Stachyurus

Abstract: Three new complex tannins, stachyuranins A (1), B (2) and C (3), were isolated from the leaves of Stachyurus praecox (Stachyuraceae), and their structures, each consisting of a catechin or gallocatechin residue and a monomeric hydrolyzable tannin moiety, were assigned. Structures 1 and 2 lack a C-C linkage between glucose C-1 and the aroyl group at glucose O-2, suggesting that they may be biogenetic precursors of complex tannins with the C-C linkage.

Abstract: Stachyuraceae consist of a single genus Stachyurus with about ten species endemic to eastern Asia. The family was recently shown to be sister to the western North American Crossosomataceae. The phylogeny of Stachyuraceae and its relatives was reconstructed based on sequences of four chloroplast DNA regions (trnL intron and adjacent trnL-trnF spacer, rpsl6 intron, ndhF gene, trnS-trnG-trnG region) and the nuclear ribosomal ITS region. The monophyly of Stachyurus was strongly supported. The divergence time between Stachyuraceae and Crossosomataceae was estimated to be 68.25 ± 10.36 million years ago (MYA) using the penalized likelihood method based on rbcL sequences data with fossil calibration. Stachyurus sigeyosii was previously synonymized as S. himalaicus, but our analysis shows that it is sister to the morphologically highly distinct S. praecox from Japan and does not form a clade with S. himalaicus.