Dihydro-p-coumaric acid

A major pathway to mesembrenol (29) by cinnamic acid, / -coumaric acid (31), and the corresponding dihydro-p-coumaric acid involves sceletenone (32), an efficient precursor for mesembrenol (29) (Fig. 33.8). This suggests that hy-droxylation of the aromatic ring occurs at a late stage of biosynthesis. 

Hydroxy benzenepropanoic acid, 9CI. 3- Hydroxy phenyl) propionic acid, SCI. Dihydro-p-coumaric acid. 4-Hydroxyhydrocinnamic acid. Phloretinic acid. HPPA [501-97-3]... 

In a series of feeding experiments, it was found that phenylalanine, cinnamic acid, wera-coumaric acid, and dihydro-m-coumaric acid were good precursors for orchinol (20) and hircinol (21) in Orchis militaris, but o- and p-coumaric acids were not. The production of both meta-substituted compounds in this orchid was confirmed (Dewick, 1984). Incor-... 

Occurrence in the Solanaceae. p-Coumaric acid, caffeic acid, methyl caffeate, and methyl ferulate as well as certain of their 2,3-dihydro derivatives have been identified as constituents of the leaves of Cestrum parqui L Herit. with good phytotoxic activity against different species (D Abrosca et al. 2004). Family-specific phenylpropanoid acids like tropic acid or 2-hydroxytropic acid as acyl moieties of tropane alkaloids are synthesized via phenylalanine -> phenylpyruvic acid (l )-3-phenyllactic acid (Fig. 3.14 Table 3.1 (T5-T7-B)]. Tropic acid may occur as a metabolite of, e.g., hyoscyamine, but the free acid is not synthesized as such (for details see Sect. 3.4). 

---