Design, synthesis, in vitro and in silico evaluation of anti-colorectal cancer activity of curcumin analogues containing 1,3-diphenyl-1H-pyrazole targeting EGFR tyrosine kinase.

Recent studies have shown that monocarbonyl analogues of curcumin (MACs) and 1H-pyrazole heterocycle both demonstrated promising anticancer activities, in which several compounds containing these scaffolds could target EGFR. In this research, 24 curcumin analogues containing 1H-pyrazole (a1-f4) were synthesized and characterized by using modern spectroscopic techniques. Firstly, synthetic MACs were screened for cytotoxicity against human cancer cell lines such as SW480, MDA-MB-231 and A549, from which the 10 most potential cytotoxic compounds were identified and selected. Subsequently, the selected MACs were further screened for their inhibition against tyrosine kinases, which showed that a4 demonstrated the most significant inhibitory effects on EGFRWT and EGFRL858R. Based on the results, a4 further demonstrated its ability to cause morphological changes, to increase the percentage of apoptotic cells, and to increase caspase-3 activity, suggesting its apoptosis-inducing activity on SW480 cells. In addition, the effect of a4 on the SW480 cell cycle revealed its ability to arrest SW480 cells at G2/M phase. In subsequent computer-based assessments, a4 was predicted to possess several promising physicochemical, pharmacokinetic, and toxicological properties. Via molecular docking and molecular dynamics simulation, a reversible binding mode between a4 and EGFRWT, EGFRL858R, or EGFRG719S, remained stable within the 100-ns simulation due to effective interactions especially the hydrogen bonding with M793. Finally, free binding energy calculations suggested that a4 could inhibit the activity of EGFRG719S more effectively than other EGFR forms. In conclusion, our work would provide the basis for the future design of promising synthetic compounds as anticancer agents targeting EGFR tyrosine kinase.

Synthesis, Biological Evaluation, and Molecular Modeling Studies of 1-Aryl-1H-pyrazole-Fused Curcumin Analogues as Anticancer Agents.

Addressing the growing burden of cancer and the shortcomings of chemotherapy in cancer treatment are the current research goals. Research to overcome the limitations of curcumin and to improve its anticancer activity via its heterocycle-fused monocarbonyl analogues (MACs) has immense potential. In this study, 32 asymmetric MACs fused with 1-aryl-1H-pyrazole (7a-10h) were synthesized and characterized to develop new curcumin analogues. Subsequently, via initial screening for cytotoxic activity, nine compounds exhibited potential growth inhibition against MDA-MB-231 (IC50 2.43-7.84 µM) and HepG2 (IC50 4.98-14.65 µM), in which seven compounds showing higher selectivities on two cancer cell lines than the noncancerous LLC-PK1 were selected for cell-free in vitro screening for effects on microtubule assembly activity. Among those, compounds 7d, 7h, and 10c showed effective inhibitions of microtubule assembly at 20.0 µM (40.76-52.03%), indicating that they could act as microtubule-destabilizing agents. From the screening results, three most potential compounds, 7d, 7h, and 10c, were selected for further evaluation of cellular effects on breast cancer MDA-MB-231 cells. The apoptosis-inducing study indicated that these three compounds could cause morphological changes at 1.0 µM and could enhance caspase-3 activity (1.33-1.57 times) at 10.0 µM in MDA-MB-231 cells, confirming their apoptosis-inducing activities. Additionally, in cell cycle analysis, compounds 7d and 7h at 2.5 µM and 10c at 5.0 µM also arrested MDA-MB-231 cells in the G2/M phase. Finally, the results from in silico studies revealed that the predicted absorption, distribution, metabolism, excretion, and the toxicity (ADMET) profile of the most potent MACs might have several advantages in addition to potential disadvantages, and compound 7h could bind into (ΔG -10.08 kcal·mol-1) and access wider space at the colchicine-binding site (CBS) than that of colchicine or nocodazole via molecular docking studies. In conclusion, our study serves as a basis for the design of promising synthetic compounds as anticancer agents in the future.

A review on functional nanoarchitectonics nanocomposites based on octahedral metal atom clusters (Nb6, Mo6, Ta6, W6, Re6): inorganic 0D and 2D powders and films.

This review is dedicated to various functional nanoarchitectonic nanocomposites based on molecular octahedral metal atom clusters (Nb6, Mo6, Ta6, W6, Re6). Powder and film nanocomposites with two-dimensional, one-dimensional and zero-dimensional morphologies are presented, as well as film matrices from organic polymers to inorganic layered oxides. The high potential and synergetic effects of these nanocomposites for biotechnology applications, photovoltaic, solar control, catalytic, photonic and sensor applications are demonstrated. This review also provides a basic level of understanding how nanocomposites are characterized and processed using different techniques and methods. The main objective of this review would be to provide guiding significance for the design of new high-performance nanocomposites based on transition metal atom clusters.

A high-throughput peptidomic strategy to decipher the molecular diversity of cyclic cysteine-rich peptides.

Cyclotides are plant cyclic cysteine-rich peptides (CRPs). The cyclic nature is reported to be gene-determined with a precursor containing a cyclization-competent domain which contains an essential C-terminal Asn/Asp (Asx) processing signal recognized by a cyclase. Linear forms of cyclotides are rare and are likely uncyclizable because they lack this essential C-terminal Asx signal (uncyclotide). Here we show that in the cyclotide-producing plant Clitoria ternatea, both cyclic and acyclic products, collectively named cliotides, can be bioprocessed from the same cyclization-competent precursor. Using an improved peptidomic strategy coupled with the novel Asx-specific endopeptidase butelase 2 to linearize cliotides at a biosynthetic ligation site for transcriptomic analysis, we characterized 272 cliotides derived from 38 genes. Several types of post-translational modifications of the processed cyclotides were observed, including deamidation, oxidation, hydroxylation, dehydration, glycosylation, methylation, and truncation. Taken together, our results suggest that cyclotide biosynthesis involves 'fuzzy' processing of precursors into both cyclic and linear forms as well as post-translational modifications to achieve molecular diversity, which is a commonly found trait of natural product biosynthesis.