Synthesis of 4-Alkylated 1,4-Dihydropyridines: Fe(II)-Mediated Oxidative Cascade Cyclization Reaction of Cyclic Ethers with Enaminones.

Syntheses of highly functionalized 4-alkylated 1,4-dihydropyridines (1,4-DHPs) from cyclic ethers and enaminones via iron(II)-mediated oxidative free radical cascade C(sp3)-H bond functionalization/C(sp3)-O bond cleavage/cyclization reaction have been first developed. This novel synthetic strategy offers an alternative method for the construction of 1,4-DHPs by using esters as the C4 sources, as well as expands the application of ethers in heterocycle synthesis.

Fe-mediated oxidative cascade [1 + 2 + 3]-cyclization/esterification reaction: synthesis of 4-alkylated 1,4-dihydropyridines.

An Fe-mediated four-component reaction of enaminones, anhydrides and tetrahydrofuran through a cascade [1 + 2 + 3]-cyclization/esterification process is presented. This protocol provides a new and effective method to construct 4-alkylated 1,4-dihydropyridines with an ester fragment. Cyclic ether is employed as the C4 source of 1,4-dihydropyridines for the first time.

Diagnostic performance of the metagenomic next-generation sequencing in lung biopsy tissues in patients suspected of having a local pulmonary infection.

PURPOSE: This study aims to evaluate the diagnostic application and performance of the metagenomic next-generation sequencing (mNGS) in patients suspected of local pulmonary infection by comparing it to the traditional pathogen detection methods in lung tissue specimens obtained by a computerized tomography-guided biopsy (CT-guided biopsy). METHODS: We retrospectively reviewed patients, admitted to the First Affiliated Hospital of Wenzhou Medical University, China from May 2018 to December 2020, who were suspected of local pulmonary infection. All cases received a CT-guided lung biopsy, tissue samples were sent both for conventional examinations (CE) and mNGS tests. The sensitivity and specificity of the two diagnostic approaches were compared. RESULTS: 106 patients enrolled, 76 patients were diagnosed with a pulmonary infection. Among 49 patients with identified pathogens, CE confirmed pathogenic infections in 32 cases. Mycobacterium spp. and fungi accounted for 37.5% (12/32) and 28.1% (9/32), respectively, with bacteria 34.4% (11/32). The mNGS examination detected extra pathogenic microorganisms in 22 patients that were consistent with the patients' clinical and radiographic pictures. The sensitivity of mNGS was 53.9% vs. 42.1% for the CE, while the specificity was 56.7% versus 96.7%. For detection rate, mNGS was significantly superior to CE in bacterial (96.3% vs. 40.7%, p < 0.05), and mixed infections (100% vs. 50%, p < 0.05), but inferior to CE in fungal (60% vs. 90%, p > 0.05) and Mycobacterium spp. infections (66.7% vs. 100%, p > 0.05) with no significant difference. Among 31 cases diagnosed with lung abscess, the diagnostic performance of the detection rate was 67.7% (21/31) in favour of mNGS compared to 29.0% (9/31) for CE (p < 0.05). Most polymicrobial infections were induced by anaerobic species that coexisted with Streptococcus constellatus. And Klebsiella pneumoniae was the most common isolated monomicrobial infection. CONCLUSIONS: The most commonly detected causative pathogens for local pulmonary infections were bacteria, Mycobacterium spp. and fungi. Compared with the CE, the advantages of mNGS in the pathogens detection lie in the discovery of bacterial and mixed infections, as well as in the detection of lung abscess. Conversely, mNGS is not good enough to be recommendable for the detection of Mycobacterium spp. and fungi.

[Analysis of chemical constituents in classical prescription Danggui Buxue Decoction based on RP-Q-TOF-MS and HILIC-Q-TOF-MS].

