Effect of Developmental Stages on Glucosinolate Contents in Kale (Brassica oleracea var. acephala)

The aim of this study was to investigate the amounts of glucosinolates (GSL) in kale at various development stages. Kale varieties 'Manchoo Collard' and 'TBC' were cultivated from 20 February 2012 to 3 July 2013 in the greenhouse at Chungnam National University. During the cultivation periods, samples were harvested at 35, 63, 91, 105, 119, and 133 days after sowing (DAS) and the amount of GSL quantified by HPLC. Ten types of GSL (progoitrin, sinigrin, glucoalyssin, gluconapin, glucoiberverin, 4-hydroxyglucobrassicin, glucobrassicin, 4-methoxyglucobrassicin, gluconasturtiin, and neoglucobrassicin) were observed in 'TBC', whereas nine types of GSL (the same as above, except glucoiberverin) were identified in 'Manchoo Collard'. The amount of total GSL in 'Manchoo Collard' was comparatively higher at 133 DAS (mean $8.64{\mu}mol{\cdot}g^{-1}$) and lower at 35 DAS ($1.16{\mu}mol{\cdot}g^{-1}$ dry weight, DW) of cultivation. In the case of 'TBC', the amount of GSL was higher at 91 DAS (mean $13.41{\mu}mol{\cdot}g^{-1}$) and lower at 35 DAS ($0.31{\mu}mol{\cdot}g^{-1}$ dry weight, DW). Sinigrin was the most abundant GSL (57% of total GSL) in 'Manchoo Collard' at 133 DAS and was also highest (44%) in 'TBC' at 91 DAS. Together, progoitrin, sinigrin, glucobrassicin, and gluconasturtiin, the precursor of crambene, allylisothiocyanate, indol-3-cabinol, and phenethylisothiocyanate accounted for 94 and 78% of GSL in 'Manchoo Collard' and 'TBC', respectively. Our results demonstrate that the amounts of GSL, which have potential anti-carcinogenic activity, change during development in kale.

생장단계에 따른 케일 내 글루코시놀레이트 함량

케일 내 유용성분인 GSL 함량은 작물의 재배방법과 기후조건, 영양상태, 유전적 특성 등 재배 환경에 따라 영향을 받을 수 있으므로 본 연구에서는 생장단계에 따른 케일(Brassica oleracea var. acephala) 내 GSL 함량을 조사하였다. 케일 품종은 'Manchoo Collard', 'TBC' 두 품종으로 재배기간은 2012년 2월 20일부터 동년 7월 3일까지 133일이었으며 수확시기는 파종 후 35, 63, 91, 105, 119, 133일(days after sowing, DAS)이었다. 'TBC'에서는 총 10종의 GSL(progoitrin, sinigrin, glucoalyssin, gluconapin, glucoiberverin, 4-hydroxyglucobrassicin, glucobrassicin, 4-methoxyglucobrassicin, gluconasturtiin, neoglucobrassicin)가 분리 및 동정되었으나 'Manchoo Collard'에서는 glucoiberverin를 제외한 9종의 GSL가 분리 및 동정되었다. 'Manchoo Collard'의 GSL 함량은 133DAS에서(평균 $6.12{\mu}mol{\cdot}g^{-1}$ DW)가장 높았고, 35DAS($1.16{\mu}mol{\cdot}g^{-1}$ DW)에서 가장 낮았다. 'TBC'의 GSL 함량은 91DAS(평균 $13.41{\mu}mol{\cdot}g^{-1}$ DW)에서 가장 높았고, 35DAS($0.31{\mu}mol{\cdot}g^{-1}$ DW)에서 가장 낮았다. 총 GSL 함량 중 sinigrin이 'Manchoo Collard'(133DAS)에서 57%, 'TBC'(91DAS)에서 44%로 가장 높았다. 항암효과가 뛰어난 crambene, allyl isothiocynate, indole-3-cabinol, phenethyl isothiocyanate의 전구체인 progoitrin, sinigrin, glucobrassicin, gluconasturtiin은 'Manchoo Collard'와 'TBC'의 총 GSL 함량 중 각각 94, 78%로 나타나 두 품종 모두 항암 효과를 가질 것으로 기대된다.