbed at 9 MPa in SFA with zeolite 13X. At this condition, CFCA and PFCA over 2 and 5 were obtained, respectively, after zeolite desorption with ethyl acetate.

Copalic Acid: Occurrence, Chemistry, and Biological Activities

Copalic Acid: Occurrence, Chemistry, and Biological Activities

Antisickling potential of compounds derived from Detarium microcarpum (Fabaceae): in vitro and in silico studies

Detarium microcarpum is a legume tree of tropical Africa, widely known for its ethno-medicinal potentials. Previous studies have reported its rich contents of phytochemicals which could be linked to the bioactive principle of the plant. The in vitro antisickling properties of D. microcarpum stem bark was evaluated using blood samples obtained from thirty-five confirmed sickle cell disease patients using standard microscopic techniques. The research outcome showed that D. microcarpum extract inhibited sickling of red blood cells with a laudable mean difference compared to p-hydrozybenzoic acid (reference antisickling drug) which is a pure compound. To further expounds it’s mechanism of action, six compounds previously isolated from D. microcarpum stem bark and fruits was docked into the active sites of deoxy-hemoglobin (PDB ID: IGZX) and 2, 3-bisphosphoglycerate mutase (PDB ID: 1T8P) using Autodock Vina algorithm. Results from the in silico studies showed that oxokolavenic acid, 5α, 8α -2-oxokalavenic acid and Copalic acid exhibited the most favorable ligand–protein molecular interaction with deoxy-hemoglobin and 2,3-bisphosphoglycerate mutase when compared with the reference antisickling drug, hydroxyurea. The interaction of these compounds with deoxy-hemoglobin could alter hemoglobin conformation, favoring the relaxed state, thereby delaying/inhibiting hemoglobin polymerization and sickling. Their interactions with 2, 3-bisphosphoglycerate mutase could inhibit 2, 3-bisphosphoglycerate synthesis, thus delaying enhanced delivery of oxygen to tissues which is twice the case seen in sickle cell anemia. This clearly shows the possible mechanism of action of D. microcarpum and further substantiates the antisickling potential of these compounds derived from D. microcarpum leaves and fruits.

Approach by Raman and infrared spectroscopy in three vegetable oils from the Brazilian Amazon.

Copaiba oils (COP), Andiroba (AND) and Brazil nuts (CDB) have been studied in several areas of science, mainly interests in the pharmacological and food industry. A rapid analysis by techniques such as Raman and Fourier Transform Infrared spectroscopy (FTIR) gives us a set of information concerning the molecular nature. Results of FTIR and Raman for COP, AND and CDB, present modes of vibrations linked to fatty acids (AFs) in the sample composition, whose structures are rich in C=O, C=C and C-H. The results suggest modes in the regions 800-2000 cm$^{-1}$ and 2500-3000 cm$^{-1}$, which fit the general characteristics of the AFs, strongly associated with oleic, linoleic, and palmitic acids. COP presents mode with intense peak at 2800-3000 cm$^{-1}$, just related to the copalic acid, that presents contributions of rings of carbon. Finally, the results were discussed with DFT calculations complementing that obtained by FTIR and Raman.

Isolation Identification and Characterization of Diterpenes from the Stem bark of Detarium Microcarpum

The antibacterial activity of the stem bark of Detarium microcarpum was investigated with the aim of isolating the most active ingredient. Extraction solvents used to prepare the crude extracts of the stem bark were, n-hexane, ethyl acetate, chloroform, methanol. Test bacteria included Escherichia coli, Salmonella enteriditis, Shigella dysenteriae, Staphylococcus aureus and Vibro cholerae. The extracts demonstrated a wide range of antibacterial activity on the microorganisms, with the ethyl acetate crude extract being the most active. Using liquid vacuum chromatography over silica gel, the extract was eluted with n- hexane, ethyl acetate and methanol and fifty- five fractions labeled Gl - G55 were obtained. Further antibacterial assays of the fractions led to the identification of fraction G34 as the most active fraction. This fraction was subjected to spectroscopic analysis using NMR, [(1H -1H NMR, 13C-NMR) and 2D-NMR (COSY and HMBC)]. The results showed good agreement with reported data on Copalic acid, a diterpene with chemical formula C O H O . This compound is 2 34 2 the most active ingredients of this plant and is likely to be responsible for its antibacterial activities.

