Chiral Phosphoric Acid Catalyzed Asymmetric Mannich Reaction of 2-Aryl-3-indol-3-ones with α-H Diazoacetates.

An asymmetric Mannich reaction between 2-aryl-3-indol-3-ones and α-H diazoacetates catalyzed by chiral phosphoric acid was developed. This strategy achieves the effective synthesis of chiral 2,2-disubstituted indolin-3-ones bearing a quaternary stereocenter and containing a diazo group in the C2 substituent (up to >99% ee and 82% yield). To demonstrate the importance of the synthesized 2,2-disubstituted indolin-3-ones and the diversity of their diazo group reactions, we successfully achieved the relevant transformation reactions with a diazo group (such as hydroxylation, hydrogenation, intramolecular cyclization, etc.

Rh(III)-Catalyzed C7-Alkylation of Isatogens with Malonic Acid Diazoesters.

Rh(III)-catalyzed C7-alkylation of isatogens (indolin-3-one -oxides) with malonic acid diazoesters has been developed. This strategy utilizes oxygen anion on the -oxide group of isatogens as a directing group and successfully achieves the synthesis of a series of C7-alkylated isatogens with moderate to good yields (48-86% yields). Moreover, the -oxides of isatogens can not only serve as the simple directing group for C7-H bond cleavage but also be deoxidized for easy removal.

Synthesis of diarylmethyl thioethers a DABCO-catalyzed 1,6-conjugate addition reaction of -quinone methides with organosulfur reagents.

A rapid and simple method was developed for the synthesis of diarylmethyl thioethers a DABCO-catalyzed 1,6-conjugate addition reaction of -quinone methides (-QMs) with organosulfur reagents. A series of diarylmethyl thioethers were synthesized at 13-85% yields by this method. After that, the antibacterial activities of synthesized diarylmethyl thioethers and their derivatives were evaluated.

Synthesis and antibacterial activity studies of indirubin-3'-monoximes.

Multi-drug-resistant microbial pathogens are a serious global health problem. New compounds with antibacterial activity serve as good candidates for developing novel antibacterial drugs which is very urgent and important. In this work, based on the unique scaffold of indirubin, an active ingredient of traditional Chinese medicine formulation Danggui Luhui Wan, we synthesized 29 indirubin-3'-monoximes and preliminarily evaluated their antibacterial activities.

Organocatalytic Asymmetric α-Sulfenylation of 2-Substituted Indolin-3-ones: A Strategy for the Synthesis of Chiral 2,2-Disubstituted Indole-3-ones with S- and N-Containing Heteroquaternary Carbon Stereocenter.

An organocatalytic asymmetric α-sulfenylation of 2-substituted indolin-3-ones with N-(alkylthio or arylthio)succinimides has been developed for the first time using Cinchona-derived squaramide as the catalyst. Various chiral 2,2-disubstituted indole-3-ones with S- and N-containing heteroquaternary carbon stereocenters were obtained with up to 98% yield and 99% ee.

Palladium-catalyzed direct C(sp)-H arylation of indole-3-ones with aryl halides: a novel and efficient method for the synthesis of nucleophilic 2-monoarylated indole-3-ones.

A novel and efficient method for the synthesis of nucleophilic 2-monoarylated indole-3-ones palladium-catalyzed direct C(sp)-H arylation of indole-3-ones with aryl halides has been developed. Various 2-monoarylated indole-3-ones were readily obtained with yields up to 95%. As a class of important nucleophilic intermediates, 2-monoarylated indole-3-ones can be used for the construction of C2-quaternary indolin-3-one skeletons.

CLEC1B Expression and PD-L1 Expression Predict Clinical Outcome in Hepatocellular Carcinoma with Tumor Hemorrhage.

Spontaneous tumor hemorrhage (TH) is frequently observed in solid tumors including human hepatocellular carcinoma (HCC). TH implies fast-growing and worse tumor immunological microenvironment; however, the underlying mechanism remains largely unknown. CLEC1B is a signature gene highly associated with tumor progression.

Synthesis, anti-HBV activity and renal cell toxicity evaluation of mixed phosphonate prodrugs of adefovir.