The chemical constituents of classical prescription Danggui Buxue Decoction were analyzed by reversed-phase(RP) chromatography and hydrophilic interaction chromatography(HILIC) coupled with quadrupole time-of-flight mass spectrometry. RP separation of Danggui Buxue Decoction was performed on ACQUITY UPLC HSS T3(2.1 mm×100 mm, 1.8 µm), while HILIC separation was on Waters BEH Amide(2.1 mm×100 mm, 1.7 µm). Mass spectrometry(MS) data were acquired in both negative and positive ion modes. Chemical constituents of Astragali Radix and Angelicae Sinensis Radix were searched from Reaxys and thus the in-house library was established. MS data were further analyzed by MassLynx 4.1 combined with in-house library, HMDB, Reaxys, and comparison with reference substances. In conclusion, a total of 154 compounds were identified and characterized: 16 saponins, 44 flavonoids, 10 phthalides, 7 phenylpropanoids, 15 bases and the corresponding nucleosides, 30 oligosaccharides, and 32 other compounds. Among them, 65 compounds were detected by HILIC-MS/MS. This study provides experimental evidences for the material basis research, quality control, and preparation development of Danggui Buxue Decoction and a reference method for comprehensive characterization of Chinese medicine decoctions typified by classical prescriptions.

[Identification of chemical constituents of Xiaochengqi Decoction by UPLC-Q-TOF/Fast DDA combined with UNIFI software].

Based on the combination of ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry(UPLC-Q-TOF) and Waters UNIFI software, the chemical constituents of the classic prescription Xiaochengqi Decoction were qualitatively analyzed and identified. The UPLC conditions are as follows: Acquity HSS T3 reverse phase column(2.1 mm ×100 mm, 1.8 µm), column temperature of 30 ℃, mobile phase of 0.1% formic acid aqueous solution(A)-acetonitrile(B), and flow rate of 0.3 mL·min~(-1). High-resolution MS data of Xiaochengqi Decoction were collected in ESI~(+/-) modes by Fast DDA. The structures of the chemical constituents were tentatively characterized or identified by UNIFI software according to the retention time of reference standards and characteristic fragment ions in MS profile, and literature data. A total of 233 components in Xiaochengqi Decoction were identified, with 93 from wine-processed Rhei Radix et Rhizoma, 104 from bran-processed Aurantii Fructus Immaturus, and 36 from ginger-processed Magnoliae Officinalis Cortex. These 233 components included anthraquinones, flavonoids, lignans, alkaloids, coumarins, and phenylethanoid glycosides. The result provided experimental evidence for the further study on establishment of quality standard and product development of the formula.

Might life-threatening acute pulmonary edema occur after using recombinant tissue plasminogen activator? A case report.

BACKGROUND: Recombinant tissue plasminogen activator (rt-pa) is the first-line drug for the treatment of acute ischemic stroke, and can lead to some complications.There were rare reports of death due to acute pulmonary edema during rt-pa thrombolysis treatment. CASE PRESENTATION: This study reports a 30-year-old man was diagnosed with acute ischemic stroke and underwent rt-pa thrombolytic therapy. Finally he died despite active rescue. CONCLUSIONS: The autopsy revealed that he died of acute pulmonary edema. This case suggests that it is necessary to pay close attention to the changes of vital signs during thrombolysis and be aware of possibility of pulmonary edema during thrombolysis.

Synthesis and biological evaluation of novel 3-benzylcoumarin-imidazolium salts.

A series of novel 3-benzylcoumarin-imidazolium salts were prepared and evaluated in vitro against a panel of human tumor cell lines. The results showed that the existence of 5,6-dimethyl-benzimidazole ring and substitution of the imidazolyl-3-position with a naphthylacyl group were vital for modulating cytotoxic activity. Notably, compound 38 was found to be the most potent derivative with IC50 values of 2.04-4.51 µM against five human tumor cell lines, while compound 34 were more selective to SW-480 cell lines with IC50 value 40.0-fold lower than DDP. Mechanism of action studies indicated that compound 38 can cause the G0/G1 phase cell cycle arrest and apoptosis in SMMC-7721 cell lines.

Efficient construction of C-N and C-S bonds in 2-iminothiazoles via cascade reaction of enaminones with potassium thiocyanate.

A novel and highly efficient protocol has been developed for the regioselective synthesis of 2-iminothiazole derivatives with potential biochemical interest by the reaction of enaminones, potassium thiocyanate (KSCN), and N-bromo succinimide (NBS) under mild conditions. The reaction proceeds via the formation of α-bromo enaminones as a versatile intermediate followed by thiocyanation/intramolecular cyclization in a one pot manner. The developed method is particularly attractive due to various advantages including operational simplicity, mild conditions, being catalyst free, and high bond-forming efficiency. The proposed protocol explores the synthetic routes of thiazoles by using various functional enaminones.