Acid diterpenes from Copaiba oleoresin (Copaifera langsdorffii): Chemical and plasma stability and intestinal permeability using Caco-2 cells

Ethnopharmacological relevanceCopaiba oleoresin has been used in folk medicine in the treatment of bronchitis, syphilis, skin diseases and ulcers due to its anti-inflammatory and antiseptic activities, but there is no information about major compounds oral absorption to support the traditional use. Aim of studyConsidering the potential of copalic (CA) and kaurenoic acid (KA) – major biological activity (in vitro) diterpenes found in the oleoresin, this study aimed to evaluate the intestinal permeability of CA and KA using Caco-2 cells model as predictive test for oral drug absorption. Materials and methodsChemical stability at pH 1.2 and 7.4 and plasma stability were evaluated to mimic physiological conditions of the gastrointestinal tract. The intestinal permeability of CA and KA was evaluated in Caco-2 cells in the presence and absence of the P-glycoprotein inhibitor verapamil. ResultsCA and KA were rapidly degraded at pH 1.2 (0.2 M Clark-Lubs buffer). At pH 7.4 (0.1 M phosphate buffer), CA was stable for up to 24 h and KA for up to 6 h. In human plasma, CA and KA can be considered stable for 24 h and 12 h at 37 °C, respectively. Caco-2 cells were considered viable when incubated with CA or KA in the range of 3.9–250 μM for 24 h. CA and KA exhibited moderate apparent permeability (Papp) of 4.67 (±0.08) × 10−6 cm/s and 4.66 (±0.04) × 10−6 cm/s, respectively. Simultaneous incubation with verapamil showed that P-glycoprotein does not play a relevant role on CA and KA oral absorption, with Papp of 4.48 (±0.26) × 10−6 cm/s and 5.37 (±0.72) × 10−6 cm/s observed for CA and KA, respectively. ConclusionThe oral absorption of both CA and KA is driven by mainly passive permeability, is not limited by p-glycoprotein, but enteric-coated dosage forms should be used to avoid chemical instability in the gastric pH.

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 of the Neotropics: A Review of the Phytochemistry and Pharmacology.

The oleoresin of Copaifera trees has been widely used as a traditional medicine in Neotropical regions for thousands of years and remains a popular treatment for a variety of ailments. The copaiba resins are generally composed of a volatile oil made up largely of sesquiterpene hydrocarbons, such as β-caryophyllene, α-copaene, β-elemene, α-humulene, and germacrene D. In addition, the oleoresin is also made up of several biologically active diterpene acids, including copalic acid, kaurenoic acid, alepterolic acid, and polyalthic acid. This review presents a summary of the ecology and distribution of Copaifera species, the traditional uses, the biological activities, and the phytochemistry of copaiba oleoresins. In addition, several biomolecular targets relevant to the bioactivities have been implicated by molecular docking methods.

Antigenotoxicity properties of Copaifera multijuga oleoresin and its chemical marker, the diterpene (−)-copalic acid

