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Estudo químico e biossintético de Peperomias / Chemistry and biosynthetic study of Peperomias

O estudo fitoquímico de Peperomia oreophila revelou a presençca de duas lignanas furofurânicas (7R, 8R, 7R, 8R)-3,4,5-trimetóxi-3,4-metilenodioxi-5-metóxi- 8.8,7.O.9,7.O.9-lignana (1), (7R, 8R, 7R, 8R)-3,4,5-trimetóxi-3,4,5-trimetóxi- 8.8,7.O.9,7.O.9-lignana (2); as duas amidas (2E)-N-isobutil-3-(5-metóxi-7,8- benzodioxol-1-il)acrilamida (3), (2E)-N-isobutil-3-(3,4,5-trimetóxifenil)acrilamida (4), três derivados de acido cinâmico (2E)-3-(3,4,5-trimetóxifenil)acrilato de metila (5), (2Z)-3- (3,4,5-trimetóxifenil)acrilato de metila (6), (2E)-3-(5-metóxi-7,8-benzodioxol-1-il)acrilato de metila (7); os dois policetídeos fenólicos [(2E)-3,7-dimetilocta-2,6-dien-1-il]-5- metil-2-(3-metilbut-2-en-1-il)benzeno-1,3-diol (8) (inédita) e [(2E)-3,7-dimetilocta- 2,6-dien-1-il]-2,2,7-trimetil-2H-cromen-5-ol (9); de P. arifolia: o policetídeo fenólico [(2E)-3,7-dimetilocta-2,6-dien-1-il]-5-metil-2-(3-metilbut-2-en-1-il) benzeno-1,3-diol, isolada também de P. oreophila (10) (inédita); de P. urocarpa: o policetídeo fenólico 5- metil-2-[(2E,6E)-3,7,11-trimetildodeca-2,6,10-trien-1-il] benzeno-1,3-diol (11) e o ácido 2,4-dihidróxi-6-metil-3-[(2E,6E)-3,7,11-trimetildodeca-2,6,10-trien-1-il] benzóico, (12); de P. nitida: o fenilpropanoide apiol (1-alil-3,6-dimetóxi-10,11- benzodioxol) (13), os cromenos 7-hidróxi-2,2,5-trimetil-2H-cromeno-carboxilato de metila (14) e o 7-metóxi-2,2,5-dimetil-2H-cromeno-6-carboxilato de metila (15). O policetídeo 2-hidróxi-4,6-dimetóxiacetofenona, principal metabólito das folhas de P. glabella, teve sua biossíntese investigada utilizando-se como precursores o acetil-CoA e o malonil-CoA. Foram realizados estudos de otimização da atividade de policetídeo sintase (PKS) em função do pH, tempo de reação, temperatura e saturação de substratos, além de estudos da variação circadiana. Estudos de genes de PKS resultaram em amplificações cujo seqüenciamento poderá determinar a identidade dessas regiões e homologia entre as seqüências dessas Peperomias e a região KS do gene AviM de Streptomyces viridochromogenes que expressa o ácido orselínico / The phytochemical investigation carried out on Peperomia oreophila revealed the accumulation of two furofuran lignans (7R,8R,7R,8R)-3,4,5-trimethoxy-3,4- methylenedioxy-8.8, 7.O.9, 9.O.7-lignan (1), (7, 8R, 7R, 8)-3,4,5-trimethoxy-3,4,5- trimethoxy-8.8-7.O.9, 9.O.7-lignan (2); two amides (2´E)-N-isobutyl-3´-(5-methoxy-7,8- benzodioxol-1-yl) acrylamide (3), (2E)-N-isobutyl-3-(3,4,5-trimethoxyphenyl)acrylamide (4), three derivate cinâmic acid methyl (2E)-3-(3,4,5-trimethoxyphenyl)acrylate (5), methyl (2Z)-3-(3,4,5-trimethoxyphenyl)acrylate (6), methyl (2E)-3-(5-methoxy-7,8- benzodioxol-1-yl)acrylate (7); two phenolic polyketides [(2E)-3,7-dimethylocta-2,6- dien-1-yl]-5-methyl-2-(3-methylbut-2-en-1-yl)benzene-1,3-diol (8) (novel), [(2´E)-3´,7´- dimethylocta-2´,6´-dien-1-yl]-2,2,7-trimethyl-2H-chromen-5-ol (9); P. arifolia, two phenolic polyketide [(2E)-3,7-dimethylocta-2,6-dien-1-yl]-5-methyl-2-(3-methylbut-2- en-1-yl)benzene-1,3-diol, also isolated from P. oreophila (10) (novel); P. urocarpa, the two phenolic polyketides 5-methyl-2-[(2E,6E)-3,7,11-trimethyldodeca-2,6,10-trien-1- yl]benzene-1,3-diol (11) and 2,4-dihydroxy-6-methyl-3-[(2E,6E)-3,7,11-trimethyldodeca- 2,6,10-trien-1-yl]benzoic acid (12); P. nitida, the phenylpropanoid apiole 1-allyl-3,6- dimethoxy-10,11-benzodioxole (13); the chromenes methyl 7-hydroxy-2,2,5-trimethyl- 2H-chromene-6-carboxylate (14) and methyl 7-methoxy-2,2,5-trimethyl-2H-chromene-6- carboxylate (15). The polyketide 2-hydroxy-4,6-dimethoxyacetophenone, the major compound in P. glabella leaves, had its biosynthetic origin investigated using acetyl-CoA and malonyl-CoA as precursors. The enzymatic activity of polyketide synthase was optimized to pH, incubation time, temperatures and substrate saturation, in addition to the analysis of circadian variation activity. The amplifications of putative PKS genes was based on primers from AviM gene of Streptomyces viridochromogenes that express for orsellinic acid. The sequencing will enable the identification of such regions and also to study the homology to fungi PKS

Identiferoai:union.ndltd.org:usp.br/oai:teses.usp.br:tde-10122009-090951
Date13 October 2009
CreatorsMalquichagua Salazar, Karina Josefina
ContributorsKato, Massuo Jorge
PublisherBiblioteca Digitais de Teses e Dissertações da USP
Source SetsUniversidade de São Paulo
LanguagePortuguese
Detected LanguageEnglish
TypeTese de Doutorado
Formatapplication/pdf
RightsLiberar o conteúdo para acesso público.

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