Design, synthesis and biological evaluation of novel tubulin inhibitors targeting colchicine sites.

Tubulin, a potential target for antitumor drug discovery, contains three main binding sites for clinical inhibitors: colchicine, vinblastine, and paclitaxel. CA-4 has been reported to be a classic tubulin inhibitor targeting the colchicine site. Herein, based on the structural modification of CA-4, 48 novel compounds were designed and synthesized by selecting structural fragments with various biological activities to replace the cis double bond of CA-4. Among these compounds, compound 8p was the most effective tubulin inhibitor (IC50 = 65 nM aganist HepG2 cells). Immunofluorescence experiment confirmed the anti-tumor effect of 8p by destroying the network structure of microtubules. Further studies showed that 8p induced tumor cell apoptosis, arrested cell cycle, inhibited tumor cell migration and invasion.

Identification of novel non-toxic and anti-angiogenic α-fluorinated chalcones as potent colchicine binding site inhibitors.

α-Fluorinated chalcones were prepared and evaluated for their cell growth inhibitory properties against six human cancer cell lines. The most potent chalcone 4c demonstrated excellent selective toxicity against cancer cells versus normal human cells, with IC50 values at nanomolar concentration ranges against 5 cancer cell lines. A further study revealed that 4c could bind to the colchicine site of tubulin, disrupt the cell microtubule networks, and effectively inhibit tubulin polymerisation. Cellular-based mechanism studies elucidated that 4c arrested MGC-803 cell cycle at G2/M phase. In addition, 4c dose-dependently caused Caspase-induced apoptosis of MGC-803 cells through mitochondrial dysfunction. Notably, compound 4c was found to inhibit the HUVECs tube formation, migration, and invasion in vitro. Furthermore, our data suggested that treatment with 4c significantly reduced MGC-803 cells metastasis and proliferation in vitro. Overall, this work showed that chalcone hybrid 4c is a potent inhibitor of tubulin assembly with prominent anti-angiogenesis and anti-cancer properties.

Isolation and structural characterization of eight impurities in aztreonam.

To comply with regulatory requirements, it is necessary to detect and separate the impurities generated during aztreonam synthesis or storage. The chromatogram of aztreonam revealed eight major impurities, which were purified through medium-pressure reversed-phase column and preparative High Performance Liquid Chromatography (HPLC). Through high resolution electrospray ionization mass spectroscopy (HRESIMS), as well as one- and two-dimensional nuclear magnetic resonance (NMR), their structures were confirmed as aztreonam acetate (Ⅰ), desulfated aztreonam (Ⅱ), anti-aztreonam (Ⅲ), open-ring aztreonam (Ⅳ), open-ring desulfated aztreonam (Ⅴ), open-ring desulfated aztreonam ethyl ester (VI), cis-deamino open-ring desulfated aztreonam (VII), and trans-deamino open-ring desulfated aztreonam (Ⅷ). Their exact concentrations were determined through quantitative nuclear magnetic resonance (qNMR) technique. Structural elucidation of the eight impurities through 1H NMR, 13C NMR, the 1H-1H COSY, NOESY, HSQC, HMBC NMR and MS spectra was conducted. Especially, ⅥI and Ⅷ were identified as undescribed impurities here.

Angiogenesis, Anti-Tumor, and Anti-Metastatic Activity of Novel α-Substituted Hetero-Aromatic Chalcone Hybrids as Inhibitors of Microtubule Polymerization.

A library of new heteroaromatic ring-linked chalcone analogs were designed and synthesized of these, compound 7m with α-CH3 substitution and bearing a benzofuran ring, displaying the most potent activity, with IC50 values of 0.07-0.183 µM against three cancer cells. Its low cytotoxicity toward normal human cells and strong potency on drug-resistant cells revealed the possibility for cancer therapy. It also could moderately inhibit in vitro tubulin polymerization with an IC50 value of 12.23 µM, and the disruption of cellular architecture in MCF-7 cells was observed by an immunofluorescence assay. Cellular-based mechanism studies elucidated that 7m arrested the cell cycle at the G2/M phase and induced apoptosis by regulating the expression levels of caspases and PARP protein. Importantly, the compound 7 m was found to inhibit HUVEC tube formation, migration, and invasion in vitro. In vivo assay showed that 7m could effectively destroy angiogenesis of zebrafish embryos. Furthermore, our data suggested that treatment with 7m significantly reduced MCF-7 cell metastasis and proliferation in vitro and in zebrafish xenograft. Collectively, this work showed that chalcone hybrid 7m deserves further investigation as dual potential tubulin polymerization and angiogenesis inhibitor.

Effects of heat-sensitive moxibustion combined with naprapathy and warming needle moxibustion combined with naprapathy in patients with periarthritis of shoulder.

OBJECTIVE: To evaluate the effects of heat-sensitive moxibustion (HSM) combined with naprapathy and warming needle moxibustion (WNM) combined with naprapathy on shoulder function and serum levels of calcitonin gene-related peptide (CGRP), substance P (SP), tumor necrosis factor-α (TNF-α) and interleukin-2 (IL-2) in patients with periarthritis of shoulder (POS). METHODS: From July 2017 to July 2020, sixty patients with POS admitted to our hospital were selected as the study subjects, and divided into HSM group (n=29) receiving HSM combined with naprapathy and WNM group receiving WNM combined with naprapathy (n=31). The changes in shoulder function, degrees of pain and serum levels of CGRP, SP, TNF-α and IL-2 were compared between the two groups. RESULTS: After treatment, the scores of myodynamia, pain, range of motion (ROM) of shoulder joint and activities of daily living (ADLs) were improved in both groups (P<0.05), and the scores in HSM group were remarkably higher than those in WNM group (P<0.05). Visual analogue scale (VAS) scores after 3 courses of treatment were lower than those after 1 and 2 courses of treatment respectively (P<0.05), and the VAS scores in HSM group were markedly lower than those in WNM group after 1, 2, and 3 courses of treatment (P<0.05). After treatment, the serum levels of CGRP, SP, TNF-α and IL-2 were decreased in both groups (P<0.05), and the levels in HSM group were noticeably lower than those in WNM group (P<0.05). CONCLUSION: HSM combined with naprapathy is superior to WNM combined with naprapathy in inhibition of inflammatory factors of pain and serum inflammatory factors, alleviating the pain and promoting the restoration of shoulder function in patients with POS.

Reversible Covalent PROTACs: Novel and Efficient Targeted Degradation Strategy.

The proteolysis targeting chimeras (PROTACs), which are composed of a target protein binding moiety, a linker, and an E3 ubiquitin ligase binder, have been a promising strategy for drug design and discovery. Given the advantages of potency, selectivity, and drug resistance over inhibitors, several PROTACs have been reported in literature, which mostly focus on noncovalent or irreversible covalent binding to the target proteins. However, it must be noted that noncovalent or irreversible PROTACs have several drawbacks such as weak binding affinity and unpredictable off-target effects. Reversible covalent PROTACs, with properties of enhanced potency, selectivity, and long duration of action, have attracted an increasing amount of attention. Here, we propose a comparison between these three patterns and highlight that reversible covalent PROTACs could pave the way for a wide variety of challenging target degradations.