Hiroshi Kondo

Asymmetric synthesis of anthracyclinones using chiral acetal: synthesis of a new chiral AB-synthon, ()-2-bromo-6-ethynyl-6-hydroxy-5, 6, 7, 8-tetrahydro-1, 4-naphthoquinone, and its application for ()-7-deoxydaunomycinone

Abstract A synthesis of a new chiral AB-synthon ( 4 ) for preparing the optically active anthracyclinones was attained through a stereospecific nucleophilic addition of trimethylsilylethynylmagnesium chloride to the chiral 2-tetralone-1-acetal ( 2 ). Synthesis of ( )-7- deoxydaunomycinone ( 1c ) was achieved by a regiospecific cycloaddition of 4 to 4-acetoxy-8-methoxyhomophthalic anhydride ( 5 ).

Diastereoselective nucleophilic addition to chiral open-chain α-ketoacetals: Synthesis of (R)- and (S)-mevalolactone

Abstract Highly stereoselective addition of Grignard reagents to chiral open-chain α,-ketoacetals ( 3a , 3b ) has been attained. Application of the reaction to syntheses of the key intermediates ( 6 , 8 ) for (R)- and (S)-mevalolactone is also described.

Diastereoselective addition of grignard reagents to chiral α-ketoacetals

Abstract High diastereoface—differenciating addition occurred in the reaction of chiral cyclic α-ketoacetals 1a and 1b with Grignard reagents

Biological Activities of Chemically Synthesized Proteus‐Type Lipid A

A bacterial lipopolysaccharide (LPS) is composed of three structural regions; an 0-polysaccharide region, a common core region, and a lipid A moiety. Lipid A is known to be responsible for various biological activities including pyrogenicity, lethal toxicity, macrophage activation, adjuvant effect, mitogenicity for B-lymphocytes, Shwartzman reaction, induction of interferon, and tumor necrosis factor, antitumor activity and so on (9). Recent chemical analyses revealed that lipid A contains a P(1 6)-linked D-glucosamine disaccharide with substituents of phos-

Regio- and stereo-selective construction of anthracyclinones: total synthesis of (–)-γ-rhodomycinone

The first asymmetric synthesis of (–)-γ-rhodomycinone (1a) was achieved through a novel regioselective coupling reaction of the chiral AB-(2) and CD-building blocks (3).

Cigarette smoking is associated with the reduction of lymphokine-activated killer cell and natural killer cell activities

Lymphokine-activated killer (LAK) cell and natural killer (NK) cell activities were determined in a group of healthy individuals with differing smoking habits. The study population consisted of 54 Japanese males, including 23 smokers, 8 ex-smokers and 23 non-smokers. Peripheral blood mononuclear cells (PBMC) were isolated and used as effector cells. LAK cells were generated by incubation of PBMC with interleukin-2 for 72 h. LAK cell activity against NK-resistant Raji cells and NK cell activity against NK-sensitive K562 cells were examined by 4-h51Cr-release assay. LAK cell activity in the smokers was significantly lower than that in the nonsmokers. The smokers showed significantly lower NK cell activity than the nonsmokers, whereas NK cell activity of the ex-smokers was comparable to that of the non-smokers. The proportion of NK cells (CD3-16+56-, CD3-16-56+, or CD3-16+56+ cells) in the smokers was significantly lower than that in the nonsmokers. The present study demonstrates for the first time that cigarette smokers have lower LAK cell activity than nonsmokers.

Effects of mental arithmetic stress on blood cell counts and the immune system

To determine whether acute mental stress alters the composition of peripheral blood cells or components of the immune system, we determined blood cell counts and leukocyte differential counts, and examined lymphocyte subsets, before, during, and after 10 min. of mental arithmetic in 20 healthy female students. During mental stress the absolute number of leukocytes, lymphocytes, CD8+ cells, and CD16+ cells increased significantly, and the rate of CD8+ cell increase was higher than CD4+ cell increase. Therefore the CD4+/CD8+ ratio decreased significantly during mental stress. Erythrocyte counts, hemoglobin concentrations and packed cell volumes remained unchanged during and after mental stress. These results demonstrate that acute mental stress is associated mainly with rapid peripheral blood lymphocyte changes, including the release of CD8+ and CD 16+ cells into circulation. The absence of significant increases in erythrocyte counts, hemoglobin concentrations, and packed cell volumes during stress indicates that changes in lymphocyte composition cannot be explained by the hemoconcentration. Thus, acute mental stress has a detectable influence on peripheral blood cell counts and the immune system.

Monte carlo calculations of mean bone marrow dose and energy imparted from CT head scanner

Because of the potential for high radiation doses in CT procedures, the object of this study was to estimate the mean bone marrow dose and the energy imparted from a 3rd generation CT head scanning procedure using Monte Carlo simulation. The simulated and calculated mean bone marrow dose (μGy) and energy imparted (mJ) per 1cm slice thickness scan are as follows:Adult 120kV,effective mAs 553mAsChild 120kV, effective mAs 213mAs173-376μGy, 16.0-18.3mJ (Western)67-136μGy, 5.5-6.5mJ (Western)110-208μGy, 16.0-18.3mJ (Japanese)64-120μGy, 5.5-6.5mJ (Japanese)