Vanessa Gisele Pasqualotto Severino

Chemical Characterization of Citrus sinensis Grafted on C. limonia and the Effect of Some Isolated Compounds on the Growth of Xylella fastidiosa

Citrus sinensis grafted on C. limonia produces a considerable number of compounds that are not common in both plants developed from germination of seeds. The chemical profile of scion and rootstock differ notably for absence in the form of flavonoids and coumarins containing C5 prenyl groups attached to the carbon atoms of aromatic and heterocyclic systems or to oxygen. Only linear pyranocoumarins xanthyletin and xanthoxyletin were found in scion. This observation indicates that the prenylated compounds once biosynthesized in the roots could have been translocated to other organs. Xylella fastidiosa colonizes the xylem of plants causing diseases on several economically important crops such as citrus variegated chlorosis (CVC). A number of flavonoids, coumarins, alkaloids, dihydrocinnamic acid derivative, anacardic acid, triterpenes, and limonoids were tested for in vitro activity on the growth of Xylella fastidiosa. Azadirachtin A was the most active. Hesperidin, which occurs in great amounts in cells of the mesophyll of the affected leaves with CVC, showed a moderate activity suggesting that it can act as a good barrier for small-size colonies from X. fastidiosa.

Isolation of secondary metabolites from Hortia oreadica (Rutaceae) leaves through high-speed counter-current chromatography.

High-speed counter-current chromatography (HSCCC) with a two-phase solvent system (hexane-ethanol-acetonitrile-water 10:8:1:1, v/v) was applied to examine the leaves of Hortia oreadica, which afforded the known limonoid guyanin (1), the alkaloids rutaecarpin (2) and dictamnine (6), the dihydrocinnamic acid derivatives methyl 5,7-dimethoxy-2,2-dimethyl-2H-1-benzopyran-6-propanoate (3), 5,8-dimethoxy-2,2-dimethyl-2H-1-benzopyran-6-propanoic acid (4), together with the new E-3,4-dimethoxy-alpha(3-hydroxy-4-carbomethoxyphenyl)cinnamic acid (5). The recovery of compounds 1-6 was determined by comparison with LC-atmospheric pressure chemical ionization MS/MS data: 66.2%, 93.1%, 102.5%, 101.2%, 99.0% and 84.9%, respectively. Compound 3 showed IC(50) of 23.6microM against Plasmodium falciparum and 15.6microM against Trypanosoma brucei rhodesienses and was not toxic to KB cells (IC(50)>100microM).

Evaluation of Effect of Triterpenes and Limonoids on Cell Growth, Cell Cycle and Apoptosis in Human Tumor Cell Lines

Six triterpenes and eight limonoids were evaluated for their capacity to inhibit the growth of three human tumour cell lines, breast adenocarcinoma (MCF-7), non-small cell lung cancer (NCI-H460) and melanoma (A375-C5). The mechanisms involved in the observed cell growth arrest of the four most potent compounds were carried out by studying their effect in cell cycle profile and programmed cell death. The results showed that one triterpene (odoratol) and two limonoids (gedunin and cedrelone) caused cell cycle arrest while only the limonoids gedunin and cedrelone were found to be very potent inducers of apoptosis.

Determination of the antibacterial activity of crude extracts and compounds isolated from Hortia oreadica (Rutaceae) against oral pathogens

Extracts from Hortia oreadica afforded four dihydrocinnamic acid derivatives, isolated from the n-hexane extract, as well as limonoid guyanin and the furoquinoline alkaloid dictamnine, both isolated from the dichloromethane extract. The extracts and the isolated compounds were tested against some oral pathogens, so as to investigate their antibacterial activity. The results showed that the n-hexane extract and the compound dictamnine are the most active against the selected microorganisms.

Structure and Absolute Configuration of Diterpenoids from Hymenaea stigonocarpa

Chemical investigations of the ethanolic extracts from the flowers and leaves of Hymenaea stigonocarpa Mart. ex Hayne afforded one new ent-halimane diterpenoid, 18-hydroxy-ent-halima-1(10),13-(E)-dien-15-oic acid (1), together with five known compounds (2-6). The structural elucidation was performed by means of NMR (COSY, HSQC, HMBC, and NOESY) and MS analyses. Complete (1)H and (13)C NMR data assignments are also reported for labd-13-en-8β-ol-15-oic (2) and labd-7,13-dien-15-oic (3) acids. The absolute configurations of 1 and 2 were established by comparison of experimental and calculated Raman optical activity spectra.

Cyclopropane- and spirolimonoids and related compounds from Hortia oreadica

The dichloromethane extract from taproots of Hortia oreadica afforded six limonoids, these are 9,11-dehydro-12α-acetoxyhortiolide A, hortiolide C, 11α-acetoxy-15-deoxy-6-hydroxyhortiolide C, hortiolide D, hortiolide E, 12β-hydroxyhortiolide E, in addition to the known limonoid, guyanin. The dichloromethane extract from stems of H. oreadica also afforded two limonoids 9,11-dehydro-12α-hydroxyhortiolide A and 6-hydroxyhortiolide C. As a result of this study and literature data, Hortia has been shown to produce highly specialized limonoids that are similar to those from the Flindersia (Flindersioideae). The taxonomy of Hortia has been debatable, with most authors placing it in the Toddalioideae. Considering the complexity of the isolated limonoids, Hortia does not show any close affinity to the genera of Toddalioideae. That is, the limonoids appear to be of little value in resolving the taxonomic situation of Hortia.

NEW DEGRADED QUINONE DITERPENOID FROM THE STEMS OF Byrsonima coccolobifolia Kunth. (Malpighiaceae)

Lorena R. F. de Sousaa,b, Marcos H. F. Santosb, Vanessa G. P. Severinob,c, Richele P. Severinob, Paulo C. Vieiraa,* aDepartamento de Química, Universidade Federal de São Carlos, 13565-905 São Carlos – SP, Brazil. bUnidade Acadêmica Especial de Química, Universidade Federal de Goiás – Regional Catalão, 75704-020 Catalão – GO, Brazil. cInstituto de Química, Universidade Federal de Goiás – Regional Goiânia, 74690-900 Goiânia – GO, Brazil. Correspondig author e-mail: dpcv@ufscar.br

Antiulcerogenic activity of species Annona coriacea Mart. and Spiranthera odoratissima A. St. Hil

Background: Medicinal plants from the Brazilian Cerrado are used in folk medicine to treat several diseases such as gastric disorders.

Identificação Estrutural e Avaliação Antioxidante de Compostos Fenólicos Isolados de Eriotheca pubescens (malvaceae)

Eriotheca pubescens is a species of the Malvaceae family and is found in areas of Cerrado, popularly known as the cerrado paineira. Previous phytochemical investigations of Malvaceae species describe the isolation of fatty acids, essential oils, sesquiterpenoids of cadinene-type, sesquiterpenelactones, triterpenoids and flavonoids, among many other compounds. There are no previous chemical studies on E. pubescens and than the present study aimed to carry out the chemical study of the ethanol extract of the stem of this species in the isolation, purification and characterization of secondary metabolites, and evaluation of the antioxidant capacity of the isolated compounds. The study has isolated and identified five phenolics compounds, of which four of derivatives of benzoic acid, p-hydroxybenzoic acid (I), 3,4-diidroxibenzoico acid (II), 4-hydroxy-3,5dimethoxybenzoic acid (III), 3-methoxy-4hydroxybenzoic acid (IV) and the flavonol quercetin (V).