Chemical composition of extracts and fractions from Miconia ibaguensis (MELASTOMATACEAE) leaves and evaluation of biological activities.

The study aimed to assess the chemical composition of Miconia ibaguensis leaves extracts and fractions obtained from the ethanolic extract (EE), along with evaluating their antifungal, antibacterial, antidiabetic, and antioxidant activities. The ethyl acetate fraction (EAF) exhibited potent antifungal activity against Candida spp (1.95 - 3.90 µg mL-1) and potent antioxidant activity in the DPPH (1.74 ± 0.07 µg mL-1), FRAP (654.01 ± 42.09 µmol ETrolox/gsample), and ORAC (3698.88 ± 37.28 µmol ETrolox/gsample) methods. The EE displayed inhibition against the α-amylase enzyme (8.42 ± 0.05 µg mL-1). Flavonoids, hydrolysable tannins, triterpenoids, and phenolic acids, identified in the EE and fractions via (-)-HPLC-ESI-MS/MS analysis, were found to contribute to the species' biological activity potentially. These findings suggest promising avenues for further research and potential applications in pharmacology and natural products, offering new possibilities in the fight against global health issues.

Exploring the composition and properties of Centella asiatica metabolites and investigating their impact on BSA glycation, LDL oxidation and α-amylase inhibition.

Centella asiatica (L.) Urb. is a small herbaceous plant belonging to the Apiaceae family that is rich in triterpenes, such as asiaticoside and madecassoside. Centella asiatica finds broad application in promoting wound healing, addressing skin disorders, and boosting both memory and cognitive function. Given its extensive therapeutic potential, this study aimed not only to investigate the Centella asiatica ethanolic extract but also to analyze the biological properties of its organic fractions, such as antioxidant antiglycation capacity, which are little explored. We also identified the main bioactive compounds through spectrometry analysis. The ethanolic extract (EE) was obtained through a static maceration for seven days, while organic fractions (HF: hexane fraction; DF: dichloromethane fraction; EAF: ethyl acetate fraction; BF: n-butanol fraction and HMF: hydromethanolic fraction) were obtained via liquid-liquid fractionation. The concentration of phenolic compounds, flavonoids, and tannins in each sample was quantified. Additionally, the antiglycation (BSA/FRU, BSA/MGO, and ARG/MGO models) and antioxidant (FRAP, ORAC, and DPPH) properties, as well as the ability to inhibit LDL oxidation and hepatic tissue peroxidation were evaluated. The inhibition of enzyme activity was also analyzed (α-amylase, α-glycosidase, acetylcholinesterase, and butyrylcholinesterase). We also evaluated the antimicrobial and cytotoxicity against RAW 264.7 macrophages. The main compounds present in the most bioactive fractions were elucidated through ESI FT-ICR MS and HPLC-ESI-MS/MS analysis. In the assessment of antioxidant capacity (FRAP, ORAC, and DPPH), the EAF and BF fractions exhibited notable results, and as they are the phenolic compounds richest fractions, they also inhibited LDL oxidation, protected the hepatic tissue from peroxidation and inhibited α-amylase activity. Regarding glycation models, the EE, EAF, BF, and HMF fractions demonstrated substantial activity in the BSA/FRU model. However, BF was the only fraction that presented non-cytotoxic activity in RAW 264.7 macrophages at all tested concentrations. In conclusion, this study provides valuable insights into the antioxidant, antiglycation, and enzymatic inhibition capacities of the ethanolic extract and organic fractions of Centella asiatica. The findings suggest that further in vivo studies, particularly focusing on the butanol fraction (BF), may be promising routes for future research and potential therapeutic applications.

Bioactive compounds from the leaves of Maytenus ilicifolia Mart. ex Reissek: Inhibition of LDL oxidation, glycation, lipid peroxidation, target enzymes, and microbial growth.

