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Three new natural cyclopentenedione derivatives (1-3) and the known coumarin xanthyletin (4) were isolated from the roots of Piper carniconnectivum. The structures were established by spectroscopic data, mainly 1D and 2D NMR and EIMS.

From the ethanolic extract of the wood of Annona dioica were isolated the known 1-aza-4-methylanthraquinone, lasiodiplodin, liriodenine, a mixture of 1-aza-5,9,10-trimethoxy-4-methyl-2-oxo-1,2-dihydroanthracene and 1-aza-8,9,10-trimethoxy-4-methyl-2-oxo-1,2-dihydroanthracene (geovanine) and the new alkaloid 1,2-methylenedioxy-6alpha,7-dehydroaporphine-4(S )-(4-hydroxy-3,5-dimethoxyphenyl)-3,4-dihydro-2(1H)-pyridinone. The structures of these natural products were elucidated on the basis of their spectral data, including NOE experiments and homonuclear ¹H-¹H-COSY e heteronuclear ¹H-13C-COSY-nJ CH (HMQC, n=1 and HMBC, n=2 and 3) 2D-shift-correlated NMR spectra.

Steroidal alkaloids, flavonoids and their glycosides occurring in numerous species of Solanum genus are known to possess a variety of biological activities. The flavonoid tiriloside (1), a rich in glycoalkaloids total fraction named GB and the glycoalkaloid solasonine (2) isolated from thricomes of young branches and fruits from Solanum crinitum Lam, and the aglycone solasodine (3) isolated from Solanum jabrense Agra & M. Nee, were assayed against murine Ehrlich carcinoma and human K562 leukaemia cultured cells. The exposure in vitro of these cancer cells to these products resulted in a dose-dependent growth inhibition evaluated by the MTT method. The results indicated significant cytotoxic activities with IC50 = 69.50 muM, 19.5 mug mL-1, and 74.20 muM for 1, GB and 2, respectively, against Ehrlich carcinoma, and IC50 = 186.50 muM, 13.65 mug mL-1 and 76.92 muM, for 1, GB, 2 and 2a, respectively, against K562 leukaemia cells. The low activity of the aglycone 3 indicates that the role of the sugar moiety is very important in the cytotoxic activity of glycoalkaloid solsonine. The cytotoxic activity revealed by the GB fraction may be attributed to the presence of 2. Additionally, these results show the viability of the MTT assay for monitoring phytochemical bioactive compounds.

From the leaves of Vellozia candida Mikan (Velloziaceae) the new flavonol 3',4',5,7-tetrahydroxy-3,6-dimethoxy-8-methylflavone and its known 7-O-methyl derivative, 3',4',5-trihydroxy-3,6,7-trimethoxy-8-methylflavone, were isolated and characterized by spectral data, including 2D NMR and tandem mass spectrometry experiments. The 5-hydroxy-3,3',4',6,7-pentamethoxy-8-methylflavone derivative was obtained by methylation with diazomethane.

Three new natural cinnamic acid and dihydrocinnamic acid derivatives were isolated from the roots of Brosimum gaudichaudii, in addition to fourteen known substances (ten coumarins, one chalcone, beta-sitosterol, 3beta-O-beta-D-glucopyranosylsitosterol and beta-amyrin). The structures were established by spectral data, including analysis of 2D-NMR experiments and mass spectra. All aromatic compounds have 4-hydroxy-3-prenylcinnamic acid as a common precursor. The new substances are derived from a precursor of the coumarins, which through an O-methylation lost its ability to form the lactone ring.

From the roots of Parahancornia amapa, family Apocynaceae, the following compounds were isolated and identified nine new and ten known 3beta-O-acyl lupeol esters, beta-sitosterol, stigmasterol, beta-sitosterone, the triterpenoids beta-amyrin, alpha-amyrin, lupeol and their acetyl derivatives. The structures of these compounds were established by spectroscopic data, mainly ¹H and 13C (HBBD and DEPT) NMR spectra. The methyl esters obtained by hydrolysis of acyl lupeol esters and methylation of the corresponding acids were characterized by MS-GC analysis.

