Coumarin-azasugar-benzyl conjugates as non-neurotoxic dual inhibitors of butyrylcholinesterase and cancer cell growth.

We have applied the copper-catalyzed azide-alkyne cycloaddition (CuAAC) reaction to prepare a library of ten coumarin-azasugar-benzyl conjugates and two phthalimide-azasugar-benzyl conjugates with potential anti-Alzheimer and anti-cancer properties. The compounds were evaluated as cholinesterase inhibitors, demonstrating a general preference, of up to 676-fold, for the inhibition of butyrylcholinesterase (BuChE) over acetylcholinesterase (AChE). Nine of the compounds behaved as stronger BuChE inhibitors than galantamine, one of the few drugs in clinical use against Alzheimer's disease. The most potent BuChE inhibitor (IC50 = 74 nM) was found to exhibit dual activities, as it also showed high activity (GI50 = 5.6 ± 1.1 µM) for inhibiting the growth of WiDr (colon cancer cells). In vitro studies on this dual-activity compound on Cerebellar Granule Neurons (CGNs) demonstrated that it displays no neurotoxicity.

Click-chemistry mediated synthesis of OTBN-1,2,3-Triazole derivatives exhibiting STK33 inhibition with diverse anti-cancer activities.

There is a continuous and pressing need to establish new brain-penetrant bioactive compounds with anti-cancer properties. To this end, a new series of 4'-((4-substituted-4,5-dihydro-1H-1,2,3-triazol-1-yl)methyl)-[1,1'-biphenyl]-2-carbonitrile (OTBN-1,2,3-triazole) derivatives were synthesized by click chemistry. The series of bioactive compounds were designed and synthesized from diverse alkynes and N3-OTBN, using copper (II) acetate monohydrate in aqueous dimethylformamide at room temperature. Besides being highly cost-effective and significantly reducing synthesis, the reaction yielded 91-98 % of the target products without the need of any additional steps or chromatographic techniques. Two analogues exhibit promising anti-cancer biological activities. Analogue 4l shows highly specific cytostatic activity against lung cancer cells, while analogue 4k exhibits pan-cancer anti-growth activity. A kinase screen suggests compound 4k has single-digit micromolar activity against kinase STK33. High STK33 RNA expression correlates strongly with poorer patient outcomes in both adult and pediatric glioma. Compound 4k potently inhibits cell proliferation, invasion, and 3D neurosphere formation in primary patient-derived glioma cell lines. The observed anti-cancer activity is enhanced in combination with specific clinically relevant small molecule inhibitors. Herein we establish a novel biochemical kinase inhibitory function for click-chemistry-derived OTBN-1,2,3-triazole analogues and further report their anti-cancer activity in vitro for the first time.

Coumarins-lipophilic cations conjugates: Efficient mitocans targeting carbonic anhydrases.

Being aware of the need to develop more efficient therapies against cancer, herein we disclose an innovative approach for the design of selective antiproliferative agents. We have accomplished the conjugation of a coumarin fragment with lipophilic cations (triphenylphosphonium salts, guanidinium) for providing mitochondriotropic agents that simultaneously target also carbonic anhydrases IX and XII, involved in the development and progression of cancer. The new compounds prepared herein turned out to be strong inhibitors of carbonic anhydrases IX and XII of human origin (low-to-mid nM range), also endowed with high selectivity, exhibiting negligible activity towards cytosolic CA isoforms. Key interactions with the enzyme were analysed using docking and molecular dynamics simulations. Regarding their in vitro antiproliferative activities, an increase of the tether length connecting both pharmacophores led to a clear improvement in potency, reaching the submicromolar range for the lead compounds, and an outstanding selectivity towards tumour cell lines (S.I. up to >357). Cytotoxic effects were also analysed on MDR cell lines under hypoxic and normoxic conditions. Chemoresistance exhibited by phosphonium salts, and not by guanidines, against MDR cells was based on the fact that the former were found to be substrates of P-glycoprotein (P-gp), the pump responsible for extruding foreign chemicals; this situation was reversed by administrating tariquidar, a third generation P-gp inhibitor. Moreover, phosphonium salts provoked a profound depolarization of mitochondria membranes from tumour cells, thus probably compromising their oxidative metabolism. To gain insight into the mode of action of title compounds, continuous live cell microscopy was employed; interestingly, this technique revealed two different antiproliferative mechanisms for both families of mitocans. Whereas phosphonium salts had a cytostatic effect, blocking cell division, guanidines led to cell death via apoptosis.

Novel tetrahydropyran-triazole hybrids with antiproliferative activity against human tumor cells.

