DE19827981A1 - New nitrate compounds useful in biochemical or pharmacological studies of e.g. cysteine/cystine system or for studies of nitrate cross-tolerance associated with certain cardiovascular drugs - Google Patents

Abstract

Nitrate compounds (I), which are useful as substrates for biochemical and pharmacological studies, are new. Nitrate compounds of formula (I) are new. R<1>-R<3> = R<4>, CH2-ONO2, CH2-OR<5>, CH2-X, COOR<5>, COX, CH2COOR<5> or CH2-COX; R<4> = CHO; R<5> = H or 1-6C alkyl; X = halo; and provided that at least one of R<1>, R<2>, R<3> is R<4>. Independent claims are included for: (A) use of compounds corresponding to (I), in which the CH2-NO2 group (which is attached to the central C atom along with R<1>, R<2> and R<3>) may be replaced by a group as defined for R<1>-R<3>, as substrates for biochemical and pharmacological investigations; and (B) the preparation of (I) (as described in (A)) form aldehyde of formula (V).

Description

Field of application of the invention

The invention presented here relates to new analytical substrates, which in particular biochemical and pharmacological studies can be used.

Known technical background

Organic nitric acid esters such as glycerol trinitrate (GTN) (Murrel, Lancet: 80, 113, 151 (1879)), Pentaerythrityl tetranitrate (PETN) (Risemann et al., Circulation, Vol. XVII, 22 (1958), U.S. Patent 2,370,437), Isosorbide-5-mononitrate (ISMN) (DE-OS-22 21 080, DE-OS-27 51 934, DE-OS-30 28 873, DE-PS-29 03 927, DE-OS-31 02 947, DE-OS-31 24 410, EP-A1-045076, EP-A1-057847, EP-A1-059664, EP-A1-064194, EP- A1-067964, EP-A1-143507, US-PS-3886186, US-PS-4065488, US-PS-4417065, US-PS-4431829), Isosorbide dinitrate (ISDN) (L. Goldberg, Acta Physiolog. Scand. 15, 173 (1948)), propatyl nitrate (Médard, Mem. Poudres 35: 113 (1953)), trol nitrate (FR-PS-984523) or Nicorandil (US-PS-4200640) and Similar compounds are vasodilators, which have mainly been used for decades in the Indication Angina pectoris or ischemic heart disease (IHK) broadest therapeutic use find (Nitrangin®, Pentalong®, Monolong®, among others). Likewise, other pentaerythrityl nitrates as well their representation is described (Simecek, Coll. Czech. Chem. Comm. 27 (1962), 363; Camp et al., J. At the. Chem. Soc. 77: 751 (1955). Comparable and improved pharmacological effectiveness in Organic nitrates of newer types such as for example SPM 3672 (N- [3-nitratopivaloyl] -L-cysteine-ethyl ester) (US-PS-5284872) and its Have derivatives. The production of 3-nitryloxy-2,2-bis (nitryloxymethyl) - is also known. propionic acid and its methyl ester (Nec, Chem. Prum. (1978), 28 (2), 84) and more recent ones from Pentaerythrityl tetranitrate-derived compounds (WO-A1-98115521). The metabolism of GTN and other organic nitrates have been extensively studied (Taylor et al., Prog. Drug Metab., 10 (1987), 207). On the one hand, there are a number of known organic nitrates (nitric acid esters) therapeutic disadvantages. So z. B. to observe the so-called nitrate tolerance, d. H. the Decrease in the nitrate effect at high doses or when long-acting nitrates are applied. As well are side effects such as headache, dizziness, nausea, weakness, reddening of the skin as well as the Risk of a severe drop in blood pressure with reflex tachycardia (Mutschler, Drug effects, Wissenschaftliche Verlagsgesellschaft mbH, Stuttgart, 1991). On the other hand PETN has a number of outstanding properties as an active ingredient, which are preferred Justify the use of this compound as a pharmaceutical against other organic nitrates, however, a limited bioavailability of this active ingredient can be observed (publication series "Pentaerythrityl tetranitrate", Dr. Dietrich Steinkopff Verlag, Darmstadt, 1994 to 1997). Remarkably the fact that despite the broad therapeutic use of  Pentaerythrityltetranitrat relatively little about the metabolism as well as the effect of its metabolites is known (ibid.). In general, the occurrence of the metabolites pentaerythrityltri- (PETriN), Pentaerythrityl di (PEDN) and pentaerythrityl mononitrate (PEMN) both in free and in conjugated form postulated (Crew et al., Biochem. Pharmacol. 20 (1971), 3077).

