Multitarget Hybrid Fasudil Derivatives as a New Approach to the Potential Treatment of Amyotrophic Lateral Sclerosis.

Hybrid compounds containing structural fragments of the Rho kinase inhibitor fasudil and the NRF2 inducers caffeic and ferulic acids were designed with the aid of docking and molecular mechanics studies. Following the synthesis of the compounds using a peptide-coupling methodology, they were characterized for their ROCK2 inhibition, radical scavenging, effects on cell viability (MTT assay), and NRF2 induction (luciferase assay). One of the compounds (1d) was selected in view of its good multitarget profile and good tolerability. It was able to induce the NRF2 signature, promoting the expression of the antioxidant response enzymes HO-1 and NQO1, via a KEAP1-dependent mechanism. Analysis of mRNA and protein levels of the NRF2 pathway showed that 1d induced the NRF2 signature in control and SOD1-ALS lymphoblasts but not in sALS, where it was already increased in the basal state. These results show the therapeutic potential of this compound, especially for ALS patients with a SOD1 mutation.

Melatonin- and Ferulic Acid-Based HDAC6 Selective Inhibitors Exhibit Pronounced Immunomodulatory Effects In Vitro and Neuroprotective Effects in a Pharmacological Alzheimer's Disease Mouse Model.

The structures of melatonin and ferulic acid were merged into tertiary amide-based histone deacetylase 6 (HDAC6) inhibitors to develop multi-target-directed inhibitors for neurodegenerative diseases to incorporate antioxidant effects without losing affinity and selectivity at HDAC6. Structure-activity relationships led to compound 10b as a hybrid molecule showing pronounced and selective inhibition of HDAC6 (IC50 = 30.7 nM, > 25-fold selectivity over other subtypes). This compound shows comparable DPPH radical scavenging ability to ferulic acid, comparable ORAC value to melatonin and comparable Cu2+ chelating ability to EDTA. It also lacks neurotoxicity on HT-22 cells, exhibits a pronounced immunomodulatory effect, and is active in vivo showing significantly higher efficacy in an AD mouse model to prevent both Aß25-35-induced spatial working and long-term memory dysfunction at lower dose (0.3 mg/kg) compared to positive control HDAC6 inhibitor ACY1215 and an equimolar mixture of the three entities ACY1215, melatonin and ferulic acid, suggesting potentially disease-modifying properties.

Accessing p-Hydroxycinnamic Acids: Chemical Synthesis, Biomass Recovery, or Engineered Microbial Production?

p-Hydroxycinnamic acids (i. e., p-coumaric, ferulic, sinapic, and caffeic acids) are phenolic compounds involved in the biosynthesis pathway of lignin. These naturally occurring molecules not only exhibit numerous attractive properties, such as antioxidant, anti-UV, and anticancer activities, but they also have been used as building blocks for the synthesis of tailored monomers and functional additives for the food/feed, cosmetic, and plastics sectors. Despite their numerous high value-added applications, the sourcing of p-hydroxycinnamic acids is not ensured at the industrial scale except for ferulic acid, and their production cost remains too high for commodity applications. These compounds can be either chemically synthesized or extracted from lignocellulosic biomass, and recently their production through bioconversion emerged. Herein the different strategies described in the literature to produce these valuable molecules are discussed.

A Series of Ferulic Acid Amides Reveals Unexpected Peroxiredoxin 1 Inhibitory Activity with in†vivo Antidiabetic and Hypolipidemic Effects.

