RESUMEN
Although propolis is one of the most popular functional foods for human health, there have been no comprehensive studies of herb-drug interactions through cytochrome P450 (CYP) inhibition. The purpose of this study was to determine the inhibitory effects of propolis on the activities of CYP1A2, 2A6, 2B6, 2C9, 2C19, 2D6, 2E1 and 3A4 using pooled human liver microsomes (HLMs). Propolis inhibited CYP1A2, CYP2E1 and CYP2C19 with an IC50 value of 6.9, 16.8, and 43.1 µg/mL, respectively, whereas CYP2A6, 2B6, 2C9, 2D6, and 3A4 were unaffected. Based on half-maximal inhibitory concentration shifts between microsomes incubated with and without nicotinamide adenine dinucleotide phosphate, propolis-induced CYP1A2, CYP2C19, and CYP2E1 inhibition was metabolism-independent. To evaluate the interaction potential between propolis and therapeutic drugs, the effects of propolis on metabolism of duloxetine, a serotonin-norepinephrine reuptake inhibitor, were determined in HLMs. CYP1A2 and CYP2D6 are involved in hydroxylation of duloxetine to 4-hydroxy duloxetine, the major metabolite, which was decreased following propolis addition in HLMs. These results raise the possibility of interactions between propolis and therapeutic drugs metabolized by CYP1A2.
RESUMEN
KIOM-MA128 is a novel Korean herbal medicine with antiatopic, anti-inflammatory, and antiasthmatic effects. Matrine is thought to be a potential chemical marker of KIOM-MA128, but pharmacokinetic studies on KIOM-MA128 had not been performed. This study describes a simple and rapid method using high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) to determine the concentration of matrine in rats plasma after administration of KIOM-MA128. The isocratic mobile phase consisted of methanol and distilled water, and the flow rate was 0.15 mL/min. The accuracy and precision of the assay, as well as stability tests, were performed in accordance with FDA regulations for the validation of bioanalytical methods. The half-life and T max of matrine after administration of KIOM-MA128 were 4.29 ± 2.20 h and 1.8 ± 1.23 h, respectively. C max and AUCinf of matrine after administration of KIOM-MA128 at 4 g/kg and 8 g/kg were 595.10 ± 182.91 ng/mL, 5336.77 ± 1503.84 ng/mL·h and 850.46 ± 120 ng/mL, 9583.10 ± 888.92 ng/mL·h, respectively. The validated method was successfully applied to a pharmacokinetic study in rats after oral administration of KIOM-MA128.
RESUMEN
Angelica gigas Nakai and its components are known to have neuroprotective, antiplatelet, and anticancer activities. The present study evaluated the in vitro and in vivo biopharmaceutical characterization of Angelica gigas component substances, including decursin (the main substance), decursinol angelate (decursin isomer), JH714 (ether form of decursin) and epoxide decursin (epoxide form of decursin). Decursin, decursinol angelate and JH714 exhibited acceptable metabolic stability (>50%) in liver microsomes from human and higher bound fraction (>90%) in human plasma operating ultrafiltration. Decursin and decursinol angelate in CYP1A2 and CYP2C19 indicated less than 50% CYP activity, suggesting inhibition of the CYP isoforms using Vivid® CYP screening kit. JH714 only showed an apparent permeability coefficient of <10 × 10â»6 cm/s in MDCK cells, suggesting that it is poorly absorbed. Blood brain barrier permeability was examined after oral administration to male Sprague-Dawley (SD) rats, and pharmacokinetic studies were performed after oral and intravenous administration of 10 mg/kg compounds. Decursin, decursinol angelate and JH714 showed ratios of compound concentration in brain with respect to plasma (Cbrain/Cplasma) of >1.5, suggesting good brain/plasma ratio at 0.5, 1, 3, and 5 h. In contrast, Cbrain/Cplasma was <0.5 for epoxide decursin. For all test compounds, >1.5% of the dose remained in GI tract after 8 h, and the excretion rate in urine was <0.5% which suggests that gastro intestinal tract may be major site of disposition following oral administration. Finally, these results may be useful for the design of dosage regimens of decursin and its derivatives.
