Synthesis of (E)-cinnamyl ester derivatives via a greener Steglich esterification

Synthesis, highly potent α-glucosidase inhibition, antioxidant and molecular docking of various novel dihydropyrimidine derivatives to treat diabetes mellitus

1,4-dihydropyrimidine-2-thiones were synthesized in five series that include 5-carboxylic acid derivatives of dihydropyrimidine (series A, 6-8), novel 5-carboxamide derivatives of dihydropyrimidine (series B, 9-14), N,S-dimethyl-dihydropyrimidine (series C, 15-20), N-hydrazinyl derivatives of dihydropyrimidine (series D, 21-24) and tetrazolo dihydropyrimidine derivatives (series E, 25-28), and evaluated for anti-diabetic capability. The prepared novel compounds were structurally established by FTIR, 1HNMR, 13CNMR, ESI and HRMS. All of these compounds from series A-E were first time examined for α-glucosidase inhibition as to evaluate their anti-diabetic potential. Most of the compounds for example 8, 11-14, 15, 17-21, 25 and 28 demonstrated greater α-glucosidase inhibitory effects (IC50 = 12.5 ± 0.21 to 47.3 ± 0.23 μM) when compared to deoxynojirimycin as standard (IC50 = 52.02 ± 0.36 μM). Compounds from series B and C found to be highly active however, the compounds from series D found generally less active. The structure-activity relationships demonstrated the importance of C-5 carboxamides, C-5 ethyl ester functionality, and the presence of N,S-dimethyl groups at pyrimidine ring for α-glucosidase inhibition. The docking studies demonstrated that all the active compounds have van der Waals and alkyl bonds interactions with the targeted site of the human lysosomal acid α-glucosidase. All these compounds were also tested for antioxidant potential by DPPH radical scavenging protocol that exhibited significant antioxidant effects (IC50 = 21.4 ± 0.45 to 92.1 ± 0.38 μM) as compared to the standard butylated hydroxyanisol (IC50 = 44.2 ± 0.36 μM). Among all, compound 13, 14 and 19 with potent α-glucosidase inhibition (IC50 = 18.9 ± 0.72, 23.3 ± 0.45 and 21.5 ± 0.16 µM, respectively) along with excellent antioxidant potential in the range of (IC50 = 21.4 ± 0.45 to 31.2 ± 0.23 μM) indicated their ability to use as valuable leads for the development of anti-diabetic drugs with the combined effects of antioxidants.

Metabolic, toxicological, chemical, and commercial perspectives on esterification of dietary polyphenols: a review

Molecular modifications have been practiced for more than a century and nowadays they are widely applied in food, pharmaceutical, or other industries to manipulate the physicochemical, bioactivity, metabolic/catabolic, and pharmacokinetic properties. Among various structural modifications, the esterification/O-acylation has been well-established in altering lipophilicity and bioactivity of parent bioactive compounds, especially natural polyphenolics, while maintaining their high biocompatibility. Meanwhile, various classic chemical and enzymatic protocols and other recently emerged cell factory technology are being employed as viable esterification strategies. In this contribution, the main motivations of phenolic esterification, including the tendency to replace synthetic alkyl phenolics with safer alternatives in the food industry to improve the bioavailability of phenolics as dietary supplements/pharmaceuticals, are discussed. In addition, the toxicity, metabolism, and commercial application of synthetic and natural phenolics are briefly introduced. Under these contexts, the mechanisms and reaction features of several most prevalent chemical and enzymatic esterification pathways are demonstrated. In addition, insights into the studies of esterification modification of natural phenolic compounds and specific pros/cons of various reaction systems with regard to their practical application are provided.

