Papers by Paulo Cezar Vieira
Química Nova, 2017
A chemical investigation of two specimens of Byrsonima coccolobifolia collected in the southeast ... more A chemical investigation of two specimens of Byrsonima coccolobifolia collected in the southeast cerrado and from central Brazil was performed. A new degraded diterpenoid, byrsonimaquinone, was isolated from the stems along with known compounds. This is the first study on the roots of B. coccolobifolia, and several triterpenes, such as α-amyrin, β-amyrin, oleanolic acid, and glochidonol, along with a mixture of stigmasterol, β-sitosterol and campesterol, were identified. These compounds were identified by spectroscopic analysis techniques, including 1D and 2D NMR, GC-MS and high-resolution mass spectrometry.
Phytochemistry, 1991
Phytochemistry, Vol. 30, No. 6, pp. 2019-2023, 1991 Printed in Great Britain. 0031-9422/91 $3.00+... more Phytochemistry, Vol. 30, No. 6, pp. 2019-2023, 1991 Printed in Great Britain. 0031-9422/91 $3.00+0.00 ) 1991 Pergamon Press pic TERPENO-P-HYDROXYBENZOIC ACID DERIVATIVES FROM RAPANEA UMBELLATA* ANA H. JANUARIO, PAULO C. VIEIRA, M. FATIMA DAS ...
Planta Medica, Jul 9, 2020
Fungi are a rich source of bioactive compounds. Fungal cocultivation is a method of potentiating ... more Fungi are a rich source of bioactive compounds. Fungal cocultivation is a method of potentiating chemical interactions and, consequently, increasing bioactive molecule production. In this study, we evaluated the bactericidal, antiprotozoal, and cathepsin V inhibition activities of extracts from axenic cultures of 6 fungi (Fusarium guttiforme, Pestalotiopsis diospyri, Phoma caricae-papayae, Colletotrichum horii, Phytophthora palmivora, and C. gloeosporioides) that infest tropical fruits and 57 extracts obtained by their cocultivation. Our results reveal that fungal cocultivation enhances the biological activity of the samples, since all extracts that were active on Gram-positive bacteria, Gram-negative bacteria, Trypanosoma cruzi, and Leishmania infantum were obtained from cocultivation. Bacterial growth is either totally or partially inhibited by 46% of the extracts. Two extracts containing mainly fusaric and 9,10-dehydrofusaric acids were particularly active. The presence of the fungus F. guttiforme in co-cultures that give rise to extracts with the highest activities against L. infantum. An axenic culture gave rise to the most active extract for the inhibition of cathepsin V; however, other coculture extracts also exhibited activity toward this biological target. Therefore, the results of the biological activities indicate that fungal cocultivation increased the biological potential of samples, likely due to the hostile and competitive environment that pushes microorganisms to produce substances important for defense and allows access to metabolic routes then silenced in milder cultivation conditions.
Química Nova, 2009
INDOLOPYRIDOQUINAZOLINE ALKALOIDS FROM Esenbeckia grandiflora MART. (RUTACEAE). The chemical comp... more INDOLOPYRIDOQUINAZOLINE ALKALOIDS FROM Esenbeckia grandiflora MART. (RUTACEAE). The chemical composition of two specimens of Esenbeckia grandiflora, collected in the south and northeast regions of Brazil, was investigated. In this study, three β-indolopyridoquinazoline alkaloids from the leaves (rutaecarpine, 1-hydroxyrutaecarpine) and roots (euxylophoricine D) were isolated for the first time in this genus. In addition, the triterpenes a-amyrin, β-amyrin, a-amyrenonol, β-amyrenonol, 3a-hydroxyursan-12-one, and 3a-hydroxy-12,13-epoxy-oleanane, the coumarins auraptene, umbelliferone, pimpinelin, and xanthotoxin, the furoquinoline alkaloids delbine and kokusaginine, and the phytosteroids sitosterol, stigmasterol, campesterol and 3β-O-β-Dglucopyranosylsitosterol were also isolated from the leaves, twigs, roots and stems of this species. Structures of these compounds were established by spectral analysis.
