Latest ArticlesA pair of neolignan enantiomers with an unprecedented carbon skeleton, (+)-/(—)-angelignanine [(+)-/(—)-1], was isolated as minor components of an aqueous extract of the Angelica sinensis root heads (guitou). Their structures were determined by spectroscopic data analysis and the absolute configurations were assigned by the circular dichroism (CD) exciton chirality method as well as electronic CD quantum calculations. The enantiomers represent the first 2, 7'-cyclo-8, 9'-neolignans, of which biosynthetic pathways originating from precursors ferulic acid and coniferyl alcohol is proposed. In an in vivo test, both the enantiomers showed significant hypnotic effects at a dose of 10 mg/kg (i.g.).
The RAS/mitogen-activated protein kinase (MAPK) pathway disorder induced by the missense mutations in the tyrosine-protein phosphatase non-receptor type 11 (PTPN11) gene which resulted in the non-receptor protein tyrosine phosphatase SHP2 dysfunction has been reported in many lung cancer cases. Moreover, the Src homology region 2 (SH2)-containing protein tyrosine phosphatase 2 (SHP2) mutation or deletion triggers multiple signaling pathway dysfunctions including RAS/MAPK, RAS/extracellular-signal-regulated kinase (ERK), phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT), Janus kinase/signal transducers and activators of transcription (JAK/STAT) and Hippo/yes-associated protein (YAP) which affect the expression of growth factors, cytokines and hormones. In recent years, the developing of the small molecule SHP2 inhibitors received a lot of attention. In this review, we summarize the recent years' progresses of the SHP2 inhibitors development for the lung cancer treatment.
The increasing incidence of osteoarthritis (OA) seriously affects life quality, posing a huge socioeconomic burden. Tissue engineering technology has become a hot topic in articular cartilage repair as one of the key treatment methods to alleviate OA. Hydrogel, one of the most commonly used scaffold materials, can provide a good extracellular matrix microenvironment for seed cells such as bone marrow mesenchymal stem cells (BMSCs), which can promote cartilage regeneration. However, the low homing rate of stem cells severely limits their role in promoting articular cartilage regeneration. Stromal cell-derived factor- 1α (SDF-1α) plays a crucial role in the activation, mobilization, homing, and migration of MSCs. Herein, a novel injectable chemotaxis hydrogel, composed of chitosan-based injectable hydrogel and embedding SDF-1α-loaded nanodroplets (PFP@NDs-PEG-SDF-1α) was designed and fabricated. The ultrasound was then used to augment the injectable chemotaxis hydrogel and promote the homing migration of BMSCs for OA cartilage repair. The effect of ultrasound augmenting injectable PFP@NDs-PEG-SDF-1α/hydrogel on the migration of BMSCs was verified in vitro and in vivo, which remarkably promotes stem cell homing and the repair of cartilage in the OA model. Therefore, the treatment strategy of ultrasound augmenting injectable chemotaxis hydrogel has a bright potential for OA articular cartilage repair.
Exosomes have attracted widespread interest due to their inherent advantages in tumor diagnosis and treatment monitoring. However, it is still a big challenge for highly sensitive and specific detection of exosome in real complexed samples. Herein, a molecular recognition triggered aptazyme cascade strategy was developed for ultrasensitive detection of cancer exosomes in clinical serum samples. In this design, one target exosome could capture a large quantity of aptazymes for the first-step signal amplification. And then the captured aptazyme was activated and recycled to release the fluorophore-abelled substrate strand for a cascaded signal amplification. Notably, the activation of aptazyme only occurs when it has bound with target exosome, ensuring a low background. The experimental results show that the limit of detection (LOD) and the limit of quantification (LOQ) are 3.5×103 particles/μL and 1.7×104 particles/μL, respectively, which is comparable to the results of most existed fluorescence-based exosome probes. Moreover, this assay possesses high specificity to distinguish exosomes derived from other cell lines. Furthermore, this fluorescence probe was utilized in cancer patient and healthy serum samples successfully, suggesting its great potential for clinical diagnosis and biological studies.
