Analysis And Evaluation On Glucosinolates Composition And Sulforaphene Content Of Radish (Raphanus Sativus L.) Germplasm Resources

Radish is an important vegetable crop in China, and contains the important secondarymetabolites-glucosinolates and anti-cancer compound-sulforaphene. At present, the difference ofglucosinolates component and their content in radish fleshy roots and leaves of some varieties havebeen reported. Also, studies were focused on biological activity of sulforaphene. However, there are fewstudies on glucosinolates composition and sulforaphene content in many accessions and in differentseasons and organs. No information about the relativity between glucosinolates content andsulforaphene content is available. All these restrict the genetic improvement of radish quality and therational use of radish resources. In this study, we developed an efficient and accurate method forquantitative analysis of sulforaphene using the HPLC, performed determination of glucosinolatescomposition and sulforaphene content in different radish germpalsms. Furthermore, we detectedglucosinolates composition and sulforaphene content of radish germplasm grown in different seasonsand of different organs. Some elite germplasms with higher glucosinolates and sulforaphene contentwere selected.The main results of this study were as follows:1. Establishment of an efficient and accurate method for quantitative analysis of the sulforaphenein radish. The optimum conditions for sulforaphene production and extraction were as follows: theproportion of sample to phosphate bufer solution volume, pH, hydrolysis time and tempreture were1:15(g/mL),5,1h,20~30℃respectively for radish glucosonolate auto-hydrolysis; and15times volumeof elthy acetate to the hydrolyzed solution was proper for sulforaphene extraction at room temperature.Sulforaphene determination was performed on reversed-phase C18high-performance liquidchromatography (HPLC) using methanol: water=3:7(v/v) as mobile phase, the flow rate at0.3mL/min,and the detection wavelength of245nm. Under these conditions, the linearity was excellent within theconcentration ranges of5~200μg/mL (r2=0.9996) without interference peak. The precision and systemsuitability were perfect, and the recovery was95.48%(RSD=0.94%). This method was successfullyused for the quantification of sulforaphene in sprouts, fleshy roots and leaves of different radishgermplasms.2. Analysis of glucosinolates and sulforaphene content and their correlation in diverse radishgermpalsms. Glucosinolates composition and their content were analyzed of73accessions of radishfleshy roots. The results indicated that the composition of glucosinolates in different germpalsms werethe same and all included four aliphatic glucosinolates and three indolyl glucosinolates, and aliphaticglucosinolates were prominent and the total content of aliphatic glucosinolates were89.96%. The majorglucosinolates component were glucoraphenin and glucoraphasatin. In radish fleshy roots, the totalglucosinolates content were0.206~22.728μmol/gï¹'DW and the sulforaphene content were34.445~1446.9mg/kgï¹'DW. The sulforaphene content in radish leaves ranged from19.5mg/kgï¹'DWto2160.96mg/kgï¹'DW. The glucoraphenin content was positive significantly related to sulforaphenecontent in radish fleshy roots with the correlation coefficient of0.64, and sulforaphene content in radishfleshy roots and leaves was not correlated. Based on these analysis, screening of5high quality of radish germplasms. According to germplasm origins, the average total content of glucosinolates and averagesulforaphene content of the radish germplasm were higher in the eastern China. As to radish types, theaverage content of total content of glucosinolates and sulforaphene was higher in green skin and whiteflesh radishs, and the variation was wide ranged. This informations laid the foundation for mining thehigh sulforaphane or glucosinolates excellent genes and the radish quality genetic improvement.3. Assay of glucosinolates composition and sulforaphene content in different typical germplasms indifferent seasons. The studies indicated that the total glucosinolates content and sulforaphene content inradish fleshy roots were highest in summer, higher in winter and spring and lowest in autumn. The totalglucosinolates and sulforaphene content in leaves were highest in summer, and lower in spring andwinter. All these information provided the basis for the establishment of cultivation techniques of highquality radish.4. Assay of glucosinolates composition and sulforaphene content in different typical germplasms indifferent organs. It was shown that seven glucosinolates were detected in siliques, stalks, fleshy roots,leaves, while glucoraphasatin was predominated in those organs. Seeds had the highest totalglucosinolate content, and only six glucosinolates was detected, followed by inflorescences with themain component of glucoraphenin. In florescences had the highest sulforaphene concentration, followedby siliques, stalks, fleshy roots and leaves. All these information provided the basis for the high qualityradish and effective utilization of radish different organs.