Molecules, 2022
Dengue is a neglected disease, present mainly in tropical countries, with more than 5.2 million c... more Dengue is a neglected disease, present mainly in tropical countries, with more than 5.2 million cases reported in 2019. Vector control remains the most effective protective measure against dengue and other arboviruses. Synthetic insecticides based on organophosphates, pyrethroids, carbamates, neonicotinoids and oxadiazines are unattractive due to their high degree of toxicity to humans, animals and the environment. Conversely, natural-product-based larvicides/insecticides, such as essential oils, present high efficiency, low environmental toxicity and can be easily scaled up for industrial processes. However, essential oils are highly complex and require modern analytical and computational approaches to streamline the identification of bioactive substances. This study combined the GC-MS spectral similarity network approach with larvicidal assays as a new strategy for the discovery of potential bioactive substances in complex biological samples, enabling the systematic and simultaneo...
This study was conducted to evaluate the insecticidal effects of Myrsine coriacea (Primulaceae) a... more This study was conducted to evaluate the insecticidal effects of Myrsine coriacea (Primulaceae) against one of the main pests of maize, the fall armyworm (Spodoptera frugiperda), as well as performing the phytochemical study of M. coriacea. In the experiments for ingestion against S. frugiperda, the leaf extract of M. coriacea showed larval mortality of 46.67 %. From M. coriacea leaves were isolated the flavonoids catechin and quercetin. This is the first report of the isolation of flavonoids in M. coriacea.
Zeitschrift für Naturforschung C, 2020
The fall armyworm, Spodoptera frugiperda, is a polyphagous pest that causes important damage in d... more The fall armyworm, Spodoptera frugiperda, is a polyphagous pest that causes important damage in different regions of America and mainly affects corn crops in both tropical and subtropical areas. Currently, control relies on both transgenic plants and/or chemical pesticides. In this work, we describe insecticidal activity against the fall armyworm from a series of Mannich bases (1–10), derived from 2-hydroxy-1,4-naphthoquinone (lawsone), substituted benzaldehydes, and two primary amines, and their Cu2+ complexes (11–20). The [Cu(L)2] complexes were more effective in larval mortality compared to the free Mannich bases. Among the tested compounds, complex 11 showed the highest toxicity, with 70.00% larval mortality.
Journal of the Brazilian Chemical Society, 2020
Cathepsin K is a papain-like cysteine protease and is responsible for collagen degradation in bon... more Cathepsin K is a papain-like cysteine protease and is responsible for collagen degradation in bone tissue and thus represents an important target for the development of new therapies for treating diseases such as osteoporosis. Quinolines are an important class of heterocyclic molecular leads with a great pharmacological potential and represent a relevant scaffold to explore the chemical space of cathepsin K (CatK) inhibitors. This study presents the synthesis of nine 2,4-diphenylquinolines, including five phthalonitrile quinolines dyads, and the evaluation of their CatK inhibitory activity. Among the evaluated compounds, 4b was the most potent inhibitor with an IC 50 (half-maximal inhibitory concentration) value of 1.55 µM (against Z-Phe-Arg-MCA substrate) acting in an uncompetitive inhibition mode. Molecular docking studies provided important information on the interaction of the inhibitor with the enzyme showing that these quinoline derivatives can play an important role as CatK inhibitors.
Zeitschrift für Naturforschung B, 2005
The stems of Pilocarpus grandiflorus have afforded the new imidazole alkaloid 4,6-dehydro- 1,2,4,... more The stems of Pilocarpus grandiflorus have afforded the new imidazole alkaloid 4,6-dehydro- 1,2,4,5-tetrahydro-2,5-dioxopilocarpine in addition to the 17 known compounds germanicol, β - amiryn, ocotillone, stigmast-4-en-3-one, 3β -hydroxy-stigmast-5-en-7-one, 6β -hydroxy-stigmast-4- en-3-one, β -sitosterol, scopoletin, 3-(1’,1’-dimethylallyl)-scopoletin, elisin, dictamine, 4-methoxy-2- quinolone, platydesmine, syringaresinol, syringaldehyde, syringic acid and vanillic acid. Their structures were elucidated on the basis of chemical and spectroscopic evidence. The phenolic compounds vanillic acid and syringaldehyde and the furoquinoline alkaloid platydesmine exhibited antifungal activity against Leucoagaricus gongylophorus, the symbiotic fungus of leaf-cutting ants (Atta sexdens rubropilosa).
