Succinic acid

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Complexation of Beryllium(II) by Maleic and Succinic Acid 

Complexation of Beryllium(II) by Maleic and Succinic Acid 

Beryllium succinate dihydrate [Be(C 4 H 404 )](H 20)2 is formed in the reaction of equimolar quantities of beryllium sulfate, succinic acid and barium hydroxide in aqueous solution at pH 3.2. Sodium, potassium, and ammonium bis(succinato)beryllates M 2 [Be(C 4 H 4 C> 4 ) 2 ] are obtained using the same reagents in the molar ratio 1:2 :1 and adjusting the pH to 6.3-6.5 with NaOH, KOH or concentrated aqueous ammonia, respectively. The corresponding potassium bis(maleato)beryllate is prepared similarly and obtained as a crystalline m onohydrate, the structure of which has been determined by X-ray methods. The lattice contains spiro-bicyclic dianions with the Be atom chelated by two dicarboxylate ligands. The com pounds undergo slow hydrolysis in water as shown by time- and pH-dependent }Be NMR spectroscopy. In the neutral region (pH 6.5-6.9) the maleinato complexes are in an equilibrium with trinuclear compounds M 3 {[Be(C 4 H 204 ) 0 H] 3 } as the predominating species, while in acid solution (at pH 1.3) only the aquo complex [Be(H20)4]2+ remains. In the intermediate pH region various complexes of the above types coexist, with only very slow ligand exchange (on the NMR time scale).
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Investigation of the mode of action of succinic acid and amino acids during hair bleaching treatment

Investigation of the mode of action of succinic acid and amino acids during hair bleaching treatment

The commercially available ammonia-based alkaline bleaching system is widely used in human hair oxidative colorants or bleaching products. However, over time the consumers can experience undesired hair damage such as poor hair feel and look, reduced hair strength, increased incidents of split ends and breakage. Scientific test methods like tensile strength evaluations as well as multiple grooming tests and differential scanning calorimetry (DSC) allow a quantitative assessment of human hair damage. A hair bleaching product formulated with succinic acid in combination with lysine and arginine demonstrated that it protects hair fibre from damage during bleaching in comparison to the conventional bleaching products [69, 70]. However, the mechanism of this protective effect was not yet fully understood. Therefore, the understanding of the mode of action was a first step in further designing a more efficient technology to protect hair fibre. As a hypothesis of the mechanism of this protective effect, there are two options: A) Interaction of the components with hair fibre and direct stabilization of the damaged sites by molecular interaction/reaction during bleaching [69, 71] or B) Modification of the reaction mechanism towards milder conditions. Therefore, the objectives of this dissertation were:
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Evaluation of pyruvate decarboxylase‐negative Saccharomyces cerevisiae strains for the production of succinic acid

Evaluation of pyruvate decarboxylase‐negative Saccharomyces cerevisiae strains for the production of succinic acid

Dicarboxylic acids are important bio-based building blocks, and Saccharomyces cere- visiae is postulated to be an advantageous host for their fermentative production. Here, we engineered a pyruvate decarboxylase-negative S. cerevisiae strain for succinic acid production to exploit its promising properties, that is, lack of ethanol production and accumulation of the precursor pyruvate. The metabolic engineering steps included genomic integration of a biosynthesis pathway based on the reductive branch of the tricarboxylic acid cycle and a dicarboxylic acid transporter. Further modifications were the combined deletion of GPD1 and FUM1 and multi-copy integration of the native PYC2 gene, encoding a pyruvate carboxylase required to drain pyruvate into the synthesis pathway. The effect of increased redox cofactor supply was tested by modulating oxygen limitation and supplementing formate. The physiologic analysis of the differently engineered strains focused on elucidating metabolic bottlenecks. The data not only highlight the importance of a balanced activity of pathway enzymes and selective export systems but also shows the importance to find an optimal trade-off between redox cofactor supply and energy availability in the form of ATP.
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Selective hydrogenation of biomass‐derived succinic acid: reaction network and kinetics

Selective hydrogenation of biomass‐derived succinic acid: reaction network and kinetics

