Essential oil vapor phase approach for antimicrobial evaluation using Hesperozygis myrtoides (A. St.-Hill. ex Benth.) Epling (Lamiaceae) as a model.

The demand for less hazardous and environmentally friendly surface disinfectants is growing and essential oils may be efficient alternatives. Vapor phase assay is a promising technique which explore the volatility of essential oils for determining the antimicrobial activity. In this study, we modified the conditions of the inverted Petri dish technique to evaluate the minimum inhibitory concentrations (MIC). As a proof of concept, the antimicrobial activity of Hesperozygis myrtoides essential oil (HM) was studied for the first time in the vapor phase. According to the established protocol the oil volatilization dynamics was used to determine the major compounds in the vapor phase. After 270 min, the relative percentage was like that observed in the crude oil analysis. The HM was also evaluated for safety (IC50=921.2 µg ml-1), being considered safe in case of acute oral exposure. The oil vapors completely inhibited the growth of Staphylococcus aureus (MIC=0.39 mg l-1), Candida albicans (MIC=0.83 mg l-1), Aspergillus brasiliensis (MIC=378 mg l-1) and Bacillus subtilis (MIC=704.8 mg l-1). This protocol offers an economical and efficient alternative for antimicrobial activity and safety determination of essential oils, can be used for the evaluation of several applications of essential oils, as disinfectant agent in inhabited environments.

Assessing forest degradation using multivariate and machine-learning methods in the Patagonian temperate rain forest.

The process of forest degradation, along with deforestation, is the second greatest producer of global greenhouse gas emissions. A key challenge that remains unresolved is how to quantify the critical threshold that distinguishes a degraded from a non-degraded forest. We determined the critical threshold of forest degradation in mature stands belonging to the temperate evergreen rain forest of southern Chile by quantifying key forest stand factors characterizing the forest degradation status. Forest degradation in this area is mainly caused by high grading, harvesting of fuelwood, and sub-canopy grazing by livestock. We established 160 500-m2 plots in forest stands that represented varied degrees of alteration (from pristine conditions to obvious forest degradation), and measured several variables related to the structure and composition of the forest stands, including exotic and native species richness, soil nutrient levels, and other landscape-scale variables. In order to identify classes of forest degradation, we applied multivariate and machine-learning analyses. We found that richness of exotic species (including invasive species) with a diameter at breast height (DBH) < 10 cm and tree density (N, DBH > 10 cm) were the two composition and structural variables that best explained the forest degradation status, e.g., forest stands with five or more exotic species were consistently found more associated with degraded forest and stands with N < 200 trees/ha represented degraded forests, while N > 1,000 trees/ha represent pristine forests. We introduced an analytical methodology, mainly based on machine learning, that successfully identified the forest degradation status that can be replicated in other scenarios. In conclusion, here by providing an extensive data set quantifying forest and site attributes, the results of this study are undoubtedly useful for managers and decision makers in classifying and mapping forests suffering various degrees of degradation.

Embelin potentiates venetoclax-induced apoptosis in acute myeloid leukemia cells.

Acute myeloid leukemia (AML) belongs to a group of hematological cancer whose relapse cases are often associated with chemoresistance that impairs treatment success and contributes to a poor outcome. For this reason, there is an urgent need for the development of new therapeutic strategies. Herein, we explore the combination of venetoclax, a BCL2 inhibitor, and embelin, an XIAP inhibitor, in the AML cell lines. Combinatory treatment of venetoclax and embelin potentiated cytotoxic effects of these drugs, demonstrating that both in combination present lower IC50 values than single treatment of either venetoclax or embelin alone in both cell lines analyzed. The combinatory treatment further increased the apoptosis-inducing properties of both compounds. Computer simulations suggest that embelin binds to both BIR2 and BIR3 domains of XIAP, reinforcing this inhibitory apoptosis protein as an embelin target. Although all AML cell lines presented similar basal levels of XIAP, the combinatory treatment effectively inhibited XIAP expression in OCI-AML3 cells. In conclusion, the inhibition of both apoptosis inhibitory players, BCL2 and XIAP, by venetoclax and embelin, respectively, potentiated their cytotoxic effects in AML cell lines.

The genus Erythrina L.: A review on its alkaloids, preclinical, and clinical studies.

Erythrina L. genus (Fabaceae) comprises about 115 species, and it has been extensively studied, mainly because of its alkaloids, which have pharmacological properties. References demonstrated that Erythrina spp. have a potential to act in the central nervous system, presenting anxiolytic and anticonvulsant properties already established. Phytochemical investigations confirmed the presence of tetracyclic alkaloids as the major compounds. However, other alkaloid classes have also been reported, including dimeric and trimeric substances, coupled through direct polymerization or two erythrinine units via an acetyl glucose. The present review covers the relevant literature from 1990 until 2017 and outlines the current data on chemical composition and preclinical and clinical studies on Erythrina species. Additionally, the quite striking analogy in the biosynthetic route of erythrin, morphinans, and Amaryllidaceae family alkaloids was also discussed.

Validation Cytotoxicity Assay for Lipophilic Substances.

It is challenging to disperse lipophilic substances in a validated cytotoxicity assay, especially for compounds with log Kow greater than or equal to 5 that may show false negative results. The purpose of this study was to explain the challenges in conducting a cytotoxicity validated test of lipophilic substances: Minthostachys setosa, Pimenta pseudocaryophyllus, and Drimysbrasiliensis essential oils. Additionally, we compared the equivalence of Neutral Red (NR) and 3- (4,5-dimethylthiazol-2-yl) -5- (3- carboxymethoxyphenyl) -2- (4-sulfophenyl) -2H -tetrazolium, inner salt (MTS) in detecting cell viability. The Hydrophile-Lipophile Balance (HLB) technique was used to evaluate the dispersion of essential oils and cytotoxicity in accordance to the guidelines of the OECD / GD 129 validated cytotoxicity assay. We compared the equivalence of vital dyes by TOST equivalence test. According to the results, we demonstrated the possibility of using other ways to disperse the lipophilic substances. Based on the HLB theory, we selected polysorbate 20 as the best solubilizing agent of the essential oils studied in D10 culture medium.

Chemical Composition, Antimicrobial and Antioxidant Activities of Essential Oils from Two Avicennia schaueriana Stapf & Leechm. Ex Moldenke (Acanthaceae) Populations.

BACKGROUND: Avicennia schaueriana Stapf & Leechm. ex Moldenke (Acanthaceae) is a native species from the Brazilian mangroves presenting ecological and economic significance. This study compared the composition and the biological activities from the essential oils obtained from two A. schaueriana populations collected at Jureia-Itatins and Ilha do Cardoso. METHODS: Essential oils were obtained by conventional means, and their compositions were analyzed by GC-MS. Screening assays for antimicrobial activity were carried out by the microdilution method and the antioxidant potential was assessed by the DPPH scavenging method. RESULTS: The GC-MS analysis indicated that the Jureia oil (1) was composed mostly of the fatty acids palmitic (46.5%) and myristic (11.6%) acids, while the main components for the Ilha do Cardoso oil (2) were eugenol (19.7%), eugenol acetate (12.9%) and palmitic acid (15.1%). The oils showed an IC50 of 0.9 ± 0.011 mg/mL for 1 and 1.13 ± 0.028 mg/mL for 2 in the DPPH assay. The antimicrobial assay indicated MIC > 217 µg/mL for all tested microorganisms. CONCLUSIONS: The different essential oil composition may indicate the presence of chemotypes for A. schaueriana. The antioxidant activity of the oils was weak if compared with flavonoids. Despite the high MIC values, these oils presented some antibacterial potential against Pseudomonas aeruginosa.

Chemical Composition, Antifungal and Antioxidant Activities of Hedyosmum brasiliense Mart. ex Miq. (Chloranthaceae) Essential Oils.

Background: Hedyosmum brasiliense Mart. ex Miq. (Chloranthaceae) is a dioecious shrub popularly used in Brazil to treat foot fungi and rheumatism. This work investigated the chemical composition, antifungal, and antioxidant activities of flowers and leaves of H. brasiliense essential oils; Methods: H. brasiliense male and female flowers and leaves were collected at Ilha do Cardoso (São Paulo) and the essential oils were extracted by hydrodistillation and analyzed by GC/MS and their similarity compared by Principal Component Analysis. Antifungal activity was performed by bioautography and antioxidant potential by 2,2-diphenyl-2-picrylhydrazyl hydrate (DPPH) free radical scavenging and ß-carotene/linoleic acid system; Results: The major compounds for all oils were sabinene, curzerene, and carotol, but some differences in their chemical composition were discriminated by Principal Component Analysis (PCA) analysis. Bioautography showed two antifungal bands at Rf's 0.67 and 0.12 in all samples, the first one was identified as curzerene. The oils presented stronger antioxidant potential in ß-carotene/linoleic acid bioassay, with IC50's from 80 to 180 µg/mL, than in DPPH assay, with IC50's from 2516.18 to 3783.49 µg/mL; Conclusions: These results suggested that curzerene might be responsible for the antifungal activity of H. brasiliense essential oils. Besides, these essential oils exhibited potential to prevent lipoperoxidation, but they have a weak radical scavenger activity.

Antispasmodic activity from Serjania caracasana fractions and their safety

Abstract In a previous study, we reported the antispasmodic and gastroprotective effects of the Serjania caracasana (Jacq.) Willd., Sapindaceae, extract. In the present study, we evaluated the LD50, hemolytic and antispasmodic activities of its fractions and characterized its major constituents by isolation and GC-MS. The animals showed non-toxic symptoms with oral doses up to 2000 mg/kg, suggesting a safe oral administration. Furthermore, a low hemolytic activity was detected for the saponin fraction. Antispasmodic activity of the fractions was evaluated through carbachol-induced contractions in rat ileum. The hexane fraction was the most potent (IC50 68.4 ± 5.9 µg/ml) followed by the dichloromethane fraction (IC50 161.3.4 ± 40.7 µg/ml). Butanol fraction was the less effective (IC50 219.8 ± 60.3 µg/ml). The phytochemical study of the S. caracasana fractions afforded the isolation of friedelin, β-amyrin, allantoin and quercitrin. This is the first time that the presence of allantoin and quercitrin in the Serjania genus has been reported. Among the isolated compounds and those characterized by GC-MS, β-amyrin and β-sitosterol were present in the most active fractions, hexane and dichloromethane, and they may be related to its antispasmodic activity. In addition, spathulenol was only found in the hexane fraction and its presence might justify the highest antispasmodic activity observed for this fraction.

Alkaloids and biological activity of beribá (Annona hypoglauca)

ABSTRACT Annona hypoglauca Mart., Annonaceae, popularly known as “beribá”, was collected in flooded areas of the Amazonian Rain Forest. The crude extract obtained from this species was found to be cytotoxic against human cancer cells. Chemical information on A. hypoglauca is scarce. So, the present work aimed the isolation and identification of its alkaloids and to test their cytotoxic activity. Alkaloids were obtained from stem by acid–base partitioning and the remaining alkaloid-free extract was partitioned with organic solvents. Gas chromatography–mass spectrometry GC/MS analysis of total alkaloids allowed the identification of four aporphine alkaloids: actinodaphnine, anonaine, isoboldine and nornuciferine. Total alkaloids were fractionated by column chromatography and were purified by preparative thin-layer-chromatography, which allowed the isolation of two aporphine alkaloids, actinodaphnine and isoboldine, characterized by NMR and CG–MS analyses. This is the first report for the occurrence of actinodaphnine in Annona species. All the samples were tested in cytotoxic and antibacterial assays. Total alkaloid extract and its fractions showed antimicrobial activity against Staphylococcus aureus and Enterococcus faecalis. In the cytotoxicity assay, the crude extract showed a lethal effect against breast and colon cancer cells. Isoboldine-containing FA5 and actinodaphnine-containing FA6 showed activity against breast cancer cell line, while the alkaloid-free fractions did not show significant activity against cancer cell lines.

Evaluation of gastroprotective activity of Passiflora alata

AbstractPassiflora alata Curtis, Passifloraceae, is a liana popularly known in Brazil as ‘maracujá-doce’ that has been used for treating different illnesses. Its leaves are described in the Brazilian Pharmacopoeia, but the gastroprotective activity has never been investigated. In the present study a freeze-dried crude 60% ethanol–water extract of P. alata aerial parts was prepared. Total flavonoid content, expressed as vitexin, was 0.67% ± 0.01. The hemolytic activity was 32 units for P. alata, using Saponin (Merck®) as reference. P. alata presented EC50 of 1061.2 ± 8.5 µg/ml in the 2,2-diphenyl-1-picryhydrazyl assay and 1076 ± 85 µmol Trolox/g in the Oxygen Radical Absorbance Capacity assay. P. alata, its solvent fractions and a P. alatananopreparation were investigated for gastroprotective activity. The test samples exhibited gastroprotective activity on HCl/ethanol induced gastric mucosal lesions in rats. P. alata at doses of 100, 200 and 400 mg/kg, using the necrotizing agent at 150 mmol/l, inhibited 100% of ulcer formation (compared to the negative control), while lansoprazole (30 mg/kg) 77%. When tested against a more concentrated necrotizing agent (300 mmol/l), fractions of P. alata at 100 mg/kg reduced 57% (n-hexane), 34% (ethyl acetate) and 72% (aqueous fraction) the ulcer formation. In this assay, lansoprazole (30 mg/kg) inhibited 47%. When encapsulated, P. alata inhibited ulcer formation at 55%, 94% and 90% for dosages of 25, 50 and 100 mg/kg. These results suggest the potential use of P. alata as a gastroprotective herbal medicine.

Chemical analysis, antioxidant, antichemotactic and monoamine oxidase inhibition effects of some pteridophytes from Brazil.

BACKGROUND: Ferns are a group of plants that have been little explored from a chemical and biological perspective but that have interesting potential, occurring in various parts of the world. OBJECTIVE: This work investigates the chemical profile and the biological effects of ferns from Brazil. MATERIALS AND METHODS: Analyses were performed using rapid performance liquid chromatography (RP-LC) with a diode array detector (DAD). Extracts were tested for their in vitro antioxidant activity, by the total reactive antioxidant potential method and for their antichemotactic potential, by the Boyden chamber method. Cytotoxic effects were assessed by lactate dehydrogenase levels, while the monoamine oxidase (MAO) assay was carried out using a fluorescence-based method. RESULTS: Different chemical compositions were found for the studied ferns, such as Asplenium gastonis, in which hesperidin was identified in its extract, while A. serra showed the presence of xanthone mangiferin. The most samples with highest antioxidant activity were the Asplenium serra, Lastreopsis amplissima and Cyathea dichromatolepis extracts, at 10 µg/mL. High antichemotactic activity was found for A. serra (94.06%) and Didymochlaena truncatula (93.41%), at 10 µg/mL. The extracts showed no cytotoxicity at the highest concentration. Against MAO-A, D. truncatula (82.61%), Alsophila setosa (82.21%), Cyathea phalerata (74.07%) and C. delgadii (70.32%) were the most active extracts (100 µg/mL). CONCLUSION: The hypothesis was considered that phenolics and triterpenes are responsible for these pronounced activities.

Native Brazilian plants against nosocomial infections: a critical review on their potential and the antimicrobial methodology.

The growing incidences of drug-resistant pathogens have increased the attention on several medicinal plants and their metabolites for antimicrobial properties. These pathogens are the main cause of nosocomial infections which led to an increasing mortality among hospitalized patients. Taking into consideration those factors, this paper reviews the state-of-the-art of the research on antibacterial agents from native Brazilian plant species related to nosocomial infections as well as the current methods used in the investigations of the antimicrobial activity and points out the differences in techniques employed by the authors. The antimicrobial assays most frequently used were broth microdilution, agar diffusion, agar dilution and bioautography. The broth microdilution method should be the method of choice for testing new antimicrobial agents from plant extracts or isolated compounds due to its advantages. At the moment, only a small part of the rich Brazilian flora has been investigated for antimicrobial activity, mostly with unfractionated extracts presenting a weak or moderate antibacterial activity. The combination of crude extract with conventional antibiotics represents a largely unexploited new form of chemotherapy with novel and multiple mechanisms of action that can overcome microbial resistance that needs to be further investigated. The antibacterial activity of essential oil vapours might also be an interesting alternative treatment of hospital environment due to their ability in preventing biofilm formation. However, in both alternatives more studies should be done on their mode of action and toxicological effects in order to optimize their use.

Morphoanatomical identification and physicochemical parameters of the drug Erythrina verna Vell. trunk bark / Identificación morfoanatómica y parámetros físico-químicos de la cortezadel leño de Erythrina verna Vell

“Mulungu” (Erythrina verna Vell., Fabaceae.) is an arboreal specie native to southeastern Brazil, used for medicinal purposes. This plant is characterized by the presence of alkaloids that have demonstrated anxiolytic activity. Due to this activity, this plant is listed by the Brazilian National Program of Medicinal Plants and Herbal Medicines. However, bibliographic information is lacking regarding this species. This study aims to describe E. verna barks, macro and microscopically, as well as some physicochemical parameters for the quality control of its raw material. In addition, the chromatographic profile of its alkaloid fraction and optimization of extraction methods for crude extract production has also been performed.

“Mulungu” (Erythrina verna Vell., Fabaceae.) es una especie arborea nativa del sudeste de Brasil, utilizada con fines medicinales. Esta planta se caracteriza por la presencia de alcaloides que han demostrado actividad ansiolítica. Debido a esta actividad, esta planta se encuentra en la lista del Programa Nacional Brasileño de las Plantas Medicinales y Medicinas Herbarias. Sin embargo, la información bibliográfica es escasa con respecto a esta especie. Este estudio tiene como objetivo describir E. Verna corteza, macro y microscópicamente, así como algunos parámetros físico-químicos para el control de la calidad de la materia prima fresca. Además, el perfil cromatográfico de la fracción alcaloidica y la optimización de métodos de extracción para la producción de extracto crudo también fue realizada.

Chemical composition and antimicrobial activity of essential oils from Chromolaena laevigata during flowering and fruiting stages.

The chemical compositions and antimicrobial activities of essential oils from the leaves, stems, capitula, and cypselas of Chromolaena laevigata were evaluated at two different phenological stages, flowering and fruiting. Thirty-eight compounds were identified in the crude oils by GC/MS. The sesquiterpene laevigatin was the major constituent of the leaf, capitulum, and cypsela oils, while the sesquiterpene spathulenol was the main component in the stem oils. The antimicrobial activities of the oils were evaluated against Candida albicans, Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli. Stem oil obtained from Chromolaena laevigata during the fruiting stage generally showed the highest activity with minimum inhibitory concentration (MIC) values of 62.5 µg/ml against Candida albicans and S. aureus, and 500 µg/ml against P. aeruginosa and E. coli. Pure laevigatin exhibited MIC values of 500 and 125 µg/ml against C. albicans and S. aureus, respectively, indicating that this constituent could be responsible, at least in part, for the antimicrobial activities detected in the crude oils. More studies concerning the biological activities of isolated derivatives are required to improve our knowledge of the antimicrobial potential of volatile compounds present in native plants.

Anticholinesterase activity evaluation of alkaloids and coumarin from stems of Conchocarpus fontanesianus

Conchocarpus fontanesianus (A. St.-Hill.) Kallunki & Pirani, Rutaceae, popularly known as pitaguará, is a native and endemic tree from São Paulo and Rio de Janeiro States, Brazil. Based in the information that anticholinesterasic derivatives could act as new prototypes to treatment of Alzheimer disease, this work describes the fractionation guided by evaluation of the anticholinesterase activity of the ethanolic stems extract from C. fontanesianus. This procedure afforded the alkaloids dictamnine (1), γ-fagarine (2), skimianine (3), and 2-phenyl-1-methyl-4-quinolone (4), as well as the coumarin marmesin (5).

Chemical constituents of the volatile oil from leaves of Annona coriacea and in vitro antiprotozoal activity

The essential oil of the leaves from Annona coriacea Mart., Annonaceae, was extracted by hydrodistillation in a Clevenger apparatus and analyzed by GC/MS and GC/FID. The oil yield was 0.05 percent m/m. Sixty compounds were identified, in a complex mixture of sesquiterpenes (76.7 percent), monoterpenes (20.0 percent) and other constituents (3.3 percent). Bicyclogermacrene was its major compound (39.8 percent) followed by other sesquiterpenes. Most of the monoterpenes were in low concentration (<1 percent). Only β-pinene and pseudolimonene presented the highest level of 1.6 percent. The volatile oil presented anti-leishmanial and trypanocidal activity against promastigotes of four species of Leishmania and trypomastigotes of Trypanosoma cruzi, showing to be more active against Leishmania (L.) chagasi (IC50 39.93 µ g/mL) (95 percent CI 28.00-56.95 µ g/mL).

Anti-inflammatory activity of essential oil from leaves of Myrciaria tenella and Calycorectes sellowianus.

The GC-MS analysis revealed that the leaf essential oils of Myrciaria tenella (DC.) Berg and Calycorectes sellowianus O. Berg (Myrtaceae) were composed of 34 and 37 compounds, respectively. The main constituents of M. tenella oil were beta-caryophyllene (25.1%), and spathulenol (9.7%), while for C. sellowianus were guaiol (13.1%) and beta-caryophyllene (8.6%). The anti-inflammatory effect of both essential oils was investigated in vitro and in vivo. Both oils reduced significantly (p < 0.005) the treated neutrophils chemotaxis with 93% and 91% inhibition for M. tenella and C. sellowianus, respectively. However, in the systemic treatment with the essential oils (50 mg/kg p.o.) only the M. tenella oil was able to significantly reduce the carrageenan-induced paw edema with a similar effect to that observed for indomethacin (10 mg/kg), the positive control.

Chemical composition and acetylcholinesterase inhibitory activity of essential oils of Myrceugenia myrcioides(Cambess.) O. Berg and Eugenia riedeliana O. Berg, Myrtaceae / Composição química e atividade inibidora de acetilcolinesterase de óleos voláteis de Myrceugenia myrcioides(Cambess.) O. Berg and Eugenia riedeliana O. Berg, Myrtaceae

The chemical composition of volatile oils from two Myrtaceae species, Myrceugenia myrcioidesand Eugenia riedeliana, both native from the Brazilian Atlantic Rain Forest, was analyzed by GC-MS. Acetylcholinesterase inhibitory activity was colorimetrically evaluated for these oils. For M. myrcioides, monoterpene hydrocarbons represented the major class in the volatile oil, with α-pinene as the most abundant component and a weak inhibitory activity was observed, whilst for E. riedeliana sesquiterpenes were found in higher amounts, being valerianol the major compound, and this oil presented a strong acetylcholinesterase inhibition.

