Stilbenes from Deguelia rufescens var. urucu (Ducke) A. M. G. Azevedo leaves: effects on seed germination and plant growth

Abstract

A biodiversidade Amazônica pode ser uma fonte de substâncias capazes de serem utilizadas no controle de plantas daninhas. Neste estudo relatamos o isolamento e a identificação de cinco estilbenos a partir das folhas do "timbó vermelho" (Deguelia rufescens var. urucu): 4-metoxilonchocarpeno (1); 3,5-dimetoxi-4′-hidroxi-3′-prenil-trans-estilbeno (2), lonchocarpeno (3), 3,5-dimetoxi-4′-O-prenil-trans-estilbeno (4) e pteroestilbeno (5). As substâncias 2 e 4 são novos produtos naturais, porém 2 já havia sido citada como produto de síntese. Foi avaliada a potencial atividade alelopática de 1, 2 e 4 sobre a germinação de sementes e o crescimento da planta daninha Mimosa pudica. Os efeitos observados sobre a germinação das sementes de M. pudica não variaram significantemente (p > 0,05) quando a análise da fitotoxidade foi realizada com as substâncias isoladamente, cuja inibição máxima não ultrapassou 20%. A inibição mais intensa, quanto ao desenvolvimento da radícula e do hipocótilo, foi encontrada para o composto 4 (p < 0,05). Isoladamente, 4 causou efeito inibitório significativamente maior (p < 0,05) no desenvolvimento da radícula e do hipocótilo, do que 1 e 2. Quando testados aos pares, apresentaram antagonismo para a germinação de sementes e sinergismo para o desenvolvimento da radícula e hipocótilo.The Amazon biodiversity may provide plants whose chemical substances are capable of controlling weeds. In this study we report the isolation and identification of five stilbenes from the leaves of "timbó vermelho" (Deguelia rufescens var. urucu): 4-methoxylonchocarpene (1); 3,5-dimethoxy-4′-hydroxy-3′-prenyl-trans-stilbene (2), lonchocarpene (3), 3,5-dimethoxy-4′-Oprenyl-trans-stilbene (4) and pterostilbene (5). Compounds 2 and 4 are new natural products although 2 has been previously cited as synthesis product. Potential allelopathic activity for 1, 2 and 4 was evaluated over seed germination and plant growth of Mimosa pudica weed. The observed effects on seed germination did not vary significantly (p > 0.05) when the analysis of phytotoxicity was performed with the substances alone, the maximum inhibition did not exceed 20%. The most intense inhibitions on radicle and hypocotyl development were found for compound 4 (p < 0.05). When tested in pairs, showed antagonism for seed germination and synergism for radicle and hypocotyl development.

New Leishmanicidal Stilbenes from a Peruvian Folk Medicine, <i>Lonchocarpus nicou</i>

“…Other isolated leishmanicidal compounds were determined to be 3,5-dimethoxy-4′-hydroxy-3′-prenyl-transstilbene (3), 15) 3,5-dimethoxy-4′-O-prenyl-cis-stilbene (4), 16) 3,5-dimethoxy-4′-O-prenyl-trans-stilbene (5), 16) rotenolone (12-hydroxyrotenone) (6) 17) and tephrosin (7), 18) as shown in Fig. 2, based on a comparison of their spectra to those in the literature.…”

Stilbenoids from Leguminosae and their Bioactivities

“…Currently, Marques reported that 18 stilbenes (98-115) and their derivatives had been isolated Minireview from the Deguelia genus. [44][45][46][47][48][49][50][51] New prenylated stilbene derivatives, 3-hydroxy-4-prenyl-5-methoxy-stilbene acid (116) and 5,4'-dihydroxy-3methoxy-2-prenyl-stilbene (117) had been isolated from methanol extract of Cajanus cajan (L.) Millsp. [52] At present, a number of resveratrol derivatives have been isolated and extracted from peanuts, trans-resvratrol, cis-resveratrol, trans-piced, cis-piceid, arachidin I, arachidin II, arachidin III (118-124), [53] cudrastilbene, 3,5,3'-trihydroxy-4'methoxy-5'-isopentenylstlbene, arahypin B, arahypin-13, arahypin-14, arahypin-15, arahypin-6, arahypin-7, arahypin-11, arahypin-12 (125-134).…”

Inhibition ofα-Glucosidase and Hypoglycemic Effect of Stilbenes from the Amazonian PlantDeguelia rufescensvar.urucu(Ducke) A. M. G. Azevedo (Leguminosae)

“…The stilbenes, lonchocarpene and DPS isolated from D. rufescens var. urucu [12], induced a potent concentration-dependent inhibition on the activity of α-glucosidase, with pIC 50 values of 5.68 ± 0.12 and 5.73 ± 0.08, respectively, as illustrated in l " Fig. 2.…”

“…1) were recently isolated from the ethanolic extract of the leaves from Deguelia rufescens var. urucu [12], known in the Amazonian region as "timbó vermelho". This vine has long been used by native Indians for fishing.…”

“…Ten-week-old male Swiss mice were kept in an environmentally controlled room with a 12-h light/dark cycle, and allowed free access to water and food. Lonchocarpene (99 % pure) and DPS (87 % pure) were obtained as previously described [12]. The purity was calculated based on 1 H NMR spectral data.…”