A series of new hybrid compounds was prepared combining tetrahydropyran rings with different aromatic systems by means of a 1,2,3-triazole, using a building block strategy. The design of these structures was guided by Lead-Likeness and Molecular Analysis (LLAMA) software, adding modifications to our most potent scaffold (the tetrahydropyran ring) to generate promising "lead-like" candidates, which were subsequently compared against reported anticancer compounds. Our synthesized compounds demonstrated significant antiproliferative activity when compared with the standards cisplatin and 5-fluorouracil, across a panel of six different tumor cell lines. Moreover, compared with our group's previous hybrid compounds, these new structures exhibit similar activity while offering simpler synthesis and greater potential for structural diversification, a fact that was previously an issue. Further investigations on the most active compounds included assessments of reproductive cell survival, inhibition of cell migration, and effects on nuclear morphology, indicating potential diverse mechanisms of action for these compounds. Pharmacokinetic properties were also calculated for the whole series of compounds using the pkCSM online software.

Exploring the Anticancer Potential of Phenolic nor-Triterpenes from Celastraceae Species.

To explore new compounds with antitumour activity, fifteen phenolic nor-tripterpenes isolated from Celastraceae species, Maytenus jelskii, Maytenus cuzcoina, and Celastrus vulcanicola, have been studied. Their chemical structures were elucidated through spectroscopic and spectrometric techniques, resulting in the identification of three novel chemical compounds. Evaluation on human tumour cell lines (A549 and SW1573, non-small cell lung; HBL-100 and T-47D, breast; HeLa, cervix, and WiDr, colon) revealed that three compounds, named 6-oxo-pristimerol, demethyl-zeylasteral, and zeylasteral, exhibited significant activity (GI50 ranging from 0.45 to 8.6 µM) on at least five of the cell lines tested. Continuous live cell imaging identified apoptosis as the mode of action of selective cell killing in HeLa cells. Furthermore, their effect on a drug-sensitive Saccharomyces cerevisiae strain has been investigated to deepen on their mechanism of action. In dose-response growth curves, zeylasteral and 7α-hydroxy-blepharodol were markedly active. Additionally, halo assays were conducted to assess the involvement of oxidative stress and/or mitochondrial function in the anticancer profile, ruling out these modes of action for the active compounds. Finally, we also delve into the structure-activity relationship, providing insights into how the molecular structure of these compounds influences their biological activity. This comprehensive analysis enhances our understanding of the therapeutic potential of this triterpene type and underscores its relevance for further research in this field.

The Ugi4CR as effective tool to access promising anticancer isatin-based α-acetamide carboxamide oxindole hybrids.

Considering early-stage drug discovery programs, the Ugi four-component reaction is a valuable, flexible, and pivotal tool, facilitating the creation of two new amide bonds in a one-pot fashion to effectively yield the desired α-aminoacylamides. Here, we highlight the reputation of this reaction approach to access number and scaffold diversity of a library of isatin-based α-acetamide carboxamide oxindole hybrids, promising anticancer agents, in a mild and fast sustainable reaction process. The library was tested against six human solid tumor cell lines, among them, non-small cell lung carcinoma, cervical adenocarcinoma, breast cancer and colon adenocarcinoma. The most potent compounds 8d, 8h and 8k showed GI50 values in the range of 1-10 µM.

Biotinylated selenocyanates: Potent and selective cytostatic agents.

Most of the currently available cytotoxic agents for tackling cancer are devoid of selectivity, thus causing severe side-effects. This situation stimulated us to develop new antiproliferative agents with enhanced affinity towards tumour cells. We focused our attention on novel chalcogen-containing compounds (thiosemicarbazones, disulfides, selenoureas, thio- and selenocyanates), and particularly on selenium derivatives, as it has been documented that this kind of compounds might act as prodrugs releasing selenium-based reactive species on tumour cells. Particularly interesting in terms of potency and selectivity was a pharmacophore comprised by a selenocyanato-alkyl fragment connected to a p-phenylenediamine residue, where the nature of the second amino moiety (free, Boc-protected, enamine-protected) provided a wide variety of antiproliferative activities, ranging from the low micromolar to the nanomolar values. The optimized structure was in turn conjugated through a peptide linkage with biotin (vitamin B7), a cellular growth promoter, whose receptor is overexpressed in numerous cancer cells; the purpose was to develop a selective vector towards malignant cells. Such biotinylated derivative behaved as a very strong antiproliferative agent, achieving GI50 values in the low nM range for most of the tested cancer cells; moreover, it was featured with an outstanding selectivity, with GI50 > 100 µM against human fibroblasts. Mechanistic studies on the mode of inhibition of the biotinylated selenocyanate revealed (Annexin-V assay) a remarkable increase in the number of apoptotic cells compared to the control experiment; moreover, depolarization of the mitochondrial membrane was detected by flow cytometry analysis, and with fluorescent microscopy, what supports the apoptotic cell death. Prior to the apoptotic events, cytostatic effects were observed against SW1573 cells using label-free cell-living imaging; therefore, tumour cell division was prevented. Multidrug resistant cell lines exhibited a reduced sensitivity towards the biotinylated selenocyanate, probably due to its P-gp-mediated efflux. Remarkably, antiproliferative levels could be restored by co-administration with tariquidar, a P-gp inhibitor; this approach can, therefore, overcome multidrug resistance mediated by the P-gp efflux system.

