Defense Date

2015

Document Type

Dissertation

Degree Name

Doctor of Philosophy

Department

Pharmaceutical Sciences

First Advisor

Phillip M Gerk

Second Advisor

Venitz Jurgen

Third Advisor

Matthew S Halquist

Fourth Advisor

Yan Zhang

Fifth Advisor

Scott W Walsh

Abstract

Lopinavir (LPV) is a potent protease inhibitor specific for HIV-1. However, LPV has poor placental penetration due to substrate activity for efflux transporter by P-glycoprotein (P-gp). Since fatty acid transporters are highly expressed in the placenta during pregnancy, we designed fatty acid ester prodrug of lopinavir as substrates of fatty acid transporter in order to improve their uptake into placenta. Seven dicarboxylic acid esters of lopinavir have been made in our lab. The structures were characterized by 1H-NMR, 13C-NMR, LC-MS/MS, HRMS, IR and melting points. After making the prodrugs, an LC-MS/MS method with high specificity and sensitivity, as well as simultaneous quantitative analyses of lopinavir and SLPV, GLPV and DLPV in the BeWo cells methanol extraction was established and validated. The uptake of prodrugs (SLPV, GLPV and DLPV) in the BeWo cells was then determined. GLPV has the highest uptake followed by SLPV and then DLPV. The results suggest that the carbon length of the promoiety may have a positive relationship with the uptake. Ideal prodrugs should be stable before they reach placenta and can be hydrolyzed in the placenta and/or in fetal plasma. We did a series of stability and hydrolysis studies in human tissue fractions. The results showed that GLPV and SLPV were very stable in HIC, HLC and human adult plasma. DLPV was stable in HIC, HLC, but can be hydrolyzed in human adult plasma. GLPV and SLPV cannot be hydrolyzed in either human placenta or fetal plasma, while DLPV can be hydrolyzed in both human placenta and fetal plasma. Anti-HIV activities study of prodrugs was also conducted. The results showed that the EC50 of three prodrugs (GLPV, SLPV and DLPV) are 0.86 μM, 0.84 μM and 0.05 μM, which are much lower than 50 μM (The active drug criteria for this assay). It suggests that prodrugs have apparently anti-HIV activity. DLPV has comparable apparent anti-HIV activity to LPV (<0.02 μM). After incubation with CEM-SS cells for 6 days, almost half of DLPV was hydrolyzed into LPV. Therefore, the high anti-HIV potent of DLPV may be due to the anti-HIV activity of generated LPV.

Rights

© The Author

Is Part Of

VCU University Archives

Is Part Of

VCU Theses and Dissertations

Date of Submission

8-6-2015

Available for download on Tuesday, August 04, 2020

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