Korean J. Breed. Sci. 50(1):45-49(2018. 3) https://doi.org/10.9787/kjbs.2018.50.1.45 Online ISSN: 2287-5174 Print ISSN: 0250-3360 슈퍼홍미쌀품종탁시폴린 (Taxifolin) 성분의환경변이 류수노 한국방송통신대학교자연과학대학농학과 Environmental Variation of Taxifolin Content in a Rice Variety Superhongmi Su-Noh Ryu Dept. of Agricultural Science, Korea National Open University, Seoul 03087, Korea Abstract : This study was conducted to obtain general information for rice breeding materials high in taxifolin content. The taxifolin was isolated from the rice variety, Superhongmi, and was identified by means of spectral methods and quantitative analysis using a high performance liquid chromatography (HPLC). The taxifolin content of the Superhongmi variety was ranged between 32mg and 68mg per 100g seed that differs depending on cultivated regions. The taxifolin content was lower grown at mid north than those at south region. A large amount of taxifolin was found in the aleurone layer of seed as well as in the node of spike of the Superhongmi. The weight of 1,000 grains was ranged between 23.5g and 27.8g that varied depending on cultivated regions. This variety showed heading in the 6 th of September, and its fertility ratio was about 83% in sejong region. These results suggest that the taxifolin-rich rice variety, Superhongmi, is a good source of functional and stable food. Keywords : Rice, Taxifolin, Environmental Variation 서론 슈퍼홍미는전통적인교배육종을통해총폴리페놀함량을높인천립중이무거운만생종으로서기능성식품소재로서유망한기능성쌀품종이다 (Ryu 2015). 페놀성화합물은식물계에널리분포되어존재하는 2차대사산물중하나로다양한구조와분자량을가지며 phenolic hydroxyl기가단백질과같은거대분자와결합하여항산화, 항암및항균등의생리기능을가지는것으로알려져있다 (Choi et al. 2003). 플라보노이드를포함한폴리페놀성화합물은유리라디칼을제거하여산화를억제하고활성산소의소거및산화적스트레스를막아항암, 항균, 항알러지, 노화등을예방하거나지연시키는효과를가진다 (Hertog et al. 1992). 플라보이드는플라본 (flavon) 을기본구조로가지는식물색소로페놀화합물과함께식물체전반에함유되어있으며항산화활성에직접적인영향을주는인자로알려져있다. 최근농진청에서개발한중만생적갈색신품종홍진주벼는기능성물 *Corresponding Author (E-mail: ryusn@knou.ac.kr, Tel: +82-2-3 668-4630, Fax: +82-2-3673-2381) (Received on January 11, 2018. Accepted on January 16, 2018.) 질인페놀릭산과플라보노이드함량이기존의유색미품종보다많이함유되어있는것으로보고되었다 (Yang et al. 2011). 미강은우리나라의중요식량자원인벼를도정할때의부산물로서현미의도정과정상에서약 7% 정도의비중으로얻어지고있으며, 국내에서는연간약 60 만톤정도의미강이발생하는것으로알려져있다. 미강의조성은벼의품종, 도정방법등에따라다르나수분함량 14% 를기준으로할때조단백질 11~ 17%, 조지방질 15~20%, 조섬유질 7~11%, 조회분 7~10%, 탄수화물 34~52% 인것으로보고되고있다. 우리나라에서는미강의약 30% 가량이미강유생산에활용되고있으며, 전세계적으로는미강의약 5% 정도만이미강유생산에이용되고있는것으로알려져있다. 특히, 식품가공기술의발달로식품의기호성증진을위해곡류의도정과정이과거보다더정교해짐에따라미강의발생량은계속증가할것으로예측되고있어, 미강을이용한새로운식품의연구개발이지속적으로이루어질것으로판단된다. 현미상태의유색미는식이섬유를다량함유하고있으며각종단백질, 불포화지방산및비타민, 무기질등이풍부하여영양학적으로우수한식품이다. 이런유색미는적갈색, 흑자색등의 Copyright c 2018 by the Korean Society of Breeding Science This is an Open-Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
