Patents by Inventor Tomo Jikihara

Tomo Jikihara has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 4357466
    Abstract: 3'-Deoxykanamycin A useful as antibacterial agent is produced from a protected kanamycin A derivative either by a process comprising imidazolylthiocarbonylation of the 3'- and 2"-hydroxyl groups of 4",6"-O-cyclohexylidene-4'-0:6'-N-carbonyl-5,2'-O-isopropylidene-1,3,3"-tr i-N-tosylkanamycin A, preferential removal of the 3'-imidazolylthiocarbonyloxy group with tributyltin hydride for the 3'-deoxygenation, followed by removal of the 2"-O-imidazolylthiocarbonyl group with aqueous ammonia, removal of the N-tosyl groups with alkali or alkaline earth metal in liquid ammonia, hydrolytic fission of the 4',6'-cyclic carbamate ring and concurrent removal of the 5,2'-O-isopropylidene group and 4",6"-O-cyclohexylidene group, or by a process comprising selective acetylation of the 2"-hydroxyl group of said protected kanamycin A derivative with acetyl chloride in pyridine, trifluoromethanesulfonylation of the 3'-hydroxyl group, followed by concurrent removal of the 3'-trifluoromethanesulfonyloxy group and N-tosyl groups w
    Type: Grant
    Filed: October 20, 1980
    Date of Patent: November 2, 1982
    Assignee: Zaidan Hojin Biseibutsu Kagaku Kenkyu Kai
    Inventors: Hamao Umezawa, Sumio Umezawa, Tsutomu Tsuchiya, Tomo Jikihara
  • Patent number: 4297485
    Abstract: Aminoglycosidic antibiotic comprising a 6-0-(3"-aminoglycosyl)-2-deoxystreptamine optionally having a 4-0-(aminogycosyl) group, such as kanamycins, gentamicins, sisomicin, forms reversible complex with zinc cations by association of the zinc cations with some pairs of aminohydroxyl groups in the aminoglycoside, and the zinc-complexed amino groups are blocked from acylation. Reaction of this zinc complex with an acylation reagent having an amino-blocking acyl group brings about acylation of the non-complexed amino groups to give an N-acylated zinc complex, namely a complex of zinc cation with an N-acylated aminoglycosidic antibiotic derivative. Removal of zinc cations from N-acylated zinc complex yields a partially N-acylated aminoglycosidic antibiotic where 1- and 3"-amino groups are unprotected but all other amino groups protected with acyl group.
    Type: Grant
    Filed: November 2, 1979
    Date of Patent: October 27, 1981
    Assignee: Zaidan Hojin Biseibutsu Kagaku Kenkyu Kai
    Inventors: Hamao Umezawa, Sumio Umezawa, Tsutomu Tsuchiya, Yasushi Takagi, Tomo Jikihara