ETHNOPHARMACOLOGICAL RELEVANCE: Maytenus ilicifolia Mart. ex Reissek, a medicinal plant used for treating gastritis, ulcers, and gastric disorders, possesses therapeutic properties attributed to diverse leaf compounds-terpenoids, alkaloids, flavonoids, phenols, and tannins, reflecting the ethnopharmacological knowledge of traditional users. AIMS OF THE STUDY: We aimed to assess the antioxidant and antiglycant capacities of Maytenus ilicifolia's ethanolic extract and organic fractions, identify bioactive compounds through HPLC-MS/MS analysis, and conduct phytochemical assessments. We also assessed their potential to inhibit digestive and cholinesterase enzymes, mitigate oxidation of human LDL and rat hepatic tissue, and examine their antimicrobial and cytotoxic properties. MATERIALS AND METHODS: Organic fractions (hexane - HF-Mi, dichloromethane - DMF-Mi, ethyl acetate - EAF-Mi, n-butanol - BF-Mi, and hydromethanolic - HMF-Mi) were obtained via liquid-liquid partitioning. Antioxidant (DPPH, FRAP, ORAC) and antiglycant (BSA/FRU, BSA/MGO, ARG/MGO/LDL/MGO models) capacities were tested. Phytochemical analysis employed HPLC-MS/MS. We also studied the inhibitory effects on α-amylase, acetylcholinesterase, butyrylcholinesterase, human LDL and rat hepatic tissue oxidation, antimicrobial activity, and cytotoxicity against RAW 264.7 macrophages. RESULTS: HPLC-ESI-MS/MS identified antioxidant compounds such as catechin, quercetin, and kaempferol derivatives. Ethanolic extract (EE-Mi) and organic fractions demonstrated robust antioxidant and antiglycant activity. EAF-Mi and BF-Mi inhibited α-amylase (2.42 µg/mL and 7.95 µg/mL) compared to acarbose (0.144 µg/mL). Most organic fractions exhibited ∼50% inhibition of acetylcholinesterase and butyrylcholinesterase, rivaling galantamine and rivastigmine. EAF-Mi, BF-Mi, and EE-Mi excelled in inhibiting lipid peroxidation. All fractions, except HMF-Mi, effectively countered LDL oxidation, evidenced by the area under the curve. These fractions protected LDL against lipid peroxidation. CONCLUSION: This study unveils Maytenus ilicifolia's ethanolic extract and organic fractions properties. Through rigorous analysis, we identify bioactive compounds and highlight their antioxidant, antiglycant, enzyme inhibition, and protective properties against oxidative damage. These findings underline its significance in modern pharmacology and its potential applications in healthcare.

An In Vivo Assessment of the Effect of Hexane Extract from Endlicheria paniculata Branches and Its Main Compound, Methyldehydrodieugenol B, on Murine Sponge-Induced Inflammation.

The present study aims to explore the anti-inflammatory potential activity of the hexane extract from branches (HEB) of Endlicheria paniculata (Lauraceae) and its main compound, methyldehydrodieugenol B, in the inflammatory response induced by a murine implant sponge model. HPLC-ESI/MS analysis of HEB led to the identification of six chemically related neolignans, with methyldehydrodieugenol B as the main compound. An in silico analysis of the pharmacokinetic parameters of the identified compounds suggested moderate solubility but good absorption and biodistribution in vivo. Thus, the treatment of mice with HEB using in vivo assays indicated that HEB promoted pro-inflammatory, antiangiogenic, and antifibrogenic effects, whereas treatment with methyldehydrodieugenol B caused anti-inflammatory, antifibrogenic, and antiangiogenic effects. The obtained results shown the therapeutic potential of HEB and methyldehydrodieugenol B in the treatment of pathologies associated with inflammation and angiogenesis, including chronic wounds.

Identification of Substances Produced by Cercospora brachiata in Absence of Light and Evaluation of Antibacterial Activity.

Cercospora brachiata is a phytopathogenic fungus. To know more about the metabolites produced by this fungus, the objective of this work was to identify, isolate and characterize substances present in extracts of the growth broth and mycelium, using gas chromatography with mass spectrometry (GC-MS) and nuclear magnetic resonance (NMR). It was also objective to evaluate the antibacterial activity of the extracts. Among the compounds identified, fatty acids, esters, and steroids can be highlighted. The main compounds identified are 9-hexadecenoic, hexadecenoic, oleic, octadecanoic, lauric, myristic, palmitic, doceno-13-enoic, stearic, linoleic, and nonadecanoic acids present in almost all extracts. For the antibacterial activity, the broth microdilution method was used. The ethyl acetate extract of the mycelium presented inhibitory concentrations (MICs) against the bacterium Actinomyces naeslundii (100 µg mL-1) and Streptococcus sanguinis (200 µg mL-1). Finally, two steroids were isolated and identified in the hexane extract of mycelium: ergosta-6,22-dien-3ß,5α,8α-triol and brassicasterol.

