Pfizer Handbook of Microbial Metabolites 



92 



explanation of this effect, and this interesting work has been 

 reviewed.^' ^° 



Some of the relationships thought to exist are : 



CH, 



CH3 



\ 



o-Ketoglutarate 



CH— CHr- CH— COOH <- 



Glufamate 

 CH3 



CoA— SH 



NH2 



Leucine 

 CO2 



transaminase, 

 pyridoxal CH3 



phosphate 



CH— CH2— C— COOH 



a-Ketoisocaproic Acid 



CH3 



o-ketoacylde- 

 hydrogenase, 

 thiamin 

 pyrophosphate 



CH3 



\ 

 < 



CH— CHo- C— S— CoA 



Isovaleryl 

 Coenzyme A 



acylde- 

 hydrogenase 



flavin 

 flavin — H2 



ADP ATP 



O \ biotin f CH3 O 



II v CO2 y \ II 



HOOC— CH2— C=CH— C— S— CoA <-^^^ — ^— ^ C=CH— C— S— CoA 



CH3 



/3-Methylglutaconyl CoA 



H2O 



/3-methyl- / 



glutaconyl CH3 

 carboxylase 



/3,/3-Dimethylacrylyl CoA 

 (SenecioyI CoA) 



/S-^methyl- 

 /^ glutaconase 



CH3 



HOOC— CH2—C—CH2—C—S— CoA 



I 

 OH 



^-Hydroxy-/3-methyl 

 glutaryl-CoA 



" G. E. W. Wolstenholme and Maeve O'Connor, "CIBA Foundation 

 Symposium on the Biosynthesis of Terpenes and Sterols," M. J. 

 Coon, F. P. Kupiecki, E. E. Dekker, M. J. Schlesinger and Alice del 

 Campillo, The enzymic synthesis of branched-chain acids. Little, 

 Brown and Co., Boston, Mass., 1959, pp. 62-74. 



^" Idem., ibid., Harry Rudney, The biosynthesis of P-hydroxy-fi- 

 methylglutaryl coenzyme A and its conversion to mevalonic acid, 

 pp. 75-94. 