2 Experimental 2.1 Materials Succinic acid ( ‡ 99.0 wt %), 1,4-butanediol ( ‡ 99.0 wt %), g-butyrolactone ( ‡ 99.0 wt %), and tetrahydrofuran ( ‡ 99.9 wt %) were received from Sigma-Aldrich. The water used for high- performance liquid chromatography (HPLC) calibrations was supplied by an ultrapure water device from Sartorius AG (Arium 611VF, 18.2 O cm, 0.055 mS cm –1 at 25 C). Water used for hydrogenation experiments was prepared with a water demineralizer supplied by behr Labor-Technik (behropur  E28dK, 0.5 mS cm –1 at 25 C). The catalyst (4 wt % Re-2 wt % Pd on activated carbon) was manufactured individually by Heraeus. It was supplied wet and did not undergo any pretreat- ment before usage. A particle diameter of x 50 = 25 mm was
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Electrochemical Crystallization Concept for Succinic Acid Reduces Waste Salt Production

Electrochemical Crystallization Concept for Succinic Acid Reduces Waste Salt Production

Bio-based carboxylic acids are promising platform chemicals. State-of-the-art fermentations produce salts of carboxylic acids at neutral pH. Downstream processing of these fermentation broths traditionally involves a pH shift producing waste salts. These waste salts reduce the sustainability and economics of bio-cased carboxylic acid production. Waste salt pro- duction can be avoided by inducing the pH shift electrochemically. Experimental feasibility studies of an electrochemical downstream process and investigations of electrochemically induced nucleation and crystal growth are given. The pre- sented electrochemical downstream concept enables in situ production of succinic acid and simultaneous pH management of pH neutral fermentations without the side production of waste salts.
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Structural Elucidation of α-Cyclodextrin-Succinic Acid Pseudo Dodecahydrate: Expanding the Packing Types of α-Cyclodextrin Inclusion Complexes

Structural Elucidation of α-Cyclodextrin-Succinic Acid Pseudo Dodecahydrate: Expanding the Packing Types of α-Cyclodextrin Inclusion Complexes

Succinic acid (SA, Figure 1 ), an aliphatic dicarboxylic acid, is essential in aerobic cellular metabolism by intervening in the citric acid cycle, a metabolic pathway for the regeneration of adenosine triphosphate (ATP), which is the main energy source of most cellular functions [ 11 ]. SA is a FDA-Generally Recognized As SAFE (GRAS) substance also used in the pharmaceutical industry for the preparation of succinate ester derivatives of active pharmaceutical ingredients. The structure of a β-CD¨SA inclusion complex (CSD refcode KIJSEC) has been previously obtained while investigating the enhancement of succinic anhydride’s reactivity using β-CD as molecular cages in aqueous solutions [ 12 ]. We found that this complex can easily be obtained with SA instead of succinic anhydride; the large cavity size of β-CD, which is 6.0–6.5 Å in diameter [ 13 ], can easily accommodate SA and the crystal structure of the complex shows several intermolecular interactions between host, guest and solvent molecules [ 12 ]. We hypothesize that with a width (5.265(13) Å, see Figure 1 ) commensurable with the cavity diameter of α-CD (4.7–5.3 Å) [ 13 ], SA could in principle form a crystalline complex with α-CD. The literature shows that similar linear compounds form inclusion complexes with α-CD (see for example CSD refcodes BUPDEV [ 14 ], CDKABA [ 15 ] and XIGBOE [ 16 ]). 2. Results and Discussion
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CO2 to Succinic Acid : Estimating the Potential of Biocatalytic Routes

CO2 to Succinic Acid : Estimating the Potential of Biocatalytic Routes

The basic economic analysis of autotrophic succinic acid production conducted here was based on minimal input of experimental data and excluded downstream processing and investment costs. Further, more detailed economic evaluations are necessary to evaluate sustainability and competitiveness similar to Zhuang and Herrgard (2015) who included land use, and agricultural features of the feedstock, impact of the energy and market sector, metabolic details of the applied strain and process designs. If similarly adapted for autotrophic succinic acid production, it is possible to more precisely identify optimal environ- mental and regulatory application niches.
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CO2 to Succinic Acid : Estimating the Potential of Biocatalytic Routes