Systematical characterization of gypenosides in Gynostemma pentaphyllum and the chemical composition variation of different origins.

Gynostemma pentaphyllum (Thunb.) Makino is an herbaceous plant of Cucurbitaceae family, which has been widely used as an herbal tea and traditional Chinese medicine. Since its saponins are similar to ginsenosides and have a wide range of activities, it has attracted wide interest. However, there are still a large number of unknown saponins that have not been isolated, especially some trace gypenosides. In the present study, a HILIC × RP offline two-dimensional liquid separation combined with a multimode data acquisition was developed for the systematical characterization of gypenosides. On top of the negative mode information, considering that saponins are prone to in-source fragmentations in positive ion mode, a precursor ion list data acquisition method was used for the targeted acquisition of multistage positive data. Reference herbal drug was taken as a golden sample to probe the chemical composition of G. pentaphyllum. The mixed sample of commercially available samples were also analyzed in parallel. Furthermore, the chemical compositions of commercially available samples from different sources were compared. In total, 1108 saponins were characterized, among which 588 were accurately characterized, with 574 identified in the reference herbal drug and 700 in the mixed commercially available samples. The commercially available samples showed great composition variation. These findings clarified the material basis and provided clues for quality control of G. pentaphyllum.

Prospective evaluation of FibroScan for the diagnosis of hepatic fibrosis compared with liver biopsy/AST platelet ratio index and FIB-4 in patients with chronic HBV infection.

BACKGROUND: The FibroScan (FS), the aspartate aminotransferase-to-platelet ratio index (APRI), and the FIB-4 index are simple and inexpensive methods to detect liver fibrosis. AIMS: The primary objective was to evaluate the performance of FS for the noninvasive diagnosis of hepatic fibrosis in Western Chinese patients with chronic hepatitis B virus (HBV) infection compared with APRI and FIB-4; the secondary objective was to determine liver stiffness measurement (LSM) cutoff values for the noninvasive diagnosis of significant fibrosis and liver cirrhosis. METHODS: Overall, 175 consecutive patients with chronic HBV infection, successful liver biopsy, and alanine aminotransferase levels ≤2× ULN were prospectively studied. Liver fibrosis was graded by an independent pathologist using the METAVIR (F0-F4) classification. APRI and FIB-4 were calculated from laboratory data. RESULTS: The area under receiver operating characteristics curves (AUROC) for LSM for significant fibrosis (METAVIR F2-3) and cirrhosis (F4) was 0.95 (95% confidence interval, 0.91-0.98) and 0.98 (0.96-0.99), respectively. For the detection of significant fibrosis and cirrhosis, the AUROC of APRI were 0.81 (0.74-0.87) and 0.83 (0.77-0.90); the AUROC of FIB-4 were 0.86 (0.80-0.91) and 0.77 (0.68-0.85). FS optimal cutoff values for the identification of significant fibrosis and cirrhosis were 7.9 and 13.8 kPa, respectively. CONCLUSIONS: FS is a reliable predictor of significant fibrosis and cirrhosis in Western Chinese patients with chronic HBV infection, and is superior to APRI and FIB-4. FS cutoff values could be considered as clinical reference for detecting significant fibrosis and cirrhosis.

[Accuracy of FibroScan for the diagnosis of liver fibrosis influenced by serum alanine aminotransferase levels in patients with chronic hepatitis B].