-COOH & -OH Condensation Reaction Utilization for Biomass FDCA-based Polyesters

A green and sustainable -COOH & -OH condensation solution polymerization method was hereby reported for FDCA-based polyesters to avoid discoloration and toxic solvents. First, taking poly(ethylene 2,5-furandicarboxylate) (PEF) as the representative of FDCA-based polyester, enabling good white appearance PEF with Mn=6.51×103 g mol-1 from FDCA and ethylene glycol in green solvent γ-valerolactone (GVL), catalyzed by 4-dimethylaminopyridine (DMAP) and N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride (EDC). Additionally, the molecular weight of PEF was rapidly improved (Mn >2.5×104 g mol-1) via remelting polycondensation within minutes, with the dispersity still kept relatively low dispersity (Đ<1.40). Importantly, the -COOH & -OH condensation solution polymerization method was successfully applied for the synthesis of various FDCA-based polyesters, including diols with varying carbon chain lengths (3 to 11 carbons) and cycloalkyl diols, especially the applicability of this method to diols containing C=C double bonds, which was found to exhibit low heat resistance. Lastly, assisting with 13C labeled 1,4-succinic acid and in-situ 13C-NMR, an in-depth study of the possible catalytic mechanism was proposed, by which, EDC activated FDCA, and then DMAP catalyzed it with diol to yield macromolecular chain of polyester. Overall, the results provided a green and sustainable strategy for the synthesis of FDCA-based polyesters.

Unveiling the Role of DMAP for the Se-Catalyzed Oxidative Carbonylation of Alcohols: A Mechanism Study

Considering the remarkable catalytic activity (160 times higher) of Se/DMAP for the oxidative carbonylation of alcohols, unveiling the role of DMAP in catalysis is highly required. We investigated DFT calculations, and the proposed intermediates were verified with in situ ATR-FTIR analysis. DFT showed that the formation of [DMAP···HSe]δ-[DMAP(CO)OR]δ+ (IV) via nucleophilic substitution of DMAP at the carbonyl group of DMAP···HSe(CO)OR is the most energetically favorable. DMAP acts as both a nucleophile and a hydrogen bond acceptor, which is responsible for its remarkable activity.

Solid chip-based detection of trace morphine in solutions via portable surface-enhanced Raman spectroscopy

The accurate, sensitive and portable detection of morphine is important to handle judicial cases, but remains to be a great challenge. In this work, a flexible route is presented for the accurate identification and efficient detection of trace morphine in solutions based on surface-enhanced Raman spectroscopy (SERS) and a solid substrate/chip. A gold-coated jagged silicon nanoarray (Au-JSiNA) is designed and prepared via Si-based polystyrene colloidal template-reactive ion etching and sputtering deposition of Au. Such Au-JSiNA has three-dimensional nanostructure with good structural uniformity, high SERS activity and hydrophobic surface. Adopting this Au-JSiNA as SERS chip, trace morphine in solutions could be detected and identified in both dropping and soaking ways, and the limit of detection is below 10-4 mg/mL. Importantly, such chip is especially suitable for the detection of trace morphine in aqueous solutions and even domestic sewage. The good SERS performance is attributed to the high-density nanotips and nanogaps on this chip as well as its hydrophobic surface. Additionally, the appropriate surface modification of this Au-JSiNA chip with 3-mercapto-1-propanol or 3-mercaptopropionic acid/1-(3-dimethylaminopropyl)-3-ethylcarbodiimide can further increase its SERS performances to morphine. This work provides a facile route and practical solid chip for SERS detection of trace morphine in solutions, which is significant to develop the portable and reliable instruments for on-site analysis of drugs in solutions.

Investigation of new ferrocenyl-artesunate derivatives as antiparasitics

Artesunate (Ars) is a semisynthetic antimalarial drug and is a part of the artemisinin-based combination therapy arsenal employed for malaria treatment. The drug functions mainly by activation of its endoperoxide bridge leading to increased oxidative stress in malaria parasites. The purpose of this study was to ascertain the antiparasitic effects of combining ferrocene and Arsvia short or long chain ester or amide linkages (C1-C4). The compounds were evaluated for growth inhibition activity on the apicomplexan parasites, Plasmodium falciparum (P. falciparum) and Toxoplasma gondii (T. gondii). All the complexes demonstrated good activity against T. gondii with IC50 values in the low micromolar range (0.28-1.2 μM) and good to excellent antimalarial activity against a chloroquine sensitive strain of P. falciparum (NF54). Further investigations on T. gondii revealed that the likely mode of action (MoA) is through the generation of reactive oxygen species. Additionally, immunofluorescence microscopy suggested a novel change in the morphology of the parasite by complex C3, an artesunate-ferrocenyl ethyl amide complex. The complexes were not cytotoxic or showed low cytotoxicity to two normal cell lines tested.