46 韓育誌 (Korean J. Breed. Sci.) 50(1), 2018 다양한천연색소를함유하는데일반적으로흑자색계쌀에는안토시아닌계색소가다량함유되어있고적갈색계쌀에는탄닌계색소가함유되어있는것으로알려져있다. 안토시아닌계색소는높은항산화기능뿐만아니라돌연변이억제효과등의높은기능성으로인체면역능을향상시키며노화방지, 질방예방등에효과가있어기능성식품소재로서이용가치가높은것으로알려져있다. 탄닌계색소역시유해성중금속을제거하고변이원생성을억제시키는것으로알려져있다 (Nam et al. 2002, Oh et al. 1996, Ryu 2014). 당뇨병은유전적또는후천적인원인에의해혈당조절호르몬인인슐린의분비량이부족하거나인슐린의기능이정상적으로이루어지지않아당대사에이상이발생하여고혈당을유발하는대사성질환이다. 당뇨병은크게제1형과제2형으로분류된다. 제1형 ( 인슐린의존성 ) 당뇨는유전적인소인으로인해췌장의베타세포가파괴되어인슐린분비가저하되어인슐린치료가절대적으로필요한반면, 제2형당뇨는유전적인소인보다고열량, 고지방식사, 운동부족, 스트레스등후천적인요인으로인해인슐린분비장애, 인슐린저항성이발생하는경우이다. 제2형당뇨는중년이후에발병율이높으며, 국내의당뇨환자의 90% 이상이제2형당뇨병으로보고되어있다. 국내당뇨병환자는약 500만명정도로예상되고있으며, 당뇨병은 5대사망원인중하나로암, 뇌혈관질환, 심장질환다음으로사망률이높아사회적으로문제가되고있다. 2014년우리나라당뇨병유병률이 13.7% 로조사됐다 (Diabets Fact Sheet in Korea 2016). 당뇨병은지속적인고혈당증상으로인해심장질환, 신장질환, 시각장애및신경장애와같은다양한합병증을동반하는것을특징으로하는데, 이러한합병증이심각한문제를야기하며, 환자들의삶의질을극도로저하시킨다. 특히대표적으로순환기계의질환에서심근경색이나뇌경색등의대혈관장애등은당뇨병상태뿐만아니라당뇨병발병이전단계인내당능장애단계에서부터발병이증가하는것으로나타나이에대한예방방법또한필수적으로필요한상태이다 (O'Brien & Granner 1996, Reaven 1988). 따라서당뇨병의치료및합병증을예방하기위해혈당을지속적으로관리하여야하며, 약물요법과함께식사요법, 운동요법등생활습관에서부터철저한관리체계가필요하며가장바람직한방법은생활습관과식습관조절을통해서당뇨병발병이전단계로부터혈당을관리하는예방차원에서의치유가가장바람직하다 (Park et al. 1996). 흑자색미에함유된안토시아닌색소의 80% 정도는 cyanidin- 3-glucoside(C3G) 이며, 그외 peonidin-3-glucoside(p3g), malvidin, pelargonidin 및 selphinidin 등을함유하고있다 (Ryu et al. 2006). 안토시아닌은항산화활성, 항염효과 (Wang H, et al. 2002), 항암효과, 항아토피효과, 항당뇨효과및심혈관계질병등의예방과치료효과등이밝혀진성분이다 (Ryu 2014, Hong et al. 1997). 반면갈색유색미에는흑자색미에없는탁시폴린 (taxifolin) 성분이있는것으로밝혀졌다 (Kwon et al. 2017). 슈퍼홍미추출물은 in vitro 실험에서항산화활성, 항당뇨활성, 혈당상승억제작용이높은것으로알려졌다. 또한슈퍼홍미의탁시폴린성분은약효가우수한당뇨병예방또는치료용약학조성물로도밝혀졌다 (Kwon et al. 2017, Xiao sun et al. 2014). 본연구는쌀에함유된혈당저하성분인탁시폴린성분의품종간차이, 재배지역과식물체및종실의부위별함량변이를조사하여육종의소재로서기본정보를얻고자수행하였다. 재료및방법 1. 재료슈퍼홍미 ( 국립종자원출원2015-339호, 2015.03.31.) 벼품종은총폴리페놀함량을높인기능성쌀품종이다 (Ryu 2015). 기능성성분추출을위해슈퍼홍미현미 100g에 1L의 MeOH(0.1% trifluou acetic acid) 을혼합한후 40 에서 2시간추출하였다. 추출액을원심분리기에서원심분리한후 (8,000rpm, 4, 30분 ) 상등액을 Whatman No. 1 필터로여과하였다. 여과액을감압농축하여용매를모두제거한후동결건조기에서동결건조하여분석하였다. 탁시폴린성분의화학구조는 Fig. 1과같으며분석조건은 Table 1과같다. 탁시폴린의표준물질을각각 25 mg 정평하여 MeOH 25 ml에용해시킨용액을 stock solution으로해서이를일정량씩취한후각각에 MeOH을가해 5, 10, 20, 50 mg/ml 가되게하여조제하였 Fig. 1. Structure of taxifolin component of rice variety Superhongmi.