A series of phosphonate ester prodrugs of adefovir incorporating l-amino (thio)acid and non-steroidal anti-inflammatory drug (NSAID) moieties were synthesized and their anti-HBV activity and renal cell toxicity were evaluated in HepG2 2.2.15 and HK-2 cells respectively.

[Design, synthesis and anti-oxidative evaluation of L-amino acid prodrugs of scutellarein].

To design and synthesize a series of novel scutellarein 4'-L-amino acid prodrugs with more potent anti-oxidative activity and improved physicochemical properties. Scutellarein was used as lead compound, according to successful experience of improving bioavailability of oral administration drugs by active transport mechanism, principle of hybridization was used to introducing L-amino acid structural fragments at 4'-position of scutellarein to design and synthesize target scutellarein 4'-L-amino acid prodrugs. The synthetic compounds were tested on their physicochemical properties and in vitro anti-oxidative activity against H202 induced oxidative damage in PC12 cells.

[Design, synthesis and anti-hBV evaluation of adefovir mono-L-amino acid ester, mono non-steroidal anti-inflammatory drugs carboxylic ester prodrugs].

A series of adefovir mono-L-amino acid esters, mono non-steroidal anti-inflammatory drugs carboxylic ester prodrugs with more potent anti-HBV activity and lower nephrotoxicity were designed and synthesized. Adefovir bis (L-amino acid) ester was used as lead compound, according to pathological and pharmacological findings that non-steroidal anti-inflammatory drugs can effectively inhibit the organic anion transporter 1 (hOAT1)-mediated adefovir phosphonic acid pairs of anion transport across tubular basement membrane thereby reducing the nephrotoxicity of adefovir. Flatten design principle was used to introducing non-steroidal anti-inflammatory drugs structural fragments to design and synthesize target adefovir mixture ester prodrugs.

Rapid screening and identification of caffeic acid and its esters in Erigeron breviscapus by ultra-performance liquid chromatography/tandem mass spectrometry.

Caffeic acid and its esters (CAEs) are widely distributed in the plant kingdom and have been reported to elicit a wide range of exceptional biological activities. Present methods for screening and characterization of CAEs normally need the use of liquid chromatography diode-array detection/multistage mass spectrometry (LC-DAD/MS(n)). In this report, a rapid and efficient method coupling ultra-performance liquid chromatography (UPLC) with fragment-targeted multi-reaction monitoring (MRM) has been developed for screening CAEs in a crude extract of Erigeron breviscapus, while a UPLC/quasi-MS(n) method has been applied in the structural identification of these compounds.

[Design, synthesis and anti-HBV activity of L-amino acid ester prodrugs of acyclic nucleoside phosphonates].

To design and synthesis a series of novel L-amino acid esters prodrugs of acyclic nucleoside phosphonates with more potent anti-HBV activity, adefovir dipivoxil was used as lead compound, according to the results of enhanced oral bioavailability and antiviral activities of nucleoside L-amino acid ester prodrugs. Eleven novel L-amino acid ester prodrugs of acyclic nucleoside phosphonates were designed and synthesized, their anti-HBV activities were evaluated in HepG2 2.2.

[Design, synthesis and vasorelaxant activity of R, S-1-(substituted phenyl)-4-[3-(naphtha-1-yl-oxy)-2-hydroxypropyl]-piperazine derivatives].

According to the results of activity-structure relationship (SAR) studies of alpha1-adrenoceptor antagonists hydantoin-phenylpiperazine and benzimidazo-arypiperazine derivatves, to design and synthesize a series of novel phenylpiperazine alpha1-adrenoceptor antagonists with more potent vasorelaxant activity, active metabolites of naftopidil were used as lead compounds. Ten novel R,S-1-substituted phenyl-4-[3-(naphthal-yl-oxy)-2-hydroxy propyl]-piperazine were designed and synthesized, their vasorelaxant activity was evaluated by calculating inhibition rate of phenylephrine-induced vasocontration of rabbit artery trips. Five compounds exhibited vasorelaxant activity, and compound 16 showed significant vasorelaxant activity in vitro.