63631-40-3Relevant articles and documents
Acyloxyalkoxy-based cyclic prodrugs of opioid peptides: Evaluation of the chemical and enzymatic stability as well as their transport properties across Caco-2 cell monolayers
Bak, Annette,Gudmundsson, Olafur S.,Friis, Gitte J.,Siahaan, Teruna J.,Borchardt, Ronald T.
, p. 24 - 29 (2007/10/03)
Purpose. To evaluate the chemical and enzymatic stability, as well as the cellular permeation characteristics, of the acyloxyalkoxy-based cyclic prodrugs 1 and 2 of the opioid peptides [Leu5]-enkephalin (H-Tyr-Gly-Gly- Phe-Leu-OH) and DADLE (H-Tyr-D-Ala-Gly-Phe-D-Leu-OH), respectively. Methods. The rates of conversion of 1 and 2 to [Leu5]-enkephalin and DADLE, respectively, were measured by HPLC in HBSS, pH = 7.4, and in various biological media (e.g., human plasma and Caco-2 cell and rat liver homogenates) having measurable esterase activity. The cellular permeation and metabolism characteristics of [Leu5]-enkephalin, DADLE and the cyclic prodrugs 1 and 2 were measured using Caco-2 cell monolayers grown onto microporous membranes and monitored by HPLC. Results. Cyclic prodrugs 1 and 2 degraded slowly but stoichiometrically to [Leu5]-enkephalin and DADLE, respectively, in HBSS, pH = 7.4. In homogenates of Caco-2 cells and rat liver, as well as 90% human plasma, the rates of disappearance of the cyclic prodrugs were significantly faster than in HBSS. The stabilities of the cyclic prodrugs 1 and 2 were increased significantly in 90% human plasma and Caco-2 cell homogenates when paraoxon, a potent inhibitor of serine-dependent esterases, was included in the incubation mixtures. A similar stabilizing effect of paraoxon was not observed in 50% rat liver homogenates, but was observed in 10% homogenates of rat liver. When applied to the AP side of a Caco-2 cell monolayer, DADLE and cyclic prodrugs 1 and 2 exhibited significantly greater stability than [Leu5]-enkephalin. Based on their physicochemical properties (i.e., lipophilicity), cyclic prodrugs 1 and 2 should have exhibited high permeation across Caco-2 cell monolayers. Surprisingly, the AP-to-BL apparent permeability coefficients (P(App)) for cyclic prodrugs 1 and 2 across Caco-2 cell monolayers were significantly lower than the P(App) value determined for the metabolically stable opioid peptide DADLE. When the P(App) values for cyclic prodrugs 1 and 2 crossing Caco-2 cell monolayers in the BL-to-AP direction were determined, they were shown to be 36 and 52 times greater, respectively, than the AP-to-BL values. Conclusions. Cyclic prodrugs 1 and 2, prepared with an acyloxyalkoxy promoiety, were shown to degrade in biological media (e.g., 90% human plasma) via an esterase-catalyzed pathway. The degradation of cyclic prodrug 1, which contained an ester formed with an L-amino acid, degraded more rapidly in esterase-containing media than did prodrug 2, which contained an ester formed with a D-amino acid. Cyclic prodrugs 1 and 2 showed very low AP-to-BL Caco-2 cell permeability, which did not correlate with their lipophilicities. These low AP-to-BL permeabilities result because of their substrate activity for apically polarized efflux systems.
Coumarinic acid-based cyclic prodrugs of opioid peptides that exhibit metabolic stability to peptidases and excellent cellular permeability
Gudmundsson, Olafur S.,Pauletti, Giovanni M.,Wang, Wei,Shan, Daxian,Zhang, Huijuan,Wang, Binghe,Borchardt, Ronald T.
, p. 7 - 15 (2007/10/03)
Purpose. To evaluate the cellular permeation characteristics and the chemical and enzymatic stability of coumarinic acid-based cyclic prodrugs 1 and 2 of the opioid peptides [Leu5]-enkephalin (H-Tyr-Gly-Gly-Phe-Leu-OH) and DADLE (H-Tyr-D-Ala-Gly-Phe-D-Leu-OH), respectively. Methods. The rates of conversion of the cyclic prodrugs 1 and 2 to [Leu5]-enkephalin and DADLE, respectively, in HBSS, pH 7.4 (Caco-2 cell transport buffer) and in various biological media having measurable esterase activity were determined by HPLC. The cell permeation characteristics of [Leu5]-enkephalin, DADLE and cyclic prodrugs 1 and 2 were measured using Caco-2 cell monolayers grown onto micropores membranes and monitored by HPLC. Results. In HBSS, pH 7.4, cyclic prodrugs 1 and 2 degraded chemically to intermediates that further degraded to [Leu5]-enkephalin and DADLE, respectively, in stoichiometric amounts. In 90% human plasma and rat liver homogenate, the disappearance of cyclic prodrugs 1 and 2 was significantly faster than in HBSS, pH 7.4. The half- lives in 90% human plasma and in rat liver homogenate were substantially longer after pretreatment with paraoxon, a known inhibitor of serine- dependent esterases. When applied to the AP side of a Caco-2 cell monolayer, cyclic prodrug 1 exhibited significantly greater stability against peptidase metabolism than did [Leu5]-enkephalin. Cyclic prodrug 2 and DADLE exhibited similar stability when applied to the AP side of the Caco-2 cell monolayer. Prodrug 1 was 665-fold more able to permeate the Caco-2 cell monolayers than was [Leu5]-enkephalin, in part because of its increased enzymatic stability. Prodrug 2 was shown to be approximately 31 fold more able to permeate a Caco- 2 cell monolayer than was DADLE. Conclusions. Cyclic prodrugs 1 and 2, prepared with the coumarinic acid promoiety, were substantially more able to permeate Caco-2 cell monolayers than were the corresponding opioid peptides. Prodrug 1 exhibited increased stability to peptidase metabolism compared to [Leu5]-enkephalin. In various biological media, the opioid peptides were released from the prodrugs by an esterase-catalyzed reaction, which is sensitive to paraoxon inhibition.
Coumarin-based prodrugs 2. Synthesis and bioreversibility studies of an esterase-sensitive cyclic prodrug of DADLE, an opioid peptide
Wang, Binghe,Wang, Wei,Zhang, Huijuan,Shan, Daxian,Smith, Terrill D.
, p. 2823 - 2826 (2007/10/03)
A coumarin-based esterase-sensitive cyclic prodrug of an opioid peptide, DADLE, was prepared. The cyclic prodrug quickly released (t( 1/4 ) = 761 min) its original peptide, DADLE, upon esterase catalyzed hydrolysis. Such a system can be used for the preparation of cyclic prodrugs of other biologically active peptides aimed at improving their bioavailability.