6493-06-7Relevant academic research and scientific papers
Two-Step Protocol for Iodotrimethylsilane-Mediated Deoxy-Functionalization of Alcohols
Chen, Yuming,He, Ru,Song, Hongjian,Yu, Guoqing,Li, Chenglin,Liu, Yuxiu,Wang, Qingmin
supporting information, p. 1179 - 1183 (2021/02/01)
We have developed a two-step protocol for iodotrimethylsilane-mediated deoxy-functionalization of primary and secondary alcohols to afford products containing a C?N, C?S, or C?O bond. In the first step the alcohol undergoes iodination with iodotrimethylsilane, and in the second, the iodine atom is replaced by a N, S, or O nucleophile. Compared with traditional Mitsunobu reaction, non-acidic pre-nucleophiles can be used, and the reaction proceeds with retention of configuration. This operationally simple, highly efficient protocol can be used for some natural products and small-molecule drugs containing hydroxy-group.
Chemoenzymatic enantioselective and stereo-convergent syntheses of lisofylline enantiomers via lipase-catalyzed kinetic resolution and optical inversion approach
Borowiecki, Pawe?,Zdun, Beata,Dranka, Maciej
, (2021/02/27)
Highly enantioselective enzymatic kinetic resolution (EKR) of racemic lisofylline is presented for the first time. A comprehensive optimization of the key parameters of lipase-catalyzed transesterification of racemic lisofylline revealed that optimal biocatalytic system consisted of immobilized lipase type B from Candida antarctica (Chirazyme L-2, C-3) suspended in a mixture of 3 equiv of vinyl acetate as an acetyl donor and ethyl acetate as a solvent. Under optimal reaction conditions, the 1 g-scale (Chirazyme L-2, C-3)-catalyzed kinetic resolution of racemic lisofylline furnished both the EKR products in a homochiral form (>99 % ee) with the 50 % conv., and the highest possible enantioselectivity. The best results in terms of the reaction yields (47–50 %) and enantiomeric purity of the kinetically-resolved optically active products were achieved when the preparative-scale EKR was carried out for 2 h at 60 °C. In addition, stereoinversion of the less biologically-relevant (S)-lisofylline into its (R)-enantiomer was successfully achieved via acetolysis of the respective optically pure (S)-mesylate by using 2 equiv of ceasium acetate and catalytic amount of 18-Crown-6 in dry toluene, followed by K2CO3-mediated methanolysis of (R)-acetate. The elaborated EKR methodology together with enantioconvergent strategy provided a useful chemoenzymatic protocol for the synthesis of complementary enantiomers of titled API. Moreover, we report on the first single-crystal X-ray diffraction (XRD) analyses performed for the synthesized lisofylline enantiomers. Insight into the source of CAL-B stereoselectivity toward racemic lisofylline was gained by molecular docking experiments. In silico theoretical predictions matched very well with experimental results.
Role of Chain Length and Degree of Unsaturation of Fatty Acids in the Physicochemical and Pharmacological Behavior of Drug-Fatty Acid Conjugates in Diabetes
Chitkara, Deepak,Italiya, Kishan S.,Mittal, Anupama,Narisepalli, Saibhargav,Singh, Arihant Kumar
, p. 14217 - 14229 (2021/10/20)
Several drug-fatty acid (FA) prodrugs have been reported to exhibit desirable physicochemical and pharmacological profile; however, comparative beneficial effects rendered by different FAs have not been explored. In the present study, four different FAs (linoleic acid, oleic acid, palmitic acid, and α-lipoic acid) were selected based on their chain length and degree of unsaturation and conjugated to Lisofylline (LSF), an antidiabetic molecule to obtain different drug-FA prodrugs and characterized for molecular weight, hydrophobicity, purity, self-assembly, and efficacy in vitro and in vivo in type 1 diabetes model. Prodrugs demonstrated a 2- to 6-fold increase in the plasma half-life of LSF. Diabetic animals treated with prodrugs, once daily for 5 weeks, maintained a steady fasting blood glucose level with a significant increase in insulin level, considerable restoration of biochemical parameters, and preserved β-cells integrity. Among the different LSF-FA prodrugs, LSF-OA and LSF-PA demonstrated the most favorable physicochemical, systemic pharmacokinetic, and pharmacodynamic profiles.
