Compounds, methods, complexes, apparatuses and uses relating to stabile forms of NAD/NADH

1. A test element for determining an analyte, comprising (i) a nicotinamide coenzyme-dependent enzyme or a substrate for such an enzyme, and (ii) a coenzyme comprising a compound of the following general formula (I) or a salt or a reduced form thereof:

in which

A=adenine or an analog thereof,

T=O or S,

U=OH, SH, BH 3 —, or BCNH 2 —,

V=OH or a phosphate group,

W=COOR, CON(R) 2 , COR, or CSN(R) 2 , in which R═H or C 1 -C 2 -alkyl

X 1 , X 2 =O, CH 2 , CHCH 3 , C(CH 3 ) 2 , NH, or NCH 3 ,

Y=NH, S, O, or CH 2 ,

Z= a saturated or unsaturated carbocyclic or heterocyclic six-membered ring, and a residue C(R 4 ) 2 bound to the six-membered ring and to X 2 , where R 4 =H, F, or CH 3,

wherein the six-membered ring and the pyrimidine residue are not linked by a glycosidic bond.

2. The test element of claim 1 , wherein said test element is configured for the determination of glucose, and said enzyme comprises glucose dehydrogenase.

3. The test element of claim 1 , wherein the six membered ring of Z comprises one or more substituents selected from the group consisting of OH, F, Cl and C 1 -C 2 alkyl.

4. The test element of claim 3 , wherein the substituent C 1 -C 2 alkyl comprises one or more of a fluorinated, chlorinated or OH-substituted O—C 1 -C 2 alkyl.

5. The test element of claim 1 , wherein Z comprises a compound having the general formula (II):

in which a single or double bond can in each case independently be present between R 1 and R 2 or between R 1 ′ and R 2 ′, wherein if a single bond is present between R 1 and R 2 or R 1 ′ and R 2 ′ respectively:

R 1 , R 1 ′═O, S, NCH 3 , NH, C(R 4 ) 2 , CHOH, or CHOCH 3 , where R 1 or R 1 ′ cannot at the same time be a heteroatom, and

R 2 , R 2 ′═C(R4) 2 , CHOH, or CHOCH 3 ;

and wherein if a double bond is present between R 1 and R 2 or R 1 ′ and R 2 ′ respectively:

R 1 , R 1 ′, R 2 , R 2 ′═CR 4 , and

R 4 ═H, F, Cl, or CH 3 ; and

R 6 , R 6 ′═CH or CCH 3 .

6. The test element of claim 1 , wherein W═CONH 2 or COCH 3 .

7. The test element of claim 1 , wherein the test element is in the form of a test strip configured for electrochemical or optical determination of the analyte.

8. The test element of claim 1 , wherein the enzyme comprises a dehydrogenase selected from glucose dehydrogenase, lactate dehydrogenase, malate dehydrogenase, glycerol dehydrogenase, alcohol dehydrogenase, alpha-hydroxybutyrate dehydrogenase, sorbitol dehydrogenase, and amino acid dehydrogenase selected from L-amino acid dehydrogenase.

9. The test element of claim 8 configured for detecting glucose and wherein the enzyme is glucose dehydrogenase.

10. A test element for determining an analyte, comprising a nicotinamide coenzyme dependent enzyme-coenzyme complex comprising the coenzyme of claim 1 in combination with a suitable nicotinamide coenzyme dependent enzyme and in combination with a suitable reaction buffer, and configured to determine one or more analytes selected from the group consisting of glucose, lactic acid, malic acid, glycerol, alcohol, cholesterol, triglycerides, ascorbic acid, cysteine, glutathione, peptides, urea, ammonia, salicylate, pyruvate, 5′-nucleotidase, creatine kinase (CK), lactate dehydrogenase (LDH), and carbon dioxide.

11. A method for detecting an analyte comprising the steps of:

(a) contacting a sample with the test element of claim 1 , and

(b) detecting the analyte by one of electrochemistry, photometry or fluorometry.