Asunto(s)
Antineoplásicos Fitogénicos/farmacocinética , Benzopiranos/farmacocinética , Butiratos/farmacocinética , Fármacos Neuroprotectores/farmacocinética , Angelica/química , Animales , Antineoplásicos Fitogénicos/administración & dosificación , Antineoplásicos Fitogénicos/química , Antineoplásicos Fitogénicos/metabolismo , Hidrocarburo de Aril Hidroxilasas/antagonistas & inhibidores , Hidrocarburo de Aril Hidroxilasas/metabolismo , Benzopiranos/administración & dosificación , Benzopiranos/química , Benzopiranos/metabolismo , Biotransformación , Barrera Hematoencefálica/metabolismo , Butiratos/administración & dosificación , Butiratos/química , Butiratos/metabolismo , Citocromo P-450 CYP1A2/metabolismo , Inhibidores del Citocromo P-450 CYP1A2 , Citocromo P-450 CYP2C19 , Perros , Inhibidores Enzimáticos/administración & dosificación , Inhibidores Enzimáticos/química , Inhibidores Enzimáticos/metabolismo , Inhibidores Enzimáticos/farmacocinética , Compuestos Epoxi/administración & dosificación , Compuestos Epoxi/química , Compuestos Epoxi/metabolismo , Compuestos Epoxi/farmacocinética , Éteres/química , Éteres/metabolismo , Éteres/farmacología , Etnofarmacología , Humanos , Absorción Intestinal , Células de Riñón Canino Madin Darby , Masculino , Medicina Tradicional de Asia Oriental , Microsomas Hepáticos/metabolismo , Fármacos Neuroprotectores/administración & dosificación , Fármacos Neuroprotectores/química , Fármacos Neuroprotectores/metabolismo , Ratas , Ratas Sprague-DawleyRESUMEN
We have evaluated the herb-drug interaction potential of Ssang-hwa-tang (SHT) mediated by cytochrome P450 (CYP) inhibition/induction. Further, the effects of fermentation on the CYP-mediated herb-drug interaction potential were determined. SHT showed inhibitory activity toward CYP1A2, but not 2A6, 2B6, 2C9, 2C19, 2D6, 2E1, and 3A4 in human liver microsomes. The results of the enzyme kinetic study suggested that the SHT-induced CYP1A2 inhibition is mixed reversible inhibition. The hepatic CYP expression and activity in rats treated with SHT were examined. The expression/activity of CYP2E1 increased as a result of SHT extract treatment (P<0.005 or P<0.001, respectively), which raises the possibility that SHT may increase the toxicity of environmental toxicants through the elevation of CYP2E1-mediated metabolic activation. SHT fermentation using Lactobacillus fermentum or Lactobacillus gasseri resulted in attenuation of the SHT-induced CYP1A2 inhibition, but not CYP2E1 induction, suggesting that changes in the chemical composition of SHT through fermentation can affect the inhibition of CYP1A2 activity.
