Sterols and the phytosterol content in oilseed rape (Brassica napus L..)
Steroller organik bileşikler olup 17 karbon atomundan ve 3 boyutlu dört halka dizisinden oluşmuşlardır. Kimyasal açıda bakıldığında steroller steroid alkolü olup, sterol adı Yunanca'da stereos, dayanıklı yada bozulmayan anlamına gelmektedir. Sterolün sonuna eklenen -ol takısı ise alkolden gelmektedir. Hücre membranlarının özel yapısından dolayı steroller tüm okaryotik canlılarda bulunurlar. Hücre membranında yapısal bir rol oynadıklarından steroller organizmaların membranlarının önemli bir kısmını teşkil ederken, hücre membranı geçirgenliğinde önemli görevler alarak bu sistem içinde görev alan enzimlerin aktif hale getirmektirler. Son olarak sterollerin insanlarda öncü steroid hormanları ile safra asitlerini, bitkilerde brassinosteroidler ile fitohormonları etkilediğini, son yapılan çalışmalarda da sterollerin canlı organizmaların önemli büyüme ve gelişme evrelerinde rol aldıkları saptanmıştır. Son yıllarda fitosterollerin LDL kolesterol düzenleyicisi özellikleri, kroner ölümleri azaltıcı fetkileri bakımından doğal önleme ürünü olmaları sebebiyle önemleri artmıştır. Bitkilerde çok iyi tespit edilip belirlenen 40'dan fazla farklı sterol bulunmuştur. Bu steroller çoğunlukla yağ bitkilerinde saptanarak fitosterol olarak adlandırılmışlardır. Yapılan çalışmalarda kültür bitkisine göre elde edilen 1 kg yağda bulunabilecek fitosterol iktarı 1,41-15,57 gr/kg aralağında olduğu saptanmıştır. Kolza dünyada üretilen en önemli yağ bitkilerinden biridir. Kolzada fitosteroller miktarı 5,13 ile 9,79 gr/kg yağ arasında değişim göstermektedir.
Kolza bitkisinde (Brassica napus L.) sterol ve fitosterol içeriği
Sterols are natural, organic compounds with a molecular nucleus of 17 carbon atoms and a characteristic three-dimensional arrangement of four rings. From the chemical point of view sterols are steroid alcohols and their name is derived from Greek stereos, which mean solid with ending -ol, which is the suffix for alcohols. As essential constituents of cell membranes, they are widely distributed in all eukaryotic organisms. Playing a structural role in cellular membranes, they present a significant part of the organism membrane biomass, while their functional role is evident through the participation in the control of membrane-associated metabolic processes, such as: regulations of membrane permeability and fluidity, signal transduction events and the activity of membrane-bound enzymes. Sterols are the precursors of steroid hormones and bile acids in humans, brassinosteroids - phytohormones in plants and, as the recent identifications of sterol mutants have shown, they are involved in important growth and developmental processes in living organisms. In recent years increased interest in phytosterols lies in their potential to reduce plasma low-density lipoprotein cholesterol level, decreasing coronary mortality and therefore acting as naturally preventive dietary product. In the last decades, more than 40 different sterols were well identified in different cultivars. These sterols are called phytosterols and they are predominantly present in oilseed plants. The phytosterol content range between 1.41-15.57 gr/ kg oil and this depends to plant species. Oilseed rape is one of the most important oil seed crop in the world, phytosterol content in new oilseed rape varieties rang between 5.13 and 9.79 gr/kg oil.
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- ISSN: 1303-3646
- Yayın Aralığı: Yılda 2 Sayı
- Yayıncı: Haliç Üniv. Fen Edebiyat Fak.
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