Synthesis and in silico study of chenodeoxycholic acid and its analogues as an alternative inhibitor of spike glycoprotein of SARS-CoV-2

COVID-19, caused by SARS-CoV-2, is a viral infection that has generated one of the most significant health problems in the world. Spike glycoprotein is a crucial enzyme in viral replication and transcription mediation. There are reports in the literature on using bile acid in the fight against this virus through in vitro tests. This work presents the synthesis of nine chenodeoxycholic acid derivatives (1-9), which were prepared by oxidation, acetylation, formylation, and esterification reactions, and the analogs 6-9 have not yet been reported in the literature and the possibility of conducting an in silico study of bile acid derivatives as a therapeutic alternative to combat the virus using glycoprotein as a macromolecular target. As a result, five compounds (1, 6-9) possessed favorable competitive interactions with the lowest energies compared to the native ligand (BLA), and the highlighted compound 9 got the best scores. At the same time, analog 1 presented the best ADME filter result. Molecular dynamics also simulated these compounds to verify their stability within the active protein site to seek new therapeutic propositions to fight against the pandemic. Physical and spectroscopic data have fully characterized all the compounds.Communicated by Ramaswamy H. Sarma.

Dimeric ferulic acid conjugate as a prodrug for brain targeting after nasal administration of loaded solid lipid microparticles

OBJECTIVE

Ferulic acid (Fer) displays antioxidant/anti-inflammatory properties useful against neurodegenerative diseases. To increase Fer uptake and its central nervous system residence time, a dimeric prodrug, optimizing the Fer loading on nasally administrable solid lipid microparticles (SLMs), was developed.

METHODS

The prodrug was synthesized as Fer dimeric conjugate methylated on the carboxylic moiety. Prodrug antioxidant/anti-inflammatory properties and ability to release Fer in physiologic environments were evaluated. Tristearin or stearic acid SLMs were obtained by hot emulsion technique. In vivo pharmacokinetics were quantified by HPLC.

RESULTS

The prodrug was able to release Fer in physiologic environments (whole blood and brain homogenates) and induce in vitro antioxidant/anti-inflammatory effects. Its half-life in rats was 18.0 ± 1.9 min. Stearic acid SLMs, exhibiting the highest prodrug loading and dissolution rate, were selected for nasal administration to rats (1 mg/kg dose), allowing to obtain high prodrug bioavailability and prolonged residence in the cerebrospinal fluid, showing AUC (Area Under Concentration) values (108.5 ± 3.9 μg∙mL-1∙min) up to 30 times over those of Fer free drug, after its intravenous/nasal administration (3.3 ± 0.3/5.16 ± 0.20 μg∙mL-1∙min, respectively) at the same dose. Chitosan presence further improved the prodrug brain uptake.

CONCLUSIONS

Nasal administration of prodrug-loaded SLMs can be proposed as a noninvasive approach for neurodegenerative disease therapy.

Synthesis and characterisation of novel composite sunscreens containing both avobenzone and octocrylene motifs

Avobenzone and octocrylene are popular sunscreen active ingredients. Experiments that probe the stability of avobenzone in binary mixtures with octocrylene are presented, together with the synthesis of a class of novel composite sunscreens that were designed by covalently linking avobenzone and octocrylene groups. Spectroscopy, both steady-state and time-resolved, of the fused molecules was performed to investigate the stability of the new molecules and their potential function as ultraviolet filters. Computational results are detailed for truncated versions of a subset of the molecules to reveal the energy states underlying the absorption processes of this new class of sunscreen. The results indicate that the combination of elements of the two sunscreen molecules into one molecule creates a derivative with good stability to UV light in ethanol and in which the main degradation pathway of the avobenzone component in acetonitrile is reduced. Derivatives containing p-chloro substituents are particularly stable to UV light.

