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Y Zama

Publications and source records attributed to Y Zama.

4 recordsLinked to original sources
PubMed1995

New compressed tablet rapidly disintegrating in saliva in the mouth using crystalline cellulose and a disintegrant.

We formulated a new compressed tablet which is rapidly disintegrated and dissolved in the mouth without the need to drink water. The crushing strength increased with increasing compression force and maximum values (8-18 kgf) for the formulations comprising crystalline cellulose and low-substituted hydroxypropylcellulose (L-HPC) were obtained at the compression force of 300 kgf. Rapid disintegration (within 30 s) was obtained in vitro using various compounding ratios of crystalline cellulose to L-HPC. Tablets prepared with crystalline cellulose and L-HPC rapidly disintegrated in saliva (small amount of water) in the mouth of humans.

Cellulose↗
PubMed1984

T4 RNA ligase mediated preparation of novel "chemically misacylated" tRNAPheS.

T4 RNA ligase was employed for the condensation of Escherichia coli tRNAPhe missing cytidine-75 and adenosine-76 (tRNAPhe-COH; the acceptor "oligomer") with each of several chemically acylated derivatives of pCpA (the donor "oligomer"). The resulting "chemically misacylated " tRNAPheS were obtained in 20-65% yields following chromatographic workup on DEAE-cellulose and benzoylated DEAE-cellulose. Characterization of the chemically misacylated tRNAs was accomplished by (i) enzymatic reaminoacylation of chemically misacylated tRNAPhe with phenylalanine by E. coli phenylalanyl-tRNA synthetase following chemical deacylation of the "incorrect" amino acid, (ii) comparison of the hydrolytic effects of Cu2+ solutions on chemically and enzymatically prepared samples of N-acetyl-L-phenylalanyl- tRNAPheS , and (iii) measurement of the chromatographic behavior of the tRNA species derived from chemical misacylation .

Escherichia coli↗
PubMed1983

Dipeptide formation with misacylated tRNAPhes.

Several misacylated P-site tRNAs have been prepared by the T4 RNA ligase-mediated coupling of Escherichia coli tRNAPhe missing the 3'-terminal cytidine and adenosine moieties and N-acetylaminoacyl-pCpA derivatives. The reaction proceeded in reasonable yield in each case and the tRNA products were purified conveniently by successive chromatographies on DEAE-cellulose and benzoylated DEAE-cellulose. The misacylated tRNAPhes were assayed for participation in the peptidyltransferase reaction, using E. coli ribosomes and poly(U) as message. When phenylalanyl-tRNAPhe was employed as the A-site tRNA, "chemically aminoacylated" N-acetyl-L-phenylalanyl-tRNAPhe produced dipeptide to virtually the same extent as authentic N-acetyl-L-phenylalanyl-tRNAPhe, which was prepared by enzymatic activation of tRNAPhe followed by chemical acetylation. Significant dipeptide formation was also obtained with N-acetyl-L-tyrosyl-tRNAPhe, but much less dipeptide was obtained when the D-isomers of these two N-acetylaminoacyl-tRNAs were employed in the same assay system. Interestingly, N-acetyl-beta-phenylalanyl-tRNAPhe formed dipeptide at least to the same extent as authentic N-acetyl-L-phenylalanyl-tRNAPhe.

Acylation↗