Ferulic-Acid Esters of Oligo-glucose from A-ilium macrostemon.

Two new ferulic acid esters of oligo-glucose, 1-Ο-(E)-feruloyl-ß--D-gentiobioside (1) and 1-Ο-(E)feruloyl-{ß-D-glucopyranosy (1->6)-[ß-D-glucopyranosyl (I--2)]}-ß-D-glucopyranoside.(allimacronoid D, 2) were isolated together with 1-Ο-(E)-feruloyl-ß-D-glucopyranoside (3) and trans-ferulic acid (4) from the leaves of Allium macrostemon Bunge. The chemical structures were elucidated based on the analyses of the spectroscopic and chemical data.

Genetic structure of a population of Potato virus Y inducing potato tuber necrotic ringspot disease in Japan; comparison with North American and European populations.

The structure of Potato virus Y (PVY) populations causing potato tuber necrotic ringspot disease (PTNRD) was analysed. The full-length sequences of the genomic RNAs of five geographically distinct isolates from Japan were determined. Recombination and phylogenetic analyses of European, North American and Japanese isolates of PVY showed that the world PVY population has three major lineages and two sublineages. Most recombinants were interlineage, and one isolate from Europe was identified as an intralineage recombinant. No recombinants were found among Japanese PTNRD isolates, which were most closely related to PTNRD isolates previously found in North America. Comparison of the within- and between population nucleotide diversities in the N lineage sequences from Japan, Europe and North America showed that Japanese population was distinct from the European and North American populations. The nucleotide sequences of the protein 1 and coat protein genes of a further 18 isolates were determined. One Japanese clade had radiated in a star burst as shown by its deviation from the neutral equilibrium model and its small nucleotide diversity. Our results suggest that PVY PTNRD was recently introduced into Japan more than once, and has expanded throughout Japan from founder populations.