Antileishmanial Activity of Cinnamic Acid Derivatives against Leishmania infantum

Leishmania infantum is the etiological agent of visceral leishmaniasis (VL) in South America, the Mediterranean basin, and West and Central Asia. The most affected country, Brazil, reported 4297 VL cases in 2017. L. infantum is transmitted by female phlebotomine sand flies during successive blood meals. There are no validated vaccines to prevent the infection and the treatment relies on drugs that often present severe side effects, which justify the efforts to find new antileishmanial drugs. Cinnamic acid derivatives have shown several pharmacological activities, including antiparasitic action. Therefore, in the present study, the biological evaluation of cinnamic acid and thirty-four derivatives against L. infantum is reported. The compounds were prepared by several synthesis methods and characterized by spectroscopic techniques and high-resolution mass spectrometry. The results revealed that compound 32 (N-(4-isopropylbenzyl)cinnamamide) was the most potent antileishmanial agent (IC₅₀ = 33.71 μM) with the highest selectivity index (SI > 42.46), followed by compound 15 (piperonyl cinnamate) with an IC₅₀ = 42.80 μM and SI > 32.86. Compound 32 was slightly less potent and nineteen times more selective for the parasite than amphotericin B (MIC = 3.14 uM; SI = 2.24). In the molecular docking study, the most likely target for the compound in L. infantum was aspartyl aminopeptidase, followed by aldehyde dehydrogenase, mitochondrial. The data obtained show the antileishmanial potential of this class of compounds and may be used in the search for new drug candidates against Leishmania species.

Synthetic Cinnamides and Cinnamates: Antimicrobial Activity, Mechanism of Action, and In Silico Study

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.

Ethyl (E)-(3-(4-((4-Bromobenzyl)Oxy)Phenyl)Acryloyl)Glycinate

In an attempt to develop new potent anti-inflammatory agents, a cinnamic -amino acid hybrid molecule was synthesized and in silico drug-likeness, in vitro COX-2 inhibition, and pharmacokinetic properties were studied. The results showed high cyclooxygenase inhibitory activity (IC50 = 6 µM) and favorable pharmacokinetic properties, being orally bioavailable according to Lipinski’s rule of five, making this compound a possible lead to design and develop potent COX inhibitors. The new compound, in comparison with its cinnamic acid precursor (E)-(3-(4-((4-bromobenzyl)oxy)phenyl)acrylic acid, showed improved biological activities. Compound ethyl (E)-(3-(4-((4-bromobenzyl)oxy)phenyl)acryloyl)glycinate can be used as a lead for the synthesis of more effective hybrids.

Synthesis of Coumarin and Homoisoflavonoid Derivatives and Analogs: The Search for New Antifungal Agents

A set of twenty-four synthetic derivatives, with coumarin and homoisoflavonoid cores and structural analogs, were submitted for evaluation of antifungal activity against various species of Candida. The broth microdilution test was used to determine the Minimum Inhibitory Concentration (MIC) of the compounds and to verify the possible antifungal action mechanisms. The synthetic derivatives were obtained using various reaction methods, and six new compounds were obtained. The structures of the synthesized products were characterized by FTIR spectroscopy: ¹H-NMR, ¹³C-NMR, and HRMS. The coumarin derivative 8 presented the best antifungal profile, suggesting that the pentyloxy substituent at the C-7 position of coumarin ring could potentiate the bioactivity. Compound 8 was then evaluated against the biofilm of C. tropicalis ATCC 13803, which showed a statistically significant reduction in biofilm at concentrations of 0.268 µmol/mL and 0.067 µmol/mL, when compared to the growth control group. For a better understanding of their antifungal activity, compounds 8 and 21 were submitted to a study of the mode of action on the fungal cell wall and plasma membrane. It was observed that neither compound interacted directly with ergosterol present in the fungal plasma membrane or with the fungal cell wall. This suggests that their bioactivity was due to interaction involving other pharmacological targets. Compound 8 was also subjected to a molecular modeling study, which showed that its antifungal action mechanism occurred mainly through interference in the redox balance of the fungal cell, and by compromising the plasma membrane; not by direct interaction, but by interference in ergosterol synthesis. Another important finding was the antifungal capacity of homoisoflavonoids 23 and 24. Derivative 23 presented slightly higher antifungal activity, possibly due to the presence of the methoxyl substituent in the meta position in ring B.