CO2 to Succinic Acid : Estimating the Potential of Biocatalytic Routes

1. Introduction Succinic acid is a valuable platform chemical for the production of bio-based polymers such as nylons and polyesters but is also valuable itself as surfactant, chelator, and as an additive in the agricultural, food, and pharmaceutical industry ( Ahn et al., 2016; Bozell and Petersen, 2010; Mazière et al., 2017 ). Succinic acid is conventionally synthesized petrochemically with an overall market size of about 60 kt in 2015 ( Jansen and van Gulik, 2014; marketsandmarkets.com, 2016 ) and highly optimistic projections of more than 600 kt exist for 2020 ( Choi et al., 2015; Pinazo et al., 2015 ). Conventional, large-scale, centralized chemical production plants inhibit modernization of pro- cess design and create hurdles for start-ups and new incomers ( Clomburg et al., 2017 ). Instead, start-ups turn to biotechnological fermentation-based strategies with lower requirements for capital investment thus allowing for more dynamic market adaptations and better adjustment to niche requirements ( Clomburg et al., 2017 ). As a consequence, bio-based production of succinic acid is advancing in recent years, and to date, a variety of microorganisms has been engineered for the synthesis of succinic acid from sugars, glycerol or acetate ( Ahn et al., 2016; Becker et al., 2015; Pinazo et al., 2015; Valderrama-Gomez et al., 2016 ). Current production hosts include
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Polysulfonylamine, XV [1] Synthese von N-bernsteinsäurediamid zu y-DimesyIamino-zl^y-butenolid Succinic Diamide to y-Dimesylamino-zl/1:'-butenolide 

Polysulfonylamine, XV [1] Synthese von N-bernsteinsäurediamid zu y-DimesyIamino-zl^y-butenolid Succinic Diamide to y-Dimesylamino-zl/1:'-butenolide 

N .N .N '.N '-T etram esyl dicarboxylic diamides Ms2N C (0 ) — Q —C (0 )N M s; [Q = (C H 2)„ with n = 0 (2a), 2 (2b), 3 (2c), 4 (2d); Q = o-phenylene (2e)] were prepared by reacting AgNM s2 (1) with the appropriate dicarboxylic dichlorides in acetonitrile at room tem perature (2a, 2 c —2e) or at 0 °C (2b), respectively. U nder similar conditions, malonic dichloride undergoes an elim ination, forming AgCl, H NM s2 and probably polymeric C , 0 2. A t 20 °C in C H 3CN, the succinic acid derivative 2b eliminates one mole of H NM s2 and, by ring closure, yields y-dimesylamino-Zl^:- butenolide (4a), the first example of a stable y-am ino-zP'-butenolide. T reatm ent of 4a with aqueous N aOH results in the form ation of NaNM s2 and sodium succinate. Crystalline 4a is thermally stable at 100 °C; no signs of an isomerization 4a —> y-dim esylam ino-zT^-butenolide could be detected. U nlike the structurally related a-angelicalactone (4c), whose brom ination affords the saturated dibrom olactone 9 as a m ixture of cis- and m w s-isom ers, 4a adds bromine (20 °C, CHC1,) under ring cleavage to form B rC (0 )C H 2C H B rC (0 )N M s2 (7). The new com­ pounds 2, 4a and 7 as well as the stereoisom ers of 9 were characterized by spectroscopic ( ‘H and l3C N M R . MS, IR) and analytical m ethods. In order to obtain reference values for the chemical shifts of 7, the following new com pounds were prepared: C H 3(C H : )2C (0 )N M s2 (10c, from 1 and butvryl chloride); C H ,C H ^C H B rC (0)N M si (12c, from 1 and 2-brom obutyryl brom ide); C 2H 50 C ( 0 ) C H 2C H B rC (0)N M s2 (13, from 7 with ethanol and from 4a by sim ultaneous reaction with brom ine and ethanol).
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Chemistry of Fenchonesulfonic Acid Derivatives 