A new natural quaternary alkaloid, Nb-methylvoachalotine (1), was obtained from the root bark of Tabernaemontana laeta together with three dimeric indole alkaloids, conodurine (2), voacamine (3) and tabernamine (4), and the monomeric indole alkaloids 19S-heyneanine (5), coronaridine (6) and voacangine (7). The known triterpenes alpha-amyrin acetate, beta-amyrin acetate, lupeol acetate and taraxasterol acetate and the phytosterol beta-sitosterol and its 3-O-beta-D-glucoside were also identified. The structures of the compounds were elucidated based on spectroscopic studies.

A new sesquiterpene, named trichotomol, and known compounds cordiachrome C, alpha-cadinol, oleanolic acid, oncocalyxone A, beta-sitosterol, beta-sitosterol-beta-D-glucoside, allantoin and sucrose were isolated from the heart wood ethanol extract of Cordia trichotoma. Their structures were assigned unambiguously by spectroscopic analyses and comparison with the published data for structurally related compounds.

Chalcone (1) and its fluorinated derivatives 2-4, as well as their cyclic analogues 5-10, were synthesized through an aldol condensation reaction between the corresponding ketone and aldehyde. These compounds were characterized by IR, EIMS and ¹H and 13C NMR spectral data. Modern NMR techniques allowed us to conclude that the compounds obtained show E configuration. These techniques were also employed to investigate the equilibrium involving the s-cis and s-trans conformations of 1-4, with this equilibrium being dependent on the fluorine substitution on both aromatic rings, A or B. IR studies indicated that the yield of the s-cis conformation in the fluorinated derivatives is 57.4±1.4; 88.1±0.4 and 66.4±0.7%, for 2, 3 and 4, respectively, based on previous ¹H NMR calculations for chalcone. Theoretical calculations, using the MMX method, were employed to justify the variation of chemical shifts for the fluorinated derivatives and cyclic analogues. These chemical shifts are consequence of the anisotropic effect showed by the carbonyl group on these compounds.

Chromatographic fractionation of the hexane extract from the wood of Ouratea floribunda (Ochnaceae) afforded friedelin (1), friedelanol (2), lupeol (3) and the depside atranorin (4). The structure elucidation of the isolated compounds was performed by spectrometric analysis involving comparison with literature data. The unambiguous assignments of ¹H and 13C NMR data of atranorin 4 and its acetyl derivative 4a are reported for the first time and involved ¹H-¹H homonuclear (COSY and NOESY) and ¹H-13C heteronuclear (HMQC and HMBC) NMR experiments.

The new pentacyclic triterpene, 11alpha-methoxy-beta-amyrin (1), was isolated from Myroxylon balsamum (L.) Harms (syn. Myroxylon peruiferum L.f.). Its structure was established on the basis of IR, MS, ¹H NMR, 13C NMR. 2D NMR experiments were also used to establish the structure and the hydrogen and carbon chemical shift assignments of the new triterpene.

From fruits of Pterodon polygalaeflorus (Leguminosae) the new diterpene 6alpha-hydroxyvouacapane, the known diterpenoids vouacapane-6alpha,7beta,14beta,19-tetraol and methyl 6alpha,7beta-dihydroxyvouacapan-17b-oate and the flavonoid taxifolin were isolated. Structural determinations were accomplished by spectroscopic analysis, including two-dimensional NMR, chemical transformation of the new diterpene and comparison with literature data.

UV irradiation of 1,2,3-indanetrione, in CH2Cl2, in the presence of 2,3-dimethyl-2-butene yields a complex mixture of products arising from hydrogen abstraction, [2pi+2pi] photocycloaddition (Paternò-Büchi reaction), and [4pi +2pi] photocycloaddition. The reaction is dependent on electronic and steric effects, with the later accounting for the high chemical yield observed for the formation of the dioxene-type product.

