Search Results (17)

Studies on chimpanzees suggest that some plants are consumed for their biological properties. Low frequency of consumption, small ingested quantities, complex food processing for a low nutritional value, and local ecological knowledge from human populations can serve as useful indicators for detecting self-medicative behavior. Since 2008, wild chimpanzees have been monitored in Sebitoli, Kibale National Park, Uganda. This study focuses on a plant locally called “Angel’s trumpet,” selectively consumed by chimpanzees but previously botanically unidentified. Across 890 observation days, 25 consumption events were recorded involving 18 chimpanzees, each ingesting about 10 g of pith. The plant was botanically identified as Acnistus arborescens, a species native to Central and South America and not previously reported in Africa. The plant is known to contain withanolides particularly studied in mice and humans for their anxiolytic effects. Chemical analysis of leaves and pith conducted during this survey revealed diverse withanolides and cinnamides, with some compounds unique to the pith. This finding highlights a chimpanzee-guided discovery of a non-native plant with known bioactive properties. This study opens avenues for further research on its distribution, potential invasiveness, and potential uses for its biological effects by both humans and wildlife in Africa. Full article

Resistance formation and considerable toxicities limit the application of currently available antiparasitic drugs. Thus, new drug candidates are required. Piperlongumine-based cinnamides are promising antiparasitic compounds. In this study, new synthetic cinnamide derivatives with variable halogen substituents (F, Cl, and Br) were prepared and analyzed. They were tested for activity against Toxoplasma gondii and Leishmania major parasites. Considerable activities against T. gondii parasites were observed for certain chloro- and bromo-substituted cinnamides (IC₅₀ = 1.88–2.72 µM), while activities against L. major were less pronounced. Structure–activity relationships were investigated, which revealed notable relations of anti-toxoplasmal activity with the nature of the applied halogen substituents and a preference for chloro- and bromo-substituents in active compounds. In contrast to piperlongumine, the new active compounds have no methoxy substituents anymore and appear to be suitable for advanced antiparasitic studies. Successful docking of selected derivatives into the colchicine binding site of tubulin provided a strong hint at a possible mode of action for these cinnamides (S-scores of −6.075 and −5.993 kcal/mol). In addition, considerable drug-like properties were determined by ADME-T calculations. Thus, in conclusion, new halo-substituted cinnamides with promising activity against Toxoplasma gondii were identified. The selectivity for Toxoplasma parasites can lead to better drugs for the therapy of toxoplasmosis. Full article

Pharmacophore hybridization is a well-established strategy for developing novel anticancer agents with improved biological profiles. In this study, a new series of (E)-4-(4-acrylamidophenoxy)-N-methylpicolinamide derivatives has been rationally designed by hybridizing key structural features of sorafenib with cinnamide pharmacophores and subsequently synthesized. The antiproliferative activities of the synthesized compounds were evaluated against a panel of human cancer cell lines, including A549 (lung), DU-145 (prostate), SKOV3 (ovarian), and HepG2 (liver), along with non-cancerous Hek293T cells. In comparison with the standard drug sorafenib, most of the (E)-4-(4-acrylamidophenoxy)-N-methylpicolinamides demonstrated significant antiproliferative activity, with specificity toward the HepG2 (liver cancer) cell line, and no effect on the noncancerous cells (Hek293T). Among them, compound 5f, the derivative containing a trifluoromethyl-substituted cinnamoyl moiety was identified as the lead candidate, exhibiting an IC₅₀ of 5.3 µM towards HepG2 (liver) cancer cells, comparable to the reference drug sorafenib. Enzyme inhibition studies showed that compound 5f inhibited both b-Raf and VEGFR-2 with IC₅₀ values of 1.45 and 0.37 µM, respectively. Furthermore, compound 5f suppressed angiogenesis in vitro and in vivo, as evidenced by the tube formation assay using HUVECs and in transgenic zebrafish Tg(fli1a:EGFP) models, respectively. Mechanistic studies indicated that compound 5f induced apoptosis in HepG2 cells through mitochondrial membrane depolarization and increased ROS generation. Molecular docking studies supported experimental findings and showed that 5f can interact with catalytically active residues via hydrogen-bonding interactions. Overall, these results highlight the potential of compound 5f as a promising dual target therapeutic lead with dual direct anticancer and antiangiogenic properties. Full article

