Abstract:
The present disclosure relates to lipid compounds of formula (I): 
                                 
wherein:
       R 1  is chosen from a C 10 -C 21  alkyl, a C 10 -C 21  alkenyl having 1-6 double bonds, and a C 10 -C 21  alkynyl having 1-6 triple bonds;   R 2  and R 3  are the same or different and are chosen from hydrogen and a C 1 -C 6  alkyl;   X is chosen from O, S, SO, SO 2 , Si, and Se;   n=1 or 3; and   P 1  is chosen from hydrogen; a C 10 -C 21  alkyl, a C 10 -C 21  alkenyl having 1-6 double bonds, a C 10 -C 21  alkynyl having 1-6 triple bonds, optionally substituted; a group of formula (II) or formula (III), wherein P 2 , P 3 , and P 4  are chosen from hydrogen, an alkyl, an alkenyl, and an alkynyl, optionally substituted; and a group of formula (IV) or formula (V), wherein P 5  is chosen from hydrogen and a C 1 -C 6  alkyl;   or a pharmaceutically acceptable salt, complex, or solvate thereof. Also disclosed are pharmaceutical compositions and lipid compositions comprising such compounds, and methods of use thereof, for example in the treatment of diseases related to cardiovascular, metabolic, and inflammatory conditions.

Description:
This is a national stage application under §371 of International Application No. PCT/NO2008/000391, filed Nov. 6, 2008, which claims priority to U.S. Provisional Application No. 60/986,698, filed Nov. 9, 2007, all of which are incorporated herein by reference in their entireties. 
    
    
     TECHNICAL FIELD 
     The present invention relates to lipid compounds of the general formula (I): 
                                
wherein
         R 1  is selected from a C 10 -C 21  alkyl, a C 10 -C 21  alkenyl having 1-6 double bonds, and a C 10 -C 21  alkynyl having 1-6 triple bonds;   R 2  and R 3  are the same or different and are selected from hydrogen and a C 1 -C 6  alkyl group; and X is selected from O, S, SO, SO 2 , Si or Se;   n=1 or 3; and   P 1  is selected from a hydrogen, a C 10 -C 21  alkyl, a C 10 -C 21  alkenyl having 1-6 double bonds, and a C 10 -C 21  alkynyl having 1-6 triple bonds, optionally substituted; or P 1  is represented by:       

                                
wherein P 2 , P 3  and P 4  are selected from a hydrogen, an alkyl, alkenyl, alkynyl, optionally substituted; or
 
P 1  is a phosphonate or a phosphate ester, represented by
 
                                
or P 1  is a sulphonate or a sulphate ester, represented by
 
                                
wherein P 5  is a hydrogen or a C 1 -C 6  alkyl;
 
or a pharmaceutically acceptable salt, complex or solvate thereof.
 
     The invention also relates to pharmaceutical compositions and lipid compositions comprising such compounds, and to such compounds for use as medicaments or for use in therapy, in particular for the treatment of diseases related to the cardiovascular, metabolic and inflammatory disease area. 
     BACKGROUND OF THE INVENTION 
     Up to date, there has been a lot of research on fatty acid analogues and their effects on diverse physiological processes impacting normal health and chronic diseases. 
     For example, dietary polyunsaturated fatty acids (PUFAs) have been shown to regulate plasma lipid levels, cardiovascular and immune functions, insulin action, and neuronal development and visual function. 
     Tetradecylthioacetic acid (TTA) is a modified fatty acid which has a number of powerful effects demonstrable both in vivo and in vitro on living organisms. 
     TTA has properties very similar to natural fatty acids, the main difference being that it cannot be oxidised by the mitochondrial β-oxidation, but significantly increases the oxidation of other fatty acids. Despite the fact that TTA is not able to undergo β-oxidation, it is metabolised in most ways as a normal saturated fatty acid. 
     
