In this short review, including 113 references, issues related to dibenzo[b,f]oxepine derivatives are presented. Dibenzo[b,f]oxepine scaffold is an important framework in medicinal chemistry, and its derivatives occur in several medicinally relevant plants. At the same time, the structure, production, and therapeutic effects of dibenzo[b,f]oxepines have not been extensively discussed thus far and are presented in this review. This manuscript addresses the following issues: extracting dibenzo[b,f]oxepines from plants and its significance in medicine, the biosynthesis of dibenzo[b,f]oxepines, the active synthetic dibenzo[b,f]oxepine derivatives, the potential of dibenzo[b,f]oxepines as microtubule inhibitors, and perspective for applications of dibenzo[b,f]oxepine derivatives. In conclusion, this review describes studies on various structural features and pharmacological actions of dibenzo[b,f]oxepine derivatives.

Cancer is one of the most common causes of human death worldwide; thus, numerous therapies, including chemotherapy, have been and are being continuously developed. In cancer cells, an aberrant mitotic spindle—a microtubule-based structure necessary for the equal splitting of genetic material between daughter cells—leads to genetic instability, one of the hallmarks of cancer. Thus, the building block of microtubules, tubulin, which is a heterodimer formed from α- and β-tubulin proteins, is a useful target in anti-cancer research. The surface of tubulin forms several pockets, i.e., sites that can bind factors that affect microtubules’ stability. Colchicine pockets accommodate agents that induce microtubule depolymerization and, in contrast to factors that bind to other tubulin pockets, overcome multi-drug resistance. Therefore, colchicine-pocket-binding agents are of interest as anti-cancer drugs. Among the various colchicine-site-binding compounds, stilbenoids and their derivatives have been extensively studied. Herein, we report systematic studies on the antiproliferative activity of selected stilbenes and oxepine derivatives against two cancer cell lines—HCT116 and MCF-7—and two normal cell lines—HEK293 and HDF-A. The results of molecular modeling, antiproliferative activity, and immunofluorescence analyses revealed that compounds 1a, 1c, 1d, 1i, 2i, 2j, and 3h were the most cytotoxic and acted by interacting with tubulin heterodimers, leading to the disruption of the microtubular cytoskeleton.

Plant polysaccharides have gained interest in medical research for their ability to suppress various diseases, including cancer. However, information on some plant polysaccharides is yet to be uncovered. In this study, we screened crude polysaccharides extracted from six different plants for their antioxidative and antiproliferative activities. Crude polysaccharides were isolated from different parts of some plants using the established extraction protocol. The crude polysaccharides were evaluated for their chemical composition (protein, total sugar, and phenolics), free radical-scavenging activities, and antiproliferative activities against breast cancer MCF-7 cells as well as non-cancerous cells, i.e., human fibroblast MRC-5 cells and Cercopithecus aethiops kidney Vero cells, via an MTT assay and CM20 Incubation Monitoring System (Olympus) for MCF-7. The investigated crude polysaccharides showed significant variations in their chemical constituents and antioxidative properties. Only Moringa seed crude polysaccharide extracts showed significant antiproliferative activities at various concentrations, with an IC₅₀ value of 0.061 mg/mL, which was about 2.6 folds higher on MRC-5 and Vero cell lines. The antiproliferative activities toward cancer cell lines and lack of significant toxicity in the case of normal cells indicate that this extract may be promising as a valuable source for novel cancer therapy.

Compounds that disrupt microtubule dynamics, such as colchicine, paclitaxel, or Vinca alkaloids, have been broadly used in biological studies and have found application in clinical anticancer medications. However, their main disadvantage is the lack of specificity towards cancerous cells, leading to severe side effects. In this paper, we report the first synthesis of 12 new visible light photoswitchable colchicine-based microtubule inhibitors AzoCols. Among the obtained compounds, two photoswitches showed light-dependent cytotoxicity in cancerous cell lines (HCT116 and MCF-7). The most promising compound displayed a nearly twofold increase in potency. Moreover, dissimilar inhibition of purified tubulin polymerisation in cell-free assay and light-dependent disruption of microtubule organisation visualised by immunofluorescence imaging sheds light on the mechanism of action as microtubule photoswitchable destabilisers. The presented results provide a foundation towards the synthesis and development of a novel class of photoswitchable colchicine-based microtubule polymerisation inhibitors.

The synthesis of biphenylmethoxydibenzo[b,f]oxepine or photoswitchable fluorinated dibenzo[b,f]oxepine derivatives with one or three azo bonds, potential microtubule inhibitors, is described. Our studies provide a concise method for constructing derivatives containing the dibenzo[b,f]oxepine skeleton. An analysis of products was run using experimental and theoretical methods. Next, we evaluated the E/Z isomerization of azo-dibenzo[b,f]oxepine derivatives, which could be photochemically controlled using visible-wavelength light.

Chalcones have garnered significant research interest due to their various medical bioactivities. Several chalcone compounds have been approved for marketing and clinical use in the treatment of various diseases. A critical aspect of the action of chalcones is their effect on microtubules. They are considered an excellent target for chemotherapeutic agents for the treatment of cancer. Consequently, scientists are constantly developing novel chalcone drug agents and also innovative drug delivery strategies. In this manuscript, we report the first synthesis of 12 new visible-light-activated, photoswitchable chalcone-based microtubule inhibitors (17a–17l). Among the obtained compounds, one photoswitch demonstrated light-dependent cytotoxicity in the PC-3 cancer cell line. The IC₅₀ value of the Z conformer was determined to be 4.75 ± 1.00 μM after 48 h of treatment. The E conformer exhibited slightly lower activity compared to the Z conformer, with an IC₅₀ value of 5.80 ± 0.80 µM following 48 h of incubation. In this study, NMR and UV spectroscopy, along with computational methods, were employed.