Antioxidant compounds of Kielmeyera coriacea Mart. with α-amylase, lipase and advanced glycation end-product inhibitory activities.

Chronic hyperglycemia and hyperlipidemia are associated with excessive formation of reactive oxygen species and advanced glycation end-products. The present study aimed to evaluate the potential in vitro antidiabetic properties of Kielmeyera coriacea inner bark. The main phytochemical compounds were identified by UHPLC-ESI/MSn and the ethanol extract and its fractions were used to evaluate their antioxidant and anti-glycation capacities, as well as their inhibitory potential against glycoside and lipid hydrolases activities. The polar fractions, especially the n-butanol fraction, had free radical scavenging and quenching properties (ORAC and FRAP values>1800 and 1000 µmol trolox eq/g, respectively, and DPPH IC50<4 µg/mL), and inhibited ROS production (p < 0.01), lipid peroxidation (p < 0.001), glycation (IC50 ~ 10 µg/mL in the BSA-fructose assay; IC50 ~ 200 µg/mL in the BSA-methylglyoxal and arginine-methylglyoxal assays), α-amylase (IC50<0.1 µg/mL) and lipase (IC50<5 µg/mL), with no cytotoxicity. Biomolecules well-known as potent antioxidants were identified for the first time in the inner bark of K. coriacea, such as protocatechuic acid, epicatechin and procyanidins A, B and C. Together, our results support the antioxidant, anti-glycation and glycoside and lipid hydrolases inhibitory properties of the inner bark of K. coriacea, a species found in the Brazilian savanna, which makes it especially useful to combat oxidative stress and hyperglycemia and hyperlipidemia.

Evaluation of Gibbilimbol B, Isolated from Piper malacophyllum (Piperaceae), as an Antischistosomal Agent.

Infections caused by parasitic worms impose a considerable worldwide health burden. One of the most impactful is schistosomiasis, a disease caused by blood-dwelling of the genus Schistosoma that affects more than 230 million people worldwide. Since praziquantel has also been extensively used to treat schistosomiasis and other parasitic flatworm infections, there is an urgent need to identify novel anthelmintic compounds, mainly from natural sources. In this study, the hexane extract from roots of Piper malacophyllum (Piperaceae) showed to be mainly composed for gibbilimbol B by HPLC/ESI-HRMS. Based on this result, this compound was isolated by chromatographic steps and its structure was confirmed by NMR. In vitro bioassays showed that gibbilimbol B was more active than praziquantel against larval stage of S. mansoni, with effective concentrations of 50 % (EC50 ) and 90 % (EC90 ) values of 2.6 and 3.4 µM, respectively. Importantly, gibbilimbol B showed no cytotoxicity to mammalian cells at a concentration 190 times greater than the antiparasitic effect, giving support for the anthelmintic potential of gibbilimbol B as lead compound for novel antischistosomal agents.

Essential oil from leaves of Eugenia calycina Cambes: Natural larvicidal against Aedes aegypti.

BACKGROUND: Eugenia calycina is an endemic species in the Brazilian savannah (the Cerrado) and it is threatened with extinction. Several species of Eugenia are used as insecticides or insect repellents. No data are available on the larvicidal activity of E. calycina. The chemical composition of the essential oil (EO) from leaves of Eugenia calycina was analyzed by gas chromatography coupled to mass spectrometry (GC-MS) and the larvicidal activity against Aedes aegypti larvae in the third stage of development was studied. RESULTS: Oxygenated and non-oxygenated sesquiterpenes were identified, and the main compounds were bicyclogermacrene, spathulenol, and ß-caryophyllene. The EO was fractionated in a chromatographic column and three compounds were isolated and identified: spathulenol, aromadendrane-4ß,10α-diol, and 1ß-11-dihydroxy-5-eudesmene. It is the first time that the last two compounds have been identified in E. calycina. The exposure times in the larvicidal test were 24 h and 48 h and the LC50 values obtained were 199.3 and 166.4 µg mL-1 . The cytotoxicity of the EO in mammalian cells (HeLa and Vero) was evaluated for 24 and 48 h of incubation. The cytotoxic concentrations of the EO for HeLa and Vero cells (266.8 ± 46.5 and 312.1 ± 42.5 µg mL-1 , respectively) in 48 h of exposure were higher than the LC50 , showing low cytotoxicity at the concentration exhibiting larvicidal activity, resulting in a positive selectivity index. CONCLUSION: These results indicate that the EO of E. calycina showed high activity against the A. aegypti larvae but lower cytotoxicity to mammalian cells. The leaves of E. calycina are therefore a very promising source of natural larvicidal products. © 2020 Society of Chemical Industry.