Asunto(s)
Inhibidores Enzimáticos del Citocromo P-450 , Medicamentos Herbarios Chinos/efectos adversos , Interacciones de Hierba-Droga , Animales , Sistema Enzimático del Citocromo P-450/química , Sistema Enzimático del Citocromo P-450/metabolismo , Medicamentos Herbarios Chinos/química , Medicamentos Herbarios Chinos/metabolismo , Fermentación , Humanos , Cinética , Lactobacillus/metabolismo , Masculino , Microsomas Hepáticos/química , Microsomas Hepáticos/efectos de los fármacos , Microsomas Hepáticos/enzimología , Microsomas Hepáticos/metabolismo , Ratas , Ratas Sprague-DawleyRESUMEN
We evaluated the herb-drug interaction potential of Galgeun-tang (GGT) extracts, mediated by cytochrome P450 (CYP) inhibition/induction. Further, the effects of fermentation on the CYP-mediated herb-drug interaction potential of GGT extracts were determined. As measured by LC-ESI/MS/MS, GGT extracts (0-300µg/mL) showed no inhibitory activity toward eight CYP isoforms (1A2, 2A6, 2B6, 2C9, 2C19, 2D6, 2E1, and 3A4) in pooled human liver microsomes, suggesting that GGT may have low potential for herb-drug interactions mediated by CYP inhibition. Hepatic CYP expression and activity in rats treated with GGT extracts twice per day for 1week was examined. Among the tested CYP isoforms (1A1, 1A2, 1B1, 2B1, 2C11, 2E1, 3A1, 3A2, and 4A1), CYP1B1 and 4A1 were increased by GGT extracts. Hepatic activities of 7-ethoxyresorufin-O-deethylase, 7-pentoxyresorufin-O-depentylase, and chlorzoxazone 6-hydroxylase, but not midazolam hydroxylase were also elevated. These results raise the possibility that GGT extracts may increase the toxicity of environmental toxicants through the elevating CYP-dependent metabolic activation. Interestingly, the increases in CYP1B1 and CYP4A1 levels, and 7-ethoxyresorufin-O-deethylase, 7-pentoxyresorufin-O-depentylase, and chlorzoxazone 6-hydroxylase activities were attenuated by fermentation of GGT extract using Lactobacillus plantarum KFRI 402, but not 144. Further studies are needed to identify the CYP regulatory component(s) from GGT and determination its metabolism.
Asunto(s)
Sistema Enzimático del Citocromo P-450/metabolismo , Medicamentos Herbarios Chinos/farmacología , Interacciones de Hierba-Droga , Microsomas Hepáticos/efectos de los fármacos , Animales , Hidrocarburo de Aril Hidroxilasas , Biotransformación , Citocromo P-450 CYP1A1/metabolismo , Citocromo P-450 CYP1B1 , Inhibidores Enzimáticos del Citocromo P-450 , Medicamentos Herbarios Chinos/farmacocinética , Fermentación , Hígado/efectos de los fármacos , Hígado/enzimología , Masculino , Microsomas Hepáticos/metabolismo , Ratas , Ratas Sprague-Dawley , Espectrometría de Masas en TándemRESUMEN
ETHNOPHARMACOLOGICAL RELEVANCE: Decursin is used as a traditional Asian medicine to treat various women's diseases. AIM OF THE STUDY: Herb-drug interaction has become a serious problem since herbal medicine is extensively used in the modern world. This study investigates effects of decursin, on the pharmacokinetics of theophylline, a typical substrate of cytochrome P450 1A2 enzyme, in rats. MATERIALS AND METHODS: After decursin pretreatment for 3 days, on the fourth day rats were administered decursin and theophylline concomitantly. The blood theophylline and its major metabolites (1-methylxanthine (1-MX), 3-methylxanthine (3-MX), 1-methyluric acid (1-MU), and 1,3-dimethyluric acid (1,3-DMU)) levels were monitored with LC-MS/MS. RESULTS: The results indicated that the clearance, elimination rate constant (K(el)) of theophylline was significantly decreased and area under concentration-time curve (AUC), C(max), half-life was increased in decursin (25mg/kg) pretreatment when theophylline (10mg/kg) was given. In the presence of decursin, the pharmacokinetic parameters of three metabolites (1-MX, 1,3-DMU, and 1-MU) were affected and the differences were statistically significant about AUC(24)(h) parameter. CONCLUSION: Our results suggest that patients who want to use CYP1A2-metabolized drugs such as caffeine and theophylline should be advised of the potential herb-drug interaction, to reduce therapeutic failure or increased toxicity of conventional drug therapy.