Efficient Transfer Hydrogenation of Ketones using Methanol as Liquid Organic Hydrogen Carrier
Garg, Nidhi,Paira, Soumen,Sundararaju, Basker
, p. 3472 - 3476 (2020/05/29)
Herein, we demonstrate an efficient protocol for transfer hydrogenation of ketones using methanol as practical and useful liquid organic hydrogen carrier (LOHC) under Ir(III) catalysis. Various ketones, including electron-rich/electron-poor aromatic ketones, heteroaromatic and aliphatic ketones, have been efficiently reduced into their corresponding alcohols. Chemoselective reduction of ketones was established in the presence of various other reducible functional groups under mild conditions.
COMPOSITIONS AND METHODS FOR THE TREATMENT OF CHRONIC DISEASES AND INFLAMMATORY DISORDERS
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, (2015/03/31)
The invention relates to the compounds of formula I or its pharmaceutical acceptable salts, as well as polymorphs, solvates, enantiomers, stereoisomers and hydrates thereof. The pharmaceutical compositions comprising an effective amount of compounds of formula I, and methods for the treatment of chronic diseases and inflammatory disorders may be formulated for oral, buccal, rectal, topical, transdermal, transmucosal, intravenous, parenteral administration, syrup, or injection. Such compositions may be used to treatment of intermittent claudication, obstructed arteries in the limbs, vascular dementia, Peyronie's disease, neuropathic injuries, sickle cell disease, nausea and headaches in the mountains (altitude sickness), acute alcoholic and non-alcoholic steatohepatitis, alcoholic liver disease, fibrotic lesions induced by radiation therapy for cancer, cytokine release syndrome, endometriosis, venous disease, inflammation, cancer, stroke, thrombosis, sepsis, gangrene, infection, type 1 diabetes, type 2 diabetes, pancreatic beta cell degeneration, beta cell dysfunction, respiratory diseases, rheumatoid arthritis, arthritis, osteoarthritis and vascular disease.
SUBSTITUTED XANTHINES AND METHODS OF USE THEREOF
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Page/Page column 661; 662, (2014/09/29)
Compounds, compositions and methods are described for inhibiting the TRPC5 ion channel and disorders related to TRPC5.
The effect of pentoxifylline and its metabolite-1 on inflammation and fibrosis in the TNBS model of colitis
Peterson, Theresa C.,Peterson, Marc R.,Raoul, Jennifer M.
experimental part, p. 47 - 54 (2012/07/28)
TNBS-induced colitis has characteristics resembling human Crohn's disease including transmural inflammation, ulceration, and fibrosis. Current treatments target acute symptoms but do not necessarily prevent fibrotic complications of the disease. The aim of this study was to determine the effect of pentoxifylline and its primary metabolite (M-1) on fibrosis in the TNBS-induced colitis model. Myeloperoxidase activity and interleukin-18 are indicators of inflammation and were elevated in the TNBS model. The morphology damage score assesses colon damage and was also elevated in the TNBS model. Collagen as the indicator of fibrosis was quantified and visualized by the Sirius Red/Fast Green staining technique and collagen type I was assessed by Western analysis. Collagen was elevated in the TNBS-induced model. Pentoxifylline and M-1 treatment significantly attenuated colon damage and inflammation in TNBS-colitis (P 0.05). M-1 treatment significantly reduced the TNBS-induced increase in colon weight, colon thickness and total collagen content (P 0.05). Results suggest that pentoxifylline and M-1 inhibit intestinal fibrosis in this experimental model and may prove beneficial in the treatment of intestinal fibrosis associated with human Crohn's disease with the added benefit of inhibiting inflammation and ulceration. This is the first study to examine the effects of racemic M-1 in vivo and one of the few studies to examine the effect of drugs on both inflammation and fibrosis in an experimental model of colitis.
Photochemistry synthesis. Part 1: Syntheses of xanthine derivatives by photolysis of 1-(5′-oxohexyl)-3,7-dimethyl-3,7-dihydro-1H-purine-2,6-dione (pentoxifylline): an ambident chromophore
Han, Ze,Bonnet, Susan L.,van der Westhuizen, Jan H.
