The building block of N-alkyl derivative of allosamidin（chitinase inhibitor）,4,6-O-benzylidene-N-octyl-D-allosamine hydrochloride was stereoselectively synthesized in two steps under mild conditions.Nucleophilic add...The building block of N-alkyl derivative of allosamidin（chitinase inhibitor）,4,6-O-benzylidene-N-octyl-D-allosamine hydrochloride was stereoselectively synthesized in two steps under mild conditions.Nucleophilic addition of octylamine to 2- oxoglucopyranoside gave a‘carbonyl group transfer＇ product in 62%yield.Subsequent stereoselective reduction of newly formed C=O with NaBH_4 produced title compound in 75%yield.X-ray diffraction analysis indicates the title compound adopts syn 1,2,3 stereochemistry and chair-chair conformation.The crystal structure is stabilized by hydrogen bonds.展开更多
A variety of β-enamino ketones were synthesized in high to excellent yields by reacting acetylacetone with amines in the presence of a catalytic amount of cerium（IV） ammonium nitrate （CAN） under ultrasonic irradi...A variety of β-enamino ketones were synthesized in high to excellent yields by reacting acetylacetone with amines in the presence of a catalytic amount of cerium（IV） ammonium nitrate （CAN） under ultrasonic irradiation.展开更多
Liver fibrosis, resulting from chronic liver damage and characterized by the accumulation of extracellular matrix (ECM) proteins, is a characteristic of most types of chronic liver diseases. The activation of hepatic ...Liver fibrosis, resulting from chronic liver damage and characterized by the accumulation of extracellular matrix (ECM) proteins, is a characteristic of most types of chronic liver diseases. The activation of hepatic stellate cells (HSC) is considered an essential pathological hallmark in liver fibrosis. Although nitric oxide (NO) can effectively induce HSC apoptosis, the systemic administration of NO is ineffective and may cause severe complications such as hypotension. To overcome this limitation, nanoparticles were designed to target HSCs and release NO locally under the exposure of near infrared light (NIR). To achieve this, upconversion nanoparticle (UCNP) cores were enveloped in mesoporous silica shells (UCNP@mSiO2), which were modified with hyaluronic acid (HA-UCNP@mSiO2) and Roussin’s black salt (RBS). HA molecules recognize and bind to CD44 proteins, which are overexpressed on activated HSCs. Under exposure to a 980-nm NIR laser, the UCNP cores convert the 980-nm wavelength into ultraviolet (UV) light, which then energizes the RBS (NO donors), resulting in an efficient release of NO inside of the HSCs. Once released, NO triggers HSC apoptosis and reverses the liver fibrosis. This targeted and controlled release method provides the theoretical and experimental basis for novel therapeutic approaches to treat hepatic fibrosis.展开更多
基金the financial supports from the National Natural Science Foundation of China(No. 20972142)the State Key Laboratory of Bio-organic and Natural Products Chemistry,CAS(No.08417).
文摘The building block of N-alkyl derivative of allosamidin（chitinase inhibitor）,4,6-O-benzylidene-N-octyl-D-allosamine hydrochloride was stereoselectively synthesized in two steps under mild conditions.Nucleophilic addition of octylamine to 2- oxoglucopyranoside gave a‘carbonyl group transfer＇ product in 62%yield.Subsequent stereoselective reduction of newly formed C=O with NaBH_4 produced title compound in 75%yield.X-ray diffraction analysis indicates the title compound adopts syn 1,2,3 stereochemistry and chair-chair conformation.The crystal structure is stabilized by hydrogen bonds.
基金the National Natural Science Foundation of China(No.20472074)the Innovation Fund for 0utstanding Scholar of Henan Province(No.0621001100)for financial support.
文摘A variety of β-enamino ketones were synthesized in high to excellent yields by reacting acetylacetone with amines in the presence of a catalytic amount of cerium（IV） ammonium nitrate （CAN） under ultrasonic irradiation.
基金This work was supported by the National Natural Science Foundation of China （No. 20972142） and the State Key Laboratory of Bio-organic and Natural Prod- ucts Chemistry, CAS （08417）.
基金This work was supported by the American Heart Association(Nos.18TPA34230092 and 19EIA34660286 to K.C.)the National Natural Science Foundation of China(No.U1904149 to H.X.L.)+1 种基金National S&T Major Project of China(No.2018ZX10301201-008 to Z.G.R.)the High Technology Research and Development Program of Henan Province(No.20A320055 to H.X.L.).
文摘Liver fibrosis, resulting from chronic liver damage and characterized by the accumulation of extracellular matrix (ECM) proteins, is a characteristic of most types of chronic liver diseases. The activation of hepatic stellate cells (HSC) is considered an essential pathological hallmark in liver fibrosis. Although nitric oxide (NO) can effectively induce HSC apoptosis, the systemic administration of NO is ineffective and may cause severe complications such as hypotension. To overcome this limitation, nanoparticles were designed to target HSCs and release NO locally under the exposure of near infrared light (NIR). To achieve this, upconversion nanoparticle (UCNP) cores were enveloped in mesoporous silica shells (UCNP@mSiO2), which were modified with hyaluronic acid (HA-UCNP@mSiO2) and Roussin’s black salt (RBS). HA molecules recognize and bind to CD44 proteins, which are overexpressed on activated HSCs. Under exposure to a 980-nm NIR laser, the UCNP cores convert the 980-nm wavelength into ultraviolet (UV) light, which then energizes the RBS (NO donors), resulting in an efficient release of NO inside of the HSCs. Once released, NO triggers HSC apoptosis and reverses the liver fibrosis. This targeted and controlled release method provides the theoretical and experimental basis for novel therapeutic approaches to treat hepatic fibrosis.
