Cyanogenic Glycosides and Lipids
Glycosides
cyanogenic compounds are widespread among plants
but one major type of biosynthetic pathway
shared in part with glucosinolates?
most of the about 60 compounds are based on phe, tyr, val, isoleucine, leucine, 2(cyclopentenyl)glycine, and nicotinic acid
2 simple color tests for HCN
most reports based on these (2650 species)
how cyanogenic compounds decompose ... see handout
channeled process ... now known to be two enzymes Birger Moeller
extremely high incorporation of label
requires NADPH
seed coats in some cases contain a powerful inhibitor for synthesis
phenylalanine compounds
tyrosine compounds
valine-isoleucine compounds
leucine compounds
(2-cyclopentenyl)glycine compounds
nicotinic acid compounds
Cyanolipids
ß-Glycosidases
Biological activity
transport in Hevea brasiliensis
defensive
cyanogenic insects
Detoxification
HCN to ß-cyanoalanine
and/or to asparagine
rhodanese in animals (mammals, mostly)
S-containing amino acids
HCN in fungi to formamide
Nitroglucosides
mostly legumes, but a few others as well
3-nitropropanoic acid
3-nitropropanol (Astragalus)
Nitrile glycosides
possibly related to cyanogenic glycosides
Pseudocyanogenic glycosides
only in cycads
in insects that feed on cycads
Cyanogenic glycoside hydroplysis
Cyanogenic glycoside biosynthesis
Phenylalanine-derived cyanogens
Complex phenylalanine-derived cyanogens
meta-substituted cyanogenic glycosides
Tyrosine-derived cyanogens with ring cleavage
Plants with Cyanogenic Compounds
© David S. Seigler, Integrative Biology 425, Plant Secondary Metabolism, Department of Plant
Biology, 265 Morrill Hall, 505 S. Goodwin Ave., University of Illinois, Urbana, Illinois 61801, USA.
217-333-7577. seigler@life.uiuc.edu.