Asunto(s)
Benzopiranos/farmacología , Broncodilatadores/farmacocinética , Butiratos/farmacología , Teofilina/farmacocinética , Angelica , Animales , Broncodilatadores/sangre , Interacciones de Hierba-Droga , Masculino , Ratas , Ratas Sprague-Dawley , Teofilina/sangreRESUMEN
Herb-drug interactions represent a serious problem as herbal medicine is used extensively in the modern world. This study investigated the effects of decursinol angelate on the pharmacokinetics of theophylline, a typical substrate of the cytochrome P450 1A2 enzyme, in rats. After 3 days of decursinol angelate pretreatment, on the fourth day, rats were administered decursinol angelate and theophylline concomitantly. Blood theophylline and its major metabolite [1-methylxanthine (1-MX), 3-methylxanthine (3-MX), 1-methyluric acid (1-MU), and 1,3-dimethyluric acid (1,3-DMU)] levels were monitored by liquid chromatography-tandem mass spectroscopy. The results indicated that theophylline clearance significantly decreased and the area under the concentration-time curve (AUC) increased in decursinol angelate (25 mg/kg)-pretreated rats administered theophylline (10 mg/kg). The elimination half-life (t1/2) of theophylline was increased by 20%. In the presence of decursinol angelate (25 mg/kg), the pharmacokinetic parameters of three metabolites (1-MX, 1,3-DMU, and 1-MU) were significantly altered (half-life for 1-MU, and AUC24 h for 1-MX, 1,3-DMU, and 1-MU). Our results suggest that patients receiving CYP1A2-metabolized drugs, such as caffeine and theophylline, should be advised of the potential herb-drug interaction to reduce the risk of therapeutic failure or increased toxicity of conventional drug therapy.
Asunto(s)
Benzopiranos/farmacocinética , Butiratos/farmacocinética , Teofilina/farmacocinética , Animales , Área Bajo la Curva , Benzopiranos/metabolismo , Butiratos/metabolismo , Interacciones Farmacológicas , Semivida , Masculino , Estructura Molecular , Ratas , Ratas Sprague-Dawley , Reproducibilidad de los Resultados , Teofilina/sangre , Teofilina/química , Teofilina/metabolismoRESUMEN
Angelica gigas NAKAI is used to treat dysmenorrhea, amenorrhea, menopause, abdominal pain, injuries, migraine, and arthritis. The present study provided a physicochemical and toxicological characterization of compounds in A. gigas NAKAI (decursin, decursinol angelate, diketone decursin, ether decursin, epoxide decursin and oxim decursin). Diketone decursin (173.16 µg/mL) and epoxide decursin (122.12 µg/mL) exhibited >100 µg/mL kinetic solubility after applying nephelometry, suggesting a highly soluble compound. The Student's t-test revealed significant differences in the pKa ranges of the compounds by automatic titration from capillary electrophoresis (p<0.05). Diketone decursin, epoxide decursin and oxim decursin might be formulated into an oral dosage form (log P: 0-3) by an automatic titration analysis. A parallel artificial membrane permeability assay demonstrated permeability coefficients of <10 x 10â»6 cm/s for all of the compounds, suggesting poor permeability. Ether decursin exhibited a toxic effect after being applied to mouse (NIH 3T3, EC50: 57.9 µM) and human (HT-29, EC50: 36.1 µM; Hep-G2, EC50: 4.92 µM) cells. Additionally, epoxide and oxim decursin were toxic through acute oral toxicity (four and three deaths of Institute of Cancer Research (ICR) mice) and mutation toxicity testing by applying Salmonella typhimurium cells with and without S9. Although diketone decursin exhibited less permeability, it is potentially valuable pharmacological compound that should be investigated.
