Hydroxylation of the native brassinosteroids 24-epicastasterone and 24-epibrassinolide by the fungus Cunninghamella echinulata.
24-Epicastasterone and 24-epibrassinolide, two naturally occurring phytohormones of the brassinosteroid type, were transformed by the fungus Cunninghamella echinulata to give the corresponding 12 beta-hydroxylated compounds. The structures of these compounds were determined by spectroscopic methods, especially heterocorrelated two-dimensional nuclear magnetic resonance investigations. In the rice lamina inclination test the 12 beta-hydroxylation lowered the bioactivity at 0.1 ppm to 10% in comparison with that of the corresponding parent hormones. The described hydroxylations represent the first biotransformations of native brassinosteroids.
Voigt
B
B
Institute of Plant Biochemistry, Halle, Weinbergweg, Germany.
Porzel
A
A
Naumann
H
H
Hörhold-Schubert
C
C
Adam
G
G
D060406:Brassinosteroids; D002777:Cholestanols / Q000737:chemistry / Q000378:metabolism*; D006900:Hydroxylation; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D009090:Mucorales / Q000378:metabolism*; D010937:Plant Growth Regulators / Q000737:chemistry / Q000378:metabolism*; D013260:Steroids, Heterocyclic / Q000737:chemistry / Q000378:metabolism*
D060406:Brassinosteroids; D002777:Cholestanols; D010937:Plant Growth Regulators; D013260:Steroids, Heterocyclic; C083545:castasterone; C023623:brassinolide