Insulin resistance is a major pathophysiological feature in the development of type 2 diabetes (T2DM). Ferulic acid is known for attenuating the insulin resistance and reducing the blood glucose in T2DM rats. In this work, we designed and synthesized a library of new ferulic acid amides (FAA), which could be considered as ring opening derivatives of the antidiabetic PPARγ agonists Thiazolidinediones (TZDs). However, since these compounds displayed weak PPAR transactivation capacity, we employed a proteomics approach to unravel their molecular target(s) and identified the peroxiredoxin 1 (PRDX1) as a direct binding target of FAAs. Interestingly, PRDX1, a protein with antioxidant and chaperone activity, has been implied in the development of T2DM by inducing hepatic insulin resistance. SPR, mass spectrometry-based studies, docking experiments and in vitro inhibition assay confirmed that compounds VIe and VIf bound PRDX1 and induced a dose-dependent inhibition. Furthermore, VIe and VIf significantly improved hyperglycemia and hyperlipidemia in streptozotocin-nicotinamide (STZ-NA)-induced diabetic rats as confirmed by histopathological examinations. These results provide guidance for developing the current FAAs as new potential antidiabetic agents.

Natural and Synthetic Derivatives of Hydroxycinnamic Acid Modulating the Pathological Transformation of Amyloidogenic Proteins.

This review presents the main properties of hydroxycinnamic acid (HCA) derivatives and their potential application as agents for the prevention and treatment of neurodegenerative diseases. It is partially focused on the successful use of these compounds as inhibitors of amyloidogenic transformation of proteins. Firstly, the prerequisites for the emergence of interest in HCA derivatives, including natural compounds, are described. A separate section is devoted to synthesis and properties of HCA derivatives. Then, the results of molecular modeling of HCA derivatives with prion protein as well as with α-synuclein fibrils are summarized, followed by detailed analysis of the experiments on the effect of natural and synthetic HCA derivatives, as well as structurally similar phenylacetic and benzoic acid derivatives, on the pathological transformation of prion protein and α-synuclein. The ability of HCA derivatives to prevent amyloid transformation of some amyloidogenic proteins, and their presence not only in food products but also as natural metabolites in human blood and tissues, makes them promising for the prevention and treatment of neurodegenerative diseases of amyloid nature.

Coumaric acid derivatives as tyrosinase inhibitors: Efficacy studies through in silico, in vitro and ex vivo approaches.

p-Coumaric acid is a known inhibitor of tyrosinase, an enzyme involved in the initial steps of the melanin synthesis in human and other species. However, its low lipophilicity impairs its penetration through skin and efficacy as antimelanogenic agent indeed. Accordingly, this paper reports the assessment of several coumaric acid derivatives as tyrosinase inhibitors and antimelanogenic agents in in vitro, in silico and ex vivo assays. The compounds were designed with modifications in the aromatic and acid moieties of p-coumaric acid, being the coumarate esters the most promising derivatives. The compounds showed higher tyrosinase inhibitory activity (pIC50 3.7-4.2) than the parent acid, being compounds 1d, 1e and 1f the most potent inhibitors. Docking analysis showed that these esters are competitive inhibitors per se, and act independently of a redox mechanism as suggested by DPPH assays. Moreover, the esters showed efficacy in reducing the melanin deposition in human skin fragments at 0.1% concentration, especially compound 1e. In summary, there is an important equilibria between tyrosinase affinity and lipophilicity that must be considered to get effective antimelanogenic agents with adequate permeability in the skin.

Design, synthesis & biological evaluation of ferulic acid-based small molecule inhibitors against tumor-associated carbonic anhydrase IX.

Carbonic anhydrase IX (CAIX) is an emerging drug target for hypoxia associated cancers. To identify potent and selective inhibitors of CAIX, a small library of ferulic acid (FA) derivatives bearing triazole moiety has been designed, synthesized and evaluated against different human CA isoforms (CAII, CAVA & CAIX). Though most of the compounds showed CAIX inhibition in the micromolar range, compound 7i selectively inhibits CAIX in the nanomolar range (IC50 = 24 nM). In silico analysis revealed binding of 7i with the catalytically important amino acid residues of CAIX. Further, cell-based studies indicate that 7i inhibits the activity of CAIX, decreases the epithelial to mesenchymal transitions, induces apoptosis, inhibits cell migration and colonization potential of cancer cells. Taken together, these results emphasized the use of 7i as a prospective pharmacological lead molecule in CAIX targeted anticancer therapeutics.