ABSTRACTIn view of the biological activities and growing therapeutic interest in oleoresin obtained from Copaifera multijuga, this study aimed to determine the genotoxic and antigenotoxic potential of this oleoresin (CMO) and its chemical marker, diterpene (−)-copalic acid (CA). The micronucleus (MN) assay in V79 cell cultures and the Ames test were used for in vitro analyses, as well as MN and comet assays in Swiss mice for in vivo analyses. The in vitro genotoxicity/mutagenicity results showed that either CMO (30, 60, or 120 µg/ml-MN assay; 0.39–3.12 mg/plate-Ames test) or CA (2.42; 4.84, or 9.7 µg/ml-MN assay; 0.39–3.12 mg/plate-Ames test) did not induce a significant effect on the frequency of MN and number of revertants, demonstrating an absence of genotoxic and mutagenic activities, respectively, in vitro. In contrast, these natural products significantly reduced the frequency of MN induced by methyl methanesulfonate (MMS), and exerted a marked inhibitory effect against indirect-acting mutagens in the Ames test. In the in vivo test system, animals treated with CMO (6.25 mg/kg b.w.) exhibited a significant decrease in rate of MN occurrence compared to those treated only with MMS. An antigenotoxic effect of CA was noted in the MN test (1 and 2 mg/kg b.w.) and the comet assay (0.5 mg/kg b.w.). Data suggest that the chemical marker of the genus Copaifera, CA, may partially be responsible for the observed chemopreventive effect attributed to CMO exposure.Abbreviations: 2-AA, 2-anthramine; 2-AF, 2-aminofluorene; AFB1, aflatoxin B1; B[a]P, benzo[a]pyrene; BOD, biological oxygen demand; BPDE, benzo[a]pyrene-7,8-diol-9,10-epoxide; CA, (−)-copalic acid; CMO, oleoresin of Copaifera multijuga, DMEM, Dulbecco`s Modified Eagles`s Medium; DMSO, dimethylsulfoxide; EMBRAPA, Brazilian agricultural research corporation; GC–MS, gas chromatography–mass spectrometry; HAM-F10, nutrient mixture F-10 Ham; HPLC, high performance liquid chromatography; LC–MS, liquid chromatography–mass spectrometry; MI, mutagenic index; MMC, mitomycin C; MMS, methyl methanesulfonate; MN, micronucleus; MNPCE, micronucleated polychromatic erythrocyte; NCE, normochromatic erythrocyte; NDI, nuclear division index; NMR, nuclear magnetic resonance; NPD, 4-nitro-o-phenylenediamine; PBS, phosphate-buffered saline; PCE, polychromatic erythrocyte; SA, sodium azide; V79, Chinese hamster lung fibroblast.

Development of a Gas Chromatography Method for the Analysis of Copaiba Oil.

A rapid, simple, precise and economic method for the quantification of main compounds of copaiba resin and essential oils (Copaifera langsdorffii Desf.) by gas chromatography (GC) has been developed and validated. Copaiba essential oil was extracted by hydrodistillation from the copaiba resin. Resin derivatization allowed the identification of diterpenes compounds. A gas chromatography-mass spectroscopy (GC/MS) method was developed to identify compounds composing the copaiba resin and essential oil. Then the GC/MS method was transposed to be used with a flame ionization detector (FID) and validated as a quantitative method. A good correlation between GC/MS and GC/FID was obtained favoring method transposition. The method showed satisfactory sensitivity, specificity, linearity, precision, accuracy, limit of detection and limit of quantitation for β-caryophyllene, α-humulene and caryophyllene oxide analyses in copaiba resin and essential oils. The main compounds identified in copaiba essential oil were β-bisabolene (23.6%), β-caryophyllene (21.7%) and α-bergamotene (20.5%). Copalic acid methyl ester (15.6%), β-bisabolene (12.3%), β-caryophyllene (7.9%), α-bergamotene (7.1%) and labd-8(20)-ene-15,18-dioic acid methyl ester (6.7%) were diterpenes identified from the derivatized copaiba resin. The proposed method is suitable for a reliable separation, identification and quantification of compounds present in copaiba resin and essential oil. It could be proposed as an analytical method for the analysis of copaiba oil fraction in raw and essential oil parent extracts and after they have been incorporate in pharmaceutical formulations.

