Kazuyuki Nakagawa

Triterpenoid glycosides from leaves of Ilex cornuta

Abstract Two new triterpene glycosides have been isolated from the methanol extract of leaves of Ilex cornuta . Their structures were established as pomolic acid 3β- O -α- l -2-acetoxyarabinopyranosyl-28- O -β- d -glucopyranoside and 29-hydroxyoleanolic acid 3β- O -α- l -arabinopyranosyl-28- O -β- d -glucopyranoside on the basis of spectroscopic data and chemical evidence. Adenosine was identified as the active principle of the methanol extract which is responsible for the increase of coronary blood flow in the isolated blood-perfused dog heart preparation.

An acylated sitosterol glucoside from Alisma plantago-aquatica

Abstract A phytosterol glucoside acylated with stearic acid has been isolated from the methanol extract of the rhizome of Alisma Plantago-aquatica , and its

Triterpenoids from the rhizome of Alisma plantago-aquatica

Abstract Two new protostane-type triterpenes have been isolated from the methanol extract of the rhizome of Alisma plantago-aquatica . Their structures have been elucidated as 16β-methoxyalisol B monoacetate and 16β-hydroxyalisol B monoacetate mainly on the basis of spectroscopic data.

The Metabolism of a Bronchodilator Procaterol HCl in the Rat in vitro and in vivo

1. The metabolism of the bronchodilator, 5-(1-hydroxy-2-isopropylamino-butyl)-8-hydroxycarbostyril hydrochloride hemihydrate (procaterol HCl), has been studied in vitro and in vivo after oral and intravenous administration to rats. 2. The recovery of [14 C] procaterol HCl and its metabolites in 72 h was about 42% each in urine and faeces for an oral dose (30 mg/kg) and about 53% in urine and 33% in faeces for an intravenous dose (30 mg/kg). 3. Six metabolites in rat excreta were identified as procaterol glucuronide, 5-(2-amino-1-hydroxybutyl)-8-hydroxycarbostyril (desisopropylprocaterol), 5-formyl-8-hydroxycarbostyril (5-formyl-8-HCS), 8-hydroxycarbostyril (8-HCS), procaterol sulphate and unchanged procaterol. 4. In experiments in vitro, procaterol HCl was metabolized into desisopropylprocaterol, 5-formyl-8-HCS, and their conjugates, by rat liver 9000 g supernatant fraction, but not by preparations of kidney, lung and small intestine. Conjugation of procaterol HCl with glucuronic acid occurred in liver and small intestine preparations.

Stable Thioaldehydes : Synthesis, Structure Assignment, and Stability of 6-Amino-5-thioformyluracils.

Abstract Stable 6-amino-5-thioformyluracils 3a-e were synthesized starting from 6-amino-1,3-disubstituted uracils 1a-e in 23–98 % yields. According to the x-ray crystal structure, although the thioaldehyde 3c possesses reasonable double-bond character of the C=S bond, the length of C=S bond of the thioaldehyde 3c is longer than those of the kinetically stabilized thioaldehydes due to the mesomeric effect of the 6-amino group.

Synthesis and biological properties of substituted 1,4-dihydro-5-methyl-4-oxo-3-quinolinecarboxylic acids

A series of substituted 1-cyclopropyl-6-fluoro-1, 4-dihydro-5-methyl-4-oxo-3-quinoline carboxylic acids was synthesized and tested for their in vitro and in vivo antibacterial activity. The introduction of a methyl group at the 5-position of quinoline nucleus enhanced characteristically the antibacterial activity against Gram-positive bacteria, including Streptococcus pneumoniae, which is a major pathogen in the respiratory tract infection, while retaining Gram-negative activity. Among them, 1-cyclopropyl-6-fluoro-1, 4-dihydro-5-methyl-7-(3-methyl-1-piperazinyl)-4-oxo-3-quinolinecarboxyli c acid hydrochloride (grepafloxacin) exhibited potent in vitro antibacterial activity against Gram-positive bacteria such as Streptococcus pneumoniae and high in vivo efficacy on the experimental systemic infections caused by the Gram-positive and -negative bacteria tested. It also showed a high distribution to the lung and bronchoalveolar lavage fluid in comparison to reference drugs and is now undergoing clinical evaluation.

The Metabolites of Procaterol HC1 in Urine and Faeces of Dog and Man

1. The metabolites of procaterol HC1 in dog urine and faeces and in human urine were qualitatively analysed by an improved g.l.c.-mass spectrometric method.2. Trimethylsilylated derivatives of procaterol metabolites were identified by mass fragmentography as procaterol glucuronide, 5-(2-amino-1-hydroxybutyl)-8-hydroxycarbostyril (desisopropylprocaterol), 5-formyl-8-hydroxycarbostyril, 8-hydroxycarbostyril and unchanged procaterol.3. The metabolic pattern of procaterol HC1 was species-independent in rats, dogs and man.