Statement of the invention

The object of the invention is to provide new compounds derived from pentaerythritol as substrates for to provide biochemical and pharmacological studies.

The object of the invention is achieved by compounds of the general formula I

wherein R ¹ , R ² and R ^{3 are} identical or different from one another R ⁴ , CH ₂ -ONO ₂ , CH ₂ OR ⁵ , CH ₂ -X, COOR ⁵ , COX, CH ₂ -COOR ⁵ , or CH ₂ -COX, where however, at least one of the substituents R ¹ to R ³ is R ⁴ , R ^{4 is} CHO, R ⁵ H or a straight-chain or branched C ₁ to C ₆ alkyl radical and X is a halogen.

Preferred embodiments are the compounds of the formulas II, III and IV.

The object of the invention is further achieved by compounds of the formula I in which the group CH ₂ -ONO ₂ next to R ¹ to R ³ may additionally have one of the other meanings given for R ¹ to R ³ , as substrates for biochemical and pharmacological studies .

Starting products of the synthesis of the compounds of the formula I are the synthesis precursor of pentaerythritol of the formula V,

Pentaerythritol or its nitric acid ester namely pentaerythritylmono- (PEMN), pentaerythrityldi- (PEDN), Pentaerythrityltri- (PETriN) and Pentaerythrityltetranitrat (PETN), which in turn in itself known manner (Simecek, Coll. Czech. Chem. Comm. 27 (1962), 363; Camp et al., J. Am. Chem. Soc. 77 (1955), 751) are synthetically accessible in good yields. Furthermore carboxylic acid esters of these compounds (Marans et al., J. Am. Chem. Soc. 76 (1954), 1304) and for the synthesis of Compounds of formula I suitable compounds, as described in WO-A1-98 / 15521. The Compounds PEMN, PEDN and PETriN are formed by complete or partial oxidation existing hydroxymethyl groups are converted into the corresponding tri-, di- or monocarboxylic acids, from which, if appropriate, by partial hydrazinolysis of the corresponding nitric ester function the corresponding derivatives carrying both nitroxy, hydroxyl and carboxy functions be preserved. The compounds of the formula I are formed via those familiar to the person skilled in the art Synthetic methods and processes, for example known aldehyde or ester formation reactions. Oxidations or reductions should be carried out under as mild conditions as possible to maintain the desired aldehyde function can be performed. For synthesis, isolation, cleaning and The person skilled in the art can characterize the target compounds of specific reaction products Aldehydes or 1,3-diols, such as hydrates, acetals, hemiacetals, mercaptals, Semi-mercaptals, all of the above compounds also in cyclic form such as. B. Lactols, thiolactols and 1,3-dioxanes, 1,3-dithiolanes, also 1,2-diols, cyanohydrins, Bisulfite compounds, aldimines, azomethines, hydrazone, azines, oximes, semicarbazones and the like. Ä., operate, which are also within the scope of the present invention. Depending on the Process conditions and the starting materials can also be the end product as a free acid or Base, base or acid addition salt or betaine are obtained, each within the scope of the invention. Acid, basic, neutral or mixed salts and hydrates can be obtained in this way become. On the one hand, the respective salts can be converted into the free acid or base in a manner known per se using appropriate means or by ion exchange. On the other hand the free acids or bases obtained can be salts with organic or inorganic bases or Form acids. In the production of base addition salts, it is primarily such bases used, which form suitable therapeutically acceptable salts. Such bases are, for example Hydroxides or hydrides of the alkali and alkaline earth metals, ammonia and amines. In the preparation of Acid addition salts also preferably use those acids which are suitable form therapeutically acceptable salts. Such acids are, for example, hydrogen halide, sulfonic, Phosphoric, nitric and perchloric acid, furthermore aliphatic, acyclic, aromatic, heterocyclic carbonic or sulfonic acids such as formic, vinegar, propionic, amber, glycolic, lactic, Apple, wine, lemon, glucon, sugar, glucuron, ascorbic, maleic, hydroxymalein, pyruvic, Phenylacetic, benzoic, p-aminobenzoic, anthranil, p-hydroxybenzoic, salicyl, acetylsalicyl, p- Aminosalicyl, embon, methanesulfone, ethanesulfone, hydroxyethanesulfone, ethylene sulfone, Halogenbenzenesulfonic, toluenesulfonic, naphthylsulfonic, or sulfanilic acid and amino acids such as for example methionine, tryptophan, lysine or arginine. These and other salts of the new can be used as  Means to purify the free acids or bases obtained. Salts of acids or bases can be formed and separated from solutions, and then the free acid or base can be removed a new salt solution can be obtained in a purer state. Because of the relationship between the new compounds in their free form and their salts, the salts lie within the Scope of the invention. Some of the new connections may vary depending on the selection of the Starting materials and the process as optical isomers or racemates, (or if they Containing at least two asymmetric carbon atoms, they can be used as a mixture of isomers (Racemate mixture) are present). The mixtures of isomers obtained (racemate mixtures) can be obtained using chromatography or fractional crystallization into two stereoisomeric (diastereomeric) pure Racemate can be separated. The racemates obtained can be prepared by methods known per se be separated, such as by recrystallization from an optically active solvent Use of microorganisms, by reaction with optically active agents to form Connections that can be separated by separation based on the different Solubilities of the diastereoisomers. Suitable optically active agents are the L and D forms of Wine, di-o-tolyl wine, apple, almond, glucon, sugar, glucuron, camphorsulfone, quinine or Binaphthylphosphoric acid. The more active part of the two antipodes is preferably isolated. The Starting materials are known or can, if they are new, according to known per se Methods can be obtained. At the same time, the use of pharmacologically acceptable Derivatives of all the compounds mentioned above are possible. Mostly common Addition compounds, salts or enzymatically or hydrolytically cleavable compounds such as esters, Amides, hydrazides, e.g. B. obtained by N-amination (DD-B1-230865 and DD-A3-240818) corresponding amino compounds, hydrazinium salts and the like, so far as above not mentioned, possible variations.

