| abstract |
PCT No. PCT/JP93/01075 Sec. 371 Date Jun. 24, 1994 Sec. 102(e) Date Jun. 24, 1994 PCT Filed Jul. 30, 1993 PCT Pub. No. WO94/03424 PCT Pub. Date Feb. 17, 1994According to the present invention, a novel compound group which can pass through blood-brain barrier (BBB) with carrying a drug thereon and stay within brain to release the drug and a well-known compound group having the properties described above are provided. The compound represented by the general formula <IMAGE> (Ia) wherein, R1 represents C1-6 alkyl which may be substituted by a group selected from hydroxyl, carboxyl, amino group which may be substituted by C1-6 alkyl, and a five- to seven-membered saturated heterocyclic ring, R2 represents hydrogen or C1-6 alkyl, R3 represents hydrogen or C1-6 alkyl which may be substituted by hydroxyl, R4 represents hydrogen or C1-6 alkyl, R5 represents an amino acid residue, or -S-R6 or -CO-R6 wherein R6 represents C1-14 alkyl which may be substituted by a five- to seven-membered saturated ring; C2-6 alkenyl; aryl; or a five- to seven-membered saturated ring; or the group represented by the general formula (IVa): <IMAGE> (IVa) wherein R1, R2, R3 and R4 have the same meanings as defined above, and +E,uns xxxxxxxxx+EE represents a single bond or a double bond provided that at least one of R1, R3 and R5 contains hydroxyl, carboxyl or amino, and a salt thereof. |