Exploring the Multi-Target Performance of Mitochondriotropic Antioxidants against the Pivotal Alzheimer's Disease Pathophysiological Hallmarks.

Alzheimer disease (AD) is the most common neurodegenerative disease featuring progressive and degenerative neurological impairments resulting in memory loss and cognitive decline. The specific mechanisms underlying AD are still poorly understood, but it is suggested that a deficiency in the brain neurotransmitter acetylcholine, the deposition of insoluble aggregates of fibrillar ß-amyloid 1-42 (Aß42), and iron and glutamate accumulation play an important role in the disease progress. Despite the existence of approved cholinergic drugs, none of them demonstrated effectiveness in modifying disease progression. Accordingly, the development of new chemical entities acting on more than one target is attracting progressively more attention as they can tackle intricate network targets and modulate their effects. Within this endeavor, a series of mitochondriotropic antioxidants inspired on hydroxycinnamic (HCA's) scaffold were synthesized, screened toward cholinesterases and evaluated as neuroprotectors in a differentiated human SH-SY5Y cell line. From the series, compounds 7 and 11 with a 10-carbon chain can be viewed as multi-target leads for the treatment of AD, as they act as dual and bifunctional cholinesterase inhibitors and prevent the neuronal damage caused by diverse aggressors related to protein misfolding and aggregation, iron accumulation and excitotoxicity.

Bioassay of ferulic acid derivatives as influenza neuraminidase inhibitors.

Four series of ferulic acid derivatives were designed, synthesized, and evaluated for their neuraminidase (NA) inhibitory activities against influenza virus H1N1 in vitro. The pharmacological results showed that the majority of the target compounds exhibited moderate influenza NA inhibitory activity, which was also better than that of ferulic acid. The two most potent compounds were 1m and 4a with IC50 values of 12.77 ± 0.47 and 12.96 ± 1.34 µg/ml, respectively. On the basis of the biological results, a preliminary structure-activity relationship (SAR) was derived and discussed. Besides, molecular docking was performed to study the possible interactions of compounds 1p, 2d, 3b, and 4a with the active site of NA. It was found that the 4-OH-3-OMe group and the amide group (CON) of ferulic acid amide derivatives were two key pharmacophores for NA inhibitory activity. It is meaningful to further modify the natural product ferulic acid to improve its influenza NA inhibitory activity.

Biophysical Properties and Cytotoxicity of Feruloylated Helix Lucorum Hemocyanin.

For the first time Helix lucorum hemocyanin (HlH) has been feruloylated. Two HlH conjugates with 40- and 120- ferulic acid residues were prepared, denoted as FA-HlH-1 and FA-HlH-2. Expectedly, the feruloylation of HlH induced a rearrangement of the protein molecule, a decrease in the ?-helical structure at the expense of ß-structures was observed. Besides, the FA-HlH conjugates were more prone to aggregation, which is probably due to the stabilization of the partially unfolded protein molecules by non-covalent bonding. Interestingly, the thermal stability of HlH was not affected by the modification. The native and feruloylated HlH were not toxic to normal fibroblasts (BJ cells). We observed a decrease in cell viability of breast cancer MCF-7 cells to about 66% after a 48h exposure to 70 µg/well of FA-HlH-2.

Design, synthesis and evaluation of novel ferulic acid derivatives as multi-target-directed ligands for the treatment of Alzheimer's disease.

