Biosynthesis of cholestanol in higher plants.
To understand the early steps of C(27) brassinosteroid biosynthesis, metabolic experiments were performed with Arabidopsis thaliana and Nicotiana tabacum seedlings, and with cultured Catharanthus roseus cells. [26, 28-2H(6)]Campestanol, [26-2H(3)]cholesterol, and [26-2H(3)]cholestanol were administered to each plant, and the resulting metabolites were analyzed by gas chromatography-mass spectrometry. In all the species examined, [2H(3)]cholestanol was identified as a metabolite of [2H(6)]campestanol, and [2H(3)]cholest-4-en-3-one and [2H(3)]cholestanol were identified as metabolites of [2H(3)]cholesterol. This study revealed that cholestanol (C(27) sterol) was biosynthesized from both cholesterol (C(27) sterol) and campestanol (C(28) sterol). It was also demonstrated that cholestanol was converted to 6-oxocholestanol, and campestanol was converted to 6-oxocampestanol.
Nakajima
Naoko
N
RIKEN (The Institute of Physical and Chemical Research), Wako-shi, Saitama 351-0198, Japan.
Fujioka
Shozo
S
Tanaka
Takashi
T
Takatsuto
Suguru
S
Yoshida
Shigeo
S
D017360:Arabidopsis / Q000378:metabolism*; D030008:Catharanthus / Q000378:metabolism; D004083:Cholestanol / Q000096:biosynthesis*; D002784:Cholesterol / Q000378:metabolism; D010840:Phytosterols / Q000378:metabolism; D014026:Nicotiana / Q000378:metabolism*
D010840:Phytosterols; C003535:campestanol; D004083:Cholestanol; D002784:Cholesterol