Dehydrodieugenol B and hexane extract from Endlicheria paniculata regulate inflammation, angiogenesis, and collagen deposition induced by a murine sponge model.

The present study reports the evaluation of hexane extract from Endlicheria paniculata and its main metabolite dehydrodieugenol B in the inflammatory response induced by a murine implant sponge model. As a result, a reduction in the inflammatory markers (myeloperoxidase and N-acetyl-ß-D-glucosaminidase) and number of mast cells were observed in comparison to the control group. All doses were also able to reduce angiogenic parameters evaluated in fibrovascular tissue. In implants treated with dehydrodieugenol B a reduction in total collagen deposition and types I and III collagen fibers were observed, while an increased in total collagen deposition and types I and III collagen fibers were observed in the treatment with hexane extract. Docking studies into cyclooxygenase-2 active site revealed that the dehydrodieugenol B had binding modes and energies comparable with celecoxib, diclofenac and ibuprofen. Therefore, dehydrodieugenol B was able to alter key components of chronic inflammation, resulting in a reduced inflammatory response and also presenting antifibrogenic and antiangiogenic effects. However, treatment with hexane extract resulted in a reduced inflammatory response with antiangiogenic effects, but caused fibrogenic effects.

Antioxidant compounds from Banisteriopsis argyrophylla leaves as α-amylase, α-glucosidase, lipase, and glycation inhibitors.

Banisteriopsis argyrophylla belongs to the Malpighiaceae family, which is a species from Cerrado, also known as "cipó-prata" or "cipó-folha-de-prata." Several species of this family present biological potential. This work reports the chemical identification of the ethanol extract (EE) and its fractions from B. argyrophylla leaves and shows the analysis of the antioxidant activity and inhibitory effects on activities of α-amylase, α-glucosidase and lipase, and non-enzymatic glycation. The ethyl acetate fraction (EAF) and n-butanol fraction (BF) showed antioxidant activity, with IC50 values of 4.1 ± 0.1 and 4.8 ± 0.1 µg mL-1, respectively, by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) method, and IC50 values of 6046.3 ± 174.2 and 6264.2 ± 32.2 µmol Trolox eq g-1 by the oxygen radical absorbance capacity (ORAC) method. Furthermore, the DPPH method with these fractions presented electroactive species with antioxidant potential, as shown by the differential pulse voltammetry (DPV) method. The inhibitory effects of the EAF and BF were demonstrated by the following results: IC50 of 5.1 ± 0.3 and 2.5 ± 0.2 µg mL-1 for α-amylase, IC50 of 1093.5 ± 26.0 and 1250.8 ± 21.9 µg mL-1 for α-glucosidase, IC50 of 8.3 ± 4.1 and 4.4 ± 1.0 µg mL-1 for lipase, and IC50 of 1.3 ± 0.1 and 0.9 ± 0.1 µg mL-1 for glycation. Some bioactive compounds were identified by (-)-ESI-MS/MS, such as catechin, procyanidins, glycosylated flavonoids, kaempferol, and megastigmane glucosides. The antidiabetic activity of B.argyrophylla has been reported for the first time.

Chemical Composition, Antifungal, and Cytotoxicity Activities of Inga laurina (Sw.) Willd Leaves.

The species Inga laurina is native to the Brazilian Cerrado. There are no studies about the chemical composition and biological activities of extracts of this endangered species. The ethanolic extract and its successive fractions are rich in phenolic compounds and presented good antifungal activities. HPLC/MS-MS/MS and H1/C13 analysis led to the identification of seventeen compounds, most of which are gallic acid derivatives, myricetin and quercetin glycosides. The ethyl acetate fraction (EAF) contained high levels of total phenolics, expressed in milligrams of gallic acid equivalents per gram of extract (475.3 ± 1.9 mg GAE gextract -1) and flavonoids expressed in milligrams of quercetin equivalents per gram of extract (359.3 ± 10.6 mg QE gextract -1). This fraction was active against fungi of the Candida genus. The EAF showed MIC value 11.7 µg mL-1 against C. glabrata and a selectivity index of 1.6 against Vero cells. The flavonol glycoside myricetin-3-O-rhamnoside was isolated for the first time from the Inga laurina. These results make I. laurina a promising plant as a source of pharmaceutical and biological active antifungal compounds.

