216 



(2) Dibenzyls 



BIOCHEMICAL SYSTEMATICS 



r\ 



CH2 



\h2 



dihydropinosylvin monomethyl ether 



(3) Flavanones 



HO HO O 



pinocembrin pinostrobin 



cryptostrobin, either 6 or 8-methyl pinocembrin 



(4) Flavones 



HO 



HO 



tectochrysin, 7 methoxychrysin 

 strobochrysin, 6 methylchrysin 



(5) Flavonols 



HO 



pinobanksin (2:2-dihydrogalangin) 

 strobobanksin 6-(8?), methyl 

 2 : 3-dihydrogalangin 



(6) Flavonols: none 



(7) Cyclitols: pinitol (d-inositol, sequoyitol and myoinositol 

 reported from P. lambertiana) 



According to Erdtman the generic sub-groups Haploxylon and 

 Diploxylon differ chemically, but Mirov, as noted elsewhere (Chapter 

 13), did not find this to be a feature of the terpene chemistry of the 

 genus. The tables in Erdtman however show clearly that the Diploxy- 

 lon group has the simpler heart wood chemistry; for example, most of 

 the compounds listed above are to be found in Haploxylon species 



