ساينوفور وايزوكلايكوسيدات PDF

LEC5 Pharmacognosy ‫ د زينب الجابري‬.‫م‬.‫ا‬ CAYNOPHORE GLYCOSIDES --------------------------------------------: Several glycosides yielding hydrocyanic acid as one of the products of hydrolysis are commonly found in rosaceous plants. They are someti...

LEC5 Pharmacognosy ‫ د زينب الجابري‬.‫م‬.‫ا‬ CAYNOPHORE GLYCOSIDES --------------------------------------------: Several glycosides yielding hydrocyanic acid as one of the products of hydrolysis are commonly found in rosaceous plants. They are sometimes designated as cyanogenic glycosides. The common cyanophore glycosides are derivative of mandelonitrile ( benzaldehyde- cyanohydrine ). The group is represented by amygdalin which is found in large quantities in bitter almonds , in kernels of apricot , cherry , peach , plum and in many other seeds of Rosaceae and also by Prunasin which occurs in Prunus serotina. ‫حامض الهيدروسيانيك‬ Kernel ‫لب البذور‬ ‫اللوز المر‬  Both amygdalin and prunasin yield D- mandelonitrile as the aglycone. The hydrolysis of amygdalin takes place in 3 steps , which briefly are as follows : 1-the molecule is hydrolyzed initially to liberate 1 molecule of glucose and 1 molecule of mandlonitrile glucoside. 2-the second molecule of glucose is liberated with the formation of mandelonitrile. 3-the mandelonitrile then break down with the formation of benzaldehyde and hydrocyanic acid. The enzyme emulsion , as obtained from almond kernels consists of a mixture of 2 enzymes : amygdalase , which causes the first step in hydrolysis , and prunase which causes the second step. ‫المخطط كاسماء مركبات مطلوب للحفظ و كاشكال المطلوبة للحفظ فقط االميغدالين والبروناسين‬ Biosynthesis Pathway -------------------------------- The aglycone of these glycosides are derivatives from the amino acids which contains 3-6 carbon atoms like phenyl alanine and tyrosine , these acids are derived from Shikimic acid , then the pathway of biosynthetic of these glycosides is shikimic acid. Shikimic acid --- phenyl alanine ----- mandlonitrile --- Prunasin ---- amygdalin ‫االشكال في المخطط للتوضيح وليست مطلوبة للحفظ‬ Preparation from plant materials containing cyanogenic glycosides are widely employed as flavoring agents. Anticancer claim, and the possibility for control of sickle cell anemia with cyanogenic glycosides has been noted. Wild cherry ‫الكرز البري‬ Wild cherry is the dried stem bark of Prunus serotina Fam : Rosaceae The plant is a tree that grows to a height of 30 meters or more in USA , Canada and other countries. Wild cherry bark containing a cynogenic glycoside prunasin ( D- mandelonitril glucoside ). Other constituents : include the hydrolytic enzyme , prunase , coumaric acid , trimemrthyl gallic acid and traces of volatile oil. Bark of Wild cherry : It has been considered a sedative expectorant , is excellent for cough , decreases of inflammation and join pain Juice of wild cherry : used as flavoring agent , reduce risk of cardiovascular disease , rich in iron : they improve the blood.and treat anemia , sleep beater ISOTHIOCYANATE GLYCOSIDES --------------------------------------------------: The seeds of several cruciferous plants ( Fam: crucifera ) contain glycosides , the aglycones of which are isothiocynates. The aglycone of these glycosides contains sulphate atom , by this atom aglycones are linked with sugar part. These aglycones may be either aliphatic or aromatic derivatives principle among these glycosides are sinigrine from black mustard , sinalbine from white mustard. When hydrolyzed by the enzyme myrosin , they yield the mustard oils. Plant Examples ------------------------ : Mustard ‫الخردل‬ Black mustard ‫ الخردل االسود‬is the dried ripe seeds of varieties of Brassica nigra ‫ الخردل االسود‬or of Brassica juncea ‫الخردل االبيض‬ Fam : cruciferae Although black mustard contains fixed oil 30 to 35 % , its principal constituents is the glycoside , sinigrin ( potassium myronate ). Upon the addition of water to the crushed or powdered seeds, the myrosin effects the hydrolysis of the sinigrin yield Allylisothiocyanate ( mustard oil ) +KHSO4 + Glucose + H2O --- S=C=N-CH2CH2 =CH2 + KHSO4 + C6H12O6 ( Glucose) Allylisothiocyanate ( mustared oil ) The allylisothiocynate produced is volatile oil , it is commonly called volatile mustard oil. White mustard White mustard of the dried , ripe seeds of Brassica alba Fam : crucifersae. White mustard is as commercially important as black mustard.White mustard contains the enzyme myrosin and a glucoside , sinalbin which upon hydrolysis , yield acrinyl isothiocynate ( mustard oil ) +KHSO4 + Glucose part used and uses as black mustard sinalbin ‫تاتي كاملة في االمتحان‬ sinalbin , singrin