Phytosterol biosynthesis: Isotope effects associated with biomethylation formation to 24-alkene sterol isomers

Tetrahedron Letters

Volumn 37, Issue 38, 1996, Pages 6823-6826

  Guo, De an ^a   Jia, Zhonghua ^a   Nes, W David ^a  

^a TEXAS TECH UNIVERSITY   (United States)

Author keywords

[No Author keywords available]

Indexed keywords

CYCLOARTENOL; LANOSTEROL; PHYTOSTEROL;

ARTICLE; BIOSYNTHESIS; ISOTOPE LABELING; PHYTOCHEMISTRY; REACTION ANALYSIS;

EID: 0030590461     PISSN: 00404039     EISSN: None     Source Type: Journal    
DOI: 10.1016/0040-4039(96)01534-1     Document Type: Article

References (12)

1. 1. (a) Zakelj, M.; Goad, L.J. Phytochemistry 1983, 22, 1931-1936;
2. (b) Misso, N.L.A.; Goad, L.J. Phytochemistry 1984, 23, 73-82.
3. 2H2O incubations with growing seedlings indicated that isomers 1 and 2, but not 3, were biosynthesized by young plants, an observation that was confirmed from subsequent in vitro enzyme assays performed on maturing roots and shoots (unpublished). SMT enzyme assays were performed in quadruplicate (n = 4), with minimal variation among the trials as discussed in the text.
4. 3. (a) Wagschal, K.; Savage, T.J.; Croteau, R.B. Tetrahedron 1991, 47, 5933-5944;
5. (b) Croteau, R.B.; Wheeler. C.J.; Cane, D.E., Ebert, R., Ha, H-J. Biochemistry 1987, 26, 5383-5389.
6. 4. Mihailovic, M.M. Dissertation ETH No. 7535 1984, 1-81.
7. 5. Venkatramesh, M.; Guo, D.; Nes, W.D. Biochim. Biophys. Acta 1996, 1299, 313-324.
8. 2H2]-Sterol was prepared from the 24-keto sterol.
9. 7. Janssen, G.G.; Nes, W.D. J. Biol. Chem. 1992, 267, 25856-25863.
10. + 441, 426, 408, 385, 259).
11. 24(25)-24-methyl sterols are never formed from direct alkylation of the 24,25-bond and is further reason to believe that the conformation of the sterol side chain in the ternary complex mediates the steric course of biomethylation of sterols cf. Zhou, W.; Guo, D.; Nes, W.D. Tetrahedron Lett. 1996, 37, 1339-1342.
12. 24(25)-24-methyl sterols are never formed from direct alkylation of the 24,25-bond and is further reason to believe that the conformation of the sterol side chain in the ternary complex mediates the steric course of biomethylation of sterols cf. Zhou, W.; Guo, D.; Nes, W.D. Tetrahedron Lett. 1996, 37, 1339-1342.