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Angelica/química , Benzopiranos/toxicidad , Butiratos/toxicidad , Extractos Vegetales/toxicidad , Animales , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Femenino , Humanos , Masculino , Ratones , Ratones Endogámicos ICR , Pruebas de Mutagenicidad , Células 3T3 NIH , Permeabilidad , Salmonella typhimurium/efectos de los fármacos , Salmonella typhimurium/genéticaRESUMEN
Purple sweet potato is a functional food rich in anthocyanins that possess disease-preventive properties. Anthocyanins are known to possess potent antidiabetic properties. However, the effect of the anthocyanin fraction (AF) from purple sweet potato on hepatic lipid metabolism remains unclear. Our hypothesis is that AF inhibits hepatic lipid accumulation through the activation of adenosine monophosphate-activated protein kinase (AMPK) signaling pathways in vitro and in vivo. In this study, we evaluated body weight, liver histology, and hepatic lipid content in high-fat diet (HFD)-fed ICR mice treated with AF. In addition, we characterized the underlying mechanism of AF's effects in HepG2 hepatocytes through Western blot analysis. Anthocyanin fraction (200 mg/kg per day) reduced weight gain and hepatic triglyceride accumulation and improved serum lipid parameters in mice fed an HFD for 4 weeks. Anthocyanin fraction significantly increased the phosphorylation of AMPK and acetyl-coenzyme A carboxylase (ACC) in the liver and HepG2 hepatocytes. In addition, AF down-regulated the levels of sterol regulatory element-binding protein 1 and its target genes including ACC and fatty acid synthase (FAS). The specific AMPK inhibitor compound C attenuated the effects of AF on the expression of lipid metabolism-related proteins such as SREBP-1 and FAS in HepG2 hepatocytes. The beneficial effects of AF on HFD-induced hepatic lipid accumulation are thus mediated through AMPK signaling pathways, suggesting a potential target for the prevention of obesity.
Asunto(s)
Proteínas Quinasas Activadas por AMP/metabolismo , Antocianinas/uso terapéutico , Ipomoea batatas/química , Metabolismo de los Lípidos/efectos de los fármacos , Hígado/efectos de los fármacos , Fitoterapia , Extractos Vegetales/uso terapéutico , Acetil-CoA Carboxilasa/genética , Acetil-CoA Carboxilasa/metabolismo , Animales , Antocianinas/farmacología , Western Blotting , Grasas de la Dieta/efectos adversos , Grasas de la Dieta/metabolismo , Activación Enzimática/efectos de los fármacos , Ácido Graso Sintasas/genética , Ácido Graso Sintasas/metabolismo , Alimentos Funcionales , Regulación de la Expresión Génica/efectos de los fármacos , Células Hep G2 , Hepatocitos/metabolismo , Humanos , Hígado/enzimología , Hígado/metabolismo , Masculino , Ratones , Ratones Endogámicos ICR , Ratones Obesos , Obesidad/prevención & control , Extractos Vegetales/farmacología , Tubérculos de la Planta , Proteína 1 de Unión a los Elementos Reguladores de Esteroles/genética , Proteína 1 de Unión a los Elementos Reguladores de Esteroles/metabolismo , Aumento de Peso/efectos de los fármacosRESUMEN
Saponins from the roots of Platycodon grandiflorum (CKS) have been shown to exhibit many pharmacological activities, including anti-cancer and anti-inflammatory activities and antioxidant effects. However, anti-skin photoaging effects of CKS have not yet been reported. In this study, we investigated the protective effects of CKS against UVA damage on immortalized human keratinocytes (HaCaT). We then explored the inhibitory effects of CKS on UVA-induced MMP-1 and investigated the molecular mechanism underlying those effects. CKS increased the cell viability and inhibited reactive oxygen species (ROS) production in HaCaT cells exposed to UVA irradiation. Pre-treatment of HaCaT cells with CKS inhibited UVA-induced production of MMP-1 and MMP-9. In addition, CKS decreased UVA-induced expression of the inflammatory cytokines IL-1ß and IL-6. Western blot analysis further revealed that CKS markedly suppressed the enhancement of collagen degradation in UVA-exposed HaCaT cells. CKS also suppressed UVA-induced activation of NF-κB or c-Jun and c-Fos, and the phosphorylation of MAPKs, which are upstream modulators of NF-κB and AP-1.