Tranilast, an anti-allergic drug with well-established anti-inflammatory, antifibrotic, and antiproliferative properties, suffers from poor water solubility and low bioavailability, which limit its therapeutic potential. To improve its pharmacological profile, we designed and synthesized a novel series of hydroxylated Tranilast analogues. The compounds were obtained through a green, single-step coupling reaction between activated methoxy-substituted hydroxycinnamic acids and anthranilic or hydroxyanthranilic acids, using a triethylamine–isobutyl chloroformate system in environmentally friendly solvents. Fifteen derivatives were isolated in good to excellent yields (63–94%) without chromatographic purification. The synthesized compounds were evaluated for antimicrobial, antioxidant, anti-inflammatory, and antiproliferative activities. Several analogues displayed notable antimicrobial effects against Candida albicans, Staphylococcus aureus, and Klebsiella pneumoniae, with minimum inhibitory concentrations as low as 75 µg/mL. Hydroxylated derivatives showed enhanced radical-scavenging activity in DPPH and ABTS assays compared with Tranilast. Selected compounds also demonstrated suggestive antiproliferative effects against LNCaP prostate cancer cells while maintaining low cytotoxicity toward HaCaT keratinocytes, indicating favourable selectivity. Furthermore, some derivatives significantly reduced nitric oxide production in LPS-stimulated HaCaT cells, confirming their anti-inflammatory potential. Overall, hydroxylation proves to be an effective strategy for improving the biological profile of Tranilast, yielding promising candidates for further pharmacological development. Full article

Natural alkylated hydroxy cinnamates (AHCs) isolated from medicinal plants and the thereby designed and synthesized cinnamides are derivatives of hydroxy cinnamic acids such as p-coumaric, sinapic, ferulic, and caffeic acids, which are naturally derived from human dietary sources. The pharmacological properties displayed by AHCs based on their inherent structure range include antioxidant, antimicrobial, antiplasmodial, anti-tyrosinase, Alzheimer’s and Parkinson’s disease therapy, anticancer therapy, metabolic disease therapy, and biopesticides, which have not been reviewed together. Based on their inherent antioxidant, antimicrobial, and UV absorption and their structure–activity relationships, these cinnamyl esters and amides can be used for food preservation in emulsions and oils, as sun-protective components of skin care formulations, and in many other multifunctional applications. In conclusion, the fine-tuning of the structural features such as the type of hydroxy cinnamic acid used, the length of alkyl chains for variable lipophilicity, conversion from cinnamic to propanoic for antioxidants, the increase in methoxy or the change to amino groups to increase the molar absorption coefficient and loss of absorption values, the substitution by halides or amino groups for potent biopesticides, and conversion from esters to amide bonds leads to different AHCs for biomedical, cosmetic, and agriculture applications as an emerging field of investigation that can overall provide natural, safe, biodegradable, and sustainable molecules. Full article

Cinnamides are common core structures that exist in a great number of pharmaceuticals and natural products. The development of efficient methods for preparing cinnamides is in great need. We report herein an efficient polyphosphoric acid (PPA)-promoted direct aldol condensation of an amide for the convenient and straightforward preparation of cinnamides. A variety of cinnamides were obtained in moderate-to-excellent yields (65–89%). This strategy features the use of equivalent amides and a short reaction time. Full article

Leishmaniasis is a group of infectious diseases caused by protozoan parasites that belong to the genus Leishmania. Currently, there is no human vaccine, and the available treatments are associated with toxicity, high cost, and the emergence of resistant strains. These factors highlight the need to identify new antileishmanial candidates. In this study, we synthesized twenty-four methoxylated cinnamides containing 1,2,3-triazole fragments and evaluated their antileishmanial activity against the Leishmania braziliensis species, which is the main etiological agent responsible for American Tegumentary Leishmaniasis (ATL). The cinnamides were synthetically prepared using nucleophilic acyl substitution and copper(I)-catalyzed azide–alkyne cycloaddition (CuAAC) reactions. The compounds were characterized using infrared, nuclear magnetic resonance, and high-resolution mass spectrometry techniques. We performed preliminary studies to evaluate the biological activity of these compounds against L. braziliensis promastigotes and axenic amastigotes. Compound 28, N-((1-(7-(diethylamino)-2-oxo-2H-chromen-3-yl)-1H-1,2,3-triazole-4-yl) methyl)-3,4-dimethoxy cinnamide, demonstrated relevant antileishmanial activity with low toxicity in murine cells. The selectivity index values for this compound were superior compared with data obtained using amphotericin B. Furthermore, this cinnamide derivative reduced the infection percentage and number of recovered amastigotes in L. braziliensis-infected macrophages. It also induced an increase in reactive oxygen species production, depolarization of the mitochondrial potential, and disruption of the parasite membrane. Taken together, these findings suggest that this synthetic compound holds potential as an antileishmanial candidate and should be considered for future studies in the treatment of ATL. Full article