1-(4?-Hydroxy-5?-methyl-2?-methoxyphenyl)-3-(2"-hydroxy-4",5"-methylenedioxyphenyl) propane (7), 1,3-diarylpropane isolated from Iryanthera laevis, 1-(4?-hydroxy-2?-methoxyphenyl)-3-(4"-hydroxyphenyl)propane (2, broussonin B) and 1-(2?-hydroxy-4?-methoxyphenyl)-3-(4"-hydroxyphenyl)propane (1, broussonin A), isolated from Broussonetia papyrifera Vent. (Moraceae), and 1-(2?,4?-dimethoxyphenyl)-3-(4"-hydroxyphenyl)propane, a synthetic product prepared by catalytic hydrogenation of 4-O-benzyl-2?,4?-dimethoxychalcone, were synthesized. The synthetic pathway employed in this work involved the catalytic hydrogenation of chalcones obtained by base condensation of acetophenones and benzaldehydes.

A new isoflavone named harpalycine and quercetin were isolated from the leaves and 3-hydroxy-4-isopentenyl-8,9-methyle-nedioxypterocarpan and betulinic acid from the roots of Harpalyce brasiliana. The structures were elucidated using spectroscopic methods, including 2D NMR techniques of the new isoflavone.

The isoflavonoids 6,7-dimethoxy-3?,4?-methylenodioxy-, 4?-hydroxy-3?,6,7-trimethoxy-, 3,4,6,7-tetramethoxy-, 7-hydroxy-6-methoxy-3,4-methylenodioxy-, 2?,6,7-trimethoxy-3?,4?-methylenedioxy-, 2?,3?,4?,6,7-pentamethoxy- and 2?,4?,5,6,7-pentamethoxyisoflavone, together with the triterpenoids lupeol and betulin and 4-methoxybenzoic acid, were isolated from acetone extracts of the sapwood and heartwood of Pterodon polygalaeflorus. The structures of these natural products have been characterized by spectrometric methods, mainly extensive 1D and 2D NMR experiments, which were also used for complete assignments of the chemical shifts of the hydrogen and carbon-13 atoms of isoflavonoids.

Phytochemical investigation of the leaves and branches of a specimen of Ouratea semiserrata led to the isolation and characterization of ent-16alpha,17-dihydroxykauran-19-oic acid, along with other natural products. This diterpenoid and its derivatives were used to unambiguous ¹H and 13C chemical shifts assignments and to indicate some mistake data described in the literature as consequence mainly of the stereochemicals of the chiral carbons C-4 and C-16. The HRMS spectra were also analysed.

Abstract Background Naringin is an important flavanone with several biological activities, including antioxidant action. However, this compound shows low solubility in lipophilic preparations, such as is used in the cosmetic and food industries. One way to solve this problem is to add fatty acids to the flavonoid sugar unit using immobilized lipase. However, there is limited research regarding hydroxylation of unsaturated fatty acids as an answer to the low solubility challenge. In this work, we describe the reaction of naringin with castor oil containing ricinoleic acid, castor oil's major fatty acid component, using immobilized lipase from Candida antarctica. Analysis of the 1H and 13 C NMR (1D and 2D) spectra and literature comparison were used to characterise the obtained acyl derivative. Results After allowing the reaction to continue for 120 hours (in acetone media, 50°C), the major product obtained was naringin 6″-ricinoleate. In this reaction, either castor oil or pure ricinoleic acid was used as the acylating agent, providing a 33% or 24% yield, respectively. The chemical structure of naringin 6″-ricinoleate was determined using NMR analysis, including bidimensional (2D) experiments. Conclusion Using immobilized lipase from C. antarctica, the best conversion reaction was observed using castor oil containing ricinoleic acid as the acylating agent rather than an isolated fatty acid. Graphical abstract

Diplopods are terrestrial arthropods important for the dynamics of terrestrial ecosystems. One of the reasons for that can be their low predation rate due to their defensive secretion. Thus, Orthoporus fuscipes, a species belonging to this group and endemic to northeastern Brazil, was investigated as to its population structure and chemical constituents of defensive secretion. The population structure showed that females are larger and have greater mass than do males, along with negative allometric growth between males and females. The defensive secretion hexane extract was submitted to fractionation using SiO2 open-column chromatography and the gas chromatographic coupled to mass spectrometric analysis was applied in the fraction possibilities to identify major fatty acid methyl esthers, along with minor alkanes, alkenes and fatty acids derivatives and the known quinoids 2-methoxy-3-methylhydroquinone, 2-methoxy-3-methyl-1,4-benzoquinone, 2,3-dimethoxy-1,4-benzoquinone and 2,3-dimethoxyhydroquinone. In addition, the cytochrome oxidase I sequence for the species was deposited for the first time.