Asunto(s)
Metaloproteinasa 1 de la Matriz/efectos de la radiación , FN-kappa B/genética , Raíces de Plantas/química , Platycodon/química , Saponinas/farmacología , Factor de Transcripción AP-1/genética , Western Blotting , Línea Celular Tumoral , Humanos , Interleucina-1beta/genética , Interleucina-1beta/metabolismo , Interleucina-1beta/efectos de la radiación , Interleucina-6/genética , Interleucina-6/metabolismo , Interleucina-6/efectos de la radiación , Queratinocitos/citología , Queratinocitos/metabolismo , Queratinocitos/efectos de la radiación , Metaloproteinasa 1 de la Matriz/genética , Metaloproteinasa 1 de la Matriz/metabolismo , Metaloproteinasa 9 de la Matriz/genética , Metaloproteinasa 9 de la Matriz/metabolismo , Metaloproteinasa 9 de la Matriz/efectos de la radiación , FN-kappa B/metabolismo , Fosforilación , Extractos Vegetales/farmacología , Proteínas Proto-Oncogénicas c-fos/genética , Proteínas Proto-Oncogénicas c-fos/metabolismo , Transducción de Señal , Factor de Transcripción AP-1/metabolismo , Rayos UltravioletaRESUMEN
Lipase-catalyzed interesterification of high oleic sunflower oil and fully hydrogenated soybean oil (70 : 30, wt/ wt) was carried out in a packed bed reactor using an immobilized lipase from Thermomyces lanuginosus (Lipozyme TL IM) and the effect of a stepwise temperature protocol involving the 2 different temperatures, 60 and 70 °C, was investigated. The melting point of a fat that was incubated at 70 °C for 9 min was 57 °C, which suggested that it should be to employ a lower reaction temperature of 60 °C, after the first 9 min of the reaction. There were no significant differences (P < 0.05) in the conversion degree, triacylglycerol profile, and solid fat content between a constant temperature protocol (70 °C) and a stepwise temperature protocol (a combination of 70 and 60 °C). After 50 cycles, the overall residual activities of enzymes employed in stepwise temperature protocol were significantly (P < 0.05) higher than those of enzymes employed in constant temperature protocol.
Asunto(s)
Manipulación de Alimentos/métodos , Lipasa/metabolismo , Aceites de Plantas/química , Aceite de Soja/química , Temperatura , Ascomicetos/enzimología , Catálisis , Enzimas Inmovilizadas/metabolismo , Esterificación , Hidrogenación , Espectroscopía de Resonancia Magnética/métodos , Ácido Oléico/análisis , Aceite de Girasol , Temperatura de Transición , Triglicéridos/análisisRESUMEN
Several strategies for overcoming the challenge of establishing bioequivalence (BE) for highly variable drugs (HVDs; drugs having within-subject variability >0.3) have been considered in recent years. Within-subject variability of the area under the curve (AUC(4h)) and peak concentration (C(max)) of doxifluridine in the minimal group (n=24) were 0.444 and 0.491, respectively, meeting the criteria for an HVD. For the large group (n=60), within-subject variability of the AUC(4h) and C(max) were 0.431 and 0.493, respectively. The 90% confidence interval for the AUC(4h) and C(max) of the ratio of the test drug to the reference drug exceeded the acceptable BE limits (0.80-1.25) of the ABE (average bioequivalence), in both the minimal and large groups. However, the 90% CI fell within the extended BE limits (0.61-1.64) of the SABE (scaled average bioequivalence), calculated using within-subject variability. The 95% CI of the AUC(4h) and C(max) of the ratio of test to reference drug were within the extended BE limit (<1.73) of the PBE (population bioequivalence), calculated using total variance. Our results suggest that the SABE method may be useful for evaluating the BE of HVDs and for meeting the need for international guidelines for BE.
