PRODUCTION

Design of New HIV-Protease Inhibitors and Ritonavir Synthesis

BY Sathaporn Prutipanlai Toxicology Program Mahidol University

OUT LINE Background Content : Processes of Ritonavir Synthesis : Possibility for synthesis new PIs Conclusion

BACKGROUND What is characteristic of HIV Protease enzyme.? HIV Protease is one type of aspartic acid enzyme.

Protease enzyme Protease’s function exists as a C 2 - symmetric homodimer. Each monomeric unit contributes one of the conserved catalytic triads(Asp-Thr-gly)

HIV Protease Enzyme

BACKGROUND (Cont) How does it work.? HIV Protease works by homodimer that cleave gag/pol polypeptide

HIV Protease inhibitor development Idea : How are enzyme and substrate interact.? Construct more potent and novel structure of enzyme

Protease enzyme

Inhibitors represent all three categories Based on peptide isosteres : statin Exploitation the symmetrical properties of the protease dimer. Based on enzyme structure.

Type of Designing Protease Inhibitor Non hydrolyzable analog of peptide substrates. Transition-state analogs. Pepstatin-Protease Complex. Two-fold symmetrical or Pseudo symmetrical inhibitor. Structure-Based inhibitor Design

Ritonavir Development Peptidomimetic inhibitor Substrate based inhibitor C 2 symmetry-based inhibitor

Ritonavir Development Design of C 2 -symmetric inhibitor from an asymmetric substrate compose of 3 steps First: Imposition an axis of symmetry on the peptide functionality in the substrate

Ritonavir Development(cont) Second: Arbitary deletion of either the N-terminal or C-terminal. Third: C 2 symmetry operation is applied to the remaining portion to generate a symmetric core unit.

C 2 -symmetric inhibitor to HIV protease enzyme Imposition of C 2 -symmetry axes on an asymmetric substrate or inhibitor Kempf, D.J. et.al. 1993

C 2 Symmetric HIV PIs Kempf, D.J. et.al 1993

Synthesis of Symmetric Inhibitor Core Units Three general categories. : Linear, nonsymmetric syntheses : Symmetric combination of identical halves : Bifunctionalization of a C 2 symmetric precursor

Linear, Nonsymmetric syntheses Kempf,D.J. 1994

Synthesis of Symmetric Inhibitor Core Units(cont) Three general categories. : Symmetric combination of identical halves : Bifunctionalization of a C 2 symmetric precursor

Effect of C 2 -symmetric inhibitors to HIV protease

Processes of Ritonavir Synthesis

+  -aminoaldehyde Scheme 1 vcl 3 Zn 2-5-bis-N- ((benzyl)oxy)carbonyl)amino-3, 4-diacydroxy-1, 6 diphenylhexane (diols) Patent#5,846,987

Scheme bis-N- ((benzyl)oxy)carbonyl) amino-3, 4-diacydroxy- 1, 6 diphenylhexane bromoacetate Hydrolysis Cyclization Reduction 2-5-bis-N-((benzyl)oxy)carbonyl)amino)1, 6 diphenyl-3-hydroxyhexane Patent#5,846,987 2,5-Bis-(N(((benzyl)oxyl)carbonyl amino)-3-4-epoxy-1,6 diphenylhaxane

Scheme 2 (cont) 2-5-bis-N-((benzyl)oxy)carbonyl)amino)1, 6 diphenyl-3-hydroxyhexane hydrolysis 2, 5, -diamino-1, 6diphenyl- 3-hydroxyhexane Patent#5,846,987

Scheme 3 acylation Patent#5,846,987 2,5,-Diamino-1,6- diphenyl-3- hydroxyhexane 6(1-Amino-2- phenyl)-4-benzyl- 2-phenyl-3-aza-2- boro-1- oxacyclohexane 5-(Thiazolyl)methyl)-(4- nitrophenyl)carbamate 5-Amino-2-(N-((5-thiazolyl)methoxy carbonyl)amino)-1,6-diphenyl-3- hydroxyhexane

Scheme 3 (cont) Patent#5,846,987 5-Amino-2-(N-((5- thiazolyl)methoxy carbonyl)amino)-1,6-diphenyl-3- hydroxyhexane Coupling reaction Ritonavir N-((N-methyl-N-((2-isopropyl-4-thiazoyl methyl)amino)carbonyl-L-valine

Molecular structure of Ritonavir

Ritonavir and protease enzyme

Indinavir and Protease Enzyme

Indinavir Saquinavir Ritonavir Nelfinavir

Possibility to design new protease inhibitor Factor : Hydrophobic : High oral bioavilability : Low hepatic clearance : Low toxicity

CONCLUSION Factor that influence drug design : Pharmacokinetic : Pharmacodynamic : Interaction between inhibitors and HIV- protease enzyme

THANK YOU Dr. Poonsak Dr. Maria Kartalou Dr. Suwit CRI’s Staff YOUR ATTENTION

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