Design, synthesis, and anti-tumor activity of derivatives of ring A and C-28 of asiatic acid.

Based on computer-aided drug design (CADD), the active groups of the known active small molecule compounds that can bind to EGFR target protein were analyzed through the molecular docking method. Then, 12 novel asiatic acid derivatives were synthesized by introducing active groups at ring A and C-28 positions of asiatic acid. The structures of these novel compounds were determined by NMR and MS.

Design, synthesis, and antitumor activity of novel oleanolic acid analogues targeting EGFR.

Based on the simulated docking of Epidermal growth factor receptor inhibitors with known active small molecule compounds, computer-aided drug design technology was used to analyze key amino acid fragments and determine the active groups binding with key sites. Then, twelve novel analogues of oleanolic acid (OA) were synthesized by introducing active groups at the C-3 and C-28 positions of OA. The structures of these novel analogues were confirmed by NMR and MS.

Synthesis and anti-tumor activity of asiatic acid derivatives targeting VEGFR.

To discovery novel VEGFR inhibitors, 12 novel asiatic acid derivatives were designed by computer-aided drug design (CADD) technology. Then, these novel asiatic acid derivatives were synthesized by introducing active groups at ring A and C-28 positions of asiatic acid. The structures of these novel analogues were confirmed by NMR and MS.

Highly Fluorinated Peptide Probes with Enhanced In Vivo Stability for F-MRI.

A labeling strategy for in vivo F-MRI (magnetic resonance imaging) based on highly fluorinated, short hydrophilic peptide probes, is developed. As dual-purpose probes, they are functionalized further by a fluorophore and an alkyne moiety for bioconjugation. High fluorination is achieved by three perfluoro-tert-butyl groups, introduced into asparagine analogues by chemically stable amide bond linkages.

Design, synthesis and anti-tumor activity of asiatic acid derivatives as VEGF inhibitors.

The VEGF receptor is mock-coupled with a known active compound and the active groups of the inhibitor which can bind to VEGF were analyzed. Using asiatic acid as a lead compound, 10 novel skeleton candidate compounds were designed through introduction of the active groups onto the special location and synthesized simultaneously. Furthermore, the structure of these compounds was determined by H NMR, C NMR and MS and 9 compounds were identified as the new compounds.

Asymmetric catalytic alkynylation of thiazolones and azlactones for synthesis of quaternary α-amino acid precursors.

Asymmetric alkynylation of thiazolones and azlactones with alkynylbenziodoxolones as the electrophilic alkyne source catalyzed by thiourea phosphonium salt is described. By using thiazolones as nucleophiles, the desired alkyne functionalized thiazolones were obtained in 55-89% yields with 31-86% ee. Azlactones gave the desired products in comparable yields with lower enantioselectivities.

Diastereo- and Enantioselective Synthesis of Quaternary α-Amino Acid Precursors by Copper-Catalyzed Propargylation.

A diastereo- and enantioselective propargylic substitution reaction between propargylic carbonates and α-substituted nitroacetates catalyzed by a Cu-pybox complex is described. This method allows the preparation of a series of non-proteinogenic quaternary α-amino acid precursors featuring two contiguous stereogenic centers and a terminal alkyne moiety in high yields with good to excellent diastereo- and enantioselectivities in most cases. The propargylated adducts were elaborated into a diverse set of quaternary α-amino acid derivatives.

Synthesis of β-1,3-glucan esters showing nanosphere formation.

Polysaccharide nanoparticles are versatile functional materials used in drug delivery applications. Here we describe a method for the synthesis of β-1,3-glucan esters which show the formation of nanoparticles. Pyridine-soluble β-1,3-glucan formate was first synthesized as an intermediate and then reacted with various anhydrates to yield β-1,3-glucan acetate and hexaonate.