Higher homologues of cycloheptatriene,tropylium ion and oxepin : The demonstration of a diamagnetic and paramagnetic ring current in novel [15]annulene systems

Syntheses of 4,7:10,13-dioxido-cyclopentadecaheptaene (2.4.6.8.10.12.14) 8, 4,7:10,13-dioxido-cyclopentadecaheptaenyl tetrafluoroborate 10, and 1-oxa-4,7:10,13-dioxido-cyclopentadecaheptaene (2.4.6.8.10.12.14) 13 are described. As expected, the NMR spectrum of 10 exhibited a marked diamagnetic ring current, and that of 13 a paramagnetic ring current. These [15]annulenes 8, 10, and 13 are looked upon as the corresponding higher member of cycloheptatriene, tropylium ion, and oxepin, respectively.Attempted preparation of sulphur containing 1-thia[15]annulene was unsuccessful, presumably because of its increased antiaromatic character.     

Recognition of hepatotoxic homologues of Microcystin using a combination of selective adsorption media

Microcystin, a hepatotoxin produced by cyanobacteria, was chromatographically discriminated with newly prepared selective adsorption media. Since the name Microcystin refers to up to 70 different homologues, we have developed a novel technique to prepare selective recognition sites, based on the "Fragment Imprinting Effect". The homologues of Microcystin can be individually discriminated from each other by antigen-antibody assay as well as by C18-based HPLC. This is mainly due to differences in the three dimensional structure of Microcystin homologues; however, differences in toxicity are relatively small among the homologues. Therefore we have to measure the total amount of Microcystin homologues present to determine contamination by Microcystins. We have demonstrated the first group recognition for Microcystin homologues through combination of two different selective adsorption media prepared by a fragment imprinting technique.     

Target-selective ion-exchange media for highly hydrophilic compounds: a possible solution by use of the “interval immobilization technique”

We prepared a crosslinked polymer as a separation and/or adsorption medium for CYN, as shown in Fig. 1. The polymers were evaluated by high-performance liquid chromatography (HPLC) and adsorption was examined under batch conditions. Results from detailed HPLC evaluation and measurement of the difference between the binding affinity for CYN and for other compounds showed the prepared polymer had specific recognition ability for CYN.     

Chemistry of renieramycins. Part 4.synthesis of a simple natural marine product, 6-hydroxy-7-methoxyisoquinolinemethanol

6-Hydroxy-7-methoxyisoquinolinemethanol (15) and mimosamycin (1) were recently isolated from a marine sponge, Haliclona sp. The former was prepared in ten steps from vanillin (22) in 26% overall yield using an isopropyl for phenol protection.     

Segal-Bargmann transforms of one-mode interacting Fock spaces associated with Gaussian and Poisson measures

Let and denote the Gaussian and Poisson measures on , respectively. We show that there exists a unique measure on such that under the Segal-Bargmann transform the space is isomorphic to the space of analytic -functions on with respect to . We also introduce the Segal-Bargmann transform for the Poisson measure and prove the corresponding result. As a consequence, when and have the same variance, and are isomorphic to the same space under the - and -transforms, respectively. However, we show that the multiplication operators by on and on act quite differently on .

     

Effect of reticuloendothelial blockade on tissue distribution of 99mTc-labeled synthetic liposomes in Ehrlich solid tumor-bearing mice

The effect of a reticuloendothelial blockade was examined on the tissue distribution of 99mTc-labeled synthetic liposomes prepared from N,N-didodecyl-N alpha-[6-(trimethylammonio)hexanoyl]-L-alaninamide bromide (N+C5Ala2C12) in Ehrlich solid tumor-bearing mice. While a pre-dose of unlabeled phosphatidyl choline liposomes (natural liposomes) hardly influenced the tissue distribution of N+C5Ala2C12 liposomes, the pretreatment of dextran sulfate depressed the uptake in liver accompanied by increasing that in tumor and other tissues except the stomach. However, the extent of liver depression of N+C5Ala2C12 liposomes by dextran sulfate was lower than that of natural liposomes and the pre-dose of unlabeled natural liposomes had a minor effect on the tissue distribution of N+C5Ala2C12 liposomes compared with that of natural liposomes. In the liver uptake of N+C5Ala2C12 liposomes, it was suggested that Kupffer cell phagocytosis was not the main mechanism.