TY - JOUR
T1 - Phytosterol biosynthesis pathway in Mortierella alpina
AU - David Nes, W.
AU - Nichols, Shawn D.
N1 - Funding Information:
The financial support of the Welch Foundation (D-1276) and the National Science Foundation (MCB-0417436) to W.D.N. is gratefully acknowledged.
PY - 2006/8
Y1 - 2006/8
N2 - The Zygomycetes fungus Mortierella alpina was cultured to growth arrest to assess the phytosterol biosynthesis pathway in a less-advanced fungus. The mycelium was found to produce 13 sterols, but no ergosterol. The sterol fractions were purified to homogeneity by HPLC and their identifies determined by a combination of GC-MS and 1H NMR spectroscopy. The principal sterol of the mycelium was cholesta-5, 24-dienol (desmosterol) (83%), with lesser amounts of 24β-methyl-cholesta-5,25(27)-dienol (codisterol) (2%), 24-methyldesmosterol (6%), 24(28)-methylene cholesterol (3%) and lanosterol (3%) and several other minor compounds (3%). The total sterol accounted for approximately 0.07% of the mycelial dry wt. Mycelium fed methionine-methyl-2H3 for 6 days, generated 3 2H-24-methyl(ene) sterols, [C28-2H2]24(28)-methylenecholesterol, [C28-2H3]24-methylcholesta-5,24-dienol and [C28-2H3]24β-methyl-cholesta-5,25(27)-dienol. The formation of the 24-methyl sterols seems to be catalyzed by the direct methylation of a common Δ24-acceptor sterol thereby bypassing the intermediacy of an isomerization step for rearrangement of the Δ24(28)-bond to Δ25(25)-position as operates in Ascomycetes fungi and all plants.
AB - The Zygomycetes fungus Mortierella alpina was cultured to growth arrest to assess the phytosterol biosynthesis pathway in a less-advanced fungus. The mycelium was found to produce 13 sterols, but no ergosterol. The sterol fractions were purified to homogeneity by HPLC and their identifies determined by a combination of GC-MS and 1H NMR spectroscopy. The principal sterol of the mycelium was cholesta-5, 24-dienol (desmosterol) (83%), with lesser amounts of 24β-methyl-cholesta-5,25(27)-dienol (codisterol) (2%), 24-methyldesmosterol (6%), 24(28)-methylene cholesterol (3%) and lanosterol (3%) and several other minor compounds (3%). The total sterol accounted for approximately 0.07% of the mycelial dry wt. Mycelium fed methionine-methyl-2H3 for 6 days, generated 3 2H-24-methyl(ene) sterols, [C28-2H2]24(28)-methylenecholesterol, [C28-2H3]24-methylcholesta-5,24-dienol and [C28-2H3]24β-methyl-cholesta-5,25(27)-dienol. The formation of the 24-methyl sterols seems to be catalyzed by the direct methylation of a common Δ24-acceptor sterol thereby bypassing the intermediacy of an isomerization step for rearrangement of the Δ24(28)-bond to Δ25(25)-position as operates in Ascomycetes fungi and all plants.
KW - Cholesterol
KW - Ergosterol biosynthesis
KW - Fungal evolution
KW - Isotope labeling
KW - Mortierella alpina
KW - Sterol methyltransferase
UR - http://www.scopus.com/inward/record.url?scp=33747349936&partnerID=8YFLogxK
U2 - 10.1016/j.phytochem.2006.02.023
DO - 10.1016/j.phytochem.2006.02.023
M3 - Article
C2 - 16647729
AN - SCOPUS:33747349936
SN - 0031-9422
VL - 67
SP - 1716
EP - 1721
JO - Phytochemistry
JF - Phytochemistry
IS - 16
ER -