The alkaloid Aspidocarpine was isolated from the bark of Aspidosperma desmanthum. Its structure was elucidated by the spectral data of 1H and 13C-NMR (1D and 2D) and high-resolution mass spectrometry (HRESIMS). The antihypertensive activity was investigated by intravenous infusion in Wistar rats. This alkaloid significantly reduced (p < 0.05) the systolic, median, and diastolic blood pressures of rodents, without causing motor incoordination and imbalance in the rotarod test. The results indicate that the alkaloid Aspidocarpine exerts its antihypertensive activity without causing sedation or the impairment of motor functions.

Mandevilla Lindl. is an important genus of the Apocynaceae family, not only as ornamental plants but also for its medicinal uses. In Brazil, Mandevilla species are indicated to treat asthma and skin infections, their anti-inflammatory potential and wound healing properties are also reported in the literature. Concerning their chemical composition, this group of plants is a conspicuous producer of pregnane glycosides. Mandevilla dardanoi is an endemic species from the Brazilian semiarid region not studied by any phytochemical methods. In view of the medicinal potential of Mandevilla species, this study aimed to isolate new pregnane glycosides from M. dardanoi . To achieve this main goal, modern chromatography techniques were employed. Five new pregnane glycosides, dardanols A-E, were isolated from the roots of M. dardanoi by HPLC. Their structures were determined using extensive 1D and 2D-NMR and mass spectrometry (MS n and HRESIMS) data. The cytotoxicity and the anti-inflammatory potential of these compounds were evaluated. The first was evaluated by measuring proinflammatory cytokines and nitric oxide production by stimulated macrophages. Dardanols were able to inhibit the production of nitric oxide and reduce IL-1β and TNF-α. The current work demonstrates the chemodiversity of Brazilian semiarid species and contributes to amplifying knowledge about the biological potential of the Mandevilla genus.

The antioxidant activity of Tetragonisca angustula honey (TAH) and its ethanolic extract (TAEE) were investigated. The total levels of phenolic (TPC) and flavonoids (TFC) were also evaluated. The results for TPC were 19.91 ± 0.38 and 29.37 ± 1.82 mg GAE g-1 and for TFC 0.20 ± 0.02 and 0.14 ± 0.01 mg QE g-1 of TAH and TAEE, respectively. Antioxidant activities were 73.29 ± 0.49% and 93.36 ± 0.27% in the DPPH● assay and 71.73 ± 4.07% and 97.86 ± 0.35% in ABTS●+ for TAH and TAEE, respectively. The total reducing activity was determined by the method of reducing power (PR) and iron ion (Fe III) and the results varied in PR from 151.7 ± 25.7 and 230.7 ± 25.2 mg GAE L-1, for TAH and TAEE respectively and for (Fe III) in EC50 0.284 in TAEE and 0.687 in TAH. Chemical analysis by HPLC-DAD of the ethanolic extract (TAEE) revealed the presence of ferulic acid as majority phenolic component in the extract. The 1H NMR analysis confirmed this structure and showed the also presence of glucose, citric acid, succinic acid, proline and hydrocarbon derivatives. In addition, the botanical origin was also investigated and showed a multifloral characteristic, having found 19 pollen types with a botanical predominance of the Anacardiaceae family, with Tapirira pollen occurring as predominant (42.6%) and Schinus as secondary (25.7%). The results showed that T. angustula honey is an interesting source of antioxidant phenolic compounds due to its floral origin and can act as a protector of human health when consumed.