The compounds according to the invention can be used themselves or as part of a pharmaceutical preparation, as Single connection in combination with each other or with known cardiovascular or Vascular therapeutics, for example ACE inhibitors, antiarteriosclerotics, antihypertensives, Beta blockers, cholesterol lowering agents, diuretics, calcium channel blockers, coronary dilators, lipid lowering agents, peripheral vasodilators, phosphodiesterase, especially - (V) -, or Platelet aggregation inhibitors or others, also as cardiovascular drugs substances used, combined, are used for their analytical use. You can especially in combination with organic nitrates for the investigation of biochemical and pharmacological processes can be used.

It has been found that the compounds according to the invention are surprisingly excellent Substrates for the investigation of biochemical and pharmacological processes in in vitro or in vivo Test systems, although such structures are not considered metabolically relevant to those skilled in the art were expected. It was also found that they are particularly suitable for the study of  Redox processes, especially for examining the system cysteine / cystine, the glutathione or of the lipoic acid redox system and related systems. With the stated invention improved and considerably expanded analytical possibilities are opened up, pathological Situations such as B. simulate, study and suppress nitrate and nitrate cross tolerance, which the compounds according to the invention in principle also for therapeutic use makes suitable. In addition, the compounds described with the present invention helpful starting and intermediate compounds in the production of chemical derivatives, which themselves can be used as active pharmaceutical ingredients.

The following examples are intended to illustrate the invention in terms of its nature and implementation explain, but without restricting their scope.  

