1H-benzimidazol-2-yl hydrazones with varying hydroxy and methoxy phenyl moieties were designed. Their effect on tubulin polymerization was evaluated in vitro on porcine tubulin. The compounds elongated the nucleation phase and slowed down the tubulin polymerization comparably to nocodazole. The possible binding modes of the hydrazones with tubulin were explored by molecular docking at the colchicine binding site. The anticancer activity was evaluated against human malignant cell lines MCF-7 and AR-230, as well as against normal fibroblast cells 3T3 and CCL-1. The compounds demonstrated a marked antineoplastic activity in low micromolar concentrations in both screened in vitro tumor models. The most active were the trimethoxy substituted derivative 1i and the positional isomers 1j and 1k, containing hydroxy and methoxy substituents: they showed IC₅₀ similar to the reference podophyllotoxin in both tumor cell lines, accompanied with high selectivity towards the malignantly transformed cells. The compounds exerted moderate to high ability to scavenge peroxyl radicals and certain derivatives—1l containing metha-hydroxy and para-methoxy group, and 1b-e with di/trihydroxy phenyl moiety, revealed HORAC values high or comparable to those of well-known phenolic antioxidants. Thus the 1H-benisimidazol-2-yl hydrazones with hydroxy/methoxy phenyl fragments were recognized as new agents exhibiting promising combined antioxidant and antineoplastic action.

(1) Background: The aim of the work is the evaluation of in vitro antiproliferative and pro-apoptotic activity of four benzimidazole derivatives containing colchicine-like and catechol-like moieties with methyl group substitution in the benzimidazole ring against highly invasive breast cancer cell line MDA-MB-231 and their related impairment of tubulin dynamics. (2) Methods: The antiproliferative activity was assessed with the MTT assay. Alterations in tubulin polymerization were evaluated with an in vitro tubulin polymerization assay and a docking analysis. (3) Results: All derivatives showed time-dependent cytotoxicity with IC₅₀ varying from 40 to 60 μM after 48 h and between 13 and 20 μM after 72 h. Immunofluorescent and DAPI staining revealed the pro-apoptotic potential of benzimidazole derivatives and their effect on tubulin dynamics in living cells. Compound 5d prevented tubulin aggregation and blocked mitosis, highlighting the importance of the methyl group and the colchicine-like fragment. (4) Conclusions: The benzimidazole derivatives demonstrated moderate cytotoxicity towards MDA-MB-231 by retarding the initial phase of tubulin polymerization. The derivative 5d containing a colchicine-like moiety and methyl group substitution in the benzimidazole ring showed potential as an antiproliferative agent and microtubule destabilizer by facilitating faster microtubule aggregation and disrupting cellular and nuclear integrity.

Fluorescent micellar carriers with controlled release of a novel anticancer drug were developed to enable intracellular imaging and cancer treatment simultaneously. The nanosized fluorescent micellar systems were embedded with a novel anticancer drug via the self-assembling behavior of well-defined block copolymers based on amphiphilic poly(acrylic acid)-block-poly(n-butyl acrylate) (PAA-b-PnBA) copolymer obtained by Atom Transfer Radical Polymerization (ATRP) and hydrophobic anticancer benzimidazole-hydrazone drug (BzH). Through this method, well-defined nanosized fluorescent micelles were obtained consisting of a hydrophilic PAA shell and a hydrophobic PnBA core embedded with the BzH drug due to the hydrophobic interactions, thus reaching very high encapsulation efficiency. The size, morphology, and fluorescent properties of blank and drug-loaded micelles were investigated using dynamic light scattering (DLS), transmission electron microscopy (TEM), and fluorescent spectroscopy, respectively. Additionally, after 72 h of incubation, drug-loaded micelles released 3.25 μM of BzH, which was spectrophotometrically determined. The BzH drug-loaded micelles were found to exhibit enhanced antiproliferative and cytotoxic effects on MDA-MB-231 cells, with long-lasting effects on microtubule organization, with apoptotic alterations and preferential localization in the perinuclear space of cancer cells. In contrast, the antitumor effect of BzH alone or incorporated in micelles on non-cancerous cells MCF-10A was relatively weak.

(1) Background: In this work, a series of benzimidazole derivatives containing colchicine-like and cathechol-like moieties with methyl group substitution in the benzimidazole ring were evaluated for their in vitro antiproliferative, pro-apoptotic and antioxidative activity against highly invasive breast cancer cell line MDA-MB-231 and related impairment of tubulin dynamics; (2) Methods: MTT assay was used to evaluate the antiproliferative activity. In vitro tubulin polymerization assay as well as docking analysis was applied to prove the alterations in tubulin polymerization. Immunofluorescent and DAPI staining reveal the pro-apoptotic potential of benzimidazole derivatives and the effect on tubulin’s dynamics in living cells. The antioxidant activity was evaluated by scavenging of H2O2 and hypochlorite ion and ortho-phenanthroline tests; (3) Results: The compounds containing colchicine-like moiety displayed significant growth inhibitory effect against cancer cell line as was highlighted the role of methyl functional group on the tubulin aggregation and blockage of mitosis. All compounds showed an ability to scavenge H2O2, while the compounds with cathecol-like moiety were more effective against hypochlorite ion and chelation of iron; (4) Conclusions: The benzimidazole derivative containing colchicine-like moiety and methyl group substitution in benzimidazole ring is a potential antiproliferative and microtubule destabilizing agent.

The present work introduces the Bulgarian Spectral Database for Painting Materials, a freely accessible web-based resource containing FTIR and Raman spectra, together with complementary analytical information, for materials commonly found in Bulgarian artworks. The database encompasses a collection of over 200 reference materials and more than 100 entries derived from authentic samples obtained from wall paintings, dating from the 5th century BC to the 20th century. The largest section of the database consists of inorganic reference materials, including natural and synthetic mineral pigments, fillers, and additives commonly identified in historical mural paintings, complemented by organic binders and natural dyes. Reference model mixtures simulating historical painting techniques are also included. The database provides interactive visualization and downloadable spectra in plain text formats (.txt) compatible with all spectroscopic software. The integration of spectral data obtained from artworks represents a distinctive feature of the resource. The database is a practical tool for material identification, comparative studies, and conservation research in the field of cultural heritage science. It also provides a robust foundation for comparative studies and facilitates interdisciplinary research across the Balkan region and beyond.