Phytochemical studies of Cespedesia spathulata (Ochnaceae) leaves using 1H, 13C NMR, and GC-MS have led to the isolation of some metabolites identified for the first time in these species such as cathechin, epicatechin, vitexin, orientin, 6''-O-acetyl-vitexin, sitosterol, stigmasterol, phytol, 4,5-dihydrovomifoliol and a mixture of aliphatic methyl esters, together with ochnaflavone, which was previously isolated from this plant. The modulating activity of some fractions and compounds from Cespedesia spathulata towards tyrosinase enzyme was assayed by spectroscopic and theoretical means/experiments. The dichloromethane fraction (133 μg mL-1) and ochnaflavone (333 μM) inhibited tyrosinase activity by 20 % and 2.0 %, respectively, whereas the ethyl acetate fraction (666 μg mL-1) and ±catechins (catechin and epicatechin - 800 μM) activated it by 104 % and 384 %, respectively. Quantum chemical calculations suggested that catechin and epicatechin are better activators than L-DOPA by interacting with Cu (II) ions. Molecular docking results suggested that hydrogen bonding and hydrophobic interactions are the main binding forces between each tyrosinase activator and the amino acid residues inside the active protein binding pocket.

Plants have historically been a rich source of successful anticancer drugs and chemotherapeutic agents, with research indicating that this trend will continue. In this contribution, we performed high-throughput cytotoxicity screening of 702 extracts from 95 plant species, representing 40 families of the Brazilian Cerrado biome. Activity was investigated against the following cancer cell lines: colon (Colo205 and Km12), renal (A498 and U031), liver (HEP3B and SKHEP), and osteosarcoma (MG63 and MG63.3). Dose-response tests were conducted with 44 of the most active extracts, with 22 demonstrating IC 50 values ranging from <1.3 to 20 µg/mL. A molecular networking strategy was formulated using the Global Natural Product Social Molecular Networking (GNPS) platform to visualize, analyze, and annotate the compounds present in 17 extracts active against NCI-60 cell lines. Significant cytotoxic activity was found for Salacia crassifolia , Salacia elliptica , Simarouba versicolor , Diospyros hispida , Schinus terebinthifolia , Casearia sylvestris var. lingua , Magonia pubescens , and Rapanea guianensis . Molecular networking resulted in the annotation of 27 compounds. This strategy provided an initial overview of a complex and diverse natural product data set, yielded a large amount of chemical information, identified patterns and known compounds, and assisted in defining priorities for further studies.

The genus Cedrela P. Browne, which belongs to the Meliaceae family, has eighteen species. Trees of this genus are of economic interest due to wood quality, as well as being the focus of studies because of relevant biologic activities as in other Meliaceae species. These activities are mainly related to limonoids, a characteristic class of compounds in this family. Therefore, the aim of this review is to perform a survey of the citations in the literature on the Cedrela genus species. Articles were found on quantitative and qualitative phytochemical studies of the Cedrela species, revealing the chemical compounds identified, such as aliphatics acid and alcohol, flavonoids, tocopherol, monoterpenes, sesquiterpenes, triterpenes, cycloartanes, steroids, and limonoids. Although some activities were tested, the majority of studies focused on the insecticidal, antifeedant, or insect growth inhibitor activities of this genus. Nonetheless, the most promising activities were related to their antimalarial and antitripanocidal effects, although further investigations are still needed.

Medicinal plants have been the focus of several studies due to their nematicide properties which can be used to control nematodes in sheep. No study has examined the morphological effects of Cymbopogon citratus on nematodes. Thus, this study evaluated the chemical composition, nematicidal activity and effects of C. citratus extracts on the morphology of eggs and infective larvae (L3) of sheep. Aqueous and methanolic extracts and fractions of C. citratus were obtained and analysed in vitro. The C. citratus extracts were effective against Haemonchus spp. and Trichostrongylus spp. larvae and eggs. Ten fractions were obtained from C. citratus, six of which had high ovicidal activity at 1000 μg mL-1, and two fractions had high activity at all tested concentrations. The phytochemical analysis identified the presence of compounds such as terpenoids, various ketones, esters, and fatty acids. The ultrastructural analysis showed deformations of the cuticle and wilting along the body of the nematodes at all concentrations. The muscular layer, intestinal cells and the mitochondria profile showed damage compared to the typical pattern. Ultra-thin sections of eggs treated with methanolic fractions of C. citratus presented modifications. This study showed the biological activity and effects of C. citratus on the gastrointestinal nematodes in sheep.