A series of new ferulic acid derivatives were designed, synthesized and evaluated as multi-target inhibitors against Alzheimer's disease. In vitro studies indicated that most compounds showed significant potency to inhibit self-induced ß-amyloid (Aß) aggregation and acetylcholinesterase (AChE), and had good antioxidant activity. Specifically, compound 4g exhibited the potent ability to inhibit cholinesterase (ChE) (IC50, 19.7 nM for hAChE and 0.66 µM for hBuChE) and the good Aß aggregation inhibition (49.2% at 20 µM), and it was also a good antioxidant (1.26 trolox equivalents). Kinetic and molecular modeling studies showed that compound 4g was a mixed-type inhibitor, which could interact simultaneously with the catalytic anionic site (CAS) and the peripheral anionic site (PAS) of AChE. Moreover, compound 4g could remarkably increase PC12 cells viability in hydrogen peroxide-induced oxidative cell damage and Aß-induced cell damage. Finally, compound 4g had good ability to cross the BBB using the PAMPA-BBB assay. These results suggested that compound 4g was a promising multifunctional ChE inhibitor for the further investigation.

Design, synthesis, and biological evaluation of ferulic acid based 1,3,4-oxadiazole hybrids as multifunctional therapeutics for the treatment of Alzheimer's disease.

Thirty ferulic acid-based 1,3,4-oxadiazole molecular hybrids were designed, synthesized, and screened them for multifunctional inhibitory potential against acetylcholinesterase (AChE), butyrylcholinesterase (BChE) and beta-secretase-1 (BACE-1). Compound 6j was the most potent inhibitor of AChE (IC50 = 0.068 µM). It also showed equipotent inhibition of BChE and BACE-1 with IC50 values of 0.218 µM and 0.255 µM, respectively. Compound 6k possessed the most significant inhibition of BChE and BACE-1 with IC50 values, 0.163 µM and 0.211 µM, respectively. Compounds 6j and 6k elicited significant displacement of propidium iodide from PAS-AChE, excellent BBB permeability in PAMPA assay, and anti-Aß aggregatory activity in self- and AChE-induced experiments with neuroprotective activity towards neuroblastoma SH-SY5Y cells. The in vivo behavioral studies suggested amelioration of cognitive dysfunction by 6j and 6k in the Y maze test. The ex vivo study signified brain AChE inhibition and antioxidant activity from these compounds. Moreover, 6j showed improvement in learning and memory behavior in the Aß-induced ICV rat model by Morris water maze test with excellent oral absorption characteristics ascertained by pharmacokinetic studies.

Methoxyphenol derivatives as reversible inhibitors of myeloperoxidase as potential antiatherosclerotic agents.

Aim: To evaluate new chemical entities, based on ferulic acid scaffolds, as reversible myeloperoxidase inhibitors (MPOI). Methodology & results:In silico docking studies are performed with MPO protein as a target for several ferulic acid analogs followed by multiple in vitro assays to validate this approach. Two lead compounds 2a and 3 are identified with optimum docking and IC50 values: -7.95 kcal/mol, 0.9 µM and -8.35 kcal/mol, 8.5 µM, respectively. These MPOIs are able to inhibit oxidation of high-density lipoprotein and further promoted functionality of high-density lipoprotein. Conclusion: Lead analogs are potent MPOIs that exert specific effects on MPO-mediated oxidation as well as inflammatory pathways. It also acts as promoters of cholesterol efflux that sheds light on pharmacological approach in atherosclerosis treatment.

Merging memantine and ferulic acid to probe connections between NMDA receptors, oxidative stress and amyloid-ß peptide in Alzheimer's disease.

N-methyl-d-aspartate receptors (NMDAR) are critically involved in the pathogenesis of Alzheimer's disease (AD). Acting as an open-channel blocker, the anti-AD drug memantine preferentially targets NMDAR overactivation, which has been proposed to trigger neurotoxic events mediated by amyloid ß peptide (Aß) and oxidative stress. In this study, we applied a multifunctional approach by conjugating memantine to ferulic acid, which is known to protect the brain from Aß neurotoxicity and neuronal death caused by ROS. The most interesting compound (7) behaved, like memantine, as a voltage-dependent antagonist of NMDAR (IC50 = 6.9 µM). In addition, at 10 µM concentration, 7 exerted antioxidant properties both directly and indirectly through the activation of the Nrf-2 pathway in SH-SY5Y cells. At the same concentration, differently from the parent compounds memantine and ferulic acid alone, it was able to modulate Aß production, as revealed by the observed increase of the non-amyloidogenic sAPPα in H4-SW cells. These findings suggest that compound 7 may represent a promising tool for investigating NMDAR-mediated neurotoxic events involving Aß burden and oxidative damage.