슈퍼홍미쌀품종탁시폴린 (Taxifolin) 성분의환경변이 47 Table 1. Analysis condition of taxifolin component in rice variety Superhongmi. Mobile phase A : DW B : 60% MeOH (ph 2.4) Detector Agilent 1260 DAD Flow 1.0 ml /min Column TOSOH TSK-GEL C 18 다. solution 용액을각각 10 μl씩취하여 chromatogram을얻고각각의 chromatogram으로부터 peak area를구하여검량선을작성하였다. 갈색쌀의탁시폴린함량차이를구명하기위하여적진주벼, 홍진주벼, 건강홍미, 슈퍼홍미와슈퍼홍미유래계통 5개를분석재료로사용하였다. 슈퍼홍미는 5개재배지역여주 ( 경기도여주시농업기술센터시험포장 ), 세종 ( 세종시전의면고등리시험포장 ), 당진 ( 당진시우강면송산리 138 시험포장 ), 김제 ( 김제시대창자연미영농법인시험포장 ), 진도 ( 전남진도군농업기술센터시험포장 ) 에서농촌진흥청표준재배법에의해재배하여 taxifolin 함량을분석하였다. 식물체를이삭, 줄기, 잎, 뿌리로구분하여분석재료로하였다. 또한, 종자를배, 배유, 호분층으로구분하여탁시폴린함량을분석하였다. 성분농도의범위를 5~50 μg / ml로하여정량곡선을측정하였다. 정량의범위는성분의농도에직선성을나타내는농도로표시하였으며, 면적비를이용한검량선으로상관계수 R 2 를구하여양호한직선성을확인한결과 5~50μg / ml구간에서 R 2 =0.999로매우유의적인상관성을확인하였다 (Fig. 3). 슈퍼홍미추출물을통해서 taxifolin 함량을 HPLC 를통해분석한결과슈퍼홍미현미 100 g에 68 mg 함유된것으로확인되었다. 2. 유색미 Taxifolin 함량의품종및식물체부위별함량차이갈색쌀에함유된탁시폴린함량은 Table 2에서와같다. 현미 100 g에함유된양은 0에서 78 mg으로품종간차이가컸다. 슈퍼홍미유래계통내에서도 26 mg에서 78 mg의함량변이가있어고탁시폴린품종육성에중요한소재가될것으로사료된다. 또한, 식물체부위와종실의부위별탁시폴린함량을 Table 3에서보면, 종실뿐만아니라이삭에도다량함유되어있어향후식물체를이용한새로운부가가치창출을위한소재로의이용도가능할것으로보인다 (Table 3). 탁시폴린성분은종실의호분층에대부분함유되어있어도정후의부산물로서쌀겨의새로운 결과및고찰 1. 슈퍼홍미 Taxifolin성분의정량분석슈퍼홍미추출물의지표성분인 Taxifolin을 HPLC를이용한정량분석방법을확립하기위해 Table 1과같은방법으로분석하였다. Detector로는 UV만사용하여분석하였다. Taxifolin 성분의 retention time은 30분대임을알수있었다 (Fig. 2). 확인된 taxifolin 성분의함량을결정하기위하여표준검량선을작성하여 Fig. 3에나타내었다. 슈퍼홍미추출물의 taxifolin Fig. 3. Calibration curves for standard materials of taxifolin component. Fig. 2. HPLC chromatogram for MeOH extract from Superhongmi rice variety. Column : Tosoh TSK-Gel C18.