Six sesquiterpenoids with unprecedented macrocyclic humulene-type structures, namely, dolichocarpols A-E ( 1 - 5 ) with ether-bridged bicyclic rings between C-10 and C-2, C-10 and C-7, C-10 and C-6 (×2), and C-6 and C-3 and dolichocarpol F ( 6 ) cyclized between C-7 and C-2 and with an ether bridge between C-10 and C-3, were isolated from Anaxagorea dolichocarpa roots. The structures of the compounds were elucidated by NMR, MS, and IR data. Absolute configurations of compounds 1 - 3 and 6 were established on the basis of data from electronic circular dichroism, whereas relative configurations of compounds 4 and 5 were suggested by the NOESY spectrum. In addition, a putative biosynthetic pathway of the compounds is proposed. Furthermore, the cytotoxicity of 3 , 4 , and 6 against HCT-116 (human colorectal carcinoma) and L929 (murine fibroblast) was evaluated., Competing Interests: The authors declare no competing financial interest., (Copyright © 2020 American Chemical Society.)

The essential oils obtained by hydrodistillation from fresh leaves of Vitex agnus-castus and Ocimum campechianum, and from fresh inflorescences of Ocimum carnosum were analysed by GC-FID and GC-MS. The major components of V. agnus-castus essential oil were identified as 1,8-cineole (47.9%), terpinyl α-acetate (11.6%), sabinene (11.2%) and caryophyllene oxide (9.7%), while in the O. campechianum essential oil were eugenol (72.1%), β-elemene (6.8%), (E)-caryophyllene (6.4%) and bicyclogermacrene (5.2%). Linalool (79.0%), α-epi-cadinol (5.4%), terpinen-4-ol (3.2%) and 1,8-cineole (2.8%) were the major constituents in the O. carnosum essential oil. The essential oils were subsequently evaluated for their larvicidal and cytotoxic activities. Larval bioassay against Aedes aegypti of V. agnus-castus, O. campechianum and O. carnosum essential oils showed LC50 values of 97.55 ± 0.35, 81.45 ± 0.35 and 109.49 ± 0.35 μg/mL, respectively. The in vitro cytotoxic activities of the essential oils has been evaluated on breast adenocarcinoma (MCF-7), lung carcinoma (NCI-H292), pro-myelocytic leukemia (HL-60), and cervical adenocarcinoma (HEP-2) human cell lines, and pro-myelocytic leukemia cells lines (HL-60) were found to be the most sensitive to all the essential oils tested than the others. This is the first report on larvicidal and cytotoxic activities of these essential oils.

Zornia brasiliensis Vogel (Leguminosae) is a species popularly known in Brazil as "urinária", "urinana", and "carrapicho", it is popularly used as a diuretic and in the treatment of venereal diseases. A specific methodology to obtain a saponin-enriched fraction and high-performance liquid chromatography coupled with diode array detection, ion trap mass spectrometry, and TOF-MS (HPLC-DAD-ESI-MS/MS) was applied for the analysis of triterpene saponins. The MS and MS/MS experiments were carried out by ionization in negative mode. Molecular mass and fragmentation data were used to support the structural characterization of the saponins. Based on retention times, high-resolution mass determination and fragmentation, 35 oleanane-triterpene saponins were tentatively identified in Z. brasiliensis .