Embodiments example 1

• a) 158 g (0.5 mol) of pentaerythrityl tetranitrate (PETN) were dissolved in a mixture of 300 ml of dioxane and 300 ml of ethanol while boiling, and various amounts of aqueous hydrazine hydrate solution (1.5-4 mol) were added in portions for 1 hour . Then the reaction mixture was refluxed for a further 2.5 hours. Nitrogen, ammonia and nitrogen oxides escape during the reaction. After the reaction, the solvents were evaporated off at 15 mm Hg and the residue was shaken out several times with 100 ml portions of water, as required, until the volume of the oil layer no longer decreased when shaken out. The aqueous extracts (A) were collected and the remaining oily layer was dissolved in twice the volume of ethanol. The possibly precipitated white precipitate of PETN was filtered after 24 hours; it showed the F _p 132 ° C. After recrystallization from acetone twice, its F _{p had} risen to 141 ° C. The filtrate was evaporated at 15 mm Hg ethanol. The viscous, oily residue consisted of the crude pentaerythrityl trinitrate (PETriN).
• b) The combined aqueous extracts A were shaken out three times with ether and the ether was evaporated from the ether layer separated from the aqueous layer B after drying over anhydrous Na ₂ SO ₄ . The very viscous, oily evaporation residue was identified as crude pentaerythrityl dinitrate (PEDN). The aqueous portion B, which contains pentaerythritol mononitrate (PEMN) and pentaerythritol denitration products, mainly hydrazine nitrite, was acidified successively with 2 NH ₂ SO ₄ until gas evolution ceased (N ₂ , N ₂ O, NO, N ₃ H), then concentrated at 20 mm Hg until solid products begin to separate and etherified. The crystalline substance of F _p 62 ° C which remained after the ether had evaporated was identified as crude PEMN. After washing with cold chloroform and recrystallization from chloroform, the leaves obtained had an F _{p of} 79 ° C. The extraction residue was evaporated to dryness at 10 mm Hg and the residue was stirred with a small amount of water. The filtered white crystals, which after recrystallization from the same weight of water had the F _p 260 ° C, were identified as pure pentaerythritol.
• c) To purify the raw substances PETriN and PEDN, these were converted into the acetates in question and, after recrystallization from ethanol, alcoholized to give the pure products. To 135.5 g (0.5 mol) of crude PETriN [or 56.5 g (0.25 mol) of PEDN], a mixture of 50 ml of acetic anhydride and 20 ml of acetyl chloride was added in portions with cooling and stirring. The mixture which solidified after the reaction was stirred twice with 50 ml of ethanol and suction filtered. The colorless crystals of pentaerythritol trinitrate acetate (PETriNAc) of F _p 85-86 ° C showed after recrystallization twice from ethanol the F _p 89 ° C, yield of pure product 121 g (77%). Pentaerythritol dinitrate diacetate (PEDNAc) also forms colorless crystals, the F _{p of} 42-43 ° C after two recrystallizations from ethanol to 47 ° C. Yield of pure product 56 g (72%). 104.4 g (0.3 mol) of PETriNAc or 51.7 g (0.15 mol) of PEDNAc were dissolved hot in 400 ml of ethanol, a solution of 1.5 g of NaOH in 50 ml of ethanol was added and the azeotropic mixture of ethanol- Ethyl acetate (K _p 71, 8 ° C / 760 mm) distilled off. After the ethyl acetate formation had ended, a further 1.5 g of NaOH in 50 ml of ethanol were added and fractionation was continued until further ethyl acetate no longer passed over. Then the ethanol was evaporated off at 15 mm Hg and the residue in the case of the substance PETriN was shaken three times with 20 ml of water and in the case of the substance PEDN stirred with 100 ml of water and etherified three times. After drying in vacuo or removing the ether, the pure substances PETriN or PEDN remain as colorless viscous liquids which have been dried for analysis in vacuo over P ₂ O ₅ .