       
                 
         
             
             
         
      
     
     TTA affects antioxidant status at different levels by having the potential of changing the antioxidant defense system in addition to being an antioxidant itself through its free radical scavenging capacity. 
     Addition of TTA may prevent the oxidative modification of LDL particles in plasma and reduce the generation of lipid peroxides. 
     SUMMARY OF THE INVENTION 
     One object of the present invention is to provide lipid compounds having pharmaceutical activity. This object is achieved by a lipid compound of formula (I) 
                                
wherein
         R 1  is selected from a C 10 -C 21  alkyl, a C 10 -C 21  alkenyl having 1-6 double bonds, and a C 10 -C 21  alkynyl having 1-6 triple bonds;   R 2  and R 3  are the same or different and are selected from hydrogen and a C 1 -C 6  alkyl group; and X is selected from O, S, SO, SO 2 , Si or Se;   n=1 or 3; and   P 1  is selected from a hydrogen, a C 10 -C 21  alkyl, a C 10 -C 21  alkenyl having 1-6 double bonds, and a C 10 -C 21  alkynyl having 1-6 triple bonds, optionally substituted; or P 1  is represented by:       

                                
wherein P 2 , P 3  and P 4  are selected from a hydrogen, an alkyl, alkenyl, alkynyl, which optionally may be substituted; or
 
P 1  is a phosphonate or a phosphate ester, represented by
 
                                
or P 1  is a sulphonate or a sulphate ester, represented by
 
                                
wherein P 5  is a hydrogen or a C 1 -C 6  alkyl;
 
or a pharmaceutically acceptable salt, complex or solvate thereof.
 
     In particular, the present invention relates to compounds of formula (I), wherein: 
     R 1  is a C 10 -C 21  alkyl, e.g. a C 14  alkyl, and said lipid compound is derived from a saturated fatty acid. 
     R 1  is a C 10 -C 22 -alkenyl with 1-6 double bonds, wherein said lipid compound is either derived from a monounsaturated fatty acid or a polyunsaturated fatty acid. 
     When derived from a monounsaturated fatty acid, R 1  is typically a C 14 -C 18  alkenyl, e.g. with 1-3 double bonds. 
     When derived from a polyunsaturated fatty acid, R 1  is typically a C 10 -C 22  alkenyl with 3-6 double bonds, e.g. 3-6 methylene interrupted double bonds in Z configuration. For example, R 1  is:
         a C 15  alkenyl with 4 double bonds, e.g. a C 15  alkenyl with 4 methylene interrupted double bonds in Z-configuration   a C 18  alkenyl with 3-5 double bonds, e.g. a C 18  alkenyl with 5 methylene interrupted double bonds in Z configuration   a C 20  alkenyl with 5 methylene interrupted double bonds in Z-configuration   a C 22  alkenyl with 6 methylene interrupted double bonds in Z-configuration       

     Furthermore, R 1  may be a C 10 -C 22  alkynyl, e.g. a C 16 -C 22  alkynyl, wherein said lipid compound is derived from lipids comprising 1-6 triple bonds. 
     The present invention also relates to salts of the compounds according to formula (I). Such salts may comprise a monovalent cation such as Li + , Na + , K + , NH 4   + , meglumine, tris(hydroxymethyl)aminomethane, diethylamine, arginine; a divalent ion such as Mg 2+ , Ca 2+ , ethylenediamine, piperazine; or a polyvalent cation such as chitosan. 
     In compounds of formula (I), wherein P 1  is represented by 
     
       
                 
         
             
             
         
      
     
     P 2 , P 3 , P 4  are typically selected from a hydrogen, a C 1 -C 6  alkyl, e.g. methyl, ethyl, n-propyl, isopropyl, n-butyl, iso-butyl, sec-butyl, n-hexyl, optionally substituted. Preferably one of P 2 , P 3 , P 4  is a hydrogen, a methyl group, or an isopropyl group. Typically, one of P 2 , P 3 , P 4  is a C 1 -C 6  alkyl, e.g. methyl and the other two are represented by hydrogen. For example P 1  in formula (I) is represented by: 
     