The new alkene lactone, (3E)-5,6-dihydro-5-(hydroxymethyl)-3-docdecylidenefuran-3(4H)-one (1), named majoranolide B, and three alkene lactones known as majorenolide (2), majoranolide (3) and majorynolide (4) were obtained from the aerial parts of Persea fulva (Lauraceae). The structures were elucidated in light of extensive spectroscopic analysis, including 1D, 2D NMR ( 1 H, 13 C, 1 H- 1 H-COSY, HMBC and HSQC) and HR-ESI-MS. These compounds were screened for their in vitro antiproliferative activity in rat C6 glioma and astrocyte cells using MTT assay and in silico by molecular docking against targets that play a central role in controlling glioma cell cycle progression. Majoranolide (3) is the most active compound with IC 50 6.69 µM against C6 glioma cells, followed by the compounds 1 (IC 50 9.06 µM), 2 (IC 50 12.04 µM) and 4 (IC 50 41.90 µM). The alkene lactones 1-3 exhibited lower toxicity in non-tumor cells when compared to glioma cells. Molecular docking results showed that majoranolide establishes hydrogen bonds with all targets through its α,β-unsaturated-γ-lactone moiety, whereas the long-chain alkyl group binds by means of several hydrophobic bonds. In the present study, it can be concluded from the anti-proliferative activity of isolates against C6 glioma cells that lactone constituents from P. fulva could have a great potential for the control of C6 glioma cells., (Copyright © 2019. Published by Elsevier Inc.)

A phytochemical study of leaves and twigs of Psychotria nuda resulted in 19 compounds, including five indole alkaloids, N , N , N -trimethyltryptamine, lyaloside, strictosamide, strictosidine, and 5α-carboxystrictosidine; two flavonolignans, cinchonain Ia and cinchonain Ib; an iridoid, roseoside; a sugar, lawsofructose; a coumarin, scopoletin; a diterpene, phytol; three triterpenes, pomolic acid, spinosic acid, and rotungenic acid; and five steroids, sitosterol, stigmasterol, campesterol, β -sitosterol-3- O - β -d-glucoside, and β -stigmasterol-3- O - β -d-glucoside. Some compounds were evaluated for their in vitro activity against Mycobacterium tuberculosis and their ability to inhibit NO production by macrophages stimulated by lipopolysaccharide (LPS). The compounds pomolic acid, spinosic acid, strictosidine, and 5α-carboxystrictosidine displayed antimycobacterial activity with minimum inhibitory concentrations ranging from 7.1 to 19.2 µg/mL. These compounds showed promising inhibitory activity against NO production (IC 50 3.22 to 25.5 μg/mL). 5 α-carboxystrictosidine did not show cytotoxicity against macrophages RAW264.7 up to a concentration of 100 µg/mL. With the exception of strictosamide, this is the first report of the occurrence of these substances in P. nuda .

This study evaluated the antibacterial, antifungal, and antioxidant effect of 7-hydroxy-4',6-dimethoxy-isoflavone and essential oil of Myroxylon peruiferum. The compound was isolated and its structure elucidated by NMR. The chemical composition of essential oil determined by GC-MS analysis. To evaluation of antimicrobial activity, the Minimum Inhibitory Concentration (MIC), Minimum Bactericidal Concentration (MBC) and Minimum Fungicidal Concentration (MFC) were performed. In addition to analysis of antioxidant activity, DPPH radical scavenging tests, iron chelating assay (FIC), antioxidant reducing power assay (FRAP) and β-carotene bleaching assay (BCB) were performed. For the essential oil were identified 24 organized compounds having as main constituents; Germacrene D (17.2%), α-pinene (14.8%) and E-caryophyllene (10.8%). The results showed that isoflavone (2000 to 156 μg/mL) and essential oil (5.0 to 1.25%) present antibacterial and antifungal activity against Gram-positive bacteria and filamentous fungi. The isoflavone and the essential oil also presented antioxidant activity in all the tests, mainly on inhibition of the oxidation of β-carotene test concentrations ranging from 60 to 100%. In conclusion, isoflavone and essential oil from M. peruiferum present an antimicrobial alternative against Gram-positive bacteria, especially of the genus Staphylococcus and dermatophyte fungi of the genus Trichophyton, as well as a natural compound antioxidant.

