Construction of pH responsive periodic mesoporous organosilica with histidine framework (His-PMO) for drug delivery
摘要:
pH-responsive drug delivery material based on histidine periodic mesoporous organosilica (His-PMO) was constructed by the condensation of histidine bissilylated organosilica precursor (His-BOP) and TEOS in acidic medium under the template P123. The organosilica precursor His-BOP was prepared by selecting histidine as the main reactant via multi-step reactions. Histidine is first introduced as the skeletal constituents of PMO to improve flexibility of the robust framework and sensitivity of pH response. The materials His-PMO maintain ordered mesostructure and facilitate entrance or exit of compounds during application process. Paclitaxel (PTX) is used as the cargo molecules to observe drug delivery in vitro. The results indicate that the maximum loading amounts of drugs are up to 28 mg/g on the material His-PMO-10% under the same conditions. In the release experiments, the different release percentage and speed of PTX are observed with the variation of pH values (pH 5.2, 6.8 and 7.4), which exhibits nonlinear over the time. Rapid accumulation of drugs at low pH are maybe helpful for improving the performance of conquering cancer.
direct and effective transformation of α-amino ketones, acetamides, and esters to the corresponding α-diazo products under mild basic conditions has been developed. This one-step synthetic approach not only allows for generation of α-substituted-α-diazo carbonyl compounds from α-amino acidderivatives but also permits preparation of α-diazo dipeptides from N-terminal dipeptides (32 examples, up to 91%)
Histidine-(N-benzyl glycinamide) inhibitors of protein farnesyl transferase
申请人:Warner-Lambert Company
公开号:US06300501B1
公开(公告)日:2001-10-09
Inhibitors of protein farnesyl transferase enzymes are described, as well as methods for the preparation and pharmaceutical compositions of the same, which are useful in treating cancer, restenosis, psoriasis, endometriosis, atherosclerosis, or viral infections.
D-isomer (D-BHisPA) derived from the corresponding chiral histidine revealed a left- and right-handed helical conformation, respectively, through intramolecular hydrogen bonding and chirality of the podand histidyl moieties. Furthermore, each helical molecule is connected by continuous intermolecular hydrogen bonds to afford a left- or right-handed helical assembly, respectively, in the crystal packing
Hydrogen‐Borrowing Alkylation of 1,2‐Amino Alcohols in the Synthesis of Enantioenriched γ‐Aminobutyric Acids
作者:Christopher J. J. Hall、William R. F. Goundry、Timothy J. Donohoe
DOI:10.1002/anie.202100922
日期:2021.3.22
For the first time we have been able to employ enantiopure 1,2‐aminoalcohols derived from abundant amino acids in C−C bond‐forming hydrogen‐borrowing alkylation reactions. These reactions are facilitated by the use of the aryl ketone Ph*COMe. Racemisation of the amine stereocentre during alkylation can be prevented by the use of sub‐stoichiometric base and protection of the nitrogen with a sterically