, p. 2619 - 2625 (2008/09/19)
We investigated the use of photochemistry to make novel derivatives of pentoxifylline. Under conditions that favour singlet excited states, we obtained 1-allyl-3,7-dimethyl-3,7-dihydro-1H-purine-2,6-dione, (R*,R*)-(±)-1-{[2-hydroxy-2-methylcyclobutyl]methyl}-3,7-dimethyl-3,7-dihydro-1H-purine-2,6-dione and 1-(5-hydroxyhexyl)-3,7-dimethyl-3,7-dihydro-1H-purine-2,6-dione. Naphthalene or molecular oxygen increases the yields and triplet sensitisers (acetophenone, benzophenone and acetone) decrease the yields. Efficient intramolecular triplet energy transfer from the carbonyl to the xanthine moiety allows the carbonyl moiety to react from a singlet excited state only. In solvents with an α-hydroxyalkyl hydrogen under conditions that favour triplet excited states, we obtained 8-substituted pentoxifylline derivatives: 8-(1-hydroxy-1-methylethyl)-3,7-dimethyl-1-(5-oxohexyl)-3,7-dihydro-1H-purine-2,6-dione in isopropanol, 8-(1-hydroxymethyl)-3,7-dimethyl-1-(5-oxo-hexyl)-3,7-dihydro-1H-purine-2,6-dione in methanol and 8-(1-hydroxyethyl)-3,7-dimethyl-1-(5-oxohexyl)-3,7-dihydro-1H-purine-2,6-dione in ethanol. The xanthine moiety reacts from a triplet state via a radical mechanism and yields are considerably improved by the addition of catalytic amounts of di-tert-butyl peroxide.
Enantioselective biotransformation of pentoxifylline into lisofylline using wine yeast biocatalysis
Kala, Elzbieta P.,Wojcik, Tomasz
, p. 109 - 113 (2008/09/17)
Lisofylline (1-(5-R-hydroxyhexyl)-3,5-dimethylxanthine (LSF)) is a new methylxanthine, a stereospecific isomer which is a metabolite of pentoxifylline (1-(5-oxohexyl)-3,5-dimethylxanthine (PTX)). Alcohol dehydrogenases (E.C. 1.1.X.Y.) are enzymes that catalyze the oxidation and reduction of hydroxyl and carbonyl compounds. They may be employed either as crude or purified enzymes or as components of whole cells. The aim of this study was to explore the stereoselective bioreduction of PTX in the presence of whole cell baker's and wine yeasts, which function as biocatalysts in the production of LSF. The experiments were conducted in water and a number of organic solvents (toluene, hexane, ethyl acetate), and we obtained LSF with different yields and ee values. Our research demonstrated that the highest activity is shown when the KKPU strain is used in an aqueous medium. The biotransformation of PTX into LSF in this case was characterized by high yield and enantioselectivity: 95% and ee = 98%, respectively.
A novel drug interaction between the quinolone antibiotic ciprofloxacin and a chiral metabolite of pentoxifylline
Raoul, Jennifer M.,Peterson, Marc R.,Peterson, Theresa C.
, p. 639 - 646 (2008/02/07)
Pentoxifylline (PTX), a methylxanthine derivative, is metabolized to seven compounds in vivo, with metabolites 1 and 5 possessing biologic activity. Metabolite-1 is a chiral molecule and its S-enantiomer is selectively formed during PTX metabolism in vivo. We have developed a reproducible method of synthesizing a racemic mixture of the chiral metabolite-1 (M-1) of PTX. In this study, we examined the kinetics of racemic M-1 in mice compared to PTX. An interaction between PTX and the quinolone antibiotic ciprofloxacin has been demonstrated. A goal of this study was to determine if a similar interaction occurs between ciprofloxacin and M-1 in vivo. M-1 and PTX had similar absorption and elimination rates. M-1 was rapidly converted to PTX, while very little PTX was converted to M-1 in vivo. The peak concentration of biologically active drug (PTX + M-1) was 36% higher when M-1 was administered compared to PTX. Combination of ciprofloxacin and PTX significantly increased serum concentrations of both PTX and M-1 (2-fold) compared to controls. The combination of M-1 and ciprofloxacin significantly increased serum concentration of M-1 (3-fold) and PTX (2-fold). The ciprofloxacin/M-1 combination produced a significantly higher sera concentration of bioactive drug compared to all other groups suggesting that this combination may enhance the anti-fibrogenic effect.
