Tsuyoshi Miura

Pharmacognostic studies on ginger and related drugs—part 1: five sulfonated compounds from Zingiberis rhizome (Shokyo)

Five sulfonated compounds, namely 4-gingesulfonic acid and shogasulfonic acids A, B, C and D, were isolated together with seven known compounds including 6-gingesulfonic acid from Zingiberis rhizome (Japanese name: Shokyo) made out of ginger. Their structures were characterized by means of spectroscopic analysis.

SYNTHETIC SIALYLPHOSPHATIDYLETHANOLAMINE DERIVATIVES BIND TO HUMAN INFLUENZA A VIRUSES AND INHIBIT VIRAL INFECTION

We synthesized the sialylphosphatidylethanolamine (sialyl PE) derivatives Neu5Ac-PE, (Neu5Ac)2-PE, Neu5Ac-PE (amide) and Neu5Ac-PE (methyl). We examined the anti-viral effects of the derivatives on human influenza A virus infection by ELISA/virus-binding, hemagglutination inhibition, hemolysis inhibition and neutralization assays. The sialyl PE derivatives that we examined bound to A/Aichi/2/68, A/Singapore/1/57 and A/Memphis/1/71 strains of H3N2 subtype, but not to A/PR/8/34 strain of H1N1 subtype. The derivatives inhibited viral hemagglutination and hemolysis of human erythrocytes with A/Aichi/2/68 and A/Singapore/1/57 (H3N2), but not with A/PR/8/34 (H1N1). The inhibitory activity of the (Neu5Ac)2-PE derivative was the strongest of all sialyl PE derivatives (IC50, 35 μM to 40 μM). Sialyl PE derivatives also inhibited the infection of A/Aichi/2/68 in MDCK cells. Complete inhibition was observed at a concentration between 0.3 to 1.3 mM. IC50 of (Neu5Ac)2-PE was 15 μM in A/Aichi/2/68 strain. Taken together, the synthetic sialyl PE derivatives may be effective reagents against infection of some types of influenza A viruses.

Application of l-threonine aldolase-catalyzed reaction for the preparation of a peptidic mimetic of RNA: A leading compound of Vero-toxin inhibitors

Abstract A peptidic mimetic of RNA having a guanine-adenine-guanine code as a base sequence was prepared as a leading compound of Vero-toxin inhibitors. The synthesized hexapeptide is composed from two γ-guanyl-β-hydroxy-α- l -amino acids and one γ-adenyl-β-hydroxy-α- l -amino acid, which were prepared by using l -threonine aldolasecatalyzed reaction, in addition to three glycines. On designing this peptide, the β-hydroxyl groups in the novel α-amino acids are compared to the 2′-hydroxyl groups of RNA, and glycine was chosen as the mimic of the phosphate groups in the RNA backbone.

Requirement of the glycosyl parts in platycodin D to stimulate pancreatic exocrine secretion.

The whole structure of platycodin D is found to be essential to stimulate the volumetric increase in the pancreatic exocrine secretion, while the prosapogenins prepared from platycodin D increased only protein output of pancreatic juice.