       
                 
         
             
             
         
      
     
     According to a preferred embodiment of the present invention, said alkyl, alkenyl or alkynyl is substituted with a carboxy group, typically a C 1 -C 6  carboxy group. In this case, P 1  according to formula (II) may be represented by: 
     
       
                 
         
             
             
         
      
     
     When P 1  is represented by formula (IIb) above, salts of the compounds according to formula (I) may be represented by 
                                
wherein Z +  is selected from the group consisting of Li + , Na + , K + , NH 4   + ,
 
                                
wherein Z 2+  is selected from the group consisting of Mg 2+ , Ca 2+ ,
 
                                
wherein Z n+  is
 
                                
In formula (I), P 1  may also be represented by:
 
                                
wherein P 2 , P 3 , P 4  is typically a hydrogen, a C 1 -C 6  alkyl, e.g. methyl, ethyl, n-propyl, isopropyl, n-butyl, iso-butyl, sec-butyl or an n-hexyl. Preferably one of P 2 , P 3 , P 4  is a hydrogen, a methyl group or an isopropyl group.
 
When P 1  is a phosphonate or a phosphate ester represented by
 
                                
P 5  is typically a hydrogen or a C 1 -C 6  alkyl; preferably a hydrogen or a methyl group according to the formulas below
 
     
       
                 
         
             
             
         
      
     
     When P 1  is a sulphonate or a sulphate ester, represented by 
                                
P 5  is typically a hydrogen or a C 1 -C 6  alkyl, preferably a hydrogen or a methyl group according to the formulas below
 
     
       
                 
         
             
             
         
      
     
     In a preferred embodiment of the present invention, n is 1. 
     As mentioned, R 2  and R 3  may be the same or different and may be selected from a hydrogen and a C 1 -C 6  alkyl group. Typically, R 2  and R 3  are both hydrogen. 
     Furthermore, in compounds of formula (I), X may be selected from O, S, SO, SO 2 , Si and Se. Preferably, X is either S, Se or O. Typically it is S. 
     The compounds of formula (I) are capable of existing in stereoisomeric forms. It will be understood that the invention encompasses all optical isomers of the compounds of formula (I) and mixtures thereof, including racemates. Therefore, the present invention includes compounds of formula (I) that are racemic, either as the (S) or (R) enantiomer. 
     The present invention also relates to a lipid compound according of formula (I) for use as a medicament. 
     Cosmetic formulations comprising compounds of formula I form a further aspect of the invention. 
     In yet a further aspect, the present invention provides a food supplement, a food additive, or a neutraceutical preparation comprising a lipid compound of formula (I). 
     Such a food supplement may be produced for administration through any route of administration. For example, the food supplement may be administered as a liquid nutritional or as a beverage. 
     The food supplement may be in the form of a capsule, preferably a gelatine capsule, and the capsule may be flavoured. 
     In still a further aspect, the present invention provides a pharmaceutical composition comprising a compound of formula (I), preferably together with one or more pharmaceutically acceptable carriers or excipients. 
     The novel lipid compounds and compositions of the invention may be formulated in conventional administration forms, e.g. tablets, coated tablets, capsules, powders, granulates, solutions, dispersions, suspensions, syrups, emulsions, sprays, suppositories, pessaries, etc using conventional excipients, e.g. solvents, diluents, binders, sweeteners, aromas, pH modifiers, viscosity modifiers, antioxidants, corn starch, lactose, glucose, microcrystalline cellulose, magnesium stearate, polyvinylpyrrolidone, citric acid, tartaric acid, water, water/ethanol, water/glycerol, water/sorbitol, water/polyethylene glycol, propylene glycol, cetylstearyl alcohol, carboxymethylcellulose or fatty substances such as hard fat or suitable mixtures thereof etc. Conventional formulation techniques, well known in the art, may be used. 
     The compositions may likewise be administered by conventional administration routes, e.g. orally, by injection, infusion, nasally, rectally, etc. The use of orally administrable compositions, e.g. tablets, coated tablets, capsules, syrups, etc is especially preferred. 
     A suitable daily dosage of the compound according to formula (I) is 1 mg to 10 g of said compound; 50 mg to 1 g of said compound, or 50 mg to 200 mg of said compound. 
     The pharmaceutical composition according to the invention may be used as a medicament. 
     The present invention also relates to lipid composition comprising a lipid compound according to formula (I). Suitably, at least 60% by weight, or at least 80% by weight of the lipid composition is comprised of said compound. 
     The lipid composition may further comprise a pharmaceutically acceptable antioxidant, e.g. tocopherol. 
     Further, the present invention relates to a lipid composition for use as a medicament. 
     Additionally, the present invention relates to the use of a lipid compound according to formula (I) for the production of a medicament for:
         the treatment and/or the prevention of peripheral insulin resistance and/or a diabetic condition   the reduction of plasma insulin, blood glucose and/or serum triglycerides.   the prevention and/or treatment of elevated triglyceride levels, LDL cholesterol levels, and/or VLDL cholesterol levels.   the prevention and/or treatment of a hyperlipidemic condition, e.g. hypertriglyceridemia   the treatment and/or prevention of type 2 diabetes   increasing serum HDL levels in humans   the treatment and/or the prevention of obesity or an overweight condition   the reduction of body weight and/or for preventing body weight gain   the treatment and/or the prevention of a fatty liver disease, e.g. non-alcoholic fatty liver disease (NAFLD).   the treatment and/or the prevention of an inflammatory disease or condition, e.g. a chronic inflammatory disease like psoriasis   the treatment and/or the prevention of a condition selected from the group consisting of dyslipidemia, hypertension, atherosclerosis, cancer, rheumatoid arthritis, and brain disorders, e.g. MS and Alzheimer&#39;s       

