In peanuts, a mechanism of resistance to fungal infection is reported on the synthesis of stilbene phytoalexins, which are antibiotic, low molecular weight metabolites. The phytoalexin-associated response of different...In peanuts, a mechanism of resistance to fungal infection is reported on the synthesis of stilbene phytoalexins, which are antibiotic, low molecular weight metabolites. The phytoalexin-associated response of different peanut varieties to the inoculation with A. flavus has not been investigated and might be useful for breed- ing resistant peanut cultivars. In this study, peanut varieties resistant or susceptible to aflatoxin accumulation caused by A. flavus were selected to compare the synthe- sis differences of the four main stilbenes （resveratrol, ε-viniferin, 6-viniferin and pterostilbene） and the activities of their resistant enzymes （PAL, POD, PPO）, and explore the relationship between stilbene synthesis and resistance to aflatoxin accu- mulation. The results indicated that the synthesis speed of stilbenes was related to the resistance to aflatoxin accumulation in peanuts seeds. The total content of the four stilbenes reached the highest value of 47.37 μg/g in the resistant cultivars （Qian huasheng 3） after inoculation by A. flavus （54 times of the control） on the 3nd day, while the total content of stilbenes in susceptible cultivars （Huayu 22） was 5.5 μg/g. The content of stilbenes and the activities of their resistant enzymes from the resistant cultivars were both higher than from the susceptible one. The four peanut varieties with relative higher stilbene contents and lower disease index and aflatoxin content were selected by using the stilbene content. Very significant negative corre- lation, with correlation coefficients （r） of -0.789, -0.851 and -0.850, was observed between the stilbene content with disease index, the content of aflatoxin B1 and the total content of aflatoxins, respectively. Therefore, the study suggested that the total content of stilbene compounds might serve as an important chemical index in peanut seeds after inoculation with A. flavus on the 3nd day, during screening and breeding of peanut varieties resistant to aflatoxin accumulation.展开更多
Two new isoflavones (8, 3'-dihydroxy-7,4'-dimethoxyisoflavone, odoratin-7-0-[3-D-glu-copyranoside) and four known isoflavones (formononetin, 7,3'-dihydroxy-8,4'-dimethoxyisoflavone, calycosin, calycosi...Two new isoflavones (8, 3'-dihydroxy-7,4'-dimethoxyisoflavone, odoratin-7-0-[3-D-glu-copyranoside) and four known isoflavones (formononetin, 7,3'-dihydroxy-8,4'-dimethoxyisoflavone, calycosin, calycosin-7-0-(3-D-glucopyranoside) were isolated from the roots of Astragalus mem-branaceus (Fisch.) Bunge. Their structures were established by spectral analysis.展开更多
Radix Astragali （Huangqi） is one of the most valuable traditional Chinese medicinal herbs. It is used in the traditional Chinese medicine to reinforce ＇qi＇, and it has immunostimulant, tonic, and antioxidant activ...Radix Astragali （Huangqi） is one of the most valuable traditional Chinese medicinal herbs. It is used in the traditional Chinese medicine to reinforce ＇qi＇, and it has immunostimulant, tonic, and antioxidant activities. There are many different sources of Huangqi in the market. In this study, the quality of Huangqi was evaluated by the measurement of four flavonoids, calycosin-7-O-β-D-glucopyranoside, ononin, calycosin and formononetin with HPLC-UV, as well as astragaloside IV with HPLC-ELSD. Samples included different plant species, different places of cultivation, different ages of plants, different seasons of collection and different commercial specifications. The results showed that the contents of isoflavonoids and astragaloside IV varied significantly in different sources. Our study provided useful information for the quality evaluation of Radix Astragali.展开更多
基金Supported by Natural Science Foundation of Hainan Province(809034)National Nonprofit Institute Research Grant of CATAS-TCGRI(1630032012025)~~
文摘In peanuts, a mechanism of resistance to fungal infection is reported on the synthesis of stilbene phytoalexins, which are antibiotic, low molecular weight metabolites. The phytoalexin-associated response of different peanut varieties to the inoculation with A. flavus has not been investigated and might be useful for breed- ing resistant peanut cultivars. In this study, peanut varieties resistant or susceptible to aflatoxin accumulation caused by A. flavus were selected to compare the synthe- sis differences of the four main stilbenes （resveratrol, ε-viniferin, 6-viniferin and pterostilbene） and the activities of their resistant enzymes （PAL, POD, PPO）, and explore the relationship between stilbene synthesis and resistance to aflatoxin accu- mulation. The results indicated that the synthesis speed of stilbenes was related to the resistance to aflatoxin accumulation in peanuts seeds. The total content of the four stilbenes reached the highest value of 47.37 μg/g in the resistant cultivars （Qian huasheng 3） after inoculation by A. flavus （54 times of the control） on the 3nd day, while the total content of stilbenes in susceptible cultivars （Huayu 22） was 5.5 μg/g. The content of stilbenes and the activities of their resistant enzymes from the resistant cultivars were both higher than from the susceptible one. The four peanut varieties with relative higher stilbene contents and lower disease index and aflatoxin content were selected by using the stilbene content. Very significant negative corre- lation, with correlation coefficients （r） of -0.789, -0.851 and -0.850, was observed between the stilbene content with disease index, the content of aflatoxin B1 and the total content of aflatoxins, respectively. Therefore, the study suggested that the total content of stilbene compounds might serve as an important chemical index in peanut seeds after inoculation with A. flavus on the 3nd day, during screening and breeding of peanut varieties resistant to aflatoxin accumulation.
基金This project is supported by National Center of New Drug Research,Science and Technology Committee and Educational Committee of Shanghai.
文摘Two new isoflavones (8, 3'-dihydroxy-7,4'-dimethoxyisoflavone, odoratin-7-0-[3-D-glu-copyranoside) and four known isoflavones (formononetin, 7,3'-dihydroxy-8,4'-dimethoxyisoflavone, calycosin, calycosin-7-0-(3-D-glucopyranoside) were isolated from the roots of Astragalus mem-branaceus (Fisch.) Bunge. Their structures were established by spectral analysis.
基金Faculty Research Grant of Hong Kong Baptist University (FRG/06-07/II-24)
文摘Radix Astragali （Huangqi） is one of the most valuable traditional Chinese medicinal herbs. It is used in the traditional Chinese medicine to reinforce ＇qi＇, and it has immunostimulant, tonic, and antioxidant activities. There are many different sources of Huangqi in the market. In this study, the quality of Huangqi was evaluated by the measurement of four flavonoids, calycosin-7-O-β-D-glucopyranoside, ononin, calycosin and formononetin with HPLC-UV, as well as astragaloside IV with HPLC-ELSD. Samples included different plant species, different places of cultivation, different ages of plants, different seasons of collection and different commercial specifications. The results showed that the contents of isoflavonoids and astragaloside IV varied significantly in different sources. Our study provided useful information for the quality evaluation of Radix Astragali.
