Disclosed is the use of the reactive components of the inverse electron-demand Diels Alder reaction for chemical masking and unmasking in vitro. This can be applied in complex chemical reactions and, particularly in the synthesis of biomolecules, e.g. on solid supports. The reactice components are a dienophile, particularly a trans-cyclooctene, and a diene, particularly a tetrazine.

A non-aqueous electrolytic solution includes a phosphoric acid diester salt, which can suppress deterioration of charge-discharge characteristics of a power storage element, and can suppress the rise in internal resistance after storage at high temperature. The phosphoric acid diester salt is represented by the following chemical formula (1):

##STR00001##

in which M.sup.n+ represents a hydrogen ion, an alkali metal ion, an alkali earth metal ion, an aluminum ion, a transition metal ion, or an onium ion, R.sup.1 and R.sup.2 are different from each other and represent a hydrocarbon group having 1 to 10 carbon atoms, or a hydrocarbon group having 1 to 10 carbon atoms and having at least one of a halogen atom, a heteroatom, and an unsaturated bond, and n represents a valence.

A non-aqueous electrolytic solution includes a phosphoric acid diester salt, which can suppress deterioration of charge-discharge characteristics of a power storage element, and can suppress the rise in internal resistance after storage at high temperature. The phosphoric acid diester salt is represented by the following chemical formula (1):

##STR00001##

in which M.sup.n+ represents a hydrogen ion, an alkali metal ion, an alkali earth metal ion, an aluminum ion, a transition metal ion, or an onium ion, R.sup.1 and R.sup.2 are different from each other and represent a hydrocarbon group having 1 to 10 carbon atoms, or a hydrocarbon group having 1 to 10 carbon atoms and having at least one of a halogen atom, a heteroatom, and an unsaturated bond, and n represents a valence.

Disclosed is a phosphoric acid diester salt which can suppress deterioration of charge-discharge characteristics of a power storage element, and can suppress the rise in internal resistance after storage at high temperature, a production method therefor, a non-aqueous electrolytic solution for a power storage element, and a power storage element. Disclosed is a phosphoric acid diester salt represented by the following chemical formula (1): ##STR00001##
wherein M.sup.n+ represents a hydrogen ion, an alkali metal ion, an alkali earth metal ion, an aluminum ion, a transition metal ion, or an onium ion; R.sup.1 and R.sup.2 are different from each other and represent a hydrocarbon group having 1 to 10 carbon atoms, or a hydrocarbon group having 1 to 10 carbon atoms and having at least one of a halogen atom, a heteroatom, and an unsaturated bond; and n represents a valence.

Disclosed is a phosphoric acid diester salt which can suppress deterioration of charge-discharge characteristics of a power storage element, and can suppress the rise in internal resistance after storage at high temperature, a production method therefor, a non-aqueous electrolytic solution for a power storage element, and a power storage element. Disclosed is a phosphoric acid diester salt represented by the following chemical formula (1): ##STR00001##
wherein M.sup.n+ represents a hydrogen ion, an alkali metal ion, an alkali earth metal ion, an aluminum ion, a transition metal ion, or an onium ion; R.sup.1 and R.sup.2 are different from each other and represent a hydrocarbon group having 1 to 10 carbon atoms, or a hydrocarbon group having 1 to 10 carbon atoms and having at least one of a halogen atom, a heteroatom, and an unsaturated bond; and n represents a valence.

The present invention provides engineered glycosyltransferase (GT) enzymes, polypeptides having GT activity, and polynucleotides encoding these enzymes, as well as vectors and host cells comprising these polynucleotides and polypeptides. The present invention provides engineered sucrose synthase (SuS) enzymes, polypeptides having SuS activity, and polynucleotides encoding these enzymes, as well as vectors and host cells comprising these polynucleotides and polypeptides. The present invention also provides compositions comprising the GT enzymes and methods of using the engineered GT enzymes to make products with -glucose linkages. The present invention further provides compositions and methods for the production of rebaudiosides (e.g., rebaudioside M, rebaudioside A, rebaudioside I, and rebaudioside D). The present invention also provides compositions comprising the SuS enzymes and methods of using them. Methods for producing GT and SuS enzymes are also provided.

The present invention provides engineered glycosyltransferase (GT) enzymes, polypeptides having GT activity, and polynucleotides encoding these enzymes, as well as vectors and host cells comprising these polynucleotides and polypeptides. The present invention provides engineered sucrose synthase (SuS) enzymes, polypeptides having SuS activity, and polynucleotides encoding these enzymes, as well as vectors and host cells comprising these polynucleotides and polypeptides. The present invention also provides compositions comprising the GT enzymes and methods of using the engineered GT enzymes to make products with -glucose linkages. The present invention further provides compositions and methods for the production of rebaudiosides (e.g., rebaudioside M, rebaudioside A, rebaudioside I, and rebaudioside D). The present invention also provides compositions comprising the SuS enzymes and methods of using them. Methods for producing GT and SuS enzymes are also provided.

A method of preparing an active agent or a salt thereof from a pro-drug first compound (1) comprising a propargyl group connected to an oxygen that is directly or indirectly connected to the active agent is provided, wherein the bond between the propargyl group and the oxygen is cleaved by reacting the first compound with palladium or gold, thereby releasing the active agent. Prodrug compositions suitable for use in the method are also provided.

Doxorubicin derivatives for targeted activation by Legumain, its preparation method and use. The doxorubicin derivatives are obtained by condensation between the amino group of compound A and the carboxyl group of compound B and have the following structure:

##STR00001##

compounds A and B have the following structures, respectively:

##STR00002##

wherein R.sub.3 in compound B is Leu or absent; R.sub.4 is any one amino acid selected from the group consisting of Ala and Thr; R.sub.5 is any one amino acid selected from the group consisting of Ala, Thr and Asn; R.sub.6 is

##STR00003##

wherein n=1-20; or

##STR00004##

wherein R.sub.7 is substituted or unsubstituted, linear or branched, saturated or unsaturated C1-C20 fatty hydrocarbon, or substituted or unsubstituted C6-C20 aromatic hydrocarbon. The doxorubicin derivatives of the present invention are specifically tumor-targeted and have a long in vivo metabolic half-life, as compared with doxorubicin. They exhibit an efficient and safe anti-tumor effect and could be used to prepare an anti-tumor drug.

Doxorubicin derivatives for targeted activation by Legumain, its preparation method and use. The doxorubicin derivatives are obtained by condensation between the amino group of compound A and the carboxyl group of compound B and have the following structure:

##STR00001##

compounds A and B have the following structures, respectively:

##STR00002##

wherein R.sub.3 in compound B is Leu or absent; R.sub.4 is any one amino acid selected from the group consisting of Ala and Thr; R.sub.5 is any one amino acid selected from the group consisting of Ala, Thr and Asn; R.sub.6 is

##STR00003##

wherein n=1-20; or

##STR00004##

wherein R.sub.7 is substituted or unsubstituted, linear or branched, saturated or unsaturated C1-C20 fatty hydrocarbon, or substituted or unsubstituted C6-C20 aromatic hydrocarbon. The doxorubicin derivatives of the present invention are specifically tumor-targeted and have a long in vivo metabolic half-life, as compared with doxorubicin. They exhibit an efficient and safe anti-tumor effect and could be used to prepare an anti-tumor drug.