Isoflavonoid composition and biological activity of extracts from soybean seedlings treated by different elicitors

Abstract

Time-course and dose-response experiments were carried out to establish the ability for synthesizing isoflavonoids of soybean seedlings (cv. Soyica P34) treated with salicylic (SA) and isonicotinic acids (INA). Then, 25 structurally-related compounds were evaluated for their isoflavonoid-eliciting activity. Next, the antimicrobial and antioxidant activities of EtOAc-soluble fraction from soybean seedlings treated with some synthetic elicitors were determined. Results showed that the concentration of isoflavonoids in soybean seedlings was significantly increased by the application of SA and INA. The major isoflavonoids detected were the malonyl-glycosidic isoflavones, followed by genistin and daidzin. The isoflavone aglycones (genistein, daidzein, and formononetin), coumestrol and glyceollins were found in lower concentrations. Maximum accumulation of glyceollins was detected after 48 and 144 h in soybean seedlings treated with 1.6 mM INA and SA, respectively. EtOAc-extracts from soybean seedlings treated with two structurally-related compounds to INA displayed a significant antimicrobial and antioxidant activity. Therefore, INA, SA and structurally-related compounds can be used to increase the amounts of natural antioxidant or antimicrobial compounds in soybean, either to protect the plant directly against pathogens or as a natural source for subsequent isolation of isoflavonoids or bioactive extracts, which have potential application in functional foods or pharmaceutical and personal care products.

Elicitation of isoflavonoids in Colombian edible legume plants with jasmonates and structurally related compounds

“…Defense-related isoflavonoids were previously identified by different methods: genistein, 2 0 -hydroxygenistein, dalbergioidin, coumestrol, phaseollin, phaseollidin, and phaseollinisoflavan were purified and confirmed by mass and NMR spectra (Durango et al, 2002(Durango et al, , 2013. In addition, the identification of daidzein, genistein, genistin, and daidzin was verified by co-elution of HPLC-DAD peaks with authentic samples (Durango et al, 2018) on a Shimadzu chromatograph (LC-20AT) equipped with a diode array detector (SPD-20AT, Prominence), and the same chromatographic conditions as described above (Section 2.5). Compounds 6 00 -O-malonyl-genistin, 6 00 -O-malonyl-daidzin, and glyceollins were also previously confirmed by liquid chromatography with mass spectrometry (LC-MS) according to Durango et al (2018).…”

“…Five working solutions were prepared for genistein, genistin, daidzin, daidzein, dalbergioidin, 2 0 -hydroxygenistein, coumestrol, and phaseollin in ethanol at 1, 10, 25, 50, and 100 mg/L. Due to genistin and daidzin show molar extinction coefficients like those of the malonyl-conjugates (Durango et al, 2018), the standard curves of genistin and daidzin were used for quantifying the malonyl conjugates and adjusted for molecular weight differences. The concentration of glyceollins was calculated from the total area of peaks for the four isomers, by interpolation in the calibration curve for phaseollin (a structurally related pterocarpan).…”

“…The regression equations were: genistein, Y ¼16164X -46085 (R 2 of 0.9703); dalbergioidin, Y ¼ 5.0x10 7 X -39883 (R 2 of 0.9970); daidzein, Y ¼ 159171X þ 146477 (R 2 of 0.9881); genistin, 16164X -46085 (R 2 of 0.9703); daidzin, Y ¼ 159171X þ 146477 (R 2 of 0.9881); coumestrol, Y ¼ 5.0x10 6 X þ 76532 (R 2 of 0.9651); 2 0 -hydroxygenistein, Y ¼ 8.0x10 7 X -17193 (R 2 ¼ 0.9985), and phaseollin, Y ¼ 106380X þ 414987 (R 2 of 0.9684). Data for each peak were recorded using the wavelength that provides a maximum response (Durango et al 2013(Durango et al , 2018. The results were expressed as μg isoflavonoid/g fresh material and presented as mean values AEstandard deviation.…”

“…In addition, the identification of daidzein, genistein, genistin, and daidzin was verified by co-elution of HPLC-DAD peaks with authentic samples (Durango et al, 2018) on a Shimadzu chromatograph (LC-20AT) equipped with a diode array detector (SPD-20AT, Prominence), and the same chromatographic conditions as described above (Section 2.5). Compounds 6 00 -O-malonyl-genistin, 6 00 -O-malonyl-daidzin, and glyceollins were also previously confirmed by liquid chromatography with mass spectrometry (LC-MS) according to Durango et al (2018). The reverse-phase column, mobile phase, and flow rate were the same as described above (Section 2.5).…”

Preparados De Plantas Bioativas Na Indução De Fitoalexinas E No Controle in Vitro De Fitopatógenos Do Tomateiro / Preparations of Bioative Plants in Phytoalexins Induction and in Vitro Control of Tomato Phytopathogens

“…Muitos produtos naturais podem ter ação elicitora e a variação química natural dos elicitores demonstram que nenhuma característica estrutural única determina a atividade biológica (RAASCH-FERNANDES et al, 2019). Nos dias atuais, tem aumentado o interesse em encontrar novas fontes de elicitores para incrementar a produção de metabólitos específicos obtidos através de plantas e culturas de células e assim, controlar importantes doenças de plantas (DURANGO et al, 2018). Para isso, deve ser realizado o fracionamento dos metabólitos secundários presentes nos extratos, processo que passa pela extração e teste da atividade biológica, as frações obtidas são testadas e a mais produtiva porção é isolada e identificada, (ABUBAKAR; HAQUE, 2020) para determinar assim a utilização ou não deste composto como método alternativo no controle de doenças e plantas.…”