TY - JOUR
T1 - Concerning the role of 24,25-dihydrolanosterol and lanostanol in sterol biosynthesis by cultured cells
AU - Nes, W. David
AU - Norton, Robert A.
AU - Parish, Edward J.
AU - Meenan, Aniko
AU - Popják, George
PY - 1989
Y1 - 1989
N2 - Rat hepatoma cells (H4-II-E-C3) efficiently converted a dietary supplement of [2-3H]24,25-dihydrolanosterol (1) to [3H]cholesterol while [2-3H]lanostanol (4,4,14α-trimethyl-cholestanol(2) was recovered from the cells without apparent transformation, although it was esterified and induced an accumulation of lanosterol. A comparison of the Chromatographic (TLC, GLC and HPLC), spectral (MS and 1H-NMR) and physical properties of 1 and 2 is given for the first time. The inability to detect 2 in nature coupled with our findings that 1 but not 2 is metabolized to cholesterol by H4 cells is interpreted to imply that the biosynthetic inclusion of the Δ8(9)-bond during the cyclization process of squalene-oxide to a tetracyclic product is an evolutionary adaptation selected for because the olefinic linkage is structually important in the subsequent conversion of lanosterol and its stereoisomers, e.g., cycloartenol, to Δ5-sterols.
AB - Rat hepatoma cells (H4-II-E-C3) efficiently converted a dietary supplement of [2-3H]24,25-dihydrolanosterol (1) to [3H]cholesterol while [2-3H]lanostanol (4,4,14α-trimethyl-cholestanol(2) was recovered from the cells without apparent transformation, although it was esterified and induced an accumulation of lanosterol. A comparison of the Chromatographic (TLC, GLC and HPLC), spectral (MS and 1H-NMR) and physical properties of 1 and 2 is given for the first time. The inability to detect 2 in nature coupled with our findings that 1 but not 2 is metabolized to cholesterol by H4 cells is interpreted to imply that the biosynthetic inclusion of the Δ8(9)-bond during the cyclization process of squalene-oxide to a tetracyclic product is an evolutionary adaptation selected for because the olefinic linkage is structually important in the subsequent conversion of lanosterol and its stereoisomers, e.g., cycloartenol, to Δ5-sterols.
UR - http://www.scopus.com/inward/record.url?scp=0024348098&partnerID=8YFLogxK
U2 - 10.1016/0039-128X(89)90025-1
DO - 10.1016/0039-128X(89)90025-1
M3 - Article
C2 - 2799854
AN - SCOPUS:0024348098
VL - 53
SP - 461
EP - 475
JO - Steroids
JF - Steroids
SN - 0039-128X
IS - 3-5
ER -