Cancer and brassinosteroids: Mechanisms of action, SAR and future perspectives.

Brassinosteroids are plant hormones whose main function is to stimulate plant growth. However, they have been studied for their biological applications in humans. Brassinosteroid compounds have displayed an important role in the study of cancer pathology and show potential for developing novel anticancer drugs. In this review we describe the relationship of brassinosteroids with cancer with focus on the last decade, the mechanisms of cytotoxic activity described to date, and a structure-activity relationship based on the available information.

New Morphiceptin Peptidomimetic Incorporating (1S,2R,3S,4S,5R)-2-Amino-3,4,5-trihydroxycyclopen-tane-1-carboxylic acid: Synthesis and Structural Study.

We present the synthesis and structural study of a new peptidomimetic of morphiceptin, which can formally be considered as the result of the replacement of the central proline residue of this natural analgesic drug with a subunit of (1S,2R,3S,4S,5R)-2-amino-3,4,5-trihydroxycyclopentane-1-carboxylic acid, previously obtained from L-idose. An optimized synthesis of this trihydroxylated cispentacin derivative is also reported. Molecular docking calculations on the target receptor support a favorable role of the hydroxy substituents of the non-natural ß-amino acid incorporated into the peptidomimetic.

Synthesis, in vitro evaluation and molecular docking of a new class of indolylpropyl benzamidopiperazines as dual AChE and SERT ligands for Alzheimer's disease.

During the last decade, the one drug-one target strategy has resulted to be inefficient in facing diseases with complex ethiology like Alzheimer's disease and many others. In this context, the multitarget paradigm has emerged as a promising strategy. Based on this consideration, we aim to develop novel molecules as promiscuous ligands acting in two or more targets at the same time. For such purpose, a new series of indolylpropyl-piperazinyl oxoethyl-benzamido piperazines were synthesized and evaluated as multitarget-directed drugs for the serotonin transporter (SERT) and acetylcholinesterase (AChE). The ability to decrease ß-amyloid levels as well as cell toxicity of all compounds were also measured. In vitro results showed that at least four compounds displayed promising activity against SERT and AChE. Compounds 18 and 19 (IC50 = 3.4 and 3.6 µM respectively) exhibited AChE inhibition profile in the same order of magnitude as donepezil (DPZ, IC50 = 2.17 µM), also displaying nanomolar affinity in SERT. Moreover, compounds 17 and 24 displayed high SERT affinities (IC50 = 9.2 and 1.9 nM respectively) similar to the antidepressant citalopram, and significant micromolar AChE activity at the same time. All the bioactive compounds showed a low toxicity profile in the range of concentrations studied. Molecular docking allowed us to rationalize the binding mode of the synthesized compounds in both targets. In addition, we also show that compounds 11 and 25 exhibit significant ß-amyloid lowering activity in a cell-based assay, 11 (50% inhibition, 10 µM) and 25 (35% inhibition, 10 µM). These results suggest that indolylpropyl benzamidopiperazines based compounds constitute promising leads for a multitargeted approach for Alzheimer's disease.

Three-Dimensional Quantitative Structure-Activity Relationships (3D-QSAR) on a Series of Piperazine-Carboxamides Fatty Acid Amide Hydrolase (FAAH) Inhibitors as a Useful Tool for the Design of New Cannabinoid Ligands.

Fatty Acid Amide Hydrolase (FAAH) is one of the main enzymes responsible for endocannabinoid metabolism. Inhibition of FAAH increases endogenous levels of fatty acid ethanolamides such as anandamide (AEA) and thus consitutes an indirect strategy that can be used to modulate endocannabinoid tone. In the present work, we present a three-dimensional quantitative structure-activity relationships/comparative molecular similarity indices analysis (3D-QSAR/CoMSIA) study on a series of 90 reported irreversible inhibitors of FAAH sharing a piperazine-carboxamide scaffold. The model obtained was extensively validated (q2 = 0.734; r2 = 0.966; r2m = 0.723). Finally, based on the information derived from the contour maps we designed a series of 10 new compounds with high predicted FAAH inhibition (predicted pIC50 of the best-proposed compounds = 12.196; 12.416).

Structure-Activity Relationships Based on 3D-QSAR CoMFA/CoMSIA and Design of Aryloxypropanol-Amine Agonists with Selectivity for the Human ß3-Adrenergic Receptor and Anti-Obesity and Anti-Diabetic Profiles.

The wide tissue distribution of the adrenergic ß3 receptor makes it a potential target for the treatment of multiple pathologies such as diabetes, obesity, depression, overactive bladder (OAB), and cancer. Currently, there is only one drug on the market, mirabegron, approved for the treatment of OAB. In the present study, we have carried out an extensive structure-activity relationship analysis of a series of 41 aryloxypropanolamine compounds based on three-dimensional quantitative structure-activity relationship (3D-QSAR) techniques. This is the first combined comparative molecular field analysis (CoMFA) and comparative molecular similarity index analysis (CoMSIA) study in a series of selective aryloxypropanolamines displaying anti-diabetes and anti-obesity pharmacological profiles. The best CoMFA and CoMSIA models presented values of r²ncv = 0.993 and 0.984 and values of r²test = 0.865 and 0.918, respectively. The results obtained were subjected to extensive external validation (q², r², r²m, etc.) and a final series of compounds was designed and their biological activity was predicted (best pEC50 = 8.561).

Combined CoMFA and CoMSIA 3D-QSAR study of benzimidazole and benzothiophene derivatives with selective affinity for the CB2 cannabinoid receptor.

The preceding years have brought an exponential increase in our understanding of the endocannabinoid system (ECS), including the knowledge of CB1 and CB2 cannabinoid receptors, endocannabinoids, and the enzymes that synthesize and degrade endocannabinoids. Among these ECS components CB2 receptors have been the subject of considerable attention, primarily due to their promising therapeutic potential to treat numerous pathologies while avoiding the adverse psychotropic effects that can accompany CB1 receptor-based therapies. Recently, our research group has reported a new series of non-cytotoxic benzo[d]imidazoles and benzo[b]thiophenes displaying high CB2/CB1 selectivity index. In order to investigate the structural requirements for CB2 ligands and to derive a predictive model that can be used for the design of novel selective CB2 ligands, a three-dimensional quantitative structure-activity relationship (3D-QSAR) study was performed on the above mentioned chemical series employing comparative molecular field analysis (CoMFA) and comparative molecular similarity index analysis (CoMSIA) techniques. The CoMFA and CoMSIA models displayed high external predictability (rpred2 0.919 and 0.908) and good statistical robustness. Valuable information regarding the steric, electrostatic and hydrophobic properties of the molecules was obtained, and several modifications around both heterocycles were evaluated with the aim to generate new promising series of benzo[d]imidazoles and benzo[b]thiophenes derivatives displaying high CB2 selectivity and low toxicity.