Ouratea fieldingiana (Gardner) Engl is popularly used for wound healing. This study describes the main chemical compounds present in extracts of O. fieldingiana and evaluates their biological potential by investigating antifungal, antioxidant, and anticholinesterase activities. The action mechanism of main antifungal compound was investigated by molecular docking using the enzyme sterol 14- α demethylase, CYP51, required for ergosterol biosynthesis. The seeds and leaves were extracted with ethanol in a Soxhlet apparatus and by maceration, respectively. Both extracts were subjected to silica gel column chromatography for isolation of main constituents, followed by purification in sephadex. The structures of compounds were established by 1 H and 13 C-NMR spectroscopy and identified by comparison with literature data as amentoflavone and kaempferol 3- O -rutinoside, respectively. The antioxidant activities of the extracts were determined by the DPPH and ABTS free radical inhibition methods. In general, the extracts with the highest antioxidant activity corresponded to those with higher content of phenolic compounds and flavonoids. The ethanol extracts and two isolated compounds presented relevant antifungal activity against several Candida strains. The in silico findings revealed that the compound amentoflavone coupled with the CYP450 protein due to the low energy stabilization (-9.39 kcal/mol), indicating a possible mechanism of action by inhibition of the ergosterol biosynthesis of Candida fungi.

The new pentacyclic triterpene 11 β -hydroxypristimerin ( 1 ), along with the known metabolites pristimerin ( 2 ), 6-oxopristimerol ( 3 ) and vitideasin ( 4 ), were isolated from a Salacia crassifolia root wood extract, following a bioassay-guided fractionation approach. Both the extract and the purified triterpenes displayed pronounced cytotoxic activity against human cancer cell lines. The NCI-60 cell line screen revealed that compound 2 was the most active, with a mean GI 50 of 0.17 μM, while compound 1 had a mean GI 50 of 8.7 μM. A COMPARE analysis of the screening results showed that pristimerin is likely to be the main compound responsible for the cytotoxic activity of the extract (mean GI 50 of 0.3 μg·mL −1 ). A targeted search for pristimerin and related derivatives using LC-MS/MS revealed the presence of pristimerin ( 2 ) and 6-oxopristimerol ( 3 ) in all Celastraceae species examined and in all plant parts tested, while vitideasin ( 4 ) was only detected in the genus Salacia .

Two new triterpenes cycloartane-type, named 24-methylencycloartan-12-oxo-3β,22α-diol and trichiliol, were isolated from the leaves of Trichilia casaretti C. DC. together with three known triterpenes—24-methylencycloart-3β,22-diol, 22,25-dihydrocycloart-23( E )-en-3β-ol, and 22( R )-hydroxycycloart-24-en-3-ol. These compounds were characterized on the basis of their spectral data, mainly 1D (¹H and 13 C) and 2D NMR (¹H-¹H-COSY, ¹H-¹H-NOESY, HMQC, HSQC, and HMBC), and mass spectra (EI-MS and HR-ESI-MS), also involving comparison with data from the literature.

This study identified two phenolic compounds in Schinus terebinthifolius Raddi fruits: naringenin (first report in this species) and gallic acid. Their structures were elucidated by nuclear magnetic resonance (NMR) data (¹H-, 13 C-NMR) and a high-performance liquid chromatography (HPLC) technique. A high content of phenolics (659.21 mg of gallic acid equivalents/g of sample-Folin-Ciocalteau method) and total flavonoids (140.69 mg of rutin equivalents/g of sample-aluminum chloride method) were quantified in S. terebinthifolius , as well as high antioxidant activity (77.47%-2,2-diphenyl-1-picrylhydrazyl, DPPH method). The antihypertensive activity related to its phenolic content was investigated. After intravenous infusion in Wistar rats, these phenolics significantly reduced ( p < 0.05) the systolic, median, and diastolic arterial pressures of individuals. The rotarod test was performed to determine the mechanism of action of the sample vasorelaxant effect. It was found that its action exceeded that of the positive control used (diazepam). This confirmed the vasodilatory activity exerted by S. terebinthifolius fruits is related to the phenolic compounds present in the plant, which are potent antioxidants and inhibit oxidative stress, mainly in the central nervous system., Competing Interests: The authors declare no conflict of interest.