Ferulic Acid Esters and Withanolides: In Search of Withania somnifera GABAA Receptor Modulators.

Nine compounds, including two undescribed withanolides, withasomniferolides A and B (1 and 2), three known withanolides (3-5), a ferulic acid dimeric ester (6), and an inseparable mixture of three long alkyl chain ferulic acid esters (7-9), were isolated from a GABAA receptor positive activator methanol extract of the roots of Withania somnifera. The structures of the isolated compounds were elucidated based on NMR, MS, and ECD data analysis. In order to bioassay the single ferulic acid derivatives, compounds 6-9 were also synthesized. The most active compound, docosanyl ferulate (9), was able to enhance the GABAA receptor inhibitory postsynaptic currents with an IC50 value of 7.9 µM. These results, by showing an ability to modulate the GABAA receptor function, cast fresh light on the biological activities of the secondary metabolites of W. somnifera roots.

Novel HDAC6 selective inhibitors with 4-aminopiperidine-1- carboxamide as the core structure enhanced growth inhibitory activity of bortezomib in MCF-7 cells.

In epigenetics, histone deacetylases (HDACs) are well validated targets for the development of anticancer drugs. In this work, we reported the design and synthesis of a series of twenty two novel (E)-N-hydroxycinnamamide-based HDAC inhibitors with 4-aminopiperidine1-carboxamide as the core structure. Most newly synthesized compounds displayed high inhibition rates toward HDAC at the concentration of 1 µM. Among them, the inhibition rates of compounds LYP-2, LYP-3, LYP-6, and LYP-15 were more than 75%. Furthermore, compounds LYP-2, LYP-3, and LYP-6 potently inhibited the activity of HDAC6 with selectivity over HDAC1. We chose LYP-2 and LYP-6 to test its antiproliferative effect on breast cancer cells MCF-7. Either LYP-2 or LYP-6 alone moderately suppressed the cell growth, but could synergistically enhance the inhibitory effect of bortezomib. These results suggested that combined HDAC6 inhibitor and bortezomib regimen might be an option for breast cancer treatment.

Synthesis, antioxidant and Aß anti-aggregation properties of new ferulic, caffeic and lipoic acid derivatives obtained by the Ugi four-component reaction.

We report herein the synthesis antioxidant and Aß anti-aggregation capacity of (E)-N-benzyl-N-[2-(benzylamino)-2-oxoethyl]-3-(aryl)acrylamides and related (R)-N-benzyl-N-(2-(benzylamino)-2-oxoethyl)-5-(1,2-dithiolan-3-yl)pentanamides 1-12. These compounds have been obtained, via Ugi four-component reaction, from modest to good yields. Their antioxidant analysis, using the DPPH and ORAC assays, allowed us to identify compounds 8 and 9, as potent antioxidant agents, showing also strong Aß1-40 self-aggregation inhibition, two biological properties of interest in pathologies linked to the oxidative stress, such as Alzheimer's disease.

Enzymatic crosslinking to fabricate antioxidant peptide-based supramolecular hydrogel for improving cutaneous wound healing.

Peptide-based supramolecular hydrogels are promising scaffold materials and have been utilized in many fields. The mechanical properties of peptide hydrogels are usually enhanced by synthetic or natural polymers to expand their application scope. In this study, antioxidant supramolecular hydrogels based on feruloyl-modified peptide and glycol chitosan were fabricated via a mild laccase-mediated crosslinking reaction. A natural polysaccharide derivative, feruloyl glycol chitosan (GC-Fer), was used to enhance the mechanical properties of peptide hydrogels. Feruloyl groups were introduced into the gel matrix via covalent bonds, which endowed the hydrogels with inherent antioxidant properties. This was beneficial for their in vivo application via scavenging harmful free radicals existing in a cutaneous wound. Further in vivo experiments demonstrated that the feruloyl-containing antioxidant hydrogel can improve the cutaneous wound healing process. The regeneration process of mature epithelium and connective tissues was accelerated in a full-thickness skin defect model.

