Abstract: 5-Membered ring compounds represented by general formula (I), optically active isomers thereof or salts of the same. These compounds have physiological activities including a carcinostatic effect. In said formula the bond shown by the dotted line in the 5-membered ring represents that this 5-membered ring may be either a cyclopentene ring having a double bond or a saturated cyclopentane ring, and when the 5-membered ring is a cyclopentene ring, X is OR1, Y is ═O and Z is H, and when it is a cyclopentane ring, X is ═O, Y is OR2 and Z is OR3, (wherein R1 is R4 or —(CO)—R5; R2 is H, —R6 or —(CO)—R7; and R3 is H, R8 or (CO)—R9 (wherein R4, R5, R6, R7, R8 and R9 are the same or different and each represents an aliphatic, aromatic or aliphatic aromatic group, and R5, R7 and R9 may be each H), provided that the case where R2═R3═H is excluded); and W represents a residue obtained by eliminating SH from an SH-containing compound.

Abstract: An apoptosis inducing agent or an anticancer agent which is characterized in containing glycerolipid and/or glyceroglycolipid as effective component(s).

Abstract: An anticancer agent in which 4-cyclopentene-1,3-dione represented by the following formula [I] and/or 4-hydroxy-2-cyclopentenone represented by the following formula [II] are/is effective component(s).

Abstract: An antirheumatic agent which is characterized in containing at least one compound selected from a group consisting of 4,5-dihydroxy-2-cyclopenten-l-one represented by the following formula [I] and an optically active substance and a salt thereof as an effective component.

Abstract: Cell compositions from which cancer cells have been selectively eliminated by using apoptosis inducers specific to cancer cells.

Abstract: An antiallergic agent which is characterized in containing at least one compound selected from a group consisting of 4,5-dihydroxy-2-cyclopenten-1-one represented by the following formula [I] and an optically active substance and a salt thereof as an effective component.

Abstract: A therapeutic or preventive agent for diabetes mellitus which is characterized in containing at least one compound selected from a group consisting of 4,5-dihydroxy-2-cyclopenten-1-one represented by the following formula [I] and an optically active substance and a salt thereof as an effective component.

Abstract: A compound represented by the following formula [I] or an optically active substance or a salt thereof. (In the formula, a bond shown by a dotted line in the five-membered ring means that said five-membered ring may be any of a cyclopentene ring having a double bond and a cyclopentane ring where said bond is saturated and, in the case of a cyclopentene ring, X is OH, Y is ═O and Z is H while, in the case of a cyclopentane ring, X is ═O, Y is OH and Z is OH. R is a residue after removal of an SH group from the SH-containing compound.

Abstract: 2,3,4-trihydroxycyclopentanone represented by the following formula [I], its optically active substance or salt thereof.

Abstract: Cyclopentenone derivative having a structure of 5-(R.sub.1 COO--)-4-(R.sub.2 COO--)--substituted 2-cyclopenten-1-one (R.sub.1 and R.sub.2 are some or different and each is alkyl group, alkenyl group or aryl group) or an optically active substance thereof; a method for the manufacture of the cyclopentenone derivative by the reaction of 4,5-dihydroxy-2-cyclopenten-1-one with the corresponding carboxylic acid or a reactive derivative thereof; and anticancer agent, apoptosis-inducing agent and antibacterial agent containing said derivative.

Abstract: 2,5-dihydroxytetrahydro-2-furancarboxylic acid represented by the following formula [I], its optically active substance or salt thereof.

Abstract: A cyclopentenone derivative represented by the following formula [I] or an optically active substance or a salt thereof. ##STR1## (In the formula, R.sub.1 and R.sub.2 are same or different and each of them is straight or branched alkyl group, straight or branched alkenyl group, aromatic group, aromatic-aliphatic group or H with a proviso that the case where R.sub.1 =R.sub.2 =H, or R.sub.1 =benzyl group and R.sub.2 =H is excluded.

Abstract: There is disclosed a method of manufacturing 4,5-dihydroxy-2-cyclopenten-1-one represented by the following formula [1] which is characterized in that at least one substance selected from the following (a), (b) and (c) is heated.(a): uronic acid or uronic acid derivative(s);(b): a saccharide compound which contains uronic acid and/or uronic acid derivative(s); and(c): a substance containing a saccharide compound which contains uronic acid and/or uronic acid derivative(s).

Abstract: An isolated SDS-resistant hyperthermostable .beta.-galactosidase gene derived from Pyrococcus furiosus. Examples thereof include genes respectively shown in SEQ ID NO: 1 and SEQ ID NO: 2 and genes each hybridizable with the above gene shown in SEQ ID NO: 1. A method of cloning the hyperthermostable .beta.-galactosidase gene in which each of the above genes or pacts thereof is used as a probe or primer. A process for producing a hyperthermostable .beta.-galactosidase by culturing a transformant into which a plasmid containing each of the above gene has been introduced.

Abstract: An isolated DNA having a promoter activity in an animal cell; a method for expressing a useful gene using the isolated DNA; and a method for producing a protein in an animal cell using the isolated DNA. The present invention provides a method for producing a desired gene product in a large quantity in an animal cell.

Abstract: An isolated hyperthermostable .beta.-galactosidase gene derived from Pyrococcus furiosus is described. Examples include DNA sequences shown in SEQ ID NO. 2 and SEQ ID NO. 4 and DNAs hybridizable with these DNAs. A method of cloning the hyperthermostable .beta.-galactosidase gene in which each of the above sequences or portions thereof is used as a probe or primer is described. A process for producing a hyperthermostable .beta.-galactosidase by culturing a transformant into which a plasmid containing each of the above genes has been introduced is described. A particularly preferred gene encodes an SDS-resistant hyperthermostable .beta.-galactosidase.

Abstract: There is provided a polypeptide having the following formula (I'), and which polypeptide is referred to as Glu-OC and a process for the preparation thereof.