Mevalonate is an intermediate in isoprenoid biosynthesis. It is product of the reaction catalyzed by HMG-CoA reductase, as follows:

HMG-CoA + 2 NADPH + H⁺  <=> Mevalonate + CoASH + 2  NADP⁺ (Figure 19.18)

Subsequently, mevalonate is converted to 5-phosphomevalonate, as shown in Figure 19.19.

1. Terpenoid Biosynthesis

2. Sterol Biosynthesis