The improvement in accuracy of in vitro diagnosis has always been the focus of early screening of thyroid dysfunction. We constructed a microfluidic chip based on a polystyrene polymer substrate. Total triiodothyronine (TT3), total thyroxine (TT4), free triiodothyronine (FT3), free thyroxine (FT4), and thyrotropin (TSH) in human whole blood samples were analysed by fluorescence immunoassay to evaluate thyroid function. The results indicate that the microfluidic chip shows a good linear relationship in the detection of TT3, TT4, FT3, FT4, and TSH standards, and the correlation coefficient (r) is not less than 0.9900. In addition, the chip also has strong anti-interference (RSD% ≤ 5%) and good repeatability (CV ≤ 8%), and its inter-batch differences are small (CV ≤ 15%). The results of practical application in clinical thyroid function measurement indicated its high accuracy (r ≥ 0.9900). It provides a new method for the determination of thyroid function and lays a foundation for subsequent clinical application.
A Zn-containing graphite carbon (Zn-GC) with uniform Zn metal sites and hierarchical pore structure was obtained by pyrolysis of Zn-based metal organic framework (MOF). Zn-GC exhibited excellent adsorption capacity and reproducibility for formaldehyde. The adsorption capacity of Zn-GC was 736 times that of commercial activated carbon and 5.6 times that of ZSM-5 adsorbents. The characterization and experimental results showed that the surface chemical characteristics of the adsorption material play an important role in the adsorption performance. The superior performance was attributed to Zn metal sites and oxygen-containing functional groups on the MOF derivative as well as hierarchical pore structure. The material showed a great potential in the field of organic pollutant removal.
A convenient synthetic protocol for the hexasubstituted benzene derivatives was successfully developed by DABCO promoted domino reaction of arylidene malononitrile with two molecules of dialkyl but-2-ynedioates. The domino reaction resulted in tetraalkyl 6-cyano-[1, 1'-biphenyl]-2, 3, 4, 5-tetracarboxylates in good to high yields. This formal [2 + 2 + 2] cycloaddition was believed to proceed with sequential nucleophilic addition, Michael addition, annulation and aromatization processes.
Three sesquiterpene-based meroterpenoids psiguamers A–C (1–3) with new skeletons were isolated from Psidium guajava leaves. Compounds (±)-1 and (±)-2 were two pairs of humulene-derived meroterpenoids bearing a rare methylated benzoylphloroglucinol unit, while 3 was an unprecedented adduct of bicyclogermacrene and methylated benzoylphloroglucinol. Their structures were determined based on comprehensive analyses of spectroscopic data, calculated electronic circular dichroism (ECD) spectra, total synthesis, and X-ray crystallographic data. The biomimetic synthesis of (±)-1 and (±)-2 was achieved. Compound (+)-1 exhibited cytotoxic activities against five human tumor cell lines (HCT-116, HepG2, BGC-823, A549, and U251), with IC50 values of 2.94, 9.01, 6.45, 5.42, and 5.33 μmol/L, respectively.
The reactive oxygen species (ROS) are tightly associated with endoplasmic reticulum (ER) stress. Thus, the deep and visual insight of aberrant ROS fluctuations in the ER can help us better investigate the ER stress-associated pathology. In this work, a fluorescent probe ERC for HOCl detection in the ER based on phenothiazine-derived coumarin platform was developed. In the presence of HOCl, ERC exhibited an emission change from 609 nm to 503 nm within seconds. It also showed high sensitivity (0.44 μmol/L) and superb photostability. Significantly, ERC displayed low cytotoxicity, good cell membrane permeability, and appreciable ER-targetability. Ultimately, the probe was successfully utilized to image exogenous and endogenous HOCl in living cells and reveal the HOCl burst in cisplatin-treated cancer cells.
The recent electrocatalytic three-component annulation-halosulfonylation of 1, 6-enynes toward 1-indanones is highlighted.