06-08-1997 дата публикации
Номер: GB2309696A
A cyclic tetrapeptide, having antiprotozoal activity, is of the formula: -D.C.B.A- wherein: ```A is -NH.CH C(=O)-.(CH2)5.C(=O).CHR9.CH3 wherein: ```R9 is H, OH, OPO3=, OC(O)Ra or OCON(Ra)2 wherein: ```Ra is selected from: (i) C1-C10 alkyl, C3-C10 alkenyl, C3-C10 alkynyl, aryl, C3-C8 cycloalkenyl or C3-C8 cycloalkyl, each of which may be substituted by from 1 to 5 groups independently selected from hydroxy, C1-C6 alkoxy, C3-C7 cycloalkyl, aryl C1-C3 alkoxy and halogen; (ii) C1-C5 perfluoroalkyl; (iii) 5- or 6-membered ring having 1 to 4 heteroatoms selected from O, S and N, optionally substituted by 1 to 4 groups independently selected from C1-C5 alkyl, C2-C5 alkenyl, C1-C5 perfluoroalkyl, amino and halogen, which rings may be saturated or partially unsaturated; ```B and C are Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Orn, Phe, Pro, Ser, Thr, Trp, Tyr, Tyr(OCH3). Val, alpha -aminobutyric acid, HyPro, Nle, Nva, ( beta -cyclohexyl)Ala, pipecolic acid and beta -(2-thienyl)Ala; ```D is Pro, pipecolic acid. Gly, Ala, HyPro, alpha -aminobutyric acid, (N-methyl)Ala or (N-methyl)Gly.
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