Seven novel seco-prezizaane-type sesquiterpenes from the pericarps of Illicium merrillianum

Seven new seco-prezizaane-type sesquiterpenes were isolated from the methanol extract of the pericarps of Illicium merrillianum. Their structures were elucidated as 3-deoxypseudoanisatin (1), 2beta-hydroxy-3,6-dedioxypseudoanisatin (2), 8alpha-hydroxy-10-deoxycyclomerrillianolide (3), 10beta-hydroxypseudoanisatin (4), 10beta-hydroxycyclopseudoanisatin (5), 1,6-dihydroxy-3-deoxyminwanensin (6), and 8-deoxymerrilliortholactone (7) by analyses of their spectroscopic data and chemical transformation. Compounds 4 and 5 as well as 6 and 7 coexist as a keto/acetal equilibrated mixture in methanol solution.     

In Situ Immobilization of Ultrafine Particles Synthesized in a Water/Oil Microemulsion

We investigated the in situ immobilization of ultrafine particles synthesized in a water/oil (w/o) microemulsion to silica for its possible application to supported metal catalysts. ZnS particles immobilized to silica by the ME method were consistent with those synthesized in a w/o microemulsion. Therefore, ZnS particles in a w/o microemulsion could be immobilized to silica without aggregation by this method. The relationship between the method of synthesizing Rh ultrafine particles in a w/o microemulsion and the diameter and diameter distribution of Rh particles immobilized to silica was studied. Rh-SiO(2) catalysts with a sharp diameter distribution could be prepared by immobilizing Rh-hydrazine complex particles because these complex particles would be very stable in a w/o microemulsion. The Rh particle diameters of Rh-SiO(2) catalysts prepared by changing the amount of silica produced were almost identical. Accordingly, the Rh particle diameter of Rh-SiO(2) catalysts could be controlled independently of Rh content by the ME method. Copyright 2001 Academic Press.     

Oxidation of alcohols with oxoperoxobis(N-phenylbenzohydroxamato)molybdenum(VI)

The title complex oxidizes primary and secondary alcohols to the corresponding carbonyl compounds. Stereoselective epoxidation of allylic alcohols is also described.     

Evaluation of radioimmunoassay of the blood tobramycin level for the purpose of setting the dosage based on the clinical pharmacokinetic theory and a comparison of radioimmunoassay with other assay methods

With the purpose to use for therapeutic drug monitoring (TDM), blood concentrations of tobramycin (TOB) in each patient were measured by radioimmunoassay (RIA). A RIA kit of TOB (Clinical assay-Japan Travenol) was evaluated for precision and recovery, in that partial improvement of the method was made, in order to measure low level of TOB. The RIA was compared with high-performance-liquid-chromatography (HPLC), bioassay (BA) and 2 kinds of enzyme immunoassay (EIA) (EMIT and SLFIA). The RIA of TOB revealed high precision (1.8-2.4% in C.V.) and high reproducibility (5.0-6.9% in C.V.). It was found that this RIA kit can be used for measuring low level of serum TOB concentrations by a modification of the method. The total range of measurable blood level is from 0.1 to 16.0 micrograms/ml. The nearly one to one correspondence was observed between RIA and other 4 methods, when 154 samples obtained from 18 cases were measured. A representative case of TDM for TOB was demonstrated, in which predicted concentrations agreed fairly well with actual measured values at steady state. It was concluded that the RIA kit is useful for clinical application of TDM for the adequate dosage regimen of TOB. Modification of the method for rapid assay of a small number of samples will increase the clinical usefulness.     

New triterpenes from a Chinese medicine, goreishi

Besides serratagenic acid, three new ursane-type triterpenes, named goreishic acids I (1), II (2), and III (3), were isolated from a Chinese medicine, Goreishi (the feces of Trogopterus xanthipes Milne-Edwards). The structures of 1, 2 and 3 were respectively determined as 2 alpha,3 beta-dihydroxyursa-12,18-dien-28-oic acid, 2 alpha,3 beta-dihydroxy-23-norursa-12,18-dien-28-oic acid and 2 alpha,3 beta-dihydroxy-24-norursa-12,18-dien-28-oic acid on the basis of spectroscopic evidence.