     The invention also relates lipid compounds according to formula (I) for the treatment of the above mentioned conditions, and to methods for the treatment and/or prevention of the conditions listed above, comprising administering to a mammal in need thereof a pharmaceutically active amount of a compound according to formula (I). 
     In addition, the present invention encompasses methods for manufacturing lipid compounds according to formula (I). 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The present inventors have found that specific pro-drugs of tetradecylthioacetic acid (TTA) or compounds that in vivo can be metabolized to TTA, in particular alcohols of these compounds and pro-drugs of the alcohol have remarkably good pharmaceutical activity. Such compounds are represented by formula (I). 
     As used herein, the term “lipid compound” relates to fatty acid analogues derived from e.g. monounsaturated fatty acids, polyunsaturated fatty acids and lipids comprising 1-6 triple bonds. 
     “Pro-drugs” are entities which may or may not possess pharmacological activity as such, but may be administered (such as orally or parenterally) and thereafter subjected to bioactivation (for example metabolization) in the body to form the agent of the present invention which is pharmacologically active. 
     A “pharmaceutically active amount” relates to an amount that will lead to the desired pharmacological and/or therapeutic effects, i.e. an amount of the combination product which is effective to achieve its intended purpose. While individual patient needs may vary, determination of optimal ranges for effective amounts of the combination product is within the skill of the art. Generally, the dosage regimen for treating a condition with the combination product of this invention is selected in accordance with a variety of factors, including the type, age, weight, sex, diet and medical condition of the patient. 
     By “a pharmaceutical composition” is meant a lipid compound according to the invention in any form suitable to be used for a medical purpose. 
     “Treatment” includes any therapeutic application that can benefit a human or non-human mammal. Both human and veterinary treatments are within the scope of the present invention. Treatment may be in respect of an existing condition or it may be prophylactic. 
     Nomenclature and Terminology: 
     Fatty acids are straight chain hydrocarbons possessing a carboxyl (COOH) group at one end (α) and (usually) a methyl group at the other (ω) end. In chemistry, the numbering of the carbon atoms starts from the α end. 
     
