197704-36-2

Upstream product

• 765935-41-9 cholesterol 
• 98-59-9 p-toluenesulfonyl chloride 

Relevant academic research and scientific papers

Design, synthesis and evaluation of liposomes modified with dendritic aspartic acid for bone-specific targeting

Bone diseases are notoriously difficult diseases to treat due to the comparatively low blood flows in bone tissue. Therefore, targeting delivery of drugs to bone may not only enhance the treatment efficacy, but also reduce the quantity of drug administered. In order to increase the distribution of paclitaxel (PTX) in bone, in this study, a series of novel dendritic aspartic acid derivatives were designed and synthesized as liposome ligands to deliver PTX to bone effectively. The liposomes were prepared by thin film hydration method and its particle size, zeta potential, encapsulation efficiency, release profile, stability, hemolysis were also characterized. All the aspartic acid-coated liposomes showed more than 60% binding rates to hydroxyapatite (HAP), especially the PTX-Asp8-Lip exhibited dramatic binding rates (> 97%) after 24 h. Moreover, the bone-targeting study in vivo indicated that all liposomes could improve the accumulation of PTX in bone, among which, the PTX-Asp8-Lip showed the best affinity due to the increase of aspartic acid residues exposed on the liposome surface. These results provided a novel and effective entry to the development of bone-targeting drugs.

Synthesis and liquid crystal behavior of new side chain aliphatic polycarbonates based on cholesterol

In this study, we synthesized a series of new liquid crystal aliphatic block polycarbonates copolymers mPEG43-b-P(MCC-Cn)51 (n = 1–4) via the ring-opening polymerization, hydrogenation reduction and coupling reaction, which contained side functionalized cholesteryl groups and were different in the number of the flexible methylene groups. The chemical structures of the chiral compounds and copolymers obtained in this study were characterized by FT-IR and 1H NMR spectra, and the average molecular weights of the copolymers were investigated by average molecular weights gel permeation chromatographic (GPC). The polarizing optical microscopy (POM), differential scanning calorimetry (DSC) and X-ray diffraction (XRD) were used to characterize the liquid crystal behavior. The relationship of the structure and phase behavior of the chiral compounds and copolymers influenced by spacer lengths was discussed. As a result, the chiral compounds with two methylene only showed a smectic A (SmA) phase, while those with more methylene showed a SmA phase and cholesteric phase. As the number of the flexible methylene groups increased, the corresponding melting temperature, the transition temperatures of LC phases and the isotropic temperature of chiral compounds all showed a decreasing trend, and mesophase temperature range narrowed. The polycarbonate copolymer with two methylene did not show mesomorphism, while the copolymers with longer spacer length seemed beneficial for the formation of mesophases at room temperature and revealed a smectic A phase with an interdigitated molecular arrangement on heating and cooling cycles. The results showed a decreased tendency toward the glass temperature, and an increased tendency toward isotropic temperature for the LC copolymers with an increase of the spacer length.

Synthesis of multivalent glucosides with high affinity for GLUT1 transporter

The novel bifunctional compounds L1 and L2 carrying cluster glucosides as ligands for brain targeting liposomes were synthesized. 2-phenyl-1,3-dioxan-5-ol (8) and tetra-antennary alcohol (13) were used as the core scaffold to attach cholesterol derivatives by a triethylene glycol chain, while their remaining branches were linked with two or three benzylglucosides, which would be debenzvlated later to produce di-antennary glucosides L1 and tri-antennary glucosides ligand L2. This design provided an effective entry for the synthesized bifunctional compounds to cross blood brain barrier (BBB).

Montmorillonite clay catalysis. Part 10. K-10 and KSF-catalysed acylation of alcohols, phenols, thiols and amines: Scope and limitation

Montmorillonite K-10 and KSF are highly efficient catalysts for the acetylation of a variety of alcohols, thiols, phenols and amines with acetic anhydride. Amino groups can be selectively acetylated in the presence of hydroxy groups, while the hydroxy groups can be preferentially acetylated in the presence of thiol groups. No selectivity is observed between primary and secondary hydroxy groups in the presence of K-10 and KSF. The catalysts are found not to be efficient for acetylation of tertiary alcohols. This method is simple and convenient with minimum environmental impact. The catalysts are also effective for the acylation of alcohols, thiols, phenols and amines with acetyl chloride and benzoyl chloride. Cyclic anhydrides such as succinic anhydride, maleic anhydride and phthalic anhydride and p-toluene sulfonyl chloride show less reactivity than acetic anhydride and acyl chlorides.