Design, Synthesis, and Evaluation of Novel Ferulic Acid Derivatives as Multi-Target-Directed Ligands for the Treatment of Alzheimer's Disease.

A novel series of ferulic acid derivatives was designed and synthesized on the basis of the multi-target-directed ligands strategy for the treatment of Alzheimer's disease (AD). In vitro results revealed that all the target compounds were highly effective and selective butyrylcholinesterase (BuChE) inhibitors. In particular, compound TM-10 showed the best BuChE inhibitory activity, with IC50 = 8.9 nM, and remarkable monoamine oxidase A and B inhibitory potency, with IC50 = 6.3 and 8.6 µM, respectively. TM-10 could inhibit (53.9%) and disaggregate (43.8%) self-induced amyloid-ß peptide (Aß) aggregation. In addition, TM-10 exhibited potent antioxidant activity (ORAC = 0.52 equiv) and neuroprotective effect against Aß1-42-mediated SH-SY5Y neurotoxicity, and it acted as an autophagic activator. TM-10 also showed good blood-brain barrier penetration. Furthermore, TM-10 exhibited a favorable dyskinesia recovery rate and response efficiency on an AlCl3-induced zebrafish AD model and a potent neuroprotective effect on Aß1-40-induced zebrafish vascular injury. Further, in vivo assays demonstrated that TM-10 showed low acute toxicity, and the step-down passive avoidance test indicated that this compound could improve scopolamine-induced memory deficit in mice. Therefore, the present study displays evidence that TM-10 is a potent, multi-functional agent against AD and could be a promising lead candidate for anti-Alzheimer's disease drug development.

Type C feruloyl esterase from Aspergillus ochraceus: a butanol specific biocatalyst for the synthesis of hydroxycinnamates in a ternary solvent system

Background: Aspergillus ochraceus was isolated from coffee pulp and selected as an interesting hydroxycinnamoyl esterase strain producer, using an activity microplate high-throughput screening method. In this work, we purified and characterized a new type C A. ochraceus feruloyl esterase (AocFaeC), which synthesized specifically butyl hydroxycinnamates in a ternary solvent system. Results: AocFaeC was produced by solid state fermentation, reaching its maximal activity (1.1 U/g) after 48 h of culture. After purification, the monomeric protein (34 kDa) showed a specific activity of 57.9 U/mg towards methyl ferulate. AocFaeC biochemical characterization confirmed its identity as a type C feruloyl esterase and suggested the presence of a catalytic serine in the active site. Its maximum hydrolytic activity was achieved at 40°C and pH 6.5 and increased by 109 and 77% with Ca2+ and Mg2+, but decreased by 90 and 45% with Hg2+ and Cu2+, respectively. The initial butyl ferulate synthesis rate increased from 0.8 to 23.7 nmol/min after transesterification condition improvement, using an isooctane:butanol:water ternary solvent system, surprisingly the synthesis activity using other alcohols was negligible. At these conditions, the synthesis specific activities for butyl p-coumarate, sinapinate, ferulate, and caffeate were 87.3, 97.6, 168.2, and 234 U/µmol, respectively. Remarkably, AocFaeC showed 5 folds higher butyl caffeate synthesis rate compared to type B Aspergillus niger feruloyl esterase, a well-known enzyme for its elevated activity towards caffeic acid esters. Conclusions: Type C feruloyl esterase from A. ochraceus is a butanol specific biocatalyst for the synthesis of hydroxycinnamates in a ternary solvent system