darunavir, and nelfinavir were
provided by the NIH AIDS Reagent Program (Germantown, MD). ((1H-Benzo[d][1,2,3]triazol-1-yl)oxy)tri(pyrrolidin-1-yl)phosphonium
hexafluorophosphate (PyBOP) was bought from GenScript Corporation
(Piscataway, NJ). DTT was purchased from Roche (Indianapolis, IN).
1-(3-Dimethylaminoproyl)-3-ethylcarbodiimide hydrochloride (EDC) was
purchased fom AK Scientific (Union City, CA). 4,4′-Dithiodibutyric
acid, N,N-dimethylpyridin-4-amine
(DMAP), and N-ethyl-N-isopropylpropan-2-amine
(DIEA) were purchased from Sigma-Aldrich (St. Louis, MO). hCMEC/D3
cells were donated from Institut National de la Sante et de la Recherche
Medicale (INSERM, Paris, France). Rat tail collagen I was purchased
from BD Biosciences (San Jose, CA). EBM-2 growth medium was purchased
from Lonza (Basel, Switzerland). Calcein-AM was bought from Invitrogen
(Carlsbad, CA), All other reagents were purchased from Sigma-Aldrich
(St. Louis, MO) or Invitrogen (Carlsbad, CA) and used without further
purification. 1H, 13C, and 2D NMR spectra were
recorded with a Bruker AC 800 and Bruker AC 500 MHz. DMSO-d6 was used to prepare NMR samples.