Chemistry of Fenchonesulfonic Acid Derivatives 

pected to accompany any attem pt to sulfonate fen­ chone, and only 50 years after these initial experi­ ments, conditions could be found where a fenchonesulfonic acid is isolated in good yields [11, 12]+. The suggestion made for the structure of this so-called &>-sulfonic acid (2) was based on a comparison of optical rotations of its salts with that of isomeric camphorsulfonic acids [11], but of course, this is not a very convincing argument. O ther authors gathered further evidence for this structure by chemical correlation [12]; they oxi­ dized fenchonesulfonyl chloride (3) with p er­ m anganate and obtained a known acid, 3,3-di- methylbicyclo[2.2.1]heptan-2-one-l-carboxylic acid. In view of the application of (camphorsulfonyl)- oxaziridine and its derivatives [14-18] as chiral oxidizing agents for the preparation of chiral sul­ foxides from sulfides and other enantioselective reactions, we thought that fenchonesulfonic acid might be well-suited as starting m aterial for such an oxidant, and set out to explore its chemistry. Some results have been published earlier [18-21].
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Activation of the Glutamic Acid-Dependent Acid Resistance System in Escherichia coli BL21(DE3) Leads to Increase of the Fatty Acid Biotransformation Activity

Activation of the Glutamic Acid-Dependent Acid Resistance System in Escherichia coli BL21(DE3) Leads to Increase of the Fatty Acid Biotransformation Activity

The metabolic responses to heptanoic acid of E. coli MG1655, a strain that is reported for its acid tolerance, were markedly smaller. The specific glucose uptake and acetate production rates remained unchanged ( Fig 1 ). A previous study of the MG1655 strain with octanoic acid challenge showed that the specific glucose uptake rate and carbon flux into the TCA cycle was decreased in the presence of octanoic acid while acetate production rate was increased [ 56 ]. In fact, the metabolic responses of MG1655 appeared to be similar to those of E. coli challenged with organic solvents (e.g., isobutanol, cyclohexanone) [ 57 , 58 ]. Addition of isobutanol or cyclohexanone into the culture broth resulted in a stimulation of the acetic acid fermentation pathway rather than the TCA cycle via activation of the ArcA/B regulatory system ( S3 Table ). In addition, in the previous study of MG1655 using octanoic acid it was reported that native acid resistance systems (e.g., the GDAR system) were not involved in supporting growth or alleviating intracellular acidification [ 47 ]. It was concluded that circumventing membrane damage is a key for tolerance to the octanoic acid-induced stress. All the results suggest that solvent-like stress of heptanoic acid might be more prominent in MG1655, whereas in BL21 (DE3) acid-induced stress appears to be the dominant mechanism.
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Synthesis of 5-AminoIevulinic Acid 

Synthesis of 5-AminoIevulinic Acid 

20 g of 4 were refluxed with 200 ml o f 6 M HC1 for 8 - 1 0 h. A fter cooling to —20 °C, the precipitated phthalic acid was rem oved by suction filtration and the clear filtrate brought to dryness in a vacuum d e­ siccator over KOH. The dry product was recrystal­ lized from m ethanol/isopropanol. Yield: 11.2 g (92%) o f white crystals, m .p. 147 °C.

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Glutamic Acid-l-semialdehyde, a Hypothetical Intermediate in the Biosynthesis of 5-Aminolevulinic Acid 

Glutamic Acid-l-semialdehyde, a Hypothetical Intermediate in the Biosynthesis of 5-Aminolevulinic Acid 

Catalytic hydrogenation o f y-benzyl-N-carboxy-L- glutamic acid anhydride (5) 5 was hydrogenated following the procedure of Kannangara and Gough [9, 12]. 1.18 g (4.5 mmol) of 5 being only sparingly soluble in diethyl ether, were dissolved in 6 ml of dry xylene. The reaction flask was flushed with nitrogen for five m inutes, then 0.1 g of P d -B aS 0 4-catalyst were added. Hydrogenation was perform ed by bubbling hydrogen through the reaction mixture. A fter 30 min this mixture was fil­ tered and the residue was washed three times with water. The combined aqueous filtrates were concen­ trated in vacuo to a 3 ml volume. To identify the products of this reaction the above aqueous solution was acidified and the products were separated on a Dowex 50 WX8 column as described [9, 12], The only products that could be detected were glutamic acid and y-benzyl-glutamate.
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Synthese des Indolalkaloids α-Cyclopiazonic Acid

