The inverse proportionality
between total catechins and total anthocyanins in the unaerated
tea of the purple coloured cultivars, which most closely represents
the situation obtained in the fresh leaf of these cultivars, may be
due to the preferential upregulation of the genes responsible for
anthocyanin synthase in the pathway for anthocyanins biosynthesis, rather than the one for leucoanthocyanin reductase in the catechin biosynthetic pathway; this was probably due to response to
some environmental stimuli (Punyasiri et al., 2004) since both
compounds are secondary metabolites derived from the general
phenyl propanoid pathway.