Drug Delivery System Institute, Ltd.

Tanabe Seiyaku Company, Limited

Satoshi Okuno

Toshiro Yano

Takayuki Kawaguchi

Kazuhiro Inoue

Kenji Tsujihara

Katsutoshi Aono

Teruomi Ito

Keiji Yamamoto

Masahiro Kajiki

Hiroshi Hamana

Hideo Nogusa

Shuichi Sugawara

Nobukazu Kashima

Camptothecin derivatives

A camptothecin derivative comprising a compound of the formula �I!: ##STR1## wherein R.sup.1, R.sup.2, R.sup.3, R.sup.4 and R.sup.5 are (A) adjacent two groups combine to form alkylene, or both are H, and one of the remaining three groups is --X.sub.n --Alk.sub.m --R.sup.6, and the other two are H, alkyl or halogen, or (B) adjacent two groups combine to form alkylene, and one of the carbon atoms of said alkylene group is substituted by --X.sub.n --Alk.sub.m --R.sup.6, and the remaining three groups are H, alkyl or a halogen, and one or two --CH.sub.2 -- of the alkylene in (A) or (B) may optionally be replaced by --O--, --S-- or --NH--, X is --O-- or --NH--, Alk is alkylene, R.sup.6 is --NH.sub.2, ##STR2## or --OH, m and n are both 0 or 1, or m is 1 and n is 0, which camptothecin compound is bound to a polysaccharide having carboxyl groups via an amino acid or a peptide, or a pharmaceutically acceptable salt thereof. Said camptothecin derivatives show enhanced antitumor activities but few side effects and are useful as a medicament.

A carboxymethylmannoglucan comprising tetrasaccharide units represented by the following general formula (I) and salt thereof. Further, the invention discloses a carboxymethylmannoglucan derivative and salt thereof produced by subjecting part or the whole of mannose of the tetrasaccharide units to ring opening and subjecting part or the whole of glucose which constitute the main chain but have no mannose as a branch ##STR1## wherein R.sup.1 to R.sup.12 each represent a hydrogen atom or a carboxymethyl group. The compounds are useful as carrier for delaying the disappearance of a drug in the blood and for enhancing the organotropism of the drug for a carcinoma.

Carboxymethylmannoglucans and derivatives thereof

A camptothecin derivative comprising a compound of the formula �I!: ##STR1## wherein R.sup.1 is a substituted or unsubstituted lower alkyl group, X.sup.1 is a group of the formula: --NHR.sup.2 (R.sup.2 is a hydrogen atom or a lower alkyl group) or a group of --OH, and Alk is a straight chain or branched chain alkylene group having optionally an oxygen atom in the chain thereof, bound to a polysaccharide having carboxyl groups via an amino acid or a peptide, or a pharmaceutically acceptable salt thereof. Said camptothecin derivatives show enhanced antitumor activities but few side effects unlike conventional anticancer agents, and hence, these compounds are extremely useful as a medicament.

Polysaccharide derivatives and drug carriers

N-acetylcarboxymethylchitosan derivatives and process for preparation

Growing community of inventors

Misato, Japan

Satoshi Okuno