Caracterização química e transformações de componentes não celulósicos de algumas espécies de Acácia existentes em Portugal

Abstract

Ao longo desta dissertação descreveram-se estudos de caracterização (Parte H), de transformação (Parte Iü) e de avaliação da actividade fungicida (Parte N), de componentes não celulósicos da A. dealbata e A. Iongifolia. A análise qualitativa da composição em voláteis das diferentes amostras, folhas, flores e sementes da A. longifolia e A. dealbata permitiu a identificação, com o recurso a GC-MS, de compostos ainda não identificados no género acácia. Nas três amostras, folhas, flores e sementes de A. Iongifolia foram identificados 25 compostos ainda não identificados no género Acácia e 14 compostos já identificados no género mas não na espécie. Nesta espécie foram identificados os se,pintes monoterpenos: p-pineno, cis-ocimeno, a-felandreno, pcimeno, 3-hijeno-2-01, a-terpineol, p-mirceno e cis-ocimeno. Nas três amostras, folhas, flores e sementes de A. dealbata foram identificados 30 compostos não identificados no género acácia. Na amostra das folhas foram identificados 8 compostos já identificados neste género, mas não na espéae A. dealbata. Nesta espécie foram identificados os seguintes monoterpenos: 3-careno, a-pineno, p-cimeno, cis-ocimeno, $-pineno, tujeno e 1,8-cineol e os sesquiterpenos: aromandendreno e y-muuroleno. O estudo da composição em triterpenos e esteróides dos extractos de hexano e metanol das folhas, flores e sementes de A. dealbaia permitiu o isolamento e caracterização de 12 compostos ainda não identificados nesta espécie e 10 destes ainda não identificados no género acácia. No extracto de hexano das folhas, foram identificados os seguintes compostos: lupenona (117), lupeol (118), 1-metilupeol (119), (22E)-4-metilergosta 7,22-dieno-3$-o1 (120), $-sitosterol (121), 12-(2'-hidroxieti1)lup-20(29)-eno-38-i10 (122) e butirato de 12R-lup-20(29)-eno-3@-ilo(1 24).

This thesis reports several studies on the characterization (Part 11), transformation (Part III) and antifungal activity studies (Part IV) of some noncellulosic components of A. dealbata and A. longifolia. Qualitative analysis of the volatile fraction of the different leaves, flowers and seeds samples from A. longifolia and A. dealbata allowed the identification of several compounds not previously reported in the genus acacia. In the three leaves, flowers and seeds samples from A. longifolia, 25 compounds were identified which had not been previously reported in this genus, and 14 compounds identified in genus acacia but not in this species. In this species the following monoterpenes were identified: p-pinene, a-felandrene, pcimene, 3-thujen-2-01, a-terpineol, $-mirceno and cis-ocimene. In the three leaves, flowers and seeds samples from A. dealbata, 30 compounds were identified not previously reported in this genus. Only in the leaves samples 8 compounds were identified already reported in this genus, although not identified in the species A. dealbata. In this species the following monoterpenes were identified: 3-carene, a-pinene, p-cimene, cis-ocimene, $- pinene, thujene and 1,s-cine01 and the sesquiterpenes: aromandendrene and ymuurolene. The study of the terpenoids composition of the hexane and metanol extracts of leaves, flowers and seeds of the A. dealbata allowed the isolation and identification of 12 compounds not reported in the genus acacia. In the hexane extract of leaves, the following compounds were identified: lupenone (117), lupeol (118), 1-metilupeol (119), (22E)-4-metilergost-7,22-diene-3pAbstract v i 01 (120), $-sitosterol (121), 12-(2'-hydroxieti1)lup-20(29)-en-3P-yl(122)a nd 12R-lup- 20(29)-en-3P-y1 butirate(l24). In the hexane extract of flowers, the following compounds were identified: lupenone (117), lupeol (118) and (22E)-4-metilergost-7,22-diene-3!3-01 (120). In the hexane extract of seeds, the following compounds were identified: lupenone (117), lupenyl palmitate (125) and lupenyl araquidate (126). In the methanol extract of flowers, the following compounds were identified: lup-20(29)-en-3$,28-diol( 68), lupenyl trans-7'-hydroxicinamate (127), lup-7,20(29)-dien-6-one-3$-ytlr ans-7'-hydroxicinamate (128). Chemical transformations of betulina (68), lupeol (118) and P-sitosterol were also studied. Acetilation, epoxidation and reaction with alkynes were tested aiming the production of furanic derivatives. Acetilated, epoxide and AL pirazolines derivatives from compound (68) were also prepared. All the compounds isolated from A. dealbata and synthesised were characterized by spectroscopic techniques (kE, IV, NM.7 of 1H, 13C, 13C coupled with 1H, HETCOR (1H/13C), COSY, DEPT and NOE). Finally, in the Part IV, antifungal activity studies of the different extracts (leaves, flowers and seeds) of A. dealbata, isolated compounds and synthesised compounds are presented.