RESUMEN
This study evaluated the synthesis of protic ionic liquids (PILs), 2-hydroxy ethylammonium formate (2-HEAF) and 2-hydroxy ethylammonium acetate (2-HEAA), and their applicability in the crystallization process of the active pharmaceutical ingredient isoniazid (INH) as anti-solvent. Isoniazid is an antibiotic used in the treatment of tuberculosis infections, being used as a first-line chemotherapeutic agent against Mycobacterium tuberculosis. Futhermore, this investigation was conducted in order to evaluate how these PILs can influence the habit, solubility, stability, and therapeutic efficiency of the obtained isoniazid crystals. The 2-HEAF and 2-HEAA PILs were easily formed in reactions between ethanolamine and carboxylic acids (formic or acetic acid), and they have no toxicity against Artemia salina. The PILs were able to crystallize isoniazid, influencing the crystal habit and size. The greatest variations in the hydrogen signals of the NH2 and NH groups of the amine and low variations in the chemical shifts of the hydrogens of the cation of the ethanolamine group from 2-HEAA and 2-HEAF indicate that PILs establish possibly weak interactions with INH. The obtained crystals were amorphous and showed higher solubility in water than standard INH. Moreover, these crystals showed therapeutic efficiency inantimycobacterial activity to inhibit the growth of Mycobacterium tuberculosis. The INH:2-HEAF only degraded 5.1 % (w/w), however, INH:2-HEAA degraded 32.8 % (w/w) after 60 days in an accelerated atmosphere. Then, the 2-HEAA and 2-HEAF were able to crystallize isoniazid, being a new application for these PILs. The used PILs also influenced the characteristics of isoniazid crystals.
Asunto(s)
Antituberculosos , Cristalización , Líquidos Iónicos , Isoniazida , Solubilidad , Isoniazida/química , Isoniazida/farmacología , Antituberculosos/farmacología , Antituberculosos/química , Líquidos Iónicos/química , Animales , Artemia/efectos de los fármacos , Mycobacterium tuberculosis/efectos de los fármacos , Tecnología Química Verde/métodos , Estabilidad de MedicamentosRESUMEN
This work studied the optimization of enzymatic saccharification of Agave tequilana bagasse (ATB) pretreated with the low-cost protic ionic liquid (PIL) ethanolamine acetate ([EOA][OAc]) using the highly available and cost-effective mixture of the enzymatic cocktails Celluclast 1.5L-Viscozyme L. Response surface methodology (RSM) was employed to maximize the sugars concentration and yield. The RSM optimization conditions of the enzymatic saccharification of pretreated ATB that achieved the maximum reducing sugars (RS) concentration were: 11.50 % w/v solids loading, 4.26 pH with 0.76 and 1.86 mg protein/mL buffer of Viscozyme L and Celluclast 1.5L, respectively. Similarly, the conditions that maximize the sugar yield (SY) were solids loading of 5.62 % w/v, and 4.51 pH as well as 1.07 and 2.03 mg protein/mL buffer of Viscozyme L and Celluclast 1.5L, respectively. Saccharification performance of the first-generation and low-cost enzyme mixture Celluclast 1.5L-Viscozyme L was compared with that reached by a second-generation and higher-cost CTec2, where Celluclast 1.5L-Viscozyme L achieved 60.86 ± 2.66 % y 79.25 ± 3.34 % of the sugars released by CTec2 at the same hydrolysis time (12 h) for the sugar concentration and yield models, respectively. These results are encouraging since they positively contribute to cost reduction and availability issues, which are key parameters to consider when thinking about scaling-up the process.