Early Pharmacological Profiling of Antiproliferative Compounds by Live Cell Imaging.

Natural products represent an excellent source of unprecedented anticancer compounds. However, the identification of the mechanism of action remains a major challenge. Several techniques and methodologies have been considered, but with limited success. In this work, we explored the combination of live cell imaging and machine learning techniques as a promising tool to depict in a fast and affordable test the mode of action of natural compounds with antiproliferative activity. To develop the model, we selected the non-small cell lung cancer cell line SW1573, which was exposed to the known antimitotic drugs paclitaxel, colchicine and vinblastine. The novelty of our methodology focuses on two main features with the highest relevance, (a) meaningful phenotypic metrics, and (b) fast Fourier transform (FFT) of the time series of the phenotypic parameters into their corresponding amplitudes and phases. The resulting algorithm was able to cluster the microtubule disruptors, and meanwhile showed a negative correlation between paclitaxel and the other treatments. The FFT approach was able to group the samples as efficiently as checking by eye. This methodology could easily scale to group a large amount of data without visual supervision.

Bioactive Potential: A Pharmacognostic Definition through the Screening of Four Hypericum Species from the Canary Islands.

In this work, we propose a general methodology to assess the bioactive potential (BP) of extracts in the quest of vegetable-based drugs. To exemplify the method, we studied the anticancer potential (AP) of four endemic species of genus Hypericum (Hypericum canariense L, Hypericum glandulosum Aiton, Hypericum grandifolium Choisy and Hypericum reflexum L.f) from the Canary Islands. Microextracts were obtained from the aerial parts of these species and were tested against six human tumor cell lines, A549 (non-small-cell lung), HBL-100 (breast), HeLa (cervix), SW1573 (non-small-cell lung), T-47D (breast) and WiDr (colon). The methanol-water microextracts were evaluated further for cell migration, autophagy and cell death. The most promising bioactive polar microextracts were analyzed by UHPLC-DAD-MS. The extraction yield, the bioactivity evaluation and the chemical profiling by LC-MS suggested that H. grandifolium was the species with the highest AP. Label-free live-cell imaging studies on HeLa cells exposed to the methanol-water microextract of H. grandifolium enabled observing cell death and several apoptotic hallmarks. Overall, this study allows us to select Hypericum grandifolium Choisy as a source of new chemical entities with a potential interest for cancer treatment.

Antiproliferative and Antibacterial Activity of Polyporoid Fungi from Veracruz, Mexico.

Polyporoid fungi represent a vast source of bioactive compounds with potential pharmacological applications. The importance of polyporoid fungi in traditional Chinese medicine has led to an extensive use of some species of Ganoderma for promoting health and longevity because their consumption is associated with several bioactivities. Nevertheless, bioactivity of some other members of the Polyporaceae family has also been reported. This work reports the antiproliferative and antibacterial activity of crude extracts obtained from fruiting bodies of polypore fungi collected from the central region of Veracruz, Mexico, aimed at understanding the diversity of polypore species with potential pharmacological applications. 29 collections were identified macro- and microscopically in 19 species of polyporoid fungi, belonging to 13 genera. The antiproliferative activity screening of extracts against solid tumor cell lines (A549, SW1573, HeLa, HBL-100, T-47D, WiDr) allow us to identify four extracts with strong bioactivity [half-maximal growth inhibition (GI50) ≤ 50 µg/mL]. After this, a phylogenetic analysis of DNA sequences from the ITS region obtained from bioactive specimens allowed us to identify three extracts as Pycnoporus sanguineus (GI50 = ≤ 10 µg/mL) and the fourth bioactive extract as Ganoderma oerstedii (GI50 = < 50 µg/mL. Likewise, extracts from P. sanguineus showed mild or moderate antibacterial activity against Escherichia coli, Staphylococcus aureus and Xanthomonas albilineas. Bioprospecting studies of polyporoid fungi add to the knowledge of the diversity of macrofungi in Mexico and allow us to select one of the bioactive P. sanguineus to continue the pursuit of bioactive compounds through mycochemical studies.