The severity of infectious diseases associated with the resistance of microorganisms to drugs highlights the importance of investigating bioactive compounds with antimicrobial potential. Therefore, nineteen synthetic cinnamides and cinnamates having a cinnamoyl nucleus were prepared and submitted for the evaluation of antimicrobial activity against pathogenic fungi and bacteria in this study. To determine the minimum inhibitory concentration (MIC) of the compounds, possible mechanisms of antifungal action, and synergistic effects, microdilution testing in broth was used. The structures of the synthesized products were characterized with FTIR spectroscopy, ¹ H-NMR, ¹³ C-NMR, and HRMS. Derivative 6 presented the best antifungal profile, suggesting that the presence of the butyl substituent potentiates its biological response (MIC = 626.62 μM), followed by compound 4 (672.83 μM) and compound 3 (726.36 μM). All three compounds were fungicidal, with MFC/MIC ≤ 4. For mechanism of action, compounds 4 and 6 directly interacted with the ergosterol present in the fungal plasmatic membrane and with the cell wall. Compound 18 presented the best antibacterial profile (MIC = 458.15 μM), followed by compound 9 (550.96 μM) and compound 6 (626.62 μM), which suggested that the presence of an isopropyl group is important for antibacterial activity. The compounds were bactericidal, with MBC/MIC ≤ 4. Association tests were performed using the Checkerboard method to evaluate potential synergistic effects with nystatin (fungi) and amoxicillin (bacteria). Derivatives 6 and 18 presented additive effects. Molecular docking simulations suggested that the most likely targets of compound 6 in C. albicans were caHOS2 and caRPD3, while the most likely target of compound 18 in S. aureus was saFABH. Our results suggest that these compounds could be used as prototypes to obtain new antimicrobial drugs. Full article

Arginase is a metalloenzyme that plays a central role in Leishmania infections. Previously, rosmarinic and caffeic acids were described as antileishmanial agents and as Leishmania amazonensis arginase inhibitors. Here, we describe the inhibition of arginase in L. amazonensis by rosmarinic acid analogs (1–7) and new caffeic acid-derived amides (8–10). Caffeic acid esters and amides were produced by means of an engineered synthesis in E. coli and tested against L. amazonensis arginase. New amides (8–10) were biosynthesized in E. coli cultured with 2 mM of different combinations of feeding substrates. The most potent arginase inhibitors showed Ki(s) ranging from 2 to 5.7 μM. Compounds 2–4 and 7 inhibited L. amazonensis arginase (L-ARG) through a noncompetitive mechanism whilst compound 9 showed a competitive inhibition. By applying an in silico protocol, we determined the binding mode of compound 9. The competitive inhibitor of L-ARG targeted the key residues within the binding site of the enzyme, establishing a metal coordination bond with the metal ions and a series of hydrophobic and polar contacts supporting its micromolar inhibition of L-ARG. These results highlight that dihydroxycinnamic-derived compounds can be used as the basis for developing new drugs using a powerful tool based on the biosynthesis of arginase inhibitors. Full article

In order to overcome the resistance of phytopathogens to commercial fungicides, a series of optical 2-methyl-2,3-diol-5-pentyl-based cinnamamide derivatives were rationally designed, synthesized, characterized, and evaluated for their in vitro and in vivo fungicidal activities. The bioassay results indicated that the EC₅₀ (concentration for 50% of maximal effect) values of (R)-11f, (R)-11m, (S)-11m and (R)-11n were 0.16, 0.28, 0.41 and 0.47 µg/mL in the in vitro evaluation against Sclerotinia sclerotiorum, respectively, while compounds (R)- and (S)-11i, (R)- and (S)-11j exhibited excellent in vivo fungicidal activity against Pseudoperonspera cubensis with inhibition rates of 100% at 400 μg/mL. These findings supported the idea that optical 2-methyl-2,3-diol-5-pentyl-containing cinnamamides (R)- and (S)-11i, (R)- and (S)-11j with 2-chloro-4-trifluoromethyl aniline and 2-(4-chlorophenyl) aniline showed excellent in vivo fungicidal activity against S. sclerotiorum and P. cubensis and were promising fungicide candidates. Full article

Caffeic acid and related natural compounds were previously described as Leishmania amazonensis arginase (L-ARG) inhibitors, and against the whole parasite in vitro. In this study, we tested cinnamides that were previously synthesized to target human arginase. The compound caffeic acid phenethyl amide (CAPA), a weak inhibitor of human arginase (IC₅₀ = 60.3 ± 7.8 μM) was found to have 9-fold more potency against L-ARG (IC₅₀ = 6.9 ± 0.7 μM). The other compounds that did not inhibit human arginase were characterized as L-ARG, showing an IC₅₀ between 1.3–17.8 μM, and where the most active was compound 15 (IC₅₀ = 1.3 ± 0.1 μM). All compounds were also tested against L. amazonensis promastigotes, and only the compound CAPA showed an inhibitory activity (IC₅₀ = 80 μM). In addition, in an attempt to gain an insight into the mechanism of competitive L-ARG inhibitors, and their selectivity over mammalian enzymes, we performed an extensive computational investigation, to provide the basis for the selective inhibition of L-ARG for this series of compounds. In conclusion, our results indicated that the compounds based on cinnamoyl or 3,4-hydroxy cinnamoyl moiety could be a promising starting point for the design of potential antileishmanial drugs based on selective L-ARG inhibitors. Full article