48 韓育誌 (Korean J. Breed. Sci.) 50(1), 2018 용도가개발될것으로보인다. 3. 재배지역에따른슈퍼홍미의작물학적특성과 taxifolin 함량변이슈퍼홍미의재배지역에따른작물학적특성과탁시폴린함량차이를 Table 4에서보면, 세종지역에서의출수기는 9월 6일로서만생종품종이다. 이미보고된슈퍼홍미의작물학적특성과유사한결과이다 (Ryu 2015). 만생종인슈퍼홍미를중북부지역 Table 2. Difference of taxifolin content in brown rice varieties. (mg/100g seed) Varieties and strains Superhongmi Strains 15074 Strains 15075 Strains 15189 Strains 15190 Strains 17079 Jeokjinju Hongjinju Keonganghongmi *ND: Not Detected Content of taxifolin 67.7±5.48 26.3±3.14 60.3±2.49 35.7±4.45 24.7±4.32 77.6±6.49 Table 3. Difference of taxifolin contents in plant and seed of rice variety Superhongmi. 인여주에서재배할때출수기가 9일늦은 9월 15일이었으며임실율도 77% 로낮고, 탁시폴린함량도다른지역에비해그함량이낮아재배지역으로부적합하였다. 반면, 세종이남지역인당진, 김제, 진도지역에서는함량차이가크지않았다. 그러나남부진도지역에서재배할때임실율이다소높았다. 적요본연구는쌀에함유된혈당을저하하는탁시폴린성분에대한육종소재로서기본정보를얻고자수행하였다. 슈퍼홍미벼품종으로부터탁시폴린성분을분리하고분광학적방법에의해확인하였다. 또한 HPLC로검량선을작성하고정량분석을하였다. 다양한유색미품종중에서슈퍼홍미와슈퍼홍미유래계통에서만탁시폴린함량이확인되었다. 슈퍼홍미의탁시폴린함량은재배지역에따라서쌀 100 g에 32 mg에서 68 mg의함량변이를보였다. 이들성분의함량은중북부지역에서재배되었을때보다남부지역에서재배되었을때높게나타났다. 천립중은재배지역에따라서 23.5 g에서 27.8 g의변이를보였다. 탁시폴린성분은슈퍼홍미의이삭뿐만아니라종자의호분층에도다량함유되어있어이들식물체를기능성소재로이용할수있을것으로사료된다. 따라서탁시폴린성분이다량함유된슈퍼홍미는식량으로서뿐만아니라기능성식품소재로서높은가치가있을것으로기대된다. Plant Seed Parts Contents of taxifolin (mg/100g seed) node of spike 143.5±8.25 leaf - root - embryo - endosperm - aleurone layer 106.6±5.32 사사 이논문은 2017년도한국방송통신대학교학술연구비지원을받아작성된것임. Table 4. Difference of major agronomnic traits and seed taxifolin content depending on cultivated region in rice variety Superghongmi. Cultivated region Transplanting date Heading date 1,000 grain weight (g) Ratio of fertility (%) Contents of taxifolin (mg/100g seed) Yeoju May 30 Sep. 15 23.5±2.89b z 76.6±3.45b 32.72±5.32b Sejeong May 30 Sep. 6 26.8±2.23a 83.4±4.14a 67.7±5.48a Dangjin May 30 Sep. 6 26.5±3.14a 82.4±3.15a 63.4±4.32a Kimje May 30 Sep. 7 27.3±2.89a 83.5±2.65a 65.4±5.11a Jindo June 5 Sep. 9 27.8±3.16a 86.6±3.19a 68.3±3.39a z Values are means±standard deviation(n=3). Means in the same column not sharing a common superscript are significantly different at p<0.05.
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