Development of a validated ultra-high-performance liquid chromatography tandem mass spectrometry method for determination of acid diterpenes in Copaifera oleoresins

Species of Copaifera genus (Fabaceae – Caesalpinoiodidaeae) produces an important commercial oleoresin that displays many medicinal properties. Copaifera oleoresins (COR) are composed mainly of a mixture of diterpenes and sequiterpenes, and the main reported acid diterpenes for this genus are kaurenoic, copalic, hardwickiic and polyaltic acids. An ultra-performance liquid chromatography tandem mass spectrometry (UPLC–MS/MS) method was developed and validated for identification and quantification of nine acid diterpenes. The developed method was applied in the analyses of 10 authentic COR samples collected in the North and Southeast of Brazil and six commercial COR samples. Samples preparation consisted of simple dilution of oleoresins in methanol followed by filtration. Validation parameters of the method for nine acid diterpenes were satisfactory: selectivity/specificity was defined by retention time and MS/MS analyses for each analyte; generally all analytical curves presented r2>0.99, Lack-of-fit test not significant and RSD<20% for all concentration levels; limit of detection and limit of quantification were on the scale of nanogram per milliliter; inter- and intra-day precision and accuracy were adequate. Regarding the robustness, the method was sensible to small deliberate variations of temperature and additives to the mobile phase, such as formic acid and ammonium hydroxide. Results of 16 analyzed samples of COR showed qualitative and quantitative differences of acid diterpenes among all samples. The diterpenes ent-kaurenoic acid 1, ent-polyalthic acid 3, ent-copalic acid 5 and, ent-3-β-acetoxy copalic acid 9 were found with more frequency in COR analyzed samples. Additionally, the content of the acid diterpenes found in 16 Copaifera oleoresin samples was analyzed by Principal Component Analysis (PCA), suggesting a botanical origin for the commercial samples. The developed UPLC method was shown to be reliable for the analysis of acid diterpenes in commercial Copaifera oleoresins.

Copaifera multijuga oleoresin and its constituent diterpene (−)-copalic acid: Genotoxicity and chemoprevention study

Copaiba oleoresins are used in alternative medicine as anti-inflammatory, antitumoral, and antimicrobial treatments. (−)-Copalic acid (CA) is the major diterpene found in exudates from Copaifera species. We have examined the genotoxicity and the chemopreventive potential of Copaifera multijuga oleoresin (CM) and CA. Genotoxicity assessment was examined with the peripheral blood micronucleus test and the comet assay (male Swiss mouse hepatocytes). In the chemoprevention study, we evaluated the effects of CM and CA on the formation of 1,2-dimethylhydrazine (DMH)-induced aberrant crypt foci (ACF) in male Wistar rat colon. Neither agent caused a significant increase in micronucleus frequency relative to controls, but the highest CM dose tested (400mg/kg b.w.) caused DNA damage in the comet assay. Both agents significantly reduced the frequency of DMH-induced ACF. Both CM and CA suppressed ACF formation and may have a protective effect against colon carcinogenesis.

Copalic acid analogs down-regulate androgen receptor and inhibit small chaperone protein

Copalic acid, one of the diterpenoid acids in copaiba oil, inhibited the chaperone function of α-crystallin and heat shock protein 27kD (HSP27). It also showed potent activity in decreasing an HSP27 client protein, androgen receptor (AR), which makes it useful in prostate cancer treatment or prevention. To develop potent drug candidates to decrease the AR level in prostate cancer cells, more copalic acid analogs were synthesized. Using the level of AR as the readout, 15 of the copalic acid analogs were screened and two compounds were much more potent than copalic acid. The compounds also dose-dependently inhibited AR positive prostate cancer cell growth. Furthermore, they inhibited the chaperone activity of α-crystallin as well.

Development and Validation of a Rapid and Reliable RP-HPLC-PDA Method for the Quantification of Six Diterpenes in Copaifera duckei, Copaifera reticulata and Copaifera multijuga Oleoresins

