The lupane-type triterpenoids are endowed with a wide range of biological activities such as antiviral, anti-inflammatory and anticancer activity. We describe here its potential application in Alzheimer's disease (AD) treatment as an inhibitor of PS1/BACE1 interaction. 3-a-Akebonoic acid, which emanated from a high throughput screening (HTS), was discovered to interfere with P S 1/BACE 1 interaction and reduce amyloid β-protein (Aβ) production. In view of the limited source, we instead used naturally rich betulinic acid (compound 2) as starting material for lead optimization and a focused library of its derivatives was constructed to gain a better understanding of the structure activity relationship (SAR) of triterpenoid-type inhibitor of PS1/BACE1 interaction. Compound 22 was finally chosen as the most potent PS 1/BACE 1 interaction inhibitor, which reduced Aβgeneration effectively.
Mycothiol (MSH) is the major low molecular weight thiol in most actinomycetes. Chemical synthesis of MSH is of value for enzymology and inhibitor screening assays, but is hampered by difficulties in large scale sysnthesis. We achieved the total synthesis of MSH by linking 2-camphanoyl-3,4,5,6-tetra-O-benzyl-D-rnyo-inositol (D-1) and 2-deoxy-2-azido-3,4,6-tri-O-benzyl- 1-p-toluene-thio-o-glucoside (2) first, followed by coupling with N-Boc-S-acetyl-L-cysteine (3). This route of synthesis allowed the efficient and convenient synthesis of mycothiol on a large scale.
A novel copper-catalyzed dual oxidative benzylic C–H aminations of methylarenes with 2-aminobenzoketones in the presence of ammonium acetate was developed. This reaction represents a new avenue for 2-arylquinazolines with good yields. A key intermediate was detected and the kinetics isotope effect(KIE) indicated that C–H bond cleavage was the rate-determining step.