Antifungal and cytotoxicity activities of Banisteriopsis argyrophylla leaves.

OBJECTIVES: This work aimed to evaluate the antifungal and cytotoxic activity of the EtOH extract and fractions of Banisteriopsis argyrophylla leaves, and to perform the identification of these bioactive metabolites. METHODS: The EtOAc fraction (EAF) obtained from the ethanolic extract of B. argyrophylla leaves showed better antifungal potential against Candida spp. In this fraction, ten flavonoids have been identified by UHPLC-ESI-MSn . Then, EAF was submitted to column chromatography to give four new fractions (A1-A4). The cytotoxicity was determined against Vero cells. KEY FINDINGS: The EAF showed better antifungal potential against Candida spp. with minimum inhibitory concentrations (MICs) between 31.25 and 93.75 µg/ml. The (-)-catechin (fraction A1) showed a MIC of 2.83 µg/ml against Candida glabrata. Fractions A2, A3 and A4 were rich in quercetins and kaempferols and showed good inhibitory concentrations (5.86-46.87 µg/ml) against C. albicans, C. glabrata and C. tropicalis. CONCLUSIONS: The EtOH extract, fractions and the isolated (-)-catechin showed lower toxicity to Vero cells than cisplatin, used as a positive control. Thus, the leaves of B. argyrophylla are a promising source of antifungal agents.

Phytochemical characterization of the Vochysia rufa (Vochysiaceae) extract and its effects on oxidative stress in the pancreata of streptozotocin-induced diabetic rats.

Aqueous extract of macerated Vochysia rufa stem bark has been commonly used in the treatment of diabetes. Therefore, we evaluated the antihyperglycemic and antioxidant effects of an extract of V. rufa on the pancreata of streptozotocin (STZ)-induced diabetic rats. Animals received one of the following treatments daily by oral gavage: water (diabetic-control), V. rufa extract (diabetic-V. rufa), or glibenclamide (diabetic-GBD). Total antioxidant capacity; levels of thiobarbituric acid reactive substances, reduced glutathione, and sulfhydryls; and superoxide dismutase, catalase, and glutathione peroxidase (GPx) activities were measured in the pancreas. Biochemical analysis of serum total cholesterol and fractions, triglycerides, creatinine, urea, acid uric, ALP, γ-GT, AST, and ALT was performed, and pancreatic ß-cells positive for insulin were evaluated by immunohistochemistry. Rats treated with extract exhibited a decrease in fasting blood glucose compared with levels in diabetic control rats. GPx activity and sulfhydryl levels were significantly lower in diabetic-V. rufa rats compared with those of diabetic-control rats. V. rufa extract acted to normalize the biochemical alterations found in diabetic rats (diabetic-controls), as demonstrated by increases in urea, HDL, ALP, AST, and ALT. Reduction in blood glucose was independent of an increase in insulin. The V. rufa extract was found to be composed of free sugars (inositol, galactose, glucose, mannose, sucrose, arabinose, and ribose) as the main metabolites. Thus, aqueous extract of the stem bark of V. rufa is capable of reducing blood glucose, resulting in an antioxidant effect on the pancreatic tissue of STZ-diabetic rats.

New alkenyl derivative from Piper malacophyllum and analogues: Antiparasitic activity against Trypanosoma cruzi and Leishmania infantum.

Alkylphenols isolated from Piper malacophyllum (Piperaceae), gibbilimbols A and B, showed interesting activity against the parasites Trypanosoma cruzi and Leishmania infantum. In continuation to our previous work, a new natural product from the essential oil of the leaves of P. malacophyllum was isolated, the 5-[(3E)-oct-3-en-1-il]-1,3-benzodioxole, and also a new set of five compounds was prepared. The antiparasitic activity of the natural product was evaluated in vitro against these parasites, indicating potential against the promastigote/trypomastigote/amastigote forms (IC50 32-83 µm) of the parasites and low toxicity (CC50  > 200 µm) to mammalian cells. The results obtained to the synthetic compounds indicated that the new derivatives maintained the promising antiparasitic activity, but the cytotoxicity was considerably lowered. The amine derivative LINS03011 displayed the most potent IC50 values (13.3 and 16.7 µm) against amastigotes of T. cruzi and L. infantum, respectively, indicating comparable activity to the phenolic prototype LINS03003, with threefold decreased (CC50 73.5 µm) cytotoxicity, leading the selectivity index (SI) towards the parasites up to 24.5. In counterpart, LINS03011 has not shown membrane disruptor activity in SYTOX Green model. In summary, this new set showed the hydroxyl is not essential for the antiparasitic activity, and its substitution could decrease the toxicity to mammalian cells.