Molecules, 2018
A high performance liquid chromatography (HPLC) method was developed for the simultaneous isolati... more A high performance liquid chromatography (HPLC) method was developed for the simultaneous isolation, on a semi-preparative scale, of chavibetol and methyleugenol from the crude essential oil of P. pseudocaryophyllus leaves. The purity of the isolated compounds and their quantifications were developed using GC/FID. Chavibetol was isolated with high purity (98.7%) and mass recovery (94.6%). The mass recovery (86.4%) and purity (85.3%) of methyleugenol were lower than those of chavibetol. Both compounds were identified on the basis of spectral analysis. The results suggest that the method can provide chavibetol with high purity, mass recovery, and productivity from crude essential, which will be used in bioassays against stored insect pests.
Journal of the Brazilian Chemical Society, 2016
A methanol-soluble fraction of the dichloromethane extract from the culture broth of A. alternata... more A methanol-soluble fraction of the dichloromethane extract from the culture broth of A. alternata AT4303 strain afforded the following five known mycotoxins: alternariol, alternariol monomethyl ether, altenusin, altenuene and altertoxin I. A hexane-soluble fraction of the dichloromethane extract yielded the steroids ergosterol and ergosterol peroxide, and alternariol monomethyl ether. The concentrated ethyl acetate extract afforded the nucleoside uridine, uracil and inosine. The micro-extracts obtained from this strain in solid media were analyzed using liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS), and the following five known toxins were identified: ACTG-C, D, E and F and AK-toxin II. The major toxins produced by the tangerine pathotype ACT-toxins appear to be absent in strain AT4303. However, the low concentration of ACT-toxins appears to be responsible for their lack of detection in this study. Some compounds isolated from citrus plants were tested for in vitro activity against this strain. The results indicated that 17.3 µM apigenin-7-O-rutinoside inhibited by 80% conidial germination and appressorium development.
Molecules, 2014
Previous investigations of H. oreadica reported the presence of a wide spectrum of complex limono... more Previous investigations of H. oreadica reported the presence of a wide spectrum of complex limonoids and dihydrocinnamic acids. Our interest in the Rutaceae motivated a reinvestigation of H. oreadica, H. brasiliana and H. superba searching for other secondary metabolites present in substantial amounts for taxonomic analysis. In a continuation of the investigation of the H. oreadica, three new limonoids have now been isolated 9α-hydroxyhortiolide A, 11β-hydroxyhortiolide C and 1(S*)-acetoxy-7(R*)-hydroxy-7deoxoinchangin. All the isolated compounds from the Hortia species reinforce its position in the Rutaceae. With regard to limonoids the genus produces highly specialized compounds, whose structural variations do not occur in any other member of the Rutaceae, thus, it is evident from limonoid data that Hortia takes an isolated position within the family. In addition, H. superba afforded the unexpected coumarin 5-chloro-8-methoxy-psoralen, which may not be a genuine natural product. Solid-state cross-polarisation/magic-anglespinning 13 C nuclear magnetic resonance, X-Ray fluorescence and Field-emission gun scanning electron microscopy experiments show that the Sephadex LH-20 was modified after treatment with NaOCl, suggesting that when xanthotoxin (8-methoxy-psoralen) was extracted from cleaning of the gel column, chlorination of the aromatic system occurred.
Zeitschrift für Naturforschung C, 2009
Six mexicanolide limonoids isolated from the dichloromethane extract of the fruits of Cipadessa f... more Six mexicanolide limonoids isolated from the dichloromethane extract of the fruits of Cipadessa fruticosa Blume (Meliaceae) were evaluated against Spodoptera frugiperda (J. E. Smith). Gedunin was used as a positive control. When incorporated into an artificial diet of neonates at 50.0 mg kg-1, febrifugin A showed 73.3% mortality. All the compounds showed moderate insecticidal activity, except for ruageanin A, when compared with the control. Febrifugin also showed growth inhibition and antifeedant activities (at 100.0 mg kg-1). The correlation between the insecticidal activity of the isolated compounds and their chemical structure was discussed.