Nematicidal activity of furanoeremophilenes against Meloidogyne incognita and Nacobbus aberrans

BACKGROUND

While searching for novel small molecules for new organic pesticide agents against plant-parasitic nematodes, we found that the hexane extract from the roots of Senecio sinuatos and its main secondary metabolite, 3β-angeloyloxy-6β-hydroxyfuranoeremophil-1(10)-ene (1), possess nematicidal activity against the second stage juvenile (J2) of Meloidogyne incognita and Nacobbus aberrans. Both species reduce yield of various vegetable crops. These results encouraged us to synthesize esters 3-9 formed by diol 2, obtained by alkaline hydrolysis of 1 and acetic anhydride, benzoic acid, 2-nitrobenzoic acid, 2-bromobenzoic acid, 4-nitrobenzoic acid, 4-bromobenzoic acid, and 4-methoxybenzoic acid, respectively. The nematicidal activity of these esters was evaluated and compared with that of the free benzoic acids.

RESULTS

Natural product 1 and derivatives 2-9 were obtained and characterized by their physical and spectroscopic properties, including one-dimensional (1D) and two-dimensional (2D) nuclear magnetic resonance (NMR) experiments; X-ray diffraction analysis established their absolute configuration. The nematicidal activity of compounds 1-9 was assessed in vitro against M. incognita and N. aberrans J2 and was compared to activity shown by benzoic acid, 2-nitrobenzoic acid, 2-bromobenzoic acid, 4-nitrobenzoic acid, 4-bromobenzoic acid, and 4-methoxybenzoic acid. The esters suppressed nematodes more than free benzoic acid. Nacobbus aberrans J2 were suppressed, with compounds 5, 6, and 8 being the most active.

CONCLUSION

Esters formed by 3β,6β-dihydroxyfuranoeremophil-1(10)-ene and ortho- or para-substituted benzoic acids containing electron acceptor groups had nematicidal activity against N. aberrans. These compound can potentially serve as a model for the development of new organic nematicidal agents. © 2022 Society of Chemical Industry.

Novelty in the development of biodegradable polymer coatings for biomedical devices: paclitaxel grafting on PDMMLA derivatives

Biocompatible and biodegradable polymers are widely used in the medical field. In some cases, the biopolymer is accompanied by an active drug, which is delivered locally in a controlled manner in order to improve the healing conditions. Poly([R,S]-3,3-dimethylmalic acid) (PDMMLA) is a synthetic amphiphilic biodegradable polymer, which unlike PLA, can be chemically modified to adapt hydrophilic/hydrophobic balance, degradation kinetics, and physicochemical and biological properties. It may contain a lateral alkyl group or a functional group for coupling bioactive molecules to release during its degradation. In this work, we realized the chemical grafting of paclitaxel (PTX), a microtubule stabilizing anti-cancer agent on PDMMLA derivatives bio-polyesters following a Steglich esterification protocol. 1D and 2D NMR analyses validated the reaction with 10% (using 0.1 equivalent) of PTX on the copolymer PDMMLAH₄₀-co-Hex₆₀ (PDMMLA 40/60) and a maximal PTX grafting rate of 55% on the homopolymer PDMMLAH (PDMMLA 100/0). In vitro adhesion and cytotoxicity assays were carried out on HUVEC cells with PDMMLA 40/60, PDMMLA-PTX 30/10/60 and PLA.