Asunto(s)
Evaluación Preclínica de Medicamentos/métodos , Floxuridina/farmacocinética , Animales , Perros , Modelos Estadísticos , Equivalencia TerapéuticaRESUMEN
The time-resolved fluorescence technique based on melanin-concentrating hormone (MCH) receptor subtype-1 (MCH-1 receptor) binding assay was adopted to carry out a bioassay-guided fractionation of the methanol extract of Morus alba leaves. This fractionation and purification led to the isolation of two compounds identified as pheophorbide a methyl ester and 13(2)(S)-hydroxypheophorbide a methyl ester. These active pheophorbides exhibited potent inhibitory activity in binding of europium-labeled MCH to the human recombinant MCH-1 receptor (IC(50) value; 4.03 and 0.33 microM, respectively). Besides binding activity, the pheophorbides inhibited MCH-mediated extracellular signal-regulated kinase (ERK) phosphorylation in Chinese hamster ovary cells expressing human MCH-1 receptor. These results suggest that pheophorbide a methyl ester and 13(2)(S)-hydroxypheophorbide a methyl ester act as modulators of MCH-1 receptor and MCH-mediated ERK signaling.
Asunto(s)
Clorofila/análogos & derivados , Morus/química , Extractos Vegetales/farmacología , Receptores de la Hormona Hipofisaria/metabolismo , Animales , Células CHO , Clorofila/farmacología , Cricetinae , Cricetulus , Quinasas MAP Reguladas por Señal Extracelular/metabolismo , Humanos , Estructura Molecular , Fosforilación , Hojas de la Planta/química , Proteínas Recombinantes/metabolismo , Transducción de SeñalRESUMEN
Structured lipids were synthesized by acidolysis of olive oil and capric acid with an immobilized lipase (Lipozyme TL IM) from Thermomyces lanuginosus. The acidolysis reaction was carried out by incubating a 1:3 molar ratio of olive oil and capric acid under solvent-free reaction systems at 50 degrees C. The effect of water activity on the incorporation of capric acid was investigated, and the tested water activity range was between 0.22 and 0.80. Capric acid incorporation into triacylglycerols of the olive oil increased as the water activity increased, but the degree of acyl migration also increased. Also, the degree of acyl migration of modified olive oils with a similar degree of incorporation was investigated. High degrees of acyl migration occurred at water activities of 0.22 and 0.32 for the degree of incorporation of ca. 50 mol %. Only 8 h of reaction time was required to achieve incorporation of ca. 50 mol % at a water activity of 0.80, and the lowest acyl migration occurred at the same water activity. These results suggest that acyl migration can be efficiently minimized by a shorter reaction time at higher water activity.
Asunto(s)
Ácidos Decanoicos/metabolismo , Lipasa/metabolismo , Aceites de Plantas/metabolismo , Agua/metabolismo , Enzimas Inmovilizadas/metabolismo , Aceite de Oliva , Páncreas/enzimología , Aceites de Plantas/química , Triglicéridos/metabolismoRESUMEN
Interesterification of a 60:40 (wt/wt) mixture of olive oil and fully hydrogenated canola oil was carried out in a batch reactor using a commercial immobilized lipase from Thermomyces lanuginose as a biocatalyst. The effects of a stepwise change of temperature on the degree of conversion, the solid fat content (SFC) of the products, and the residual activity of the enzyme were investigated. As a reference condition, an interesterification trial was conducted at a constant temperature of 70 degrees C for 48 h. For trials in which a temperature of 70 degrees C was used for the first 4 h of reaction and a temperature of 60 degrees C was employed for the following 44 h, there were no significant differences (p < 0.05) in the overall degree of conversion relative to the reference condition. Oils interesterified for only 1 or 2 h at 70 degrees C had melting points higher than 60 degrees C, whereas an oil produced by interesterification at 70 degrees C for only 4 h had a melting point of 58 degrees C. There was little difference (p < 0.05) between the SFC profiles of the interesterification products prepared by two different temperature protocols (70 degrees C for 24 h; 70 degrees C for 4 h followed by 60 degrees C for 20 h). Use of the protocol involving a step decrease in temperature significantly decreased catalyst deactivation effects, thereby increasing the residual activity of the immobilized lipase.