Oleoresins from Copaifera species are extensively used in folk medicine in Brazil, which are employed mainly in the production of cosmetic formulations in Brazil, North America and Europe. Considering the lack of validated analytical methods for the analyses of diterpenes in Copaifera oleoresins, it was developed a validated and reliable reversed-phase high-performance liquid chromatography with photodiode array detection (RP-HPLC-PDA) method for the analysis of six diterpenes, including: (-)-polyalthic acid; (13E)-ent-labda-7,13-dien-15-oic acid; ent-8(17)-labden-15,18-dioic acid; (-)-copalic acid; (-)-3β-acetoxycopalic acid and (-)-3β-hydroxycopalic acid. These compounds were isolated from C. duckei, C. reticulata and C. multijuga oleoresins by chromatographic means. The analytical curves were linear with regression coefficients (r2) between 0.9903 and 0.9999. The limits of detection (LOD) and quantification (LOQ) values were 0.35 to 3.09 µg mL-1 and 1.05 to 9.36 µg mL-1, respectively. The method also displayed good precision and accuracy. The developed analytical method is reliable and a useful tool for the analysis of Copaifera oleoresin and its products.

Copaiba Oil and Its Constituent Copalic Acid as Chemotherapeutic Agents against Dermatophytes

Copaiba oil, an oleoresin extracted from Copaifera genus, has been widely used in popular medicine for the treatment of several diseases. The aim of this study was to investigate the antifungal activity of the copaiba oil and its isolated compounds caryophyllene oxide, copalic acid and acetoxycopalic acid against Trichophyton rubrum, Trichophyton mentagrophytes and Microsporum gypseum strains, using microdilution method and microscopy techniques. It was found that the copaiba oil and the copalic acid were active against dermatophytes by minimal inhibitory concentration (MIC) and minimal fungicidal concentration (MFC) tests. The MIC and MFC of copaiba oil against T. rubrum, T. mentagrophytes and M. gypseum were 125 µg mL-1 (250 µg mL-1), 500 µg mL-1 (500 µg mL-1) and 250 µg mL-1 (250 µg mL-1), respectively. For copalic acid, the MIC and MFC were 50 µg mL-1 (100 µg mL-1), 100 µg mL-1 (100 µg mL-1) and 50 µg mL-1 (100 µg mL-1), respectively. Fluorescence microscopy and scanning electronic microscopy were used to investigate inhibition on hyphal growth by compounds, copaiba oil and copalic acid, showing a strong inhibition and an irregular growth pattern. Cell wall, cytoplasmic membrane and intracellular contents were also damaged. In conclusion, copaiba oil and copalic acid showed great activity against dermatophytes, being potential compounds for the development of antifungal drugs.

Antitubercular Activity Increase in Labdane Diterpenes from Copaifera Oleoresin through Structural Modification

The labdane diterpenes copalic acid, 3β-acetoxy-copalic acid, 3β-hydroxy-copalic acid and ent-agathic acid were isolated from Copaifera langsdorffii oleoresin. These four compounds were submitted to structural modifications by reduction with hydrogen/palladium, esterification with diazomethane, esterification with methanol/sulfuric acid and conversion into sodium salt, furnishing 15 compounds. All compounds were assayed in vitro against Mycobacterium tuberculosis (H37Rv, ATCC 27294). The four compounds displayed minimum inhibitory concentration (MIC) value of 125 μg mL, and were not considered active. A methylated derivative of compound 3β-hydroxy-copalic acid, and a sodium salt of copalic acid displayed MIC values of 25 μg mL (71.7 μM) and 6.25 μg mL (19.2 μM), respectively. The sodium salt of copalic acid stood out by displaying similar activity in comparison with streptomycin (MIC 6.25 μg mL) and a better activity compared to μM value of pyrazinamide (MIC 3.12 μg mL; 25.34 μM). Therefore, the methylated derivative of compound 3β-hydroxy-copalic acid and the sodium salt of copalic acid should be considered for further studies.

Synthesis of (−)-agathic acid and (−)-copalic acid from andrographolide via a regioselective Barton-McCombie reaction

The first synthesis of the ent-labdane diterpenoid (−)-agathic acid (1) with antibacterial activity is described. A chiral pool approach was employed with a linear sequence of 14 steps starting from readily available and inexpensive andrographolide. The regioselective deoxygenation in terms of Barton-McCombie free radical reaction completed a key step in the synthesis. (−)-Copalic acid (2), an analogue of (−)-agathic acid, has been conveniently synthesized from the key intermediate 7 in five steps.