Dermal Absorption of Sesquiterpene Lactones from Arnica Tincture

Arnica tincture is a traditional herbal medicine used to treat blunt injuries, e.g., bruises and squeezes. In addition, a potential new use in the treatment of cutaneous leishmaniasis is currently under investigation. Therefore, detailed information about the dermal absorption of the tincture and especially its bioactive constituents, sesquiterpene lactones (STLs) of the helenalin- and 11α,13-dihydrohelenalin type, is mandatory. Consequently, this article reports on dermal absorption studies of Arnica tincture using diffusion cells and porcine skin as well as two human skin samples with different permeability. The amounts of STLs on the skin surfaces, in skin extracts and in the receptor fluids were quantified by ultra-high-performance liquid chromatography with high-resolution mass spectrometry (UHPLC-HRMS). It was found that Arnica STLs permeated into the receptor fluid already 4 h after the application, but the amount was rather low. Within 48 h, a maximum of 8.4%, 14.6% and 36.4% of STLs permeated through porcine skin, human skin A (trans-epidermal water loss (TEWL) = 11.518 g·m⁻²·h⁻¹) and the more permeable human skin B (TEWL = 17.271 g·m⁻²·h⁻¹), respectively. The majority of STLs was absorbed (penetrated into the skin; 97.6%, 97.8% and 99.3%) after 48 h but a huge portion could not be extracted from skin and is expected to be irreversibly bound to skin proteins. To better visualize the analytes in different skin layers, a fluorescence-labeled STL, helenalin 3,4-dimethoxycinnamate, was synthesized. Fluorescence microscopic images depict an accumulation of the fluorescent derivative in the epidermis. For the treatment of local, cutaneous complaints, an enrichment of the bioactive substances in the skin may be considered beneficial.

Characterization of novel cellulose nanofibril and phenolic acid-based active and hydrophobic packaging films

Cellulose nanofibril (CNF) is a natural biodegradable biopolymer with excellent mechanical and barrier properties. However, it is susceptible to moisture-induced deterioration of its properties. Attachment of phenolic acids can improve its hydrophobicity and provide additional active functionalities such as antioxidant properties. In this study, CNF films were esterified to vanillic and syringic acid through two different reaction mechanisms. The films were investigated for evidence of modification, hydrophobicity, mechanical properties, crystallinity, thermal stability, and antioxidant properties. Results indicate that esterification with vanillic and syringic acids imparted antioxidant activity to CNF films, with a significantly higher ABTS^+· scavenging activity (76 ± 18%) when compared to control CNF films (30 ± 6%). Similarly, esterification of phenolic acids significantly improved the hydrophobicity of the films with a water contact angle of 94 ± 3° when compared to control CNF films (46 ± 5°). Covalent attachment of phenolic acids can improve hydrophobicity while providing additional functionality to CNF important for food packaging applications.

Amination of 5-Spiro-Substituted 3-Hydroxy-1,5-dihydro-2H-pyrrol-2-ones

The 3-hydroxy-1,5-dihydro-2H-pyrrol-2-one motif is a valuable scaffold in drug discovery. The replacement of the 3-oxy fragment in 3-hydroxy-1,5-dihydro-2H-pyrrol-2-ones-based compounds with a 3-amino one (3-amino analogs of 3-hydroxy-1,5-dihydro-2H-pyrrol-2-ones, 3-amino-1,5-dihydro-2H-pyrrol-2-ones) can play a crucial role in their biological effect. Thus, approaches to 3-amino-1,5-dihydro-2H-pyrrol-2-ones are of significant interest. We developed an approach to 5-spiro-substituted 3-amino-1,5-dihydro-2H-pyrrol-2-ones that could not be obtained using previously reported approaches (reactions of 3-hydroxy-1,5-dihydro-2H-pyrrol-2-ones with amines). The developed approach is based on the thermal decomposition of 1,3-disubstituted urea derivatives of 5-spiro-substituted 3-hydroxy-1,5-dihydro-2H-pyrrol-2-ones, which were prepared via their reaction with carbodiimides.