• d) The PETriN was also processed in such a way that, after washing with water, it was mixed with 100 ml of water and then left at a temperature not higher than 20 ° C. until the next day. It gave stable, colorless crystals in the air of F _p 32 ° C, in which 2.14 ± 0.05% water was found with Karl Fischer reagent and 2.15% water by vacuum drying at 60 ° C, corresponding to a hydrate of composition C ₅ H ₉ O ₁₀ N ₃ . _{^1/3 of} H ₂ O.
• e) PETriN is represented by nitration of pentaerythritol with HNO ₃ (95%) in the presence of urea.
• f) PEDN and PEMN are prepared from PETriN by hydrazinolysis (4 mol NH ₂ NH ₂ (50%)) with subsequent column chromatography separation of the 1: 1 mixture.
• g) A solution of 0.0037 mol pentaerythrityltrinitrate (PETriN), 5.5 ml benzene, 9 ml water and 0.15 ml Aliquat® 336 is mixed with 0.0074 mol KMnO ₄ in portions with vigorous stirring. After the addition has ended, the temperature is kept at 15 ° C. for 2 hours. Then aqueous hydrogen sulfite solution is added, acidified with H ₂ SO ₄ and the benzene layer is separated off. After removal of the solvent, 3-nitryloxy-2,2-bis (nitryloxymethyl) propionic acid (Tri-PS) is obtained as a solid residue which is recrystallized several times from methylene chloride (yield: 72%).
• h) To a mixture of 2.5 g of 95% HNO ₃ , a spatula tip of urea and 10 ml of water cooled to 0 ° C., 1.0 g (0.0061 mol) of 2,2-bis ( hydroxy methyl) malonic acid. After 10 minutes, 2.5 g of 94% H ₂ SO _{4 are added} dropwise with stirring and the mixture is stirred at 0 ° C. for a further hour. The organic layer is separated and evaporated. The residue obtained is 2,2-bis (nitryloxymethyl) malonic acid as a viscous oil, which is purified by column chromatography. Yield: 45%. Elemental analysis: (C: corresponds, H: corresponds, N: corresponds).
• i) 1.0 g (0.004 mol) of carboxy-2-hydroxymethylmalonic acid is added to a mixture of 2.5 g of 95% HNO ₃ , a spatula tip of urea and 10 ml of water, cooled to 0 ° C., while stirring and cooling with ice. After 10 minutes, 2.5 g of 94% H ₂ SO _{4 are added} dropwise with stirring and the mixture is stirred at 0 ° C. for a further hour. The organic layer is separated and evaporated. The residue obtained is 2-carboxy-2-nitryloxymethylmalonic acid as a viscous oil, which is purified by column chromatography. Yield: 30%. Elemental analysis: (C: corresponds, H: corresponds, N: corresponds).
• j) 1 g (3.5 mmol) of Tri-PS is refluxed with 5.3 mmol of thionyl chloride for 1.5 hours: the Excess thionyl chloride is distilled off first on a water bath, then in vacuo. The Residue is taken up in diethyl ether and washed quickly with a little ice water. The organic Phase is separated off, dried over sodium sulfate and the solvent in vacuo evaporates. The resulting oily 3-nitryloxy-2,2-bis (nitryloxymethyl) propionic acid chloride (Tri-PSCl) is pure enough for further implementations. Yield: 75%.
• k) The acid chlorides of the compounds 2,2-bis (nitryloxymethyl) malonic acid (Bis-MS) and 2-carboxy 2-nitryloxymethylmalonic acid (CN-MS) is obtained analogously. To represent 2.2- Bis (nitryloxymethyl) malonic acid dichloride (bis-MSCl) is twice the amount of thionyl chloride and of 2-chlorocarbonyl-2-nitryloxymethyl-malonic acid dichloride (CN-MSCl) three times the amount Thionyl chloride used. Yield: 70 or 45%.
• l) 7 mmol of Tri-PS are mixed with 1 ml of thionyl chloride and 1 drop of dry DMF and stirred with exclusion of moisture for 20 min at room temperature. Excess thionyl chloride is then distilled off and 10 ml of dry methanol are added to the reaction mixture which is cooled to 0.degree. After 30 min, the mixture is diluted with 30 ml of water and extracted five times with diethyl ether. Purification by column chromatography (hexane: ethyl acetate = 2: 1) of the crude product obtained after evaporation of the solvent gives methyl 3-nitryloxy-2,2-bis (nitryloxymethyl) propionate as colorless crystals. Yield: 44%.
  C ₆ H ₉ N ₃ O _11, M = 299.14; F _p = 66 ° C; R _f = 0.65 (silica gel, hexane: ethyl acetate = 1: 1).