Peel of araticum fruit (Annona crassiflora Mart.) as a source of antioxidant compounds with α-amylase, α-glucosidase and glycation inhibitory activities.

Annona crassiflora Mart., whose fruit is popularly known as araticum, is a member of the Annonaceae family found in the Brazilian Cerrado. Although this plant has several medicinal uses, its bioactive molecules are not fully understood. A bioguided assay was performed to identify the main bioactive compounds of A. crassiflora fruit peel from the ethanol extract fractions with antioxidant capacity and α-amylase, α-glucosidase and glycation inhibitory activities. Ethyl acetate and n-butanol fractions showed, respectively, higher antioxidant capacity (DPPH IC50 1.5±0.1 and 0.8±0.1µgmL-1, ORAC 3355±164 and 2714±79µmoltroloxeq/g, and FRAP 888±16 and 921±9µmoltroloxeq/g) and inhibitory activities against α-amylase (IC50 4.5±0.8 and 1.7±0.3µgmL-1), α-glucosidase (IC50 554.5±158.6 and 787.8±140.6µgmL-1) and glycation (IC50 14.3±3.3 and 16.0±4.2µgmL-1), and lower cytotoxicity, compared to the other fractions and crude ethanol extract. The HPLC-ESI-MS/MS analysis identified various biomolecules known as potent antioxidants, such as chlorogenic acid, (epi)catechin, procyanidins, caffeoyl-hexosides, quercetin-glucosides and kaempferol. The fruit peel of A. crassiflora, a specie from Cerrado, the Brazilian Savanna, provided a source of antioxidant compounds with properties to block carbohydrate digestive enzymes and formation of glycation products. Thus, there is potential to use the by-products of araticum in order to identify and isolate phytochemicals for application in nutraceutical supplements, food additives and pharmaceuticals products.

Batch-injection analysis with amperometric detection of the DPPH radical for evaluation of antioxidant capacity.

This work proposes the application of batch-injection analysis with amperometric detection to determine the antioxidant capacity of real samples based on the measurement of DPPH radical consumption. The efficient concentration or EC50 value corresponds to the concentration of sample or standard required to scavenge 50% DPPH radicals. For the accurate determination of EC50, samples were incubated with DPPH radical for 1h because many polyphenolic compounds typically found in plants and responsible for the antioxidant activity exhibit slow kinetics. The BIA system with amperometric detection using a glassy-carbon electrode presented high precision (RSD = 0.7%, n = 12), low detection limit (1 µmol L(-1)) and selective detection of DPPH (free of interferences from antioxidants). These contributed to low detection limits for the antioxidant (0.015 and 0.19 µmol L(-1) for gallic acid and butylated hydroxytoluene, respectively). Moreover, BIA methods show great promise for portable analysis because battery-powered instrumentation (electronic micropipette and potentiostats) is commercially available.

Chemical Constituents and Evaluation of Antimicrobial and Cytotoxic Activities of Kielmeyera coriacea Mart. & Zucc. Essential Oils.

Many essential oils (EOs) of different plant species possess interesting antimicrobial effects on buccal microorganisms and cytotoxic properties. EOs of Kielmeyera coriacea Mart. & Zucc. were analyzed by gas chromatography coupled to mass spectrometry (GC-MS). The EO from leaves is rich in sesquiterpenes hydrocarbons and oxygenated sesquiterpenes. The three major compounds identified were germacrene-D (24.2%), (E)-caryophyllene (15.5%), and bicyclogermacrene (11.6%). The inner bark EO is composed mainly of sesquiterpenes hydrocarbons and the major components are alpha-copaene (14.9%) and alpha-(E)-bergamotene (13.0%). The outer bark EO is composed mainly of oxygenated sesquiterpenes and long-chain alkanes, and the major components are alpha-eudesmol (4.2%) and nonacosane (5.8%). The wood EO is mainly composed of long-chain alkanes and fatty acids, and the major components are nonacosane (9.7%) and palmitic acid (16.2%). The inner bark EO showed the strongest antimicrobial activity against the anaerobic bacteria Prevotella nigrescens (minimum inhibitory concentration-MIC of 50 µg mL(-1)). The outer bark and wood EOs showed MICs of 100 µg mL(-1) for all aerobic microorganisms tested. The EOs presented low toxicity to Vero cells. These results suggest that K. coriacea, a Brazilian plant, provide initial evidence of a new and alternative source of substances with medicinal interest.