BioAssay, 2010
Actvity of Cedrela fissilis and Cipadessa fruticosa (Meliaceae) against Spodoptera frugiperda (J.... more Actvity of Cedrela fissilis and Cipadessa fruticosa (Meliaceae) against Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) ABSTRACT-The biological activity of organic extracts of leaves, branches and fruits of Cedrela fissilis and Cipadessa fruticosa (Meliaceae), besides stems and roots of C. fissilis was evaluated against Spodoptera frugiperda (J.E. Smith), maintained in laboratory conditions. The organic extracts (at 1000 mg kg-1) were incorporated into an artificial diet and offered to S. frugiperda during its larval period. It was evaluated the duration and the mortality of larval and pupal periods and pupae weight. The results showed that the dichromethane extract of leaves of C. fissilis was the more active one. It was observed the prolongation of the larval phase, followed by the reduced pupal weight, besides larval mortality of 63,3%.
Revista Brasileira de Farmacognosia, 2006
Química Nova, 2005
SESQUITERPENES FROM THE STEM OF Pilocarpus riedelianus AND ANTIMICROBIAL ACTIVITY. Pilocarpus rie... more SESQUITERPENES FROM THE STEM OF Pilocarpus riedelianus AND ANTIMICROBIAL ACTIVITY. Pilocarpus riedelianus was studied in order to obtain compounds with activity against fungi and bacteria. The dichloromethane extract, the most active one, was chromatographed yielding hexane and dichloromethane fractions. Six known sesquiterpenes, α-calacorene, β-calacorene, γ-calacorene, cadalene, sesquichamaenol and 1-hydroxy-1,3,5-bisabolatrien-10-one were identified in the hexane fractions. The identification of these compound was done by NMR and GC/MS analyses. The hexane fraction from the dichloromethane extract showed activity against several fungi and bacteria.
Química Nova, 2014
CHEMICAL CONSTITUENTS OF THE STEM BARK OF Vochysia thyrsoidea POHL. (VOCHYSIACEAE) AND EVALUATION... more CHEMICAL CONSTITUENTS OF THE STEM BARK OF Vochysia thyrsoidea POHL. (VOCHYSIACEAE) AND EVALUATION OF THEIR CYTOTOXICITY AND INHIBITORY ACTIVITY AGAINST CATHEPSINS B AND K. A new flavonoid, catechin-3-O-(3"-O-trans-cinnamoyl)-α-rhamnopyranoside, along with known compounds, catechin-3-O-α-rhamnopyranoside, 3-oxo-urs-12en-28-oic acid, 2,4,6-trimethoxybenzoic acid, 2-butyl-D-fructofuranoside and 1-butyl-D-fructofuranoside, has been isolated from the stem bark of V. thyrsoidea. These compounds were assayed for inhibition of protease activity (cathepsins B and K) and against cancer cell lines. Catechin-3-O-(3"-O-trans-cinnamoyl)-α-rhamnopyranoside showed moderate inhibitory activity (IC 50 = 62.02 µM) against cathepsin B while 2-butyl-D-fructofuranoside was the most potent against a strain of CNS (SF-295) and human leukemia (HL-60) with IC 50 = 36.80 µM and IC 50 = 25.37 µM, respectively.
Química Nova, 2008
NEW PYRANOFLAVONES AND TRYPANOCIDAL ACTIVITY OF COMPOUNDS ISOLATED FROM Conchocarpus heterophyllu... more NEW PYRANOFLAVONES AND TRYPANOCIDAL ACTIVITY OF COMPOUNDS ISOLATED FROM Conchocarpus heterophyllus. The phytochemical investigation of trypanocidal extracts from leaves and stems of Conchocarpus heterophyllus (A. St.-Hil.) Kallunki & Pirani (Rutaceae) afforded new pyranoflavones along with the known compounds flavone, 7-methoxyflavone, 5-hydroxyflavone, haplotusine, 1-methyl-2-phenyl-4-quinolone alkaloid, β-sitosterol, stigmasterol, and β-sitosteryl benzoate. Their structures were established based on their spectral data. NMR data for the alkaloid haplotusine and the new pyranoflavones are described for the first time herein. These compounds were assayed on the tripomastigote forms of Trypanosoma cruzi. Among them, haplotusine and 1-methyl-2-phenyl-4-quinolone showed moderate values of IC 50 136.9 and 144.9 µM, respectively.
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Papers by Paulo Cezar Vieira