• m) 1 g (3.5 mmol) of Tri-PS is mixed with 10.5 mmol of ethanol, 20 mg of toluenesulfonic acid and 30 ml of chloroform added and heated under reflux for 12 hours on a water separator. The chloroform phase is washed with aqueous bicarbonate solution and with water, the solvent in vacuo evaporated and the residue purified by column chromatography. 3-Nitryloxy-2,2- bis (nitryloxymethyl) propionic acid ethyl ester as a colorless oil.  Yield: 85%.
• n) 1 ml of n-butanol is dissolved in 5 ml of pyridine and 0.5 g (1.7 mmol) of tri-PSCl dissolved in ice cooling in 5 ml of tetrahydrofuran. It is heated on the water bath for 1 hour. Then pours one in 50 ml ice water and carefully neutralized with hydrochloric acid. The oily separated ester is taken up in diethyl ether, washed with aqueous sodium carbonate solution and water, the organic phase dried over sodium sulfate and the solvent evaporated in vacuo. The column chromatography purification of the residue 3-nitryloxy-2,2- bis (nitryloxymethyl) propionate as a colorless oil. Yield: 69%.
• o) The esters of the carboxylic acid Bis-MS and CN-MS are analogously doubled (in the case of bis- MS) or tripling (in the case of CN-MS) of the added reagents.
• p) 0.015 mol of 2,2-bis (hydroxymethyl) malonic acid diethyl ester are slowly added to a solution of 90 g of degassed 100% nitric acid at -5 ° C. under a stream of air. The reaction mixture is gasified for a further 120 min at -5 ° C. and then poured into ice water. The aqueous phase is etherified twice, the organic phase washed with 10% hydrogen carbonate solution and with water, dried over sodium sulfate and the solvent evaporated in vacuo. The residue is separated by column chromatography. Yield: 94%. R _f = 0.52 (silica gel, hexane: ethyl acetate = 2: 1); ¹ H-NMR (300 MHz, CDCl ₃ ): corresponds to; ¹³ C-NMR (75 MHz, CDCl ₃ ): corresponds.
• q) 1 g (3.4 mmol) of Tri-PSCL is dissolved in 25 ml of dioxane and concentrated with excess Ammonia solution added. After 30 minutes, pour into 100 ml of ice water and weakly acidify dilute hydrochloric acid. The oily separated 2,2-bis (nitryloxymethyl) -3-nitryloxy propanoic acid amide is purified by column chromatography. Yield: 65%.
• r) 7 mmol of Tri-PS are mixed with 1 ml of thionyl chloride and 1 drop of dry DMF and stirred with exclusion of moisture for 20 min at room temperature. Then 3 ml of cold concentrated NH ₃ solution are added to the reaction mixture and the solution is allowed to cool to room temperature. After extracting the aqueous phase five times with diethyl ether and removing the solvent, an oily crude product is obtained, from which 3-nitryloxy-2,2-bis (nitryloxymethyl) propionic acid amide is isolated as colorless crystals by means of column chromatography (hexane: ethyl acetate = 1: 1) . Yield: 32%; C ₅ H ₈ N ₄ O ₁₀ , M = 284.13; R _f = 0.52 (silica gel, hexane: ethyl acetate = 1: 1). F _p = 71-72 ° C (CHCl3).
• s) 1 g (3.5 mmol) of 3-nitryloxy-2,2-bis (nitryloxymethyl) propionic acid methyl ester is mixed with 3 ml Benzylamine and 100 mg ammonium chloride heated to 130 ° C for 3 hours, cooled, in 50 ml  Chloroform added and successively with water, dilute hydrochloric acid, aqueous Bicarbonate solution and washed again with water. That after evaporation of the solvent the crude product obtained is purified by column chromatography. 3-Nitryloxy-2,2- bis (nitryloxymethyl) propionic acid-N-benzylamide as a colorless oil. Yield: 73%.
• t) 1 g (3.5 mmol) of 2,2-bis (nitryloxymethyl) -3-nitryloxypropanoic acid methyl ester is mixed with excess aqueous hydrazine hydrochloride solution heated on a water bath for 5 hours. You pour on ice and weakly acidifies with hydrochloric acid. After separation by column chromatography of the deposited oil, 3-nitryloxy-2,2-bis (nitryloxymethyl) propionic acid hydrazide is obtained as colorless oil. Yield: 63%.
• u) The amides or hydrazides of the carboxylic acids Bis-MS and CN-MS are analogous to Doubling or tripling of the reagents shown.

The compounds described above under a) to u) serve as starting and Interconnections for further implementations.

Example 2

• a) The compound tri-PSCl is subjected to a Rosenmund reduction in the presence of a strongly deactivated Pd catalyst. The reaction product is isolated in the form of its bisulfite compound, purified and released from it. Yield: 43%. ¹ H-NMR (300 MHz, CDCl ₃ ): corresponds to; ¹³ C-NMR (75 MHz, CDCl ₃ ): corresponds.
• b) Pentaerythrityl trinitrate is oxidized by the action of cystine. The reaction product is trapped in the form of its bisulfite compound, isolated, purified and released from it. Yield: 51%. ¹ H-NMR (300 MHz, CDCl ₃ ): corresponds to; ¹³ C-NMR (75 MHz, CDCl ₃ ): corresponds.

Example 3

• a) The compound Bis-MSCl is reacted analogously to Example 2a). Yield: 35%. ¹ H-NMR (300 MHz, CDCl ₃ ): corresponds to; ¹³ C-NMR (75 MHz, CDCl ₃ ): corresponds.
• b) Pentaerythrityl dinitrate is reacted analogously to Example 2b). Yield: 46%. ¹ H-NMR (300 MHz, CDCl ₃ ): corresponds to; ¹³ C-NMR (75 MHz, CDCl ₃ ): corresponds.

Example 4

• a) The compound CN-MSCl is reacted analogously to Example 2a). Yield: 27%. ¹ H-NMR (300 MHz, CDCl ₃ ): corresponds to; ¹³ C-NMR (75 MHz, CDCl ₃ ): corresponds.
• b) Pentaerythrityl mononitrate is reacted analogously to Example 2b). Yield: 32%. ¹ H-NMR (300 MHz, CDCl ₃ ): corresponds to; ¹³ C-NMR (75 MHz, CDCl ₃ ): corresponds.

Example 5

Investigation of the biochemical effects of the compounds:

• a) The investigation is carried out using the compounds according to Examples 2 to 4 in vitro System cysteine / cystine performed. The redox processes taking place are based on IR and UV spectroscopic data tracked.
• b) The investigation is carried out using the compounds according to Examples 2 to 4 in vitro Glutathione redox system performed. The redox processes taking place are based on IR and UV spectroscopic data.

Claims (10)

1. Compounds of the general formula I,
wherein
R ¹ , R ² and R ^{3 are} identical or different from one another,
R ⁴ , CH ₂ -ONO ₂ , CH ₂ -OR ⁵ , CH ₂ -X, COOR ⁵ , COX, CH ₂ -COOR ⁵ , or CH ₂ -COX, but at least one of the substituents R ¹ to R ³ being R ⁴ is
R ⁴ CHO,
R ⁵ H or a straight-chain or branched C ₁ - to C ₆ -alkyl radical and
X is a halogen
are. 2. Compounds according to claim 1 of the formulas II, III and IV.
3. Compounds of the formula I
wherein the group CH ₂ -ONO ₂ next to R ¹ to R ³ may additionally have one of the other meanings given for R ¹ to R ³ , as substrates for biochemical and pharmacological studies. 4. Use of the compounds according to claim 1 and 2 or the biochemical and pharmacological substrates according to claim 3 for the investigation of biochemical and pharmacological processes.   5. Use of the compounds according to claim 1 and 2 or the biochemical and pharmacological substrates according to claim 3 for the investigation of enzyme-catalyzed biochemical and pharmacological processes. 6. Use according to claim 4 and 5 for the investigation of biochemical and pharmacological Redox processes, especially in the presence of oxidoreductases. 7. Use according to claim 6 for the investigation of enzyme-catalyzed biochemical and pharmacological redox processes of sulfur-containing compounds. 8. Use according to claim 7 for examining the system cysteine / cystine, the glutathione or the lipoic acid redox system. 9. Use according to claim 4 to 8 for the investigation of nitrate or Nitrate cross tolerance phenomena. 10. Use of the compound of formula V
for the preparation of compounds according to claims 1 and 2 or the biochemical and pharmacological substrates according to claim 3.