       
                 
         
             
             
         
      
     
     The α carbon refers to the first carbon after the carbon that attaches to the functional group, and the second carbon is the β carbon. 
     As used herein, the expression “methylene interrupted double bonds” relates to the case when a methylene group is located between to separate double bonds in a carbon chain of a lipid compound. 
     The basic idea of the present invention is a lipid compound of formula (I): 
                                
wherein R 1 , R 2 , R 3 , X, n, and P 1  are as defined above.
 
     The resulting compound is a lipid compound with a heteroatom incorporated in the lipid chain, i.e. a lipid compound with a heteroatom preferably in the β-position. 
     More particularly, the present inventors have surprisingly found that the following lipid compound categories A-D are particularly preferable. 
     Category A 
     derived from saturated fatty acids 
     R 1  is a C 10 -C 21  alkyl 
     Example 1 
     R 1 ═C 14 , n=1 
                                
Category B
 
     derived from monounsaturated fatty acids 
     R 1  is a C 10 -C 21  alkenyl having 1 double bond 
     Example 2 
     R 1 ═C 18 , n=1 
     
       
                 
         
             
             
         
      
     
     Example 3 
     R 1 ═C 14 , n=1, X═S 
                                
Category C
 
     derived from polyunsaturated fatty acids 
     R 1  is a C 10 -C 22  alkenyl having 1-6 double bonds 
     Example 4 
     R 1 ═C 20  with 5 methylene interrupted double bonds in Z-configuration, n=1, X═S 
     
       
                 
         
             
             
         
      
     
     Example 5 
     R 1 ═C 22  with 6 methylene interrupted double bonds in Z-configuration, n=1 
     
       
                 
         
             
             
         
      
     
     Example 6 
     R 1 ═C 18  with 3 methylene interrupted double bonds in Z-configuration, n=1 
     
       
                 
         
             
             
         
      
     
     Example 7 
     R 1 ═C 15  with 4 methylene interrupted double bonds in Z-configuration, n=1 
     
       
                 
         
             
             
         
      
     
     Example 8 
     R 1 ═C 15  with 4 double bonds, n=1 
     
       
                 
         
             
             
         
      
     
     Example 9 
     R 1  is C 18  with 5 double bonds methylene interrupted double bonds in Z-configuration, n=1 
     
       
                 
         
             
             
         
      
     
     Example 10 
     R 1 ═C 18  with 5 double bonds, n=1 
                                
Category D
 
     derived from lipids containing 1-6 triple bonds 
     Example 11 
     R 1 ═C 18  with 1 triple bond, n=1 
     
       
                 
         
             
             
         
      
     
     The present invention will now be further described by the following non-limiting examples. 
     General Synthesis for Compounds Wherein X is Sulphur and n=1 
     The compounds of general formula (I) can be prepared by the following general procedures: 
     
       
                 
         
             
             
         
      
     
     
       
                 
         
             
             
         
      
     
     The unsaturated alcohols may be prepared directly from the carboxylic esters of the naturally occurring unsaturated fatty acids; alpha-linolenic acid, oleic acid, conjugated linoleic acid, linoleic acid, eicosapentaenoic acid, etc. by reduction with diisobutylaluminiumhydride. The alcohols can also be prepared by degradation of the polyunsaturated fatty acids EPA and DHA as described by Holmeide et al. ( J. Chem. Soc., Perkin Trans.  1, 2000, 2271). In this case one can start with purified EPA or DHA, but it is also possible to start with fish oil containing EPA and DHA in mixture. 
     The saturated alcohols can be obtained from their corresponding carboxylic acids or carboxylic esters. 
     Examples 1 to 4 
     In the following examples the structures were verified by NMR. The NMR spectra were recorded in CDCl 3 . J values are given in Hz. 
     The following lipid derivatives have been prepared and characterised, and thus in accordance with the present invention there is provided compounds of the formula (I) 
     Preparation and characterisation of specific fatty acid derivatives of formula (I) 
     Example 1 
     2-Tetradecylsulfanyl-ethanol 
                                