OBJECTIVE: To analyze whether or not the accuracy of liver stiffness measurement (LSM) with transient elastography (FibroScan) for the diagnosis of liver fibrosis influenced by serum alanine aminotransferase (ALT) levels in patients with chronic hepatitis B. METHODS: 213 consecutive CHB patients who underwent liver biopsy and LSM were enrolled and divided into three groups by the criteria of ALT < 1 x ULN, 1 x ULN ≤ ALT < 2 x ULN and ALT ≥ 2 x ULN. The areas under the receiver operating curve(AUC) were analyzed and the accuracy of FibroScan for the diagnosis of liver fibrosis were detected in the three groups. RESULTS: Significant correlation existed between the stages of liver fibrosis and LSM (rs = 0.773, 0.889 and 0.412, P < 0.05). AUCs of LSM in all patients for significant fibrosis (F ≥ 2, F0-1 vs F2-4) and cirrhosis (F = 4, F0-3 vs F4) were 0.916 and 0.971 respectively. The accuracy of diagnosis for significant fibrosis and cirrhosis were 84.0% and 93.4% respectively. AUCs of LSM in ALT < 1 x ULN, 1 x ULN ≤ ALT < 2 x ULN and ALT ≥ 2 x ULN groups for significant fibrosis were 0.939, 0.967 and 0.687 respectively. The sensitivity of the three groups was 90.0%, 89.7% and 47.8% respectively. The accuracies of the three groups was 90.5%, 93.9% and 68.4% respectively. The AUC, sensitivity and accuracy of ALT ≥ 2 x ULN group for significant fibrosis were significantly lower than the other two groups. AUCs of LSM in three groups for cirrhosis were 0.970, 0.985 and 0.952 respectively. The sensitivities of the three groups were 93.8%, 100% and 100% respectively. The accuracies of the three groups were 88.9%, 95.9% and 92.1% respectively. The AUCs, sensitivity and accuracy for cirrhosis of the three groups didn't change with elevated ALT. CONCLUSIONS: Transient elastography (FibroScan) is a reasonable noninvasive tool to diagnose significant fibrosis, especially liver cirrhosis in CHB patients. The accuracy of FibroScan for diagnosis of liver cirrhosis may not be influenced by elevated ALT. While in ALT ≥ 2 x ULN group, the accuracy of FibroScan for diagnosis of significant fibrosis was significantly lower as compared to the ALT ≤ 2 x ULN groups.

Highly Regioselective and Chemoselective [3 + 3] Annulation of Enaminones with ortho-Fluoronitrobenzenenes: Divergent Synthesis of Aposafranones and Their N-Oxides.

A base-promoted unprecedented strategy for the regioselective and chemoselective divergent synthesis of highly functionalized aposafranones and their N-oxides has been developed from the [3 + 3] annulation of enaminones with o-fluoronitrobenzenenes. This novel synthetic strategy offers an alternative method for the construction of aposafranones and their N-oxides are meaningful in the fields of both biology and organic synthesis. The established protocol explores the annulation scope of enaminones, and it expands the application of nitro-based cyclization.

Three-Component One-Pot Synthesis of Highly Functionalized Bis-Indole Derivatives.

In this study, we detail the development of a concise and efficient three-component protocol for the regioselective synthesis of highly functionalized bis-indoles through a one-pot, two-step sequential process starting from enaminones 1, indoles 2, and acenaphthylene-1,2-dione 3 that is catalyzed by piperidine and p-methyl benzenesulfonic acid. This protocol has several advantages including simplicity of experimental operation, high efficiency of bond formation, ready availability and low cost of starting materials, environmentally benign conditions, and target molecular diversity.

Divergent synthesis of dual 1,4-dihydropyridines with different substituted patterns from enaminones and aldehydes through domino reactions.

A concise and efficient protocol for the regioselective synthesis of dual 1,4-dihydropyridines with several substituted patterns has been developed from a cascade cyclization of enaminones and aldehydes in different media (EtOH/CH3CN). The one-pot cascade reaction involves at least five reactive sites and generates multiple C-C and C-N bonds. The established protocol explores the chemistry of enaminones by employing their three reactive sites. The method has several advantages including mild conditions, operational simplicity, and high bond-forming efficiency. It may offer promise in a variety of biochemical applications.

Green synthesis of new pyrrolidine-fused spirooxindoles via three-component domino reaction in EtOH/H2O.

An efficient, green and sustainable approach for the synthesis of novel polycyclic pyrrolidine-fused spirooxindole compounds was developed. The synthesis included a one-pot, three-component, domino reaction of (E)-3-(2-nitrovinyl)-indoles, isatins and chiral polycyclic α-amino acids under catalyst-free conditions at room temperature in EtOH-H2O. The salient features of this methodology are eco-friendliness, high yields and the ease of obtaining target compounds without the involvement of toxic solvents and column chromatography. These novel polycyclic pyrrolidine-fused spirooxindoles provide a collection of structurally diverse compounds that show promise for future bioassays and medical treatments.