Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico / Este trabalho relata o estudo quÃmico dos constituintes nÃo-volÃteis de duas espÃcies do gÃnero Erythroxylum: Erythroxylum barbatum O. E. Schulz e Erythroxylum amplifolium (Mart.) O. E. Schulz (Erytrhoxylaceae) e o estudo dos constituintes volÃteis de Croton sonderianus Muell. Arg (Euphorbiaceae). A investigaÃÃo fitoquÃmica do lenho do caule, cascas do caule, raÃzes e folhas de Erythroxylum barbatum resultou no isolamento de quatorze compostos micromoleculares: -sitosterol, devadarool, erythroxytriol Q, a mistura dos glicosÃdeos de -sitosterol e estigmasterol, erythroxylisina A, erythroxylisina B, procesterol, erythroxydiol X, ent-11-acetoxi-devadarano-15-16-diol, ent-rosan-1-ona-5-15-16-triol, friedelina, estigmast-4-en-3-ona, triacontanol e palmitato de -amirila. O estudo dos constituintes nÃo-volatÃis das folhas de Erythroxylum amplifolium resultou no isolamento de quatro micromolÃculas: Palmitato de -amirila, quercetina, quercetina-3-O--LrhamnopiranosÃdeo e linolenato de etila. Em adiÃÃo foi realizado o estudo da variabilidade de quimiotipos de espÃcimens de Croton sonderianus dentro de uma populaÃÃo, a partir da anÃlise dos constituintes volÃteis do Ãleo essencial das folhas foram identificados trinta e cinco constituintes e um total de oito quimiotipos para esta espÃcie: CS-A biciclogermacreno/marmelerin; CS-B biciclogermacreno/-felandreno; CS-C biciclogermacreno/mirceno; CS-D curzereno; CS-E biciclogermacreno/-pineno; CS-F espatulenol/1,8-cineol; CS-G guaiazuleno/Z-calameneno; e CS-H espatulenol/-cariofileno. TÃcnicas espectroscÃpicas, tais como, IV, EM, Raio X, RMN 1D e 2D e comparaÃÃo com dados da literatura foram utilizados para a determinaÃÃo estrutural dos constituintes nÃo volÃteis. Os constituintes volÃteis foram identificados por CG/EM, comparaÃÃo dos Ãndices de Kovat corrigidos e espectros de massa em espectroteca, seguida de comparaÃÃo visual com dados da literatura. / This work describes the chemical study of the non volatile constituents of two species of Erythroxylum genus: Erythroxylum barbatum O. E. Schulz and Erythroxylum amplifolium (Mart.) O. E. Schulz (Erythroxylaceae) and the study of the volatile constituents of Croton sonderianus Muell. Arg. (Euphorbiaceae). Phytochemical investigations of the trunk heartwood, stem, roots and leaves of Erythroxylum barbatum yielded fourteen compounds: -sitosterol, -sitosterol and stigmasterol glucosides, devadarool, erythroxytriol Q, erythroxylisin A and erythroxylisin B, procesterol, erythroxydiol X, ent-11-acethoxydevadaran-15,16-diol, ent-rosan-1-one-5-15,16-triol, friedelin, stigmast-4-en-3-one, triacontanol and -amyril palmitate. The study of the non volatile constituents of Erythroxylum amplifolium yielded four compounds: -amyril palmitate, quercetin-3-O--rhamnopyranoside and ethyl linolenate. In addition, the study of the variability of chemotypes of Croton sonderianus specimens from the analyses of volatile constituents of the essential oil from the leaves was accomplished. In this work were identified thirty five constituents and eight chemotypes: CS-A bicyclogermacrene/marmelerin; CS-B bicyclogermacrene/-phellandrene; CS-C bicyclogermacrene/myrcene; CS-D curzerene; CS-E bicyclogermacrene/-pinene; CS-F spathulenol/1,8-cineole; CS-G guaiazulene/Z-calamenene; CS-H spathulenol/-caryophyllene. The structural characterization of the non volatile constituents was made by spectrometric methods as IV, MS, X-ray, NMR 1D and 2D and comparison with the literature data. The volatile constituents were identified by comparing their mass spectra with those of the spectrometer data base using the Wiley L-built library, and two computer library MS search based on their Kovatâs retention indices as a preselection routine, and comparison of the fragmentation pattern with published spectral data.

<p>Within this doctoral thesis, eighteen new compounds, polycyclic polyprenylated<br />acylphloroglucinols, were isolated from petrol ether extract of <em>Hypericum barbatum</em><br />plant. The compounds are named hyperibarbins A&ndash;R. For hyperibarbins A&ndash;D,<br />cytotoxicity towards carcinogenic cells and antibacterial activity were evaluated. All<br />four compounds exhibited intermediate activity towards tumor cells in vitro. Although<br />inactive towards Gram negative bacteria, examined compounds have expressed<br />extraordinary bacteriostatic activity towards Gram positive bacterial strains.<br />Hyperibarbins C, E, N and K were, since having endoperoxide bridge in their structures,<br />tested for antiprotozoal activity, but shown intermediate activity towards the examined<br />parasite strains. All goals set for this doctoral thesis at the beginning have been fully<br />met, with isolation of new compounds, described andcompletely chemically<br />characterized for the first time.</p> / <p>U okviru ove doktorske disertacije izolovano je osamnaest novih jedinjenja, policikličnih&nbsp; poliprenilovanih acilfloroglucinola, iz petroletarskog ekstrakta biljke <em>Hypericum&nbsp; barbatum</em>. Imena jedinjenja su hiperibarbini A&ndash;R. Za hiperibarbine A&ndash;D, ispitana je&nbsp; citotoksičnost prema kancerogenim ćelijama i antibakterijska aktivnost. Sva četiri&nbsp; jedinjenja su ispoljila srednju aktivnost prema tumorskim ćelijama <em>in vitro</em>.&nbsp; Iako neaktivni&nbsp; prema Gram negativnim bakterijama, ispitana jedinjenja su ispoljila izuzetnu bakteriostatsku aktivnost prema sojevima Gram pozitivnih bakterija. Hiperibarbini C, E, N i K su, zbog posedovanja endoperoksidnog prstena u svojoj strukturi, testirana na antiprotozoalnu aktivnost, ali su pokazali srednju aktivnost prema ispitanim sojevima parazita. Svi ciljevi postavljeni na početku izrade ove doktorske disertacije su do kraja ispunjeni, sa izolacijom novih, prvi put opisanih i u potpunosti hemijski okarakterisanih jedinjenja.</p>