PHARM. DChemical Pharmacognosy- I

Lecture May 9th, 2011

Cyanophore (Cyanogenic)GLYCOSIDES

M. M. AhsanAhsan KhalidKhalid, , B.PharmB.Pharm, Pharm. D, Pharm. DM.PhilM.Phil Scholar (RIPS/RIU)Scholar (RIPS/RIU)

HIPSHIPS--HUKICHUKIC

Cyanophore (Cyanogenic) Glycosides• Glycosides that yield hydrocyanic acid (HCN) on

hydrolysis• common glycosides are derivatives of

mandelonitrile (benzaldehyde - cyanohydrin)1. Amygdalin ------- mandelonitrile (aglycone)

• prunasin

2. Sambunigrin ------- S - mandelonitrile (aglycone)

• accompanied by enzymes (β-glucosidases) that catalyze reactions

amygdalin glucose + prunasin glucose + mandelonitrile HCN + benzaldehyde

Cyanophore (Cyanogenic) Glycosidesamygdalin A glucose + prunasin B glucose

+ mandelonitrile C HCN + benzaldehyde– A - amygdalin hydrolase– B - prunasin hydrolase– C - mandelonitrile lyase

• widely used as flavoring agent• anti cancer claim ---- amygdalin (laetrile or Vit

B17) - control of sickle cell anemia– not recognized by FDA as a cancer drug because

of high HCN content, potential for overdose or poisoning

Cyanogenic Glycoside

• aglycones are derived from nitrogen intermediates (amino acid)

Test:1. Sodium picrate (yellow) --HCN-- Na isopurpurate

(brick red)2. Guaiacum resin (in methanol) + CuSO4 --HCN-----

blue coloration of paper3. Quantitative analysis of glycoside

plant in water + tartaric acid ---Steam distilled------HCN(determine by AgCl)

other methods GC, TMS

Wild Cherry USP XVIII (1970)Synonym: wild black cherry, Virginian prune

bark, rum or whisky barkOrigin: carefully dried stem bark of Prunus

serotina (Rosaceae)- also known as Prunus virginiana (wild black

cherry tree)Constituent: prunasin ---partial H+---- HCN

p-coumaric acid, trimethyl gallic acidUse: flavoring vehicle (cough remedies)

sedative expectorant, antitussive, astringentused for colds, bronchitis, whooping cough

Adverse: fatal poisoning when ingested in large amounts

Apricot pits

Kernel of various varieties of Prunus americana(Rosaceae)

sold as a health food as source of laetrile or amygdalin

- sold due to amygdalin but banned by FDA due to ineffectivity and potential danger

Other Cyanogenic glycosides1. Linamarin – Flax, linseed, lint bells

Linum usitatissimum (Linaceae)- treatment of diarrhea, constitpation, gastritis; poultice skin inflammation- adverse effect: intestinal blockage

- capable of cholesterol and bleeding time2. Prulaurasin (Cherry - laurel leaves)

Prunus laurocerasus (Rosaceae)3. Manihotoxin(cassava)

Manihot utilissima (Euphorbiaceae)4. Dhurrin

Sorghum vulgare (Poaceae)

Other Cyanogenic glycosides5. Sambunigrin

Sambucwas nigra (Caprifoliaceae)6. Vicianin

Vicia angustifolia (Fabaceae)7. Phaseolunatin

Phaseolus lunatus (Fabaceae)8. Amygdalin

Prunus amygdalus (Rosaceae)Prunus persica (Rosaceae) - peach- constipation, cough, bad breath, blisters, bronchitis- abundant in persic oil, peach kernel oil , seed,

bark, leaves and flowers