Eisai R&d Management Co., Ltd.

Eisai Company, Limited

National Institute of Advanced Industrial Science and Technology

Kappei Tsukahara

Norihiro Ueda

Keigo Tanaka

Itaru Tsukada

Kazutaka Nakamoto

Katsura Hata

Koji Sagane

Mamiko Tsuchiya

Tatsuo Watanabe

Yoshihiko Kotake

Kyosuke Kitoh

Jun Niijima

Takeshi Nagasu

Nozomu Koyanagi

Kentaro Yoshimatsu

Hiroshi Yoshino

Makoto Asada

Toshimi Okada

Naoaki Watanabe

Atsumi Iijima

Fuminori Ohba

Junko Kai

Hiroyuki Sugumi

Kaoru Ogawa

Toshihiro Horii

Yoshifumi Jigami

Kenichi Nakayama

Mariko Umemura

Michiyo Okamoto

Hirovuki Sugumi

The present invention enables screening for compounds that inhibit the transport of GPI-anchored proteins to fungal cell walls, using a simple assay for transacylation to GlcN-PI using membrane fraction expressing GWT1 protein. New antifungal agents can be created that inhibit the synthesis of fungal cell walls and also inhibit adhesion to host cells by inhibiting the transport of GPI-anchored proteins to fungal cell walls.

Method of screening for compounds that inhibit the enzymatic activity of GWT1 gene product

The present inventors succeeded in isolating GWT1 (PfGWT1), which is one of the enzymes involved in GPI biosynthesis in the malaria parasite. In addition, the inventors revealed that degenerate mutant DNAs, with a lower AT content than the DNA encoding the PfGWT1 protein, can complement the phenotype of GWT1-deficient yeast. Based on the findings, the present invention provides the GWT1 protein of malaria parasites and the use of the protein in methods of screening for antimalarial drugs. The present invention also provides degenerate mutant DNAs encoding proteins involved in GPI biosynthesis, and which have a lower AT content than the original DNAs. The present invention also provides methods of screening for antimalarial drugs which use the degenerate mutant DNAs.

Methods of screening for compounds that inhibit the biosynthesis of GPI in malaria parasites

The present invention provides isolated DNA encoding a GWT1 protein having activity to confer resistance of a fungus against a compound of formula Ia, and wherein a defect of a function of the GWT1 protein leads to a decrease in the amount of a glycosylphosphatidylinositol (GPI)-anchored protein in the cell wall of a fungus.

Fungal cell wall synthesis gene

A reporter system reflecting the transport process that transports GPI-anchored proteins to the cell wall was constructed and compounds inhibiting this process were discovered. Further, fungal genes conferring resistance to the above compounds were identified and methods of screening for compounds that inhibit the activity of the proteins encoded by these genes were developed. These genes encode proteins participating in fungal cell wall synthesis. Therefore, through the novel compounds, the present invention showed that antifungal agents having a novel mechanism, i.e. inhibiting the process that transports GPI-anchored proteins to the cell wall, could be achieved.

A reporter system reflecting the transport process that transports GPI-anchored proteins to the cell wall was constructed and compounds inhibiting this process were discovered. Further, genes conferring resistance to the above compounds were identified and methods of screening for compounds that inhibit the activity of the proteins encoded by these genes were developed. Therefore, through the novel compounds, the present invention showed that antifungal agents having a novel mechanism, i.e. inhibiting the process that transports GPI-anchored proteins to the cell wall, could be achieved.

Sulfonamide compounds of formula (I) or a pharmacologically acceptable salt thereof: ##STR1## exhibit excellent antitumor activity and low toxicity.

Pyrimidinyl or pyridinyl sulfonamide substituted compounds

Sulfonamide compounds of the formula or pharmacologically acceptable salts thereof: ##STR1## wherein: R.sup.1 is a hydrogen atom, halogen atom, lower alkyl group, lower alkoxy group, hydroxyl group, nitro group, phenoxy group, cyano group, acetyl group, amino group or a protected amino group; R.sup.2 and R.sup.3 may be the same or different from each other and each is a hydrogen atom, halogen atom, lower alkyl group or lower alkoxy group; R.sup.4 and R.sup.7 may be the same or different from each other and each is a hydrogen atom or a lower alkyl group; R.sup.5 and R.sup.6 may be the same or different from each other and each is a hydrogen atom, halogen atom, lower alkoxy group, amino group or amino group substituted with a lower alkyl or a phenyl group; A is .dbd.CH--; B is .dbd.CH--; and E is selected from the group consisting of ##STR2## in which Q is an oxygen atom or a sulfur atom; and R.sup.11 is a hydrogen atom, a lower alkyl group, an amino group which may be substituted with a lower alkyl group, a lower alkoxy group, a 2-thienyl group, a 2-furyl group, phenyl group or a phenyl group having from 1 to 3 substituents, said substituents being the same or different from one another and selected from the group consisting of a halogen atom, lower alkyl group, lower alkoxy group, hydroxyl group, carboxyl group, esterified carboxyl group, amidated carboxyl group, lower alkylthio group and phenoxy group; and (b) a phenyl group or a phenyl group having from 1 to 3 substituents.