Antiparasitic activity of natural and semi-synthetic tirucallane triterpenoids from Schinus terebinthifolius (Anacardiaceae): structure/activity relationships.

Leishmaniasis and Chagas are diseases caused by parasitic protozoans that affect the poorest population in the World, causing a high mortality and morbidity. As a result of highly toxic and long-term treatments, the discovery of novel, safe and more efficacious drugs is essential. In this work, the in vitro antiparasitic activity and mammalian cytotoxicity of three natural tirucallane triterpenoids, isolated from leaves of Schinus terebinthifolius (Anacardiaceae), and nine semi-synthetic derivatives were investigated against Leishmania (L.) infantum and Trypanosoma cruzi. Trypomastigotes of T. cruzi were the most susceptible parasites and seven compounds demonstrated a trypanocidal activity with IC50 values in the range between 15 and 58 µg/mL. Four compounds demonstrated selectivity towards the intracellular amastigotes of Leishmania, with IC50 values in the range between 28 and 97 µg/mL. The complete characterization of triterpenoids was afforded after thorough analysis of nuclear magnetic resonance (NMR) data as well as electrospray ionization mass spectrometry (ESI-MS). Additionally, structure-activity relationships were performed using Decision Trees.

Seasonal variation of the chemical composition and antimicrobial and cytotoxic activities of the essential oils from Inga laurina (Sw.) Willd.

The seasonal chemical composition of essential oils from Inga laurina was determined by GC/MS. In the stem bark's essential oil extracted during the dry season, the presence of terpenoids (30.05%) stood out, and phytol (9.76%) was the major compound identified. For the stem bark oil obtained during the rainy season, in addition to terpenoids (26.63%), a large amount of fatty acids (46.84%) were identified, in particular palmitic acid (25.40%). Regarding the leaves' essential oil obtained in the dry season, esters (42.35%) were the main components. The main ester present was (Z)-hex-3-enyl benzoate (10.15%) and the major compound of this oil was (Z)-hex-3-en-1-ol (14.23%). Terpenoids (33.84%), long-chain alkanes (27.04%) and fatty acids (21.72%) were the main components of the essential oil from leaves in the rainy season. Phytol (33.21%), nonacosane (21.95%) and palmitic acid (15.20%) were the major compounds identified. The antimicrobial activity against aerobic and anaerobic oral bacteria was evaluated by the microdilution broth method and cytotoxic activity was carried out with Vero cells. The essential oils from the rainy season showed a better inhibition of the bacterial growth with Minimal Inhibitory Concentrations (MIC) values of 25 or 50 µg·mL⁻¹ for aerobic bacteria, and high selectivity against bacteria was observed. The large amount of fatty acids in rainy season oils may be related to the better inhibitory effects observed.

Chemical composition, cytotoxic and antimicrobial activity of essential oils from Cassia bakeriana Craib. against aerobic and anaerobic oral pathogens.

The chemical composition of the essential oils from leaves, bark and wood of Cassia bakeriana Craib. was determined by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). Alcohols, aldehydes and fatty acids were the major components in leaf and bark oil, while wood essential oil was rich in fatty acids. Terpenes such as linalool, (E)-nerolidol and phytol were present in low concentrations. The antimicrobial activity against aerobic and anaerobic oral bacteria was evaluated using the microdilution method, as was the cell viability test carried out with Vero cells. The oils from leaves and bark showed high antimicrobial activity, with minimum inhibitory concentrations between 62.5 and 125 µg·mL⁻¹ for most of the tested bacteria, including Streptococcus mutans, the main etiological agent of dental caries. Leaves oil displayed the lowest cytotoxic effect (EC50 of 153 µg·mL⁻¹), while wood oil exhibited the highest toxicity to Vero cells. C. bakeriana oils are thus a source of biologically active compounds against aerobic and anaerobic oral microorganisms. This study is the first report on the chemical composition, antimicrobial activity and cytotoxicity of C. bakeriana.