Gx-50 is a bioactive compound for the treatment of Alzheimer’s disease (AD) found in Sichuan pepper (Zanthoxylum bungeanum). In order to find a stronger anti-AD lead compound, 20 gx-50 (1–20) analogs have been designed and synthesized, and their molecular structures were determined based on nuclear magnetic resonance (NMR) and mass spectrometry (MS) analysis, as well as comparison with literature data. Compounds 1–20 were evaluated for their anti-AD potential by using DPPH radical scavenging assay for considering their anti-oxidant activity, thioflavin T (ThT) fluorescence assay for considering the inhibitory or disaggregate potency of Aβ, and transgenic Drosophila model assay for evaluating their rescue effect on memory loss. Finally, compound 13 was determined as a promising anti-AD candidate. Full article

Dysregulated human monocytes/macrophages can synthesize and secrete matrix metalloproteinases (MMPs), which play important roles in the progression of sepsis. In this study, we investigated the effects and mechanism of a novel histone deacetylase (HDAC8) inhibitor, (E)-N-hydroxy-4-methoxy-2-(biphenyl-4-yl)cinnamide (WK2-16), on MMP-9 production and activation in stimulated human monocytic THP-1 cells. Our results demonstrated that the acetylation level of structural maintenance of chromosomes 3 (SMC3) was up-regulated by WK2-16 in THP-1 cells. Consistently, an in vitro enzyme study demonstrated that WK2-16 selectively inhibited HDAC8 activity. Moreover, the WK2-16 concentration dependently suppressed MMP-9-mediated gelatinolysis induced by tumor necrosis factor-α (TNF-α) or lipopolysaccharide (LPS). Additionally, WK2-16 significantly inhibited both MMP-9 protein and mRNA expression without cellular toxicity. Nevertheless, WK2-16 suppressed the extracellular levels of interleukin (IL)-6 from LPS-stimulated THP-1 cells. For the signaling studies, WK2-16 had no effect on LPS/TLR4 downstream signaling pathways, such as the NF-κB and ERK/JNK/P38 MAPK pathways. On the other hand, WK2-16 enhanced the recruitment of acetylated Yin Yang 1 (YY1) with HDAC1. Finally, in vivo studies indicated that WK2-16 could reduce the serum levels of TNF-α and IL-6 in endotoxemic mice. These results suggested that HDAC8 inhibition might provide a novel therapeutic strategy of hypercytokinemia in sepsis. Full article

Arginases are enzymes that are involved in many human diseases and have been targeted for new treatments. Here a series of cinnamides was designed, synthesized and evaluated in vitro and in silico for their inhibitory activity against mammalian arginase. Using a microassay on purified liver bovine arginase (b-ARG I), (E)-N-(2-phenylethyl)-3,4-dihydroxycinnamide, also named caffeic acid phenylamide (CAPA), was shown to be slightly more active than our natural reference inhibitor, chlorogenic acid (IC₅₀ = 6.9 ± 1.3 and 10.6 ± 1.6 µM, respectively) but it remained less active that the synthetic reference inhibitor N^ω-hydroxy-nor-l-arginine nor-NOHA (IC₅₀ = 1.7 ± 0.2 µM). Enzyme kinetic studies showed that CAPA was a competitive inhibitor of arginase with Ki = 5.5 ± 1 µM. Whereas the activity of nor-NOHA was retained (IC₅₀ = 5.7 ± 0.6 µM) using a human recombinant arginase I (h-ARG I), CAPA showed poorer activity (IC₅₀ = 60.3 ± 7.8 µM). However, our study revealed that the cinnamoyl moiety and catechol function were important for inhibitory activity. Docking results on h-ARG I demonstrated that the caffeoyl moiety could penetrate into the active-site pocket of the enzyme, and the catechol function might interact with the cofactor Mn²⁺ and several crucial amino acid residues involved in the hydrolysis mechanism of arginase. The results of this study suggest that 3,4-dihydroxycinnamides are worth being considered as potential mammalian arginase inhibitors, and could be useful for further research on the development of new arginase inhibitors. Full article