Derivatives of Deoxypodophyllotoxin Induce Apoptosis through Bcl-2/Bax Proteins Expression

BACKGROUND

Deoxypodophyllotoxin, isolated from the Traditional Chinese Medicine Anthriscus sylvestris, is well-known because of its significant anti-tumor activity with strong toxicity in vitro and in vivo.

OBJECTIVE

In this article, a series of deoxypodophyllotoxin derivatives were synthesized and their anti-tumor effectiveness was evaluated.

METHODS

The anti-tumor activity of deoxypodophyllotoxin derivatives was investigated by the MTT assay method. Apoptosis percentage was measured by flow cytometer analysis using Annexin-V-FITC.

RESULTS

The derivatives revealed obvious cytotoxicity in the MTT assay by decreasing the number of late cancer cells. The decrease of Bcl-2/Bax could be observed in MCF-7, HepG2, HT-29, and MG-63 using Annexin V-FITC. The ratio of Bcl-2/Bax in the administration group was decreased, which was determined by the ELISA kit.

CONCLUSION

The derivatives of deoxypodophyllotoxin could induce apoptosis in tumor cell lines by influencing Bcl-2/Bax.

Larvicidal Activity of Cinnamic Acid Derivatives: Investigating Alternative Products for Aedes aegypti L. Control

The mosquito Aedes aegypti transmits the virus that causes dengue, yellow fever, Zika and Chikungunya viruses, and in several regions of the planet represents a vector of great clinical importance. In terms of mortality and morbidity, infections caused by Ae. aegypti are among the most serious arthropod transmitted viral diseases. The present study investigated the larvicidal potential of seventeen cinnamic acid derivatives against fourth stage Ae. aegypti larvae. The larvicide assays were performed using larval mortality rates to determine lethal concentration (LC₅₀). Compounds containing the medium alkyl chains butyl cinnamate (7) and pentyl cinnamate (8) presented excellent larvicidal activity with LC₅₀ values of around 0.21-0.17 mM, respectively. While among the derivatives with aryl substituents, the best LC₅₀ result was 0.55 mM for benzyl cinnamate (13). The tested derivatives were natural compounds and in pharmacology and antiparasitic studies, many have been evaluated using biological models for environmental and toxicological safety. Molecular modeling analyses suggest that the larvicidal activity of these compounds might be due to a multi-target mechanism of action involving inhibition of a carbonic anhydrase (CA), a histone deacetylase (HDAC2), and two sodium-dependent cation-chloride co-transporters (CCC2 e CCC3).

Chemical grafting of cholesterol on monomer and PDMMLA polymers, a step towards the development of new polymers for biomedical applications

Racemic α,α,β-trisubstituted β-lactones are the monomer units of poly((R,S)-3,3-dimethylmalic acid) (PDMMLA) derivatives, new biopolyesters showing great potential for biomedical applications. Using different groups during the synthesis of these β-lactones allows a tailored synthesis of PDMMLA copolymers with adjustable hydrophilic/phobic ratio. The degradation kinetics of the employed material is one of the most important criteria in the development of bioresorbable implants. The degradation time of PDMMLA derivatives can be controlled using different β-lactones of different hydrophilicity levels during the polymerization stage. Furthermore, PDMMLA has chemically available groups on its side chain allowing to graft functional groups on the polymer via covalent bonds. In this work, following a Steglich esterification protocol, the chemical grafting of cholesterol was carried out on a PDMMLA monomer derived β-lactone as well as on homopolymer PDMMLA-H, and copolymer PDMMLAH40-co-Hex60 (PDMMLA 40/60). Nuclear magnetic resonance (NMR) analyses of the products confirm and quantify the grafting ratio. 100% of cholesterol grafting has been realized on the homopolymer PDMMLA-H giving PDMMLA-Chol, and 10% on the copolymer PDMMLA 40/60, giving PDMMLAH30-ter-Chol10-ter-Hex60 (PDMMLA-Chol 30/10/60) as wished. Fourier-transform infrared (FT-IR) spectra, elemental analