Antimicrobial substances from Amazonian Aniba (Lauraceae) species.

Extracts and six isolated substances from Aniba (Lauraceae) Amazonian species A. parviflora, A. panurensis and A. rosaeodora were analysed in vitro to their antibacterial, antiparasitic and antiplasmodial activities. NMR and MS experiments led to the identification of three styrylpyrones (5,6-dihydrokawain [I], 4-methoxy-11,12-methylenedioxy-6-trans-styryl-pyran-2-one [II] and rel-(6R,7S,8S,5'S)-4'-methoxy-8-(11,12-dimethoxyphenyl-7-[6-(4-methoxy-2-pyranyl)]-6-(E)-styryl-1'-oxabicyclo[4,2,0]oct-4'-en-2'-one [III]), a pyridine alkaloid (anibine [IV]) and two kavalactones (tetrahydroyangonin [V] and dihydromethysticin [VI]). The best antibacterial result was observed at the hexane fraction of A. panurensis (MIC 7.8 µg/mL against the three bacteria). Equal MIC were observed by the extract and dichloromethane fraction of A. panurensis against S. simulans and S. aureus; and 15.62 µg/mL against MRSA. Similarly, only A. panurensis extracts showed in vitro activities against Tripanossoma cruzi and Leishmania amazonensis parasites. In Plasmodium falciparum assay, 5,6-dihydrokawain was considered an active antimalarial (14.03 µM), and substances II (132.94 µM) and III (41.84 µM) presented moderate activities.

Mutagenic and cytostatic activities of the Xylopia laevigata essential oil in human lymphocytes.

Hydro-distilled essential oil from leaves of Xylopia laevigata was characterized by GC-MS. Twenty-seven components were identified and the oil's major constituents comprised germacrene D, bicyclogermacrene, (E)-caryophyllene and germacrene B. The cytotoxicity of the essential oil of X. laevigata (EOXL), determined by MTT and mitotic index methods in cultured human lymphocytes was observed in all tested concentrations. Cultures treated with EOXL demonstrated significant increase in the frequencies of micronuclei in the cytokinesis-block micronucleus assay (CBMN) and reduction of the cytokinesis-block proliferation index (CBPI) rates. Results demonstrated the cytostatic and mutagenic effects of EOXL, the latter for the first time.

Chemical composition, larvicidal and cytotoxic activity of Annona salzmannii (Annonaceae) seed oil

The seed oil of Annona salzmannii A. DC. was analyzed by GC-MS and 1H qNMR, revealing a mixture of unsaturated (80.5%) and saturated (18.7%) fatty acids. Linoleic (45.3%) and oleic (33.5%) acid were the major unsaturated fatty acids identified, while palmitic acid (14.3%) was the major saturated fatty acid. The larvicidal effects of A. salzmannii seed oil were evaluated against third-instar larvae of Aedes aegypti (Linn.). The oil exhibited moderate larvicidal activity, with a LC50 of 569.77 ppm (95% CI = 408.11 to 825.88 ppm). However, when the cytotoxic effects of the oil were evaluated, no expressive antiproliferative effects were observed in tumor cell lines B16-F10 (mouse melanoma), HepG2 (human hepatocellular carcinoma), K562 (human chronic myelocytic leukemia), HL-60 (human promyelocytic leukemia), and non-tumor cell line PBMC (peripheral blood mononuclear cells), with IC50 values > 50 µg·mL-1. This is the first study to evaluate the chemical composition, larvicidal and cytotoxic activity of A. salzmannii seed oil

Palmatine antioxidant and anti-acetylcholinesterase activities: A pre-clinical assessment.

There is evidence that palmatine (PA), an alkaloid isolated from the Guatteria friesiana plant, has some important biological activities, including anti-inflammatory and antidepressant effects. In this study, the antioxidant and anti-acetylcholinesterase (AChE) effects of PA were assessed. The antioxidant capacity was evaluated in vitro and in vivo through 7 distinct assays, and the anti-AChE activity was determined in vitro. The standards, trolox and ascorbic acid were used for the in vitro antioxidant test, while hydrogen peroxide was selected as a stressor for the Saccharomyces cerevisiae test. Additionally, PA was also combined with trolox and ascorbic acid to determine the likelihood of synergistic effects occurrence to what concerns to antioxidant potential. PA exhibited a potent and concentration-dependent antioxidant potential, although a stronger antioxidant activity was stated using the PA + trolox combination. PA was also found to inhibit AChE activity when compared to the negative control. Thus, PA may be viewed as a promissory phytotherapeutic agent to manage oxidative stress-mediated neurological diseases, especially the Alzheimer's and Parkinson's diseases.

Characterization of aporphine alkaloids by electrospray ionization tandem mass spectrometry and density functional theory calculations.

RATIONALE: Aporphine alkaloids represent a large group of isoquinoline natural products with important roles in biological and biomedical areas. Their characterization by electrospray ionization tandem mass spectrometry (ESI-MS/MS) can contribute to their rapid identification in complex biological matrices. METHODS: We report the fragmentation of protonated 7,7-dimethylaporphine alkaloids by ESI-MS/MS, and the putative annotation of aporphine alkaloids in plant extracts. We used low- and high-resolution MS/MS analyses to rationalize the fragmentation pathways, and employed the B3LYP/6-31 + G(d,p) density functional theory (DFT) model to provide thermochemical parameters and to obtain the reactive sites. RESULTS: DFT calculations of a set of 7,7-dimethylaporphine alkaloids suggested the heterocyclic amino group as the most basic site due to the proton affinity of the nitrogen atom. Collision-induced dissociation experiments promoted • OCH3 elimination instead of the expected neutral loss of the heterocyclic amino group, pointing to the [M - 15 + H]•+ ion as the diagnostic fragment for 7,7-dimethylaporphine alkaloids. The analysis of plant extracts led to the annotation of 25 aporphine alkaloids. Their fragmentation initiated with the loss of the amino group followed by formation of a cyclic carbocation. Further reactions derived from consecutive charge-remote and/or charge-induced fragmentations of the substituents attached to the aromatic system. The mechanisms were re-examined based on plausible gas-phase ion chemistry reactions. CONCLUSIONS: Taken together, the diagnostic product ions and the series of radical and neutral eliminations provided information about the location of methylenedioxy, aromatic methoxy, and vicinal methoxy and hydroxy groups in aporphine alkaloids, assisting their characterization via MS/MS.

Inhibitory effects of Morus nigra L. (Moraceae) against local paw edema and mechanical hypernociception induced by Bothrops jararacussu snake venom in mice.

BACKGROUND: Bothropic venoms cause intense local damage, pain, edema, and myonecrosis. Morus nigra L. (Moraceae) has several uses in folk medicine and can be a promising candidate for the treatment of several inflammatory disorders. HYPOTHESIS/PURPOSE: The present study aims to evaluate the anti-inflammatory and antinociceptive effects of the ethanolic extract of Morus nigra L. (Mn-EtOH) on paw lesions induced by Bothrops jararacussu snake venom (BjcuV) in mice. METHODS: UV-vis absorption of BjcuV was evaluated. A phytochemical study was performed, which led to the isolation and characterization of three compounds. These compounds were identified using spectrometric methods, namely LC-MS and NMR (1D and 2D), followed by the validation of their spectra with the data available in the literature. Further, the flavonoids i.e. rutin and quercetin (chemical markers of M. nigra), Mn-EtOH or Mn-EtOH-encapsulated electrospun fibers of Eudragit L100 (FB/Mn-EtOH), and Mn-EtOH-encapsulated microparticles of Eudragit L100 (MP/Mn-EtOH) were evaluated, in paw edema test induced by BjcuV. RESULTS: UV-vis spectra showed the presence of phospholipases A2 as component of BjcuV. The chemical examination resulted in the isolation of ß-sitosterol, quercetin-3-O-glucopyranoside, and kaempferol-3-O-glucopyranoside. Mn-EtOH, FB/Mn-EtOH, MP/Mn-EtOH, rutin, and quercetin reduced the local edema induced by BjcuV. The Mn-EtOH also prevented edema provoked by serotonin and bradykinin. Moreover, it reduced paw edema and peritoneal leukocyte infiltration induced by carrageenan, and decreased the mechanical hypernociception of BjcuV. Mn-EtOH exerted anti-inflammatory and antinociceptive effects, possibly by the inhibition of leukocyte migration and the modulation of serotonin and bradykinin actions. This anti-inflammatory activity was maintained even upon incorporation of the M. nigra extract into the drug delivery systems (i.e., Mn-EtOH-encapsulated FBs and MPs of Eudragit L100). CONCLUSION: These results reinforce the therapeutic potential of M. nigra in the treatment of inflammatory conditions, in addition to, its role as a complementary treatment of snakebites.

Physicochemical Characterization and Antinociceptive Effect of ß-cyclodextrin/Lippia pedunculosa Essential Oil in Mice.

BACKGROUND: Some research studies have shown that Lippia pedunculosa essential oil (EOLP) has interesting biological activities. However, its low water solubility is the main challenge to achieve its therapeutic potential. In this context, Cyclodextrins (CDs) have been widely used in order to overcome this problem due to your capability to improve the physicochemical properties of drugs. OBJECTIVE: In this perspective, the main goal of this study was to investigate how the improvement of the physicochemical properties of inclusion complexes (EOLP and ß-CD) enhance the antinociceptive effect in mice. METHODS: To achieve that, we prepared samples by Physical Mixture (PM), Paste Complexation (PC) and Slurry Complexation (SC) methods, followed by their physicochemical characterization. In addition, it was evaluated if the use of ß-CD enhances the antinociceptive effect of EOLP in mice. RESULTS: The analysis showed that rotundifolone (72.02%) was the major compound of EOLP and we found out based on DSC results that ß-CD protected it from oxidation. In addition, TG techniques demonstrated that the best inclusion methods were PC and SC, due to their greater weight loss (10.8 and 11.6%, respectively) in the second stage (171-312°C), indicating that more complexed oil was released at the higher temperature than oil free. Other characteristics, such as changes in the typical crystalline form, and reduced particle size were observed by SEM and laser diffraction, respectively. The SC was the most effective complexation method, once the presence of rotundifolone was detected by FTIR. Based on that, SC method was used in all mice tests. In this regard, the number of paw licks was reduced for both compounds (all doses), but EOLP was more effective in reducing the nociceptive behavior. CONCLUSION: Therefore, CDs seem not to be a good tool to enhance the pharmacological properties of EOs rich in peroxide compounds such as rotundifolone.

Synthesis and Chemometrics of Thymol and Carvacrol Derivatives as Larvicides against Aedes aegypti.

BACKGROUND: Thymol and carvacrol have previously demonstrated larvicidal activity against Aedes aegypti (Diptera: Culicidae). In view of this fact, it was of our interest to obtain synthetic derivatives and evaluate their larvicidal activity on Ae. aegypti larvae. METHODS: Structural modifications were performed on thymol and carvacrol in an effort to understand the functional groups necessary for modulating their activities and to lead possibly to more effective larvae control agents. The derivatives were further subjected to SAR and computational studies (molecular modeling and chemometric tools (CPCA and PCA)) to extract structural information regarding their larvicidal properties. Field collected and Rockefeller populations of Ae. aegypti were used. RESULTS: Carvacrol and thymol exhibited LC50 of 51 and 58ppm for field collected larvae, respectively. Carvacrol derivatives exhibited LC50 ranging from 39 to 169ppm, while thymol derivatives exhibited LC50 ranging from 18 to 465ppm. Substitution of the acidic proton of carvacrol by esters, ethers, and acetic acid resulted in either maintenance or reduction of potency. CONCLUSION: Thymol derivatives were, to a certain extent, more efficient larvicides against Ae. aegypti than carvacrol derivatives, particularly to Rockefeller larvae. The chemometrics tools applied in this study showed that the independent variables indicate a mixed profile. Nevertheless, hydrophobic interactions increased the larvicidal activity.

Antinociceptive effect of Aristolochia trilobata stem essential oil and 6-methyl-5-hepten-2yl acetate, its main compound, in rodents.

Aristolochia trilobata L. is an aromatic plant, popularly known as "mil-homens", and its essential oil (EO) is generally used to treat colic, diarrhea and dysentery disorders. We evaluated the antinociceptive effect of A. trilobata stem EO and of its major compound, the (R)-(-)-6-methyl-5-hepten-2-yl acetate (sulcatyl acetate: SA), using acetic acid (0.85%)-induced writhing response and formalin-induced (20 µL of 1%) nociceptive behavior in mice. We also evaluated the EO and SA effect on motor coordination, using the rota-rod apparatus. EO (25, 50 and 100 mg/kg) or SA (25 and 50 mg/kg) reduced nociceptive behavior in the writhing test (p<0.001). EO (100 mg/kg) and SA (25 and 50 mg/kg) decreased the nociception on the first phase of the formalin test (p<0.05). On the second phase, EO (25: p<0.01; 50: p<0.05 and 100 mg/kg: p<0.001) and SA (25 and 50 mg/kg; p<0.001) reduced the nociceptive response induced by formalin. EO and SA were not able to cause changes in the motor coordination of animals. Together, our results suggest that EO has an analgesic profile and SA seems to be one of the active compounds in this effect.

Xylopine Induces Oxidative Stress and Causes G2/M Phase Arrest, Triggering Caspase-Mediated Apoptosis by p53-Independent Pathway in HCT116 Cells.

Xylopine is an aporphine alkaloid that has cytotoxic activity to cancer cells. In this study, the underlying mechanism of xylopine cytotoxicity was assessed in human colon carcinoma HCT116 cells. Xylopine displayed potent cytotoxicity in different cancer cell lines in monolayer cultures and in a 3D model of cancer multicellular spheroids formed from HCT116 cells. Typical morphology of apoptosis, cell cycle arrest in the G2/M phase, increased internucleosomal DNA fragmentation, loss of the mitochondrial transmembrane potential, and increased phosphatidylserine externalization and caspase-3 activation were observed in xylopine-treated HCT116 cells. Moreover, pretreatment with a caspase-3 inhibitor (Z-DEVD-FMK), but not with a p53 inhibitor (cyclic pifithrin-α), reduced xylopine-induced apoptosis, indicating induction of caspase-mediated apoptosis by the p53-independent pathway. Treatment with xylopine also caused an increase in the production of reactive oxygen/nitrogen species (ROS/RNS), including hydrogen peroxide and nitric oxide, but not superoxide anion, and reduced glutathione levels were decreased in xylopine-treated HCT116 cells. Application of the antioxidant N-acetylcysteine reduced the ROS levels and xylopine-induced apoptosis, indicating activation of ROS-mediated apoptosis pathway. In conclusion, xylopine has potent cytotoxicity to different cancer cell lines and is able to induce oxidative stress and G2/M phase arrest, triggering caspase-mediated apoptosis by the p53-independent pathway in HCT116 cells.

Spectroscopic investigation, vibrational assignments, HOMO-LUMO, NBO, MEP analysis and molecular docking studies of oxoaporphine alkaloid liriodenine.

A combined experimental and theoretical DFT study of the structural, vibrational and electronic properties of liriodenine is presented using B3LYP function with 6-311G (2d, p) basis set. The theoretical geometry optimization data were compared with the X-ray data for a similar structure in the associated literature, showing similar values. In addition, natural bond orbitals (NBOs), HOMO-LUMO energy gap, mapped molecular Electrostatic Potential (MEP) surface calculation, first and second order hyperpolarizabilities were also performed with the same calculation level. Theoretical UV spectrum agreed well with the measured experimental data, with transitions assigned. The molecular electrostatic potential map shows opposite potentials regions that forms hydrogen bonds that stabilize the dimeric form, which were confirmed by the close values related to the CO bond stretching between the dimeric form and the experimental IR spectra (1654cm-1 for the experimental, 1700cm-1 for the dimer form). Calculated HOMO/LUMO gaps shows the excitation energy for Liriodenine, justifying its stability and kinetics reaction. Molecular docking studies with Candida albicans dihydrofolate reductase (DHFR) and Candida albicans secreted aspartic protease (SAP) showed binding free energies values of -8.5 and -8.3kcal/mol, suggesting good affinity between the liriodenine and the target macromolecules.

Chemical Composition of the Essential Oil from the Fresh Fruits of Xylopia laevigata and its Cytotoxic Evaluation.

The essential oil obtained by hydrodistillation from the fresh fruits of Xylopia laevigata was analyzed by gas chromatography using a flame ionization detector (GC-FID) coupled to a mass spectrometer (GC-MS). Monoterpenes predominated, forming 95.0% of the total essential oil. The major constituents identified were limonene (56.2%), α-pinene (28.0%), and ß-pinene (5.5%). Cytotoxic activity against tumor cell lines and non-tumor cells was also investigated; however, neither the essential oil nor its major constituents evaluated presented any cytotoxic activity (IC50 > 25.0 µg mL⁻¹).

Chemical composition of the essential oil from the leaves of Anaxagorea brevipes (Annonaceae) and evaluation of its bioactivity.

The essential oil obtained by hydrodistillation from leaves of Anaxagorea brevipes was analysed by gas chromatography fitted with a flame ionisation detector (GC-FID) and coupled to mass spectrometry (GC-MS). Thirty one components were identified, representing around 75.7% of total oil. The major components were ß-eudesmol (13.16%), α-eudesmol (13.05%), γ-eudesmol (7.54%), guaiol (5.12%), caryophyllene oxide (4.18%) and ß-bisabolene (4.10%). The essential oil showed antimicrobial activity against Gram-positive bacteria and yeast with the MIC values between 25.0 and 100 µg/mL. The highest antiproliferative activity was observed for the oil against MCF-7 (breast, TGI = 12.8 µg/mL), NCI-H460 (lung, TGI = 13.0 µg/mL) and PC-3 (prostate, TGI = 9.6 µg/mL) cell lines, while against no cancer cell line HaCat (keratinocyte) the TGI was 38.8 µg/mL. The oil exhibited a small antioxidant activity assessed through ORAC-FL assay (517 µmol TE/g). This is the first report regarding the chemical composition and bioactivity of A. brevipes essential oil.

Amebicidal activity of the essential oils of Lippia spp. (Verbenaceae) against Acanthamoeba polyphaga trophozoites.

Amoebic keratitis and granulomatous amoebic encephalitis are caused by some strains of free-living amoebae of the genus Acanthamoeba. In the case of keratitis, one of the greatest problems is the disease recurrence due to the resistance of parasites, especially the cystic forms, to the drugs that are currently used. Some essential oils of plants have been used as potential active agents against this protist. Thus, the aim of this study was to determine the amebicidal activity of essential oils from plants of the genus Lippia against Acanthamoeba polyphaga trophozoites. To that end, 8 × 10(4) trophozoites were exposed for 24 h to increasing concentrations of essential oils from Lippia sidoides, Lippia gracilis, Lippia alba, and Lippia pedunculosa and to their major compounds rotundifolone, carvone, and carvacrol. Nearly all concentrations of oils and compounds showed amebicidal activity. The IC50 values for L. sidoides, L. gracilis L. alba, and L. pedunculosa were found to be 18.19, 10.08, 31.79, and 71.47 µg/mL, respectively. Rotundifolone, carvacrol, and carvone were determined as the major compounds showing IC50 of 18.98, 24.74, and 43.62 µg/mL, respectively. With the exception of oil from L. alba, the other oils evaluated showed low cytotoxicity in the NCI-H292 cell line. Given these results, the oils investigated here are promising sources of compounds for the development of complementary therapy against amoebic keratitis and granulomatous amoebic encephalitis and can also be incorporated into cleaning solutions to increase their amebicidal efficiency.

Chemical composition, antinociceptive, anti-inflammatory and redox properties in vitro of the essential oil from Remirea maritima Aubl. (Cyperaceae).

BACKGROUND: The present study was carried out to evaluate antioxidant, antinociceptive and anti-inflammatory activities of essential oil from R. maritima (RMO) in experimental protocols. METHODS: The essential oil from the roots and rhizomes of RMO were obtained by hydrodistillation using a Clevenger apparatus, and analyzed by gas chromatography/mass spectrometry (GC/MS). Here, we evaluated free radical scavenging activities and antioxidant potential of RMO using in vitro assays for scavenging activity against hydroxyl radicals, hydrogen peroxide, superoxide radicals, and nitric oxide. The total reactive antioxidant potential (TRAP) and total antioxidant reactivity (TAR) indexes and in vitro lipoperoxidation were also evaluated. The ability of RMO to prevent lipid peroxidation was measured by quantifying thiobarbituric acid-reactive substances (TBARS). NO radical generated at physiological pH was found to be inhibited by RMO, that showed scavenging effect upon SNP-induced NO production at all concentrations. Antinociceptive and anti-inflammatory properties were evaluated by acetic acid writhing reflex, Formalin-induced nociception and Carrageenan-induced edema test. RESULTS: The majors compounds identified was remirol (43.2%), cyperene (13.8%), iso-evodionol (5.8%), cyperotundone (5.7%), caryophyllene oxide (4.9%), and rotundene (4.6%). At the TRAP assay, RMO concentration of 1 mg.mL(-1) showed anti-oxidant effects and at concentration of 1 and 10 ng.mL(-1) RMO showed pro-oxidant effect. RMO at 1 mg.mL(-1) also showed significant anti-oxidant capacity in TAR measurement. Concentrations of RMO from 1 ng.mL(-1) to 100 µg.mL(-1) enhanced the AAPH-induced lipoperoxidation. RMO reduced deoxyribose oxidative damage, induced by the Fenton reaction induction system, at concentrations from 1 ng.mL(-1) to 100 µg.mL(-1). We observed that RMO caused a significant increase in rate of adrenaline auto-oxidation. On the other hand RMO did not present any scavenging effect in H2O2 formation in vitro. The results of this study revealed that RMO has both peripheral and central analgesic properties. The RMO, all doses, orally (p.o.) administered significantly inhibited (p < 0.05, p < 0.01 and p < 0.001) the acetic acid-induced writhings and two phases of formalin-induced nociception in mice. CONCLUSION: The RMO demonstrated antioxidant and analgesic profile which may be related to the composition of the oil.

A new source of (R)-limonene and rotundifolone from leaves of Lippia pedunculosa (verbenaceae) and their trypanocidal properties.

Investigation by GC-FID and GC-MS of the essential oil (LPOE) from the leaves of Lippia pedunculosa revealed, as the major compounds, the monoterpenes rotundifolone (71.7%) and (R)-limonene (21.8%). These two compounds and the minor constituent piperitenone (1.2%) were also isolated from the leaves and identified by spectrometric analysis. LPOE and isolated compounds were evaluated for their trypanocidal activity against epimastigote and trypomastigote forms of Trypanosoma cruzi. Significant results with IC50 values lower than 34.0 microg.mL(-1) were observed against these forms of T. cruzi for LPOE and isolated compounds. Rotundifolone was the most active compound with an ICso lower than 10.0 ig.mL"' for both forms of T. cruzi. The effects of LPOE and isolated compounds were also evaluated in cultures of macrophages infected with T. cruzi. Treatment with (R)-limonene and rotundifolone caused a moderate reduction in the percentage of macrophages infected by T. cruzi and in the number of intracellular parasites at concentrations non-toxic to macrophages.

Chemical composition and anti-Trypanosoma cruzi activity of essential oils obtained from leaves of Xylopia frutescens and X. laevigata (Annonaceae).

Essential oils from leaves of Xylopia frutescens (XFMJ) and two specimens of Xylopia laevigata (XLMC and XLSI) were obtained by hydrodistillation using a Clevenger-type apparatus, and analyzed by GC-MS and GC-FID. Sesquiterpenes dominated the essential oils. The main constituents of XFMJ were (E)-caryophyllene (24.8%), bicyclogermacrene (20.8%), germacrene D (17.0%), beta-elemene (7.9%), and (E)-beta-ocimene (6.8%). XLMC contained significant quantities of germacrene D (18.9%), bicyclogermacrene (18.4%), beta-elemene (9.5%), delta-selinene (9.2%), (E)-caryophyllene (8.5%), germacrene B (5.7%) and gamma-muurolene (5.7%), while germacrene D (27.0%), bicyclogermacrene (12.8%), (E)-caryophyllene (8.6%), gamma-muurolene (8.6%), delta-cadinene (6.8%), and germacrene B (6.0%) were the main components of XLSI. The essential oils had trypanocidal activity against the Y strain of Trypanosoma cruzi, with IC50 values lower than 30 microg x mL(-1) and 15 microg x mL(-1) against epimastigote and trypomastigote forms of T. cruzi, respectively, and were also able to reduce the percentage in vitro of T. cruzi-infected macrophages and the intracellular number of amastigotes at concentrations that were non-cytotoxic to macrophages.

Antioxidant and antimicrobial activities of aporphinoids and other alkaloids from the bark of Annona salzmannii A. DC. (Annonaceae).

The antioxidant capacity by oxygen radical absorbance capacity (ORAC)-FL method and antimicrobial activity using the broth microdilution method of aporphinoids (liriodenine 1, anonaine 2 and asimilobine 3) and other alkaloids (reticuline 4 and cleistopholine 5) isolated from the bark of Annona salzmannii A. DC. (Annonaceae) were evaluated. For antioxidant activity, the most active alkaloid was asimilobine with ORAC value of 2.09 relative trolox equivalents. For antimicrobial activity, some alkaloids showed significant minimal inhibitory concentration (MIC) values in the range of 25-100 µg mL(-1). The most active compounds were the aporphinoids liriodenine, anonaine and asimilobine, some of them more active than the positive control.

Chemical composition of the essential oils of Annona pickelii and Annona salzmannii (Annonaceae), and their antitumour and trypanocidal activities.

The essential oils from the leaves of Annona pickelii and Annona salzmannii (Annonaceae) were obtained by hydrodistillation using a Clevenger apparatus, and analysed by GC-MS and GC-FID. A total of 21 compounds were identified in the essential oil of A. pickelii and 23 in that of A. salzmannii; sesquiterpenes predominated in both essential oils. Bicyclogermacrene (38.0%), (E)-caryophyllene (27.8%), α-copaene (6.9%) and α-humulene (4.0%) were the main components of A. pickelii, while δ-cadinene (22.6%), (E)-caryophyllene (21.4%), α-copaene (13.3%), bicyclogermacrene (11.3%) and germacrene D (6.9%) were the main components of A. salzmannii. The biological activities of the essential oils against Trypanosoma cruzi epimastigote forms and cytotoxicity against tumour cell lines (antitumour) were investigated. The essential oils showed potent trypanocidal and antitumour activities with values of IC50 lower than 100 µg mL(-1).

Essential oil from the leaves of Annona vepretorum: chemical composition and bioactivity.

The essential oil from the leaves of Annona vepretorun was obtained by hydrodistillation using a Clevenger-type apparatus and analyzed by GC-MS and GC-FID. Eighteen compounds representing 98.1% of the crude essential oil were identified. The major compounds identified were bicyclogermacrene (43.7%), spathulenol (11.4%), alpha-felandrene (10.0%), alpha-pinene (7.1%), (E)-beta-ocimene (6.8%), germacrene D (5.8%), and p-cymene (4.2%). The trypanocidal activity against Trypanosoma cruzi epimastigote forms, as well as, the antimicrobial and antioxidant proprieties was investigated. The essential oil showed a potent trypanocidal activity with IC50 value of 31.9 +/-1.3 microg x mL(-1). For antimicrobial activity, the best result was observed against Candida tropicalis with a MIC value of 100 microg x mL(-1). For antioxidant capacity the essential oil showed weak activity.