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Biomedical subjects

A Takatsuki

Publications and source records attributed to A Takatsuki.

At least 73 records · Page 4Linked to original sources
PubMed1979

Biologically active polycycloalkanes. 6. Antiviral 1-tricyclo[4.3.1.1 2,5]undecyl derivatives.

Functionalization reactions via cationic intermediates of tricyclo[4.3.1.1 2,5]undecane (2) were investigated to prepare derivatives with potential antiviral activities. Bromination of 2 took place regiospecifically at C-1, and the resulted bromide 5 was converted into the hydroxide 9, the carboxylic acid 12, and the amine 22, from which were synthesized a variety of secondary derivatives, including homologous esters 10 and 20, amides 14 and 19, carbamates 24, and ureas 17 and 25. The hydroxide 9, the acid 12, and the acetamide 21 were also obtainable directly from tricyclo[5.2.1.0 2,6]dec-endo-2-ylcarbinol (1), the precursor for the synthesis of the hydrocarbon 2. Success in these functionalization-rearrangements was attributed to the inability of the intermediate 2-1-yl cation (2+) for further skeletal isomerizations. Among the 1-substituted derivatives of 2 prepared, the amine hydrochlorides (16 and 23), a few esters (20b and 20d), and some N-alkylamides (19c, 19d, and 19e) exhibited marked antiviral activities as compared to amantadine hydrochloride, when tested in vitro on a monolayer culture of chick embryo fibroblasts against Newcastle disease virus.

Animals↗
PubMed1978

Glycosylation of interferons. Effects of tunicamycin on human immune interferon.

Human immune interferon, induced in leukocytes by phytohemagglutinin, was prepared in the absence and presence of tunicamycin, an antibiotic which selectively inhibits the glycosylation of newly synthesized glycoproteins. Interferon preparations, produced in the absence of the antibiotic, displayed a considerable chromatographic heterogeneity on: (a) concanavalin A-agarose, (b) phenyl-agarose, (c) Cibacron Blue F3GA-agarose, and (d) polyuridylic acid-agarose. This heterogeneity was completely eliminated when tunicamycin (2 microgram/ml) was present during induction of interferon; all activity was then recovered in the breakthrough fractions from all sorbents. The level of interferon activity in leukocyte culture fluid was not affected by tunicamycin within the range of concentration 0.05 to 2.0 microgram/ml. These data indicate that (a) human immune interferon undergoes glycosylation, and tunicamycin is an effective inhibitor of this process. Thus, it appears that (b) at least some of the carbohydrates of human immune interferon are N-glycosidically linked. Moreover, it seems that (c) glycosylation is not necessary for an interferon molecule to either be secreted by the cell or (d) to express its antiviral function. Such properties of human immune interferon as (e) the apparent hydrophobicity and (f) an affinity for a polyribonucleotide are conferred only when its glycosylation is unimpaired.

Glucosamine↗
PubMed1975

Biologically active polycycloalkanes. 1. Antiviral adamantane derivatives.

Convenient methods for the synthesis of 1-substituted 3-adamantyl chlorides and bromides (2), 1-adamantylphenols and -cresols (3), and 1-adamantylacetic (6) as well as 1,3-adamantanediacetic (11) acids are described. Several novel derivatives were synthesized from these key intermediates: adamantylcyclohexanols (4) and -cyclohexanones (5) from adamantylphenols (3), and esters (7,12, and 22), amides (13 and 18), thioamides (9 and 16), amidine (10), nitrile (15), and amines (14 and 17) from 1-adamantanecarboxylic (19) and -acetic (6) acids and 1,3-adamantanediacetic acid (11). Some adamantylpyrimidines (24) and -purines (25 and 26) were also prepared. Antiviral activities of the compounds obtained in this work and a series of new 1-adamantyl alkyl ketones synthesized before, together with those of some known adamantane derivatives, were tested in vitro on monolayer culture of chick ambryo fibroblasts against Newcastle disease virus.

Adamantane↗
PubMed1969

Antiviral and antitumor antibiotics. XIV. Effects of ascochlorin and other respiration inhibitors on multiplication of Newcastle disease virus in cultured cells.

Antiviral activity on Newcastle disease virus was examined with some respiration inhibitors including ascochlorin, rotenone, antimycin A(3), piericidin A, dicoumarol, 2, 4-dinitrophenol, pentachlorophenol, and fatty acids. Of the chemicals tested, ascochlorin and rotenone showed significant inhibitory effect on the viral growth in cultured cells as determined by the plate and tube assay methods. Dose response of ascochlorin and rotenone was observed in rate and final yield of hemagglutinin synthesis. Ratio of infectivity for hemagglutinin was nearly equal at any test concentrations of ascochlorin. Thus, the possibility of inhibition of virus maturation by the antibiotic was excluded. Ascochlorin had no activity on virus particles and on viral adsorption onto host cells.

Adsorption↗
PubMed1969

Antiviral and antitumor antibiotics. XX. Effects of rotenone, deguelin, and related compounds on animal and plant viruses.

Rotenoids and related compounds were investigated for their effects on animal and plant viruses. Of 35 compounds examined, rotenone, rotenone norketone, acetylrotenone, acetylrotenone norketone, deguelin, deguelic acid, dehydrodeguelin, and isotubanol norketone, all used at low concentrations, suppressed the growth of Newcastle disease and herpes simplex viruses as determined by the agar diffusion, plaque inhibition method. Most of the compounds likewise decreased the number of necrotic spots on tobacco mosaic virus-infected leaf discs. Only derrisic acid completely inhibited the local lesion formation at subphytotoxic concentrations. Correlation of antiviral activity with respiratory inhibition of these compounds is discussed.

Animals↗