Snow Brand Milk Products Co., Ltd.

Noboru Kwaguchi

Susumu Ishiguro

Shin Nomoto

Yasuyoshi Takeshita

Motohide Seya

Shin'ichi Shimada

Tadayoshi Koyama

Hiroshi Nakamura

Noriko Abe

The invention provides novel compounds and salts thereof, have the structure ##STR1## wherein R.sub.1 is a guianidinobenzoyloxy group and R.sub.2 is a hydrogen atom, a hydroxy, cyano, --COR.sub.3 (wherein R.sub.3 is an amino or lower alkyl group) or --COOR.sub.4 group [wherein R.sub.4 is a hydrogen atom, lower alkyl, phenyl, benzyl or --CH.sub.2 CONR.sub.5 R.sub.6 group (wherein R.sub.5 and R.sub.6 are the same or different and selected from a hydrogen atom and lower alkyl groups)], and wherein R.sub.1 is a hydroxy group and wherein R.sub.2 is a --COR.sub.3 (wherein R.sub.3 is an amino or lower alkyl group) or --COOR.sub.4 group [wherein R.sub.4 is a (C.sub.1, C.sub.3 or C.sub.4) alkyl, phenyl, benzyl or --CH.sub.2 CONR.sub.5 R.sub.6 group (wherein R.sub.5 and R.sub.6 are the same or different and selected from a hydrogen atom and lower alkyl groups)]. The compounds, wherein R.sub.1 is a guanidinobenzoyloxy group, are useful protease inhibitors as anti-trypsin agents.

Isoquinoline derivatives and salts thereof

Growing community of inventors

Tochigi, Japan

Noboru Kwaguchi