Gerardo Magela Vieira Júnior

Casearin X, Its Degradation Product and Other Clerodane Diterpenes from Leaves of Casearia sylvestris: Evaluation of Cytotoxicity against Normal and Tumor Human Cells

An EtOH extract of the leaves of Casearia sylvestris afforded new clerodane diterpene, casearin X, together with the known compounds casearins B, D, L, and O, and caseargrewiin F. Casearin X degraded to the corresponding dialdehyde when stored in CDCl3. The diterpenes isolated were cytotoxic to human cancer cell lines, with caseargrewiin F being the most active and the new clerodane, casearin X, the second active compound with IC50 values comparable to the positive control doxorubicin. All isolated diterpenes showed lower activities against normal human cells than against cancer cell lines, which might indicate a possible selective action on cancer cells. Casearin X dialdehyde was not cytotoxic to cancer cells indicating that the occurrence of these CO groups at C(18) and C(19) is incompatible with the cytotoxic activity.

Resina de Protium heptaphyllum: isolamento, caracterização estrutural e avaliação das propriedades térmicas

Three mixtures of triterpenes (maniladiol and breine; a and b-amyrin; lupenone, a and b-amyrinone) were isolated from Protium heptaphyllum March resin. The structural identification was based on NMR and mass spectrometry data. Lupenone, and a and b-amyrinone were not reported before as constituents of this resin. The resin was submitted to methylation and acetylation reactions. The pure and derivatized resins and the mixtures (maniladiol and breine; a and b-amyrin) were analyzed by TG and DSC. The TG curves revealed that the derivatization decreases the thermal stability of the resin. The DSC curves showed peaks that can be assigned to evaporation and phase transitions processes.

Cytotoxic clerodane diterpenoids from Casearia obliqua.

A crude bioactive EtOH extract of the twigs of Casearia obliqua afforded two new clerodane diterpenes, caseobliquins A (1) and B (2). Additionally, bioactivity-directed fractionation on a bioactive hexane extract of the leaves from this species led to the isolation of the known clerodane diterpenes rel-6beta-hydroxyzuelanin-2beta-benzoate and rel-2alpha-hydroxyzuelanin-6beta-benzoate (3 and 4) as a mixture and 2beta-hydroxyzuelanin-6beta-cinnamate (5). The structures of the new clerodanes 1 and 2 were established on the basis of their 1D and 2D NMR spectroscopic data, and the new compound 1 and the known substance 5 had their absolute configurations determined by circular dichroism spectroscopy. The cytotoxicity of several of the compounds isolated was evaluated against a small panel of human tumor cell lines.

TERPENOS E ÁCIDOS GRAXOS DE Dipteryx lacunifera Ducke

This paper describes the isolation of the furanocassane-type diterpene, named vinhaticoic acid, along with b-farnesene and spatulenol from fruit shells of D. lacunifera. Structural determinations were accomplished by chemical derivatization and spectral analysis, including 1D and 2D NMR and X-ray crystallography. The fatty portion was extracted from the fruit kernels, transesterfied and analysed by HRGC/MS. Oleic acid (75.8 ± 4.3%) was the major component. Essential oil extracted from the fruit shells of D. lacunifera was analysed by HRGC/MS and nine sesquiterpenes were identified; b-farnesene (48.6%) and spatulenol (21.61%) were the major constituents.

Constituintes químicos e atividade antioxidante de extratos das folhas de Terminalia fagifolia Mart. et Zucc

Phytochemical investigation of ethanolic leaves extracts of T. fagifolia led to the isolation of (+)-catechin, sitosterol-3-O-β-D-glucopyranoside, α- and β-tocopherol, a mixture of lupeol, α- and β-amyrin, sitosterol and a mixture of glicosid flavonoids (CP-13). The structures of these compounds were identified by 1H and 13C NMR spectral analysis and comparison with literature data. Absolute configuration of the catechin was determinate by circular dichroism. Antioxidant activity (EC50), evaluated by 2,2-diphenyl-1-picrylhidrazyl (DPPH) assay system, decreased in the order: (+)-catechin > hydroalcoholic fraction > CP-13 > aqueous fraction > EtOH extract.

Cromatografando em coluna com resina de almécega: um projeto para química orgânica experimental

The use of natural products to demonstrate the silica gel column chromatography technique is proposed in the present article. It describes the separation of the triterpenes a- and b-amirin from the diol breine and maniladiol, obtained from almecega resin (Protium heptaphyllum March.). The experiment uses an accessible material, was accomplished in 4 h, and can be applied with success an the experimental course of organic chemistry for undergraduate students.

Dammarane Triterpenoids from Carnauba, Copernicia prunifera (Miller) H. E. Moore (Arecaceae), Wax

Phytochemical investigation from carnauba (Copernicia prunifera) wax led to the identification of sixteen dammarane-type triterpenes, including thirteen new characterized as: (24R*)-methyldammara-20,25-dien-3α-ol and a mixture of alkyl (24R*)-methyldammar-25-en-20-ol-3β-carboxylates, together with three previously described triterpenes: carnaubadiol, (24R*)-methyldammara-20,25-dien-3β-ol and (24R*)-24-methyldammara-20,25-dien-3-one. Moreover, four fatty alcohols (eicosanol, docosanol, tetracosanol and hexacosanol) as well as four sterols (cholesterol, campesterol, stigmasterol, and sitosterol) were also obtained. These compounds were isolated using classical chromatographic methods and their structures were determined by spectroscopic and chemical methods.

PHENOLIC DERIVATIVES AND ANTIOXIDANT ACTIVITY OF POLAR EXTRACTS FROM Bauhinia pulchella

Adonias Almeida Carvalhoa,b, Lucivania Rodrigues dos Santosb, Ruth Raquel Soares de Fariasb, Mariana Helena Chavesb,*, Chistiane Mendes Feitosab, Gerardo Magela Vieira Júniorb, Mônica Regina Silva de Araújob,e, Paulo Michel Pinheiro Ferreirac and Claudia do Ó Pessoad Diretoria de Ensino, Instituto Federal do Piauí, 64260-000 Piripiri – PI, Brasil Departamento de Química, Universidade Federal do Piauí, 64049-550 Teresina – PI, Brasil Departamento de Biofísica e Fisiologia, Universidade Federal do Piauí, 64049-550 Teresina – PI, Brasil Departamento de Fisiologia e Farmacologia, Universidade Federal do Ceará, 60431-970 Fortaleza – CE, Brasil Instituto de Ciências Exatas da Natureza, Universidade da Integração Internacional da Lusofonia Afro-Brasileira, 62785-000 Acarape – CE, Brasil

Corrigendum to "New steroidal saponins and antiulcer activity from Solanum paniculatum L." [Food Chem. 186 (2015) 160-167].

Mato Grosso Federal University – UFMT – Institute of Natural Humanities and Social Sciences