Synthese des Indolalkaloids α-Cyclopiazonic Acid

Benzoesäureanhydrid (471 mg, 2.08 mmol) gelöst in DMF (1.6 ml) wird tropfenweise bei 0 °C unter Stickstoffatmosphäre über eine Glasspritze zugegeben und die Reaktion anschließend noch [r]

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Lyophilization of nucleic acid nanoparticles

Lyophilization of nucleic acid nanoparticles

discussed [17]. According to the “preferential exclusion hypothesis”, established for protein stabilization, solutes are preferentially excluded from the surface resulting in the formation of a stabilizing solvent layer [17, 178-179]. However, it is questionable if this hypothesis can be adapted to nucleic acid nanoparticles, as the relatively high amounts of cryoprotectants required point to a nonspecific bulk stabilization [17, 178-179]. Based on the “glass formation or vitrification hypothesis”, nucleic acid nanoparticles are entrapped in the amorphous gassy matrix when the sample is cooled below the glass transition temperature (Tg`) limiting particle mobility and thus, preventing particle aggregation [17, 178]. As some sugars were able to preserve particle size at temperatures well above Tg` vitrification cannot be the only stabilization mechanism [180]. The “particle isolation hypothesis” states that particles have to be sufficiently separated in the freeze-concentrate in order to inhibit particle aggregation, which is observed above a critical excipient to complex ratio [180]. However, these three mechanisms are not suitable to solely explain the stabilization of nucleic acid nanoparticles during freezing. Thus, the influence of freezing on nucleic acid nanoparticles and underlying stabilization mechanisms during freezing will be addressed in detail in Chapter 6.
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Biosynthesis of Stizolobinic Acid and Stizolobic Acid in the Etiolated Seedlings of Stizolobium hassjoo 

Biosynthesis of Stizolobinic Acid and Stizolobic Acid in the Etiolated Seedlings of Stizolobium hassjoo 

Stizolobic acid was recrystallized from n-propa- nol/water (6:4, v/v) after adding the authentic amino acid (32 mg) dissolved in a minimum amount (3 —4 ml) of hot solvent and allowing the solution to stand overnight in a cold room. The crystals (specific activity 4.2 x 103 dpm//miol) were washed with ice-cold solvent and recrystallization were further repeated until the compounds show constant specific radioactivity (9 — 12 times).

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Electrocatalytic upgrading of itaconic acid to methylsuccinic acid using fermentation broth as a substrate solution

Electrocatalytic upgrading of itaconic acid to methylsuccinic acid using fermentation broth as a substrate solution

One of the key steps in the production of biofuels or value- added chemicals from biomass presents a suitable connection between the highly selective biotechnological transformation of biomass, e.g. cellulose, into platform chemicals such as ethanol and lactic acid or IA with subsequent processing. 2,19,20 Indeed, fermentation processes delivering high-boiling and polar products in aqueous electrolyte-solutions often cause highly demanding and energy intensive separation processes. 21–24 These challenges make a close integration with further transformation attractive avoiding intermediate product separation. 25 However, despite promising progress in the design of efficient catalysts for a valorisation of biomass- derived platform chemicals, few examples demonstrate a direct catalytic transformation of crude fermentation broth.
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Docosahexaenoic acid suppresses arachidonic acid-induced proliferation of LS
174T human colon carcinoma cells

Docosahexaenoic acid suppresses arachidonic acid-induced proliferation of LS 174T human colon carcinoma cells

