The present invention is concerned with a nonaqueous electrolytic solution having an electrolyte salt dissolved in a nonaqueous solvent, the nonaqueous electrolytic solution containing a compound represented by the following general formula (X), in which a polar group (X) is bound to a phosphorus atom (P), and capable of improving electrochemical characteristics in a broad temperature range; an energy storage device using the same; and a novel compound.

##STR00001##

In the formula, R.sup.10 and R.sup.20 are each independently an organic group selected from the group consisting of an alkyl group having 1 to 8 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, an alkynyl group having 3 to 6 carbon atoms, and an aryl group having 6 to 12 carbon atoms, or a lithium atom; and X is a polar group (i) containing a —C(═O) group, a —P(═O) group, or an —S(═O).sub.2 group, a polar group (ii) containing a —CN group or an alkyl group having 1 to 6 carbon atoms, in which a part of hydrogen atoms is substituted with a fluorine atom, or a 4- to 7-membered ring polar group (iii) containing a —C(═O)—O— group or a —C(═O)—N— group, provided that when X is a 4- to 7-membered ring polar group (iii) containing a —C(═O)—N— group, at least one of R.sup.10 and R.sup.20 is a lithium atom.

The present invention provides a novel electrolyte solution capable of providing electrochemical devices having a high storage capacity retention. The electrolyte solution of the present invention contains a fluorinated phosphoric acid ester containing a non-fluorinated alkylene group having one or more carbon atoms as a linking group.

Provided are prodrugs of various therapeutic agents that provide enhanced bioavailability of the therapeutic agent, and methods of treatment conditions in a subject by administration of the one or prodrugs. As provided herein a prodrug includes a therapeutic agent covalently attached to a cap, the cap having a structure according to formula (I) where: R.sup.1 is a branched or linear substituted or unsubstituted C2-C6 alkyl, alkenyl, or alkynl; X is —S(0).sub.2-; R.sup.2 is a branched or linear substituted or unsubstituted C4-C20 alkyl, alkenyl, or alkynyl; and R.sup.3 is —H, C3-C5 cycloalkyl, C3-C5 cycloheteroalkyl, —C(CH.sub.3).sub.3, —CF.sub.3, —C(CF.sub.3).sub.3, or a substituted or unsubstituted phenyl.

##STR00001##

The present invention provides a nonaqueous electrolytic solution capable of suppressing worsening of heat stability of a negative electrode and improving safety of an energy storage device while maintaining high-load charging and discharging cycle properties at a high temperature, an energy storage device using the same, and a phosphonoformic acid compound to be used for the same. The nonaqueous electrolytic solution having an electrolyte salt dissolved in a nonaqueous solvent contains 0.001 to 5% by mass of at least one selected from a phosphonoformic acid compound having at least one carbon-carbon unsaturated bond, which is represented by the following general formula (I), and a phosphonoformic acid compound having a carbon-carbon unsaturated bond or two phosphonocarbonyl groups, which is represented by the following general formula (II). ##STR00001## In the formula (I), each of R.sup.1 to R.sup.3 is an aliphatic organic group, provided that at least one of R.sup.1 to R.sup.3 represents a carbon-carbon unsaturated bond-containing aliphatic organic group. ##STR00002## In the formula (II), each of R.sup.4 and R.sup.5 represents an alkyl group, a cycloalkyl group, or an aryl group, and R.sup.4 and R.sup.5 may be bonded to each other to form a ring structure. m represents 1 or 2; when m is 1, then R.sup.6 represents an aryl group; when m is 2, then R.sup.6 represents an alkylene group, an alkenylene group, or an alkynylene group; and a part of hydrogen atoms of R.sup.4 to R.sup.6 may be substituted with a halogen atom.

Novel inhibitors of DXP synthase and methods of use thereof are disclosed.

Provided are prodrugs of various therapeutic agents that provide enhanced bioavailability of the therapeutic agent, and methods of treatment conditions in a subject by administration of the one or prodrugs. As provided herein a prodrug includes a therapeutic agent covalently attached to a cap, the cap having a structure according to formula (I) where: R.sup.1 is a branched or linear substituted or unsubstituted C2-C6 alkyl, alkenyl, or alkynl; X is S(0).sub.2-; R.sup.2 is a branched or linear substituted or unsubstituted C4-C20 alkyl, alkenyl, or alkynyl; and R.sup.3 is H, C3-C5 cycloalkyl, C3-C5 cycloheteroalkyl, C(CH.sub.3).sub.3, CF.sub.3, C(CF.sub.3).sub.3, or a substituted or unsubstituted phenyl. ##STR00001##