Sulfonamide phenyl substituted compounds

Sulfonamide derivatives of the general formula (I): ##STR1## wherein preferably R.sup.1 represents a lower alkoxy group, R.sup.2, R.sup.3, R.sup.4, R.sup.5, R.sup.6 and R.sup.7 may be the same or different from one another and each represent a hydrogen atom, halogen atom or lower alkyl group, A and B may be the same or different from each other and each represent .dbd.N-- or .dbd.CH--, E represents an aromatic 6-membered cyclic group, which may have 1 or 2 nitrogen atoms in the ring, and be substituted with 1 to 3 substituents which may be the same or different from one another with the proviso that a combination of R.sup.1 which is a hydrogen atom, lower alkyl group, nitro group or amino group which may be protected, R.sup.2 and R.sup.3 which are each a hydrogen atom, A and B which are each .dbd.CH-- and E which is a phenyl group which may be substituted with 1 to 3 substituents G which may be the same or different from one another is excluded, or pharmacologically acceptance salts of them, have an excellent antitumo-activity.

Sulfonamide derivatives

Sulfonamide derivatives of the general formula (I): ##STR1## wherein preferably R.sup.1 represents a lower alkoxy group, R.sup.2, R.sup.3, R.sup.4, R.sup.5, R.sup.6 and R.sup.7 may be the same or different from one another and each represent a hydrogen atom, halogen atom or lower alkyl group, A and B may be the same or different from each other and each represent .dbd.N-- or .dbd.CH--, E represents an aromatic 6-membered cyclic group, which may have 1 or 2 nitrogen atoms in the ring, and be substituted with 1 to 3 substituents which may be the same or different from one another with the proviso that a combination of R.sup.1 which is a hydrogen atom, lower alkyl group, nitro group or amino group which may be protected, R.sup.2 and R.sup.3 which are each a hydrogen atom, A and B which are each .dbd.CH-- and E which is a phenyl group which may be substituted with 1 to 3 substituents G which may be the same or different from one another is excluded, or pharmacologically acceptable salts of them, have an excellent antitumor activity.

Pyridine carboxamide compounds which have useful as pharmaceutical

Sulfonamide derivatives of the general formula (I): ##STR1## wherein preferably R.sup.1 represents a lower alkoxy group, R.sup.2, R.sup.3, R.sup.4, R.sup.5, R.sup.6 and R.sup.7 may be the same or different from one another and each represent a hydrogen atom, halogen atom or lower alkyl group, A and B may be the same or different from each other and each represent .dbd.N-- or .dbd.CH--, E represents an aromatic 6-membered cyclic group, which may have 1 or 2 nitrogen atoms in the ring, and be substituted with 1 to 3 substituents which may be the same or different from one another with the proviso that a combination of R.sup.1 which is a hydrogen atom, lower alkyl group, nitro group or amino group which may be protected, R.sup.2 and R.sup.3 which are each a hydrogen atom, A and B which are each .dbd.CH-- and E which is a phenyl group which may be substituted with 1 to 3 substituents G which may be the same or different from one another is excluded, or pharmacologically acceptance salts of them, have an excellent antitumor activity.

Sulfonamide derivatives of the general formula (I): ##STR1## wherein preferably R.sup.1 represents a lower alkoxy group, R.sup.2, R.sup.3, R.sup.4, R.sup.5, R.sup.6 and R.sup.7 are as defined in the specification, A and B may be the same or different from each other and each represents .dbd.N-- or .dbd.CH--, E represents an aromatic 6-membered cyclic group, which may have 1 or 2 nitrogen atoms in the ring, and may be substituted with 1 to 3 substituents which may be the same or different from one another with the proviso that a combination of R.sup.1 which is a hydrogen atom, lower alkyl group, nitro group or amino group which may be protected, R.sup.2 and R.sup.3 which are each a hydrogen atom, A and B which are each .dbd.CH-- and E which is a phenyl group which may be substituted with 1 to 3 substituents G which may be the same or different from one another is excluded, or pharmacologically acceptance salts of them.

Growing community of inventors

Tsukuba, Japan

Kappei Tsukahara