In this context it has been proposed that the human genetic profile was originally established on a n-6 to n-3 PUFA ratio of approximately 1:1 as found in “ancient” diets, whereas today’s Western diet has been estimated to provide n-6 to n-3 PUFAs in a ratio of 15:1–20:1. It has been hypothesized that this may contribute to many serious health issues typically found in Western societies, including CRC. However, previous in vitro observations have led to some uncertainty regarding differential roles of n-3 and n-6 PUFAs in CRC cells. While the majority of investigations conducted in this field addressed neither the effects of n-6 PUFAs nor the impact of a balanced n-6 to n-3 PUFA ratio, several other studies reported n-3 and n-6 PUFAs to exert anti-cancerous effects in vitro. Hence, it was the aim of the present study to investigate the impact of n-3 PUFA docosahexaenoic acid (DHA) and n-6 PUFA AA and their combination on CRC cell line LS 174T in vitro.
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Composite nanocarriers for nucleic acid delivery

Composite nanocarriers for nucleic acid delivery

hand, delivery of nucleic acids using delivery vehicles such as liposomes, polymers and nanoparticles has been met with considerable success [18-20]. 1,2-dioleoyl-3- trimethylammonium-propane (DOTAP), 1,2-di-O-octadecenyl-3-trimethylammonium propane (DOTMA), (1-[2-(9-(Z)-octadecenoyloxy)ethyl] -2-(8-(Z)-heptadecenyl) -3 (hydroxyethyl) imidazolinium chloride (DOTIM), N-methyl-4(dioleyl)methylpyridiniumchloride (SAINT), 1,2-dimyristyloxy-propyl-3-dimethyl-hydroxy ethyl ammonium bromide (DMRIE), 1,2-di- (9Z-octadecenoyl)-sn-glycero-3- [(N- (5-amino-1-carboxypentyl) iminodiacetic acid) succinyl (DOGS), and 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE) are the most frequently used lipids for delivery of nucleic acids [21, 22]. Among polymers, polyethylenimine (PEI; linear and branched) of various molecular weights, poly-L-lysine (PLL), chitosan, polyamidoamine (PAMAM) are widely used [23, 24]. Poly (lactic-co-glycolic acid) (PLGA) and silica particles have been proven to be indispensable for formulation of nanoparticles for gene delivery [20]. Several therapies which are under clinical evaluation are based upon one of these vectors [25].
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Acid Sphingomyelinase Deficiency Ameliorates Farber Disease

Acid Sphingomyelinase Deficiency Ameliorates Farber Disease

* Correspondence: alexander.carpinteiro@uk-essen.de; Tel.: +49-201-723-84579; Fax: +49-201-723-5974 Received: 11 October 2019; Accepted: 7 December 2019; Published: 11 December 2019    Abstract: Farber disease is a rare lysosomal storage disorder resulting from acid ceramidase deficiency and subsequent ceramide accumulation. No treatments for Farber disease are clinically available, and affected patients have a severely shortened lifespan. We have recently reported a novel acid ceramidase deficiency model that mirrors the human disease closely. Acid sphingomyelinase is the enzyme that generates ceramide upstream of acid ceramidase in the lysosomes. Using our acid ceramidase deficiency model, we tested if acid sphingomyelinase could be a potential novel therapeutic target for the treatment of Farber disease. A number of functional acid sphingomyelinase inhibitors are clinically available and have been used for decades to treat major depression. Using these as a therapeutic for Farber disease, thus, has the potential to improve central nervous symptoms of the disease as well, something all other treatment options for Farber disease can’t achieve so far. As a proof-of-concept study, we first cross-bred acid ceramidase deficient mice with acid sphingomyelinase deficient mice in order to prevent ceramide accumulation. Double-deficient mice had reduced ceramide accumulation, fewer disease manifestations, and prolonged survival. We next targeted acid sphingomyelinase pharmacologically, to test if these findings would translate to a setting with clinical applicability. Surprisingly, the treatment of acid ceramidase deficient mice with the acid sphingomyelinase inhibitor amitriptyline was toxic to acid ceramidase deficient mice and killed them within a few days of treatment. In conclusion, our study provides the first proof-of-concept that acid sphingomyelinase could be a potential new therapeutic target for Farber disease to reduce disease manifestations and prolong survival. However, we also identified previously unknown toxicity of the functional acid sphingomyelinase inhibitor amitriptyline in the context of Farber disease, strongly cautioning against the use of this substance class for Farber disease patients.
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