Biosynthesis of bitter acids in hops. A (13)C-NMR and (2)H-NMR study on the building blocks of humulone.
The biosynthesis of humulone, an antibacterial bitter acid from hops, was studied by isotope-incorporation experiments using (13)C-labelled glucose or (2)H(2)O. (13)C enrichments, (2)H enrichments and (13)C(13)C coupling patterns identify isovaleryl-CoA, malonyl-CoA and dimethylallyl pyrophosphate as precursors for humulone. Dimethylallyl pyrophosphate, which serves as a building block for the bitter acid, is generated via the deoxyxylulose pathway of terpenoid biosynthesis. The data confirm that a symmetrical intermediate is involved in humulone formation.
Lehrstuhl für Organische Chemie und Biochemie, Technische Universität München, Garching, Germany.
M
M
Goese
K
K
Kammhuber
A
A
Bacher
M H
MH
Zenk
W
W
Eisenreich
D000214:Acyl Coenzyme A / Q000737:chemistry; D053138:Cyclohexenes; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008956:Models, Chemical; D010944:Plants / Q000737:chemistry*; D012855:Sitosterols / Q000737:chemistry / Q000302:isolation & purification; D013729:Terpenes / Q000032:analysis* / Q000737:chemistry / Q000302:isolation & purification
D000214:Acyl Coenzyme A; D053138:Cyclohexenes; D012855:Sitosterols; D013729:Terpenes; C025473:gamma-sitosterol; C017447:isovaleryl-coenzyme A; C007966:humulon