Asunto(s)
Agave , Celulosa , Líquidos Iónicos , Análisis Costo-Beneficio , Carbohidratos , Hidrólisis , AzúcaresRESUMEN
Here, we have assessed the use of one packed bed or two packed bed reactors in series in which Burkholderia cepacia lipase (BCL) was immobilized on protic ionic liquid (PIL)-modified silica and used as a biocatalyst for the transesterification of crude coconut oil. Reaction parameters including volumetric flow, temperature, and molar ratio were evaluated. The conversion of transesterification reaction products (ethyl esters) was determined using gas chromatography and the quantities of intermediate products (diglyceride and monoglyceride [MG]) were assessed using high-performance liquid chromatography. Packed bed reactors in series produced ethyl esters with the greatest efficiency, achieving 65.27% conversion after 96 H at a volumetric flow rate of 0.50 mL Min-1 at 40 °C and a 1:9 molar ratio of oil to ethanol. Further, within the first 24 H of the reaction, increased MG (54.5%) production was observed. Molecular docking analyses were performed to evaluate the catalytic step of coconut oil transesterification in the presence of BCL. Molecular docking analysis showed that triglycerides have a higher affinity energy (-5.7 kcal mol-1 ) than the smallest MG (-6.0 kcal mol-1 ), therefore, BCL catalyzes the conversion of triglycerides rather than MG, which is consistent with experimental results.
Asunto(s)
Reactores Biológicos , Aceite de Coco/metabolismo , Ésteres/metabolismo , Lipasa/metabolismo , Biocatálisis , Burkholderia cepacia/enzimología , Aceite de Coco/química , Enzimas Inmovilizadas/química , Enzimas Inmovilizadas/metabolismo , Ésteres/química , Lipasa/químicaRESUMEN
Treated silica xerogel with protic ionic liquid (PIL) and bifunctional agents (glutaraldehyde and epichlorohydrin) is a novel support strategy used in the effective immobilization of lipase from Burkholderia cepacia (LBC) by covalent binding. As biocatalysts with the highest activity recovery yields, LBC immobilized by covalent binding with epichlorohydrin without (203%) and with PIL (250%), was assessed by the following the hydrolysis reaction of olive oil and characterized biochemically (Michaelisâ»Menten constant, optimum pH and temperature, and operational stability). Further, the potential transesterification activity for three substrates: sunflower, soybean, and colza oils, was also determined, achieving a conversion of ethyl esters between 70 and 98%. The supports and the immobilized lipase systems were characterized using Fourier transform infrared spectra (FTIR), scanning electron microscopy (SEM), elemental analysis, and thermogravimetric (TG) analysis.
Asunto(s)
Proteínas Bacterianas/química , Enzimas Inmovilizadas/química , Líquidos Iónicos/química , Lipasa/química , Aceite de Oliva/química , Aceite de Soja/química , Aceite de Girasol/química , Proteínas Bacterianas/aislamiento & purificación , Biocombustibles/provisión & distribución , Burkholderia cepacia/química , Burkholderia cepacia/enzimología , Reactivos de Enlaces Cruzados/química , Enzimas Inmovilizadas/aislamiento & purificación , Epiclorhidrina/química , Esterificación , Geles , Glutaral/química , Humanos , Concentración de Iones de Hidrógeno , Lipasa/aislamiento & purificación , Dióxido de Silicio/química , TemperaturaRESUMEN
To enhance the enzymatic digestibility of cashew apple bagasse (CAB) feedstock in order to produce sugar fermentation-derived bioproducts, the CAB was subjected to three different pretreatments with the ionic liquid 2-hydroxyl-ethylammonium acetate (2-HEAA) and characterized by FTIR, NMR and chemical methods. All conditions were able to delignify CAB, however the best lignin removal (95.8%) was achieved through the method performed with 8.7% w/w of CAB/2-HEAA ratio at 130°C for 24h. Although the cellulose crystallinity has been increased in CAB treated with the ionic liquid, but this fact did not influence its digestibility. Nevertheless, the pretreatment with 2-HEAA enhanced significantly the cellulose digestibility, increasing the glucose yield from 48 to 747.72mgglucose/gCAB. Furthermore, 2-HEAA pretreatment was efficient even with reused ionic liquid, obtaining high glucose concentration.