A composição química dos óleos voláteis de duas espécies de Myrtaceae, Myrceugenia myrcioidese Eugenia riedeliana, ambas nativas da Mata Atlântica, foi analisada por CG-EM. A atividade inibidora de acetilcolinesterase foi determinada colorimetricamente para estes óleos. Em M. myrcioides, hidrocarbonetos monoterpênicos representaram a classe majoritária de compostos presentes no óleo volátil, sendo α-pineno o componente mais abundante e a atividade inibidora de acetilcolinesterase foi baixa, enquanto para E. riedelianaos sesquiterpenos foram observados em maiores concentrações, sendo o valerianol o componente majoritário, e este óleo apresentou uma forte atividade inibidora da enzima.

Differential acetyl cholinesterase inhibition by volatile oils from two specimens of Marlierea racemosa (Myrtaceae) collected from different areas of the Atlantic Rain Forest.

The volatile oil composition and anti-acetyl cholinesterase activity were analyzed in two specimens of Marlierea racemosa growing in different areas of the Atlantic Rain Forest (Cananéia and Caraguatatuba, SP, Brazil). Component identifications were performed by GC/MS and their acetyl cholinesterase inhibitory activity was measured through colorimetric analysis. The major constituent in both specimens was spathulenol (25.1% in Cananéia and 31.9% in Caraguatatuba). However, the first one also presented monoterpenes (41.2%), while in the Carguatatuba plants, this class was not detected. The oils from the plants collected in Cananéia were able to inhibit the acetyl cholinesterase activity by up to 75%, but for oils from the other locality the maximal inhibition achieved was 35%. These results suggested that the monoterpenes are more effective in the inhibition of acetyl cholinesterase activity than sesquiterpenes as these compounds are present in higher amounts in the M. racemosa plants collected in Cananéia.

Isolamento e avaliação da atividade biológica dos alcalóides majoritários de Tabernaemontana angulata Mart. ex Müll. Arg., Apocynaceae / Isolation and evaluation of the biological activity related to the major alkaloids in Tabernaemontana angulata Mart. ex Müll. Arg., Apocynaceae

A necessidade da introdução de novos agentes quimioterápicos é uma realidade no controle de doenças infecciosas. O Brasil é o país mais rico em biodiversidade, e o Laboratório de Extração da Universidade Paulista tem coletado plantas na Amazônia e Mata Atlântica com a finalidade de identificar extratos vegetais antibacterianos e antitumorais. Estudos prévios demonstraram que a fração etanólica obtida do extrato bruto orgânico do caule de Tabernaemontana angulata Mart. ex Müll. Arg. apresentou atividade antimicrobiana significante contra Staphylococcus aureus ATCC6538, no ensaio de diluição em caldo. Verificou-se por cromatografia em camada delgada que os compostos majoritários presentes na fração ativa eram alcalóides. No presente trabalho, foi obtida a fração de alcalóides totais a partir do extrato bruto, da qual os compostos majoritários foram isolados por sucessivas cromatografias e, posteriormente, identificados por CG-EM e ¹H-RMN como os alcalóides indólicos coronaridina e voacangina. As frações obtidas do isolamento foram testadas no ensaio biológico, porém não demonstraram atividade antimicrobiana.

Introducing new chemotherapeutic agents is a great demand in the control of infectious diseases. Brazil is one of the richest countries in biodiversity and the Laboratório de Extração at UNIP has been collecting plants from the Amazon and Atlantic Rain Forests with the aim of screening for new antibacterial and antitumor plant extracts. Previous studies demonstrated that the ethanol fraction obtained from the crude extract of Tabernaemontana angulata stems showed an antibacterial activity against Staphylococcus aureus (ATCC 6538) in the microdilution broth assay. Two alkaloids were the major compounds in the active fraction, verified by thin layer chromatography analysis. In the present study, the total alkaloids were obtained from the crude extract and were fractionated by preparative thin layer chromatography for the isolation of the main components. The isolated compounds were identified by GC/MS and ¹H-NMR as coronaridine and voacangine. The alkaloid fractions obtained from the isolation procedure were tested for antibacterial activity, but no activity was detected.