A solution of tetradecylsulfanyl-acetic acid (1.50 g, 520 mmol) in dry THF (10 ml) was added drop wise to a suspension of LiAlH 4  (0.40 g, 10.4 mmol) in dry THF (30 ml) at 0° C. The mixture was stirred at 0° C. for one hour and then at ambient temperature for 18 hours. Saturated NH 4 Cl (40 ml) was added, and the resulting mixture was filtered through a short pad of celite. The phases were separated and the aqueous layer was extracted with diethyl ether (50 ml). The combined organic phases was washed with brine (50 ml), dried (Na 2 SO 4 ) and concentrated in vacuo. Purification by flash chromatography on silica gel (heptane:EtOAc 4:1) afforded 0.76 g (54%) of the title compound as a colourless solid.
 
       1 H-NMR (200 MHz, CDCl 3 ): δ 0.85 (t, 3H), 1.23-1.49 (m, 22H), 1.55 (m, 2H), 2.48 (t, 2H), 2.69 (t, 2H), 3.68 (t, 2H) 
     MS (ESI): 297 [M+Na + ] + . 
     Example 2 
     (2-tetradecylsulfanyl-ethyl)acetate 
                                
2-Tetradecylsulfanyl-ethanol (0.54 g, 1.97 mmol) was dissolved in dry THF (10 ml) and pyridine (0.16 ml, 1.97 mmol) was added followed by acetyl chloride (0.15 m, 2.16 mmol). The resulting mixture was allowed to stir at ambient temperature for 23 hours, then another portion of acetyl chloride (0.075 ml, 1.08 mmol) and pyridine (0.080 ml, 0.95 mmol) was added. The mixture was stirred at ambient temperature for a further 90 minutes and then portioned between diethyl ether (30 ml) and 10% NH 4 Cl (30 ml). The organic layer was washed with brine (40 ml), dried (Na 2 SO 4 ) and concentrated in vacuo. Toluene (10 mL) was added to the residue. The solvents were evaporated in vacuo and the crude product was purified by flash chromatography on silica gel (heptane:EtOAc 9:1) to afford 0.45 g (72%) of the title compound as a colorless solid.
 
       1 H-NMR (200 MHz, CDCl 3 ): δ 0.85 (t, 3H), 1.23-1.49 (m, 22H), 1.49-1.60 (m, 2H), 2.04 (s, 3H), 2.53 (t, 2H), 2.71 (t, 2H), 4.19 (t, 2H); 
     MS (ESI): 317 [M+H + ] + , 339 [M+Na + ] + . 
     Example 3 
     (5E,9Z,12Z,15Z,18Z)-3-thia-heneicosa-pentaen-1-ol 
     Step 1: Ethyl (5E,9Z,12Z,15Z,18Z)-3-thia-heneicosa-pentaenoate 
                                
Et 3 N (0.28 ml, 2.07 mmol) followed by bromo ethylacetate (0.22 ml, 1.97 mmol) were added to a mixture of (2E,6Z,9Z,12Z,15Z)-octadecapentaene-1-thiol (0.52 g, 1.88 mmol) in dry CH 2 Cl 2  (10 ml) under an inert atmosphere. The resulting solution was stirred at ambient temperature for 18 hours. CH 2 Cl 2  (20 ml) was added. The resulting mixture was washed with water (20 ml) and brine (30 ml), dried (Na 2 SO 4 ) and concentrated in vacuo. The residue was purified by flash chromatography on a short silica column (heptane:EtOAc 99:1 then 95:5) to afford 0.54 g (79%) of the title compound as a colorless oil.
 
       1 H-NMR (200 MHz, CDCl 3 ): δ 0.95 (t, 3H), 1.27 (t, 3H), 1.98-2.19 (m, 6H), 2.76-2.90 (m, 6H), 3.13 (s, 2H), 3.18 (d, 2H), 4.16 (q, 2H), 5.22-5.50 (m, 9H), 5.53-5.71 (m, 1H); 
     MS (ESI): 385 [M+Na + ] + . 
     Step 2: (5E,9Z,12Z,15Z,18Z)-3-thia-heneicosa-pentaen-1-ol 
                                
A solution of ethyl (5E,9Z,12Z,15Z,18Z)-3-thia-heneicosa-pentaenoate (0.54 g, 1.49 mmol) in dry THF (5 ml) was added drop wise to a stirred suspension of LiAlH 4  (0.062 g, 1.64 mmol) in dry THF (10 ml) at 0° C. under inert atmosphere. The resulting solution was stirred at 0° C. for 15 minutes. 10% NH 4 Cl(20 ml) was added drop wise and the resulting mixture was filtered through a short pad of celite. The celite pad was washed with water (20 ml) and diethyl ether (20 ml) and the phases were separated. The aqueous phase was extracted with diethyl ether (2×20 ml). The combined organic extracts were washed with brine (20 ml), dried (Na 2 SO 4 ) and concentrated in vacuo. The residue was purified by flash chromatography on silica gel (heptane:EtOAc 4:1). This afforded 0.39 g (81%) of the title compound as a colorless oil.
 
       1 H-NMR (200 MHz, CDCl 3 ): δ 0.96 (t, 3H), 1.98-2.12 (m, 7H), 2.66 (t, 2H), 2.76-2.85 (m, 6H), 3.08 (d, 2H), 3.67 (q, 2H), 5.26-5.56 (m, 10H); 
     MS (ESI): 343 [M+Na + ] + . 
     Example 4 
     (all-Z)-2-ethyl-3-thia-tricosa-8,11,14,17,20-pentaen-1-ol 
     Step 1: (all-Z)-eicosa-5,8,11,14,17-pentaen-1-yl thioacetate 
                                
Triphenylphosphine, PPh 3  (79.11 g, 302 mmol) was dissolved in dry THF (600 ml) at 0° C. under inert atmosphere and added DIAD (59.06 ml, 305 mmol) dropwise. After 40 minutes at 0° C. a solution of (all-Z)-5,8,11,14,17-eicosapentaen-1-ol (43.50 g, 151 mmol) and thioacetic acid (21.56 ml, 302 mmol) in dry THF (400 mL) was added dropwise. The resulting turbid mixture was stirred at 0° C. for 40 minutes, followed by ambient temperature for 1.5 h. Heptane (600 ml) was added, the mixture was stirred for ten minutes and the precipitated white solid removed by filtration. This procedure was repeated twice and finally the residue after concentration was stirred in heptane (400 ml) for 24 h. Filtration and purification of the residue by flash chromatography (SiO 2 , EtOAc:Heptane 2:98) provided 46.6 g (89%) of the title compound as a colourless oil.
 
       1 H-NMR (200 MHz, CDCl 3 ); δ 0.95 (t, 3H), 1.41-1.63 (m, 4H), 2.05 (m, 4H), 2.30 (s, 3H), 2.76-2.89 (m, 10H), 5.22-5.44 (m, 10H) 
     MS (ESI): 369 [M+Na + ] + . 
     Step 2: (all Z)-eicosa-5,8,11,14,17-pentaene-1-thiol 
                                
K 2 CO 3  (18.6 g, 134 mmol) was added to a solution of (all-Z)-eicosa-5,8,11,14,17-pentaen-1-yl thioacetate (46.6 g, 134 mmol) in dry MeOH (500 ml) under inert atmosphere. The mixture was stirred at ambient temperature for 1.5 h. 1M HCl (350 m), water (350 m) and diethyl ether (500 ml) was added. The phases were separated and the aqueous phase was extracted with diethyl ether (500 ml). The combined organic extracts were washed with brine (250 m), dried (Na 2 SO 4 ), filtered and concentrated in vacuo. Purification by flash chromatography (SiO 2 , 1%-2%-3% EtOAc in heptane) afforded 30.0 g (75%) of the title compound as a pale yellow oil.
 
       1 H-NMR (200 MHz, CDCl 3 ): δ 0.95 (t, 3H), 1.35-1.61 (m, 4H), 2.06 (m, 4H), 2.51 (m, 2H), 2.76-2.85 (m, 8H), 5.23-5.44 (m, 10H). 
     Step 3: (all-Z)-2-ethyl-3-thia-tricosa-8,11,14,17,20-pentaenoic acid 
                                
A solution of (all Z)-eicosa-5,8,11,14,17-pentaene-1-thiol (20.0 g, 65.7 mmol) in dry DMF (150 m) at 0° C. under inert atmosphere was added NaH (2.84 g, 72.2 mmol). The resulting yellow suspension was stirred at 0° C. for 30 min and then added to a pre made mixture of 2-bromo butyric acid (7.73 ml, 72.2 mmol) and NaH (3.15 g, 78.8 mmol) in DMF (150 m) at 0° C. The resulting clear solution was stirred at ambient temperature under inert atmosphere for 3 h, and then poured into cold saturated NH 4 Cl (300 ml). 1M HCl was added until pH=1 and the resulting mixture was extracted twice with diethyl ether (400 ml each). The combined organic extracts were washed with brine (250 ml), dried (MgSO 4 ), filtered and concentrated in vacuo to afford 28 g of crude product. The crude product was first filtered through a short pad of silica gel (heptane: EtOAc (with 5% HCOOH) 95:5-90:10) to afford 11.5 g of impure product. A second purification by ordinary flash chromatography (SiO 2 , heptane: EtOAc (with 5% HCOOH) 9:1-8:2-7:3) afforded 10.15 g (40%) of the title compound as a pale yellow oil.
 
       1 H-NMR (300 MHz, CDCl 3 ): δ 0.97 (t, 3H), 1.07 (t, 3H), 1.46 (m, 2H), 1.64-1.74 (m, 3H), 1.79 (m, 1H), 2.10 (m, 4H), 2.66 (m, 2H), 2.83 (m, 8H), 3.20 (t, 1H), 5.35-5.42 (m, 10H) 
     MS (ESI): 389 [M−H + ] − . 
     Step 4: (all-Z)-2-ethyl-3-thia-tricosa-8,11,14,17,20-pentaen-1-ol 
                                
(all-Z)-2-ethyl-3-thia-tricosa-8,11,14,17,20-pentaenoic acid (100 mg, 0.26 mmol) was dissolved in dry THF (1 ml) and added drop wise to a solution of lithium aluminium hydride (19 mg, 0.51 mmol) in dry THF (4 m) at 0° C. The resulting turbid mixture was stirred at 0° C. for 30 min, and then carefully added saturated NH 4 Cl (15 ml). The resulting mixture was extracted twice with heptane (15 ml each). The combined organic extracts were dried (Na 2 SO 4 ), filtered and purified by flash chromatography (SiO 2 , heptane: EtOAc 95:5-90:10) to afford 70 mg (71%) of the title compound.
 
       1 H-NMR (300 MHz, CDCl 3 ): δ 0.95 (t, 3H), 1.05 (t, 3H), 1.40-1-70 (m, 6H), 2.10 (m, 4H), 2.30 (m, 1H), 2.50 (m, 2H), 2.65-2.75 (m, 1H), 2.75-2.90 (m, 8H), 3.50 (m, 1H), 3.65 (m, 1H), 5.25-5.50 (m, 10H) 
       13 C-NMR (75 MHz, CDCl 3 ): δ 12.12, 14.66, 20.95, 25.22, 26.03 (3 signals), 27.17, 29.24, 30.02. 30.45. 51.76, 63.86, 127.40, 128.26, 128.43, 128.50, 128.56, 128.94, 130.04, 132.41 (three signals hidden) 
     MS (ESI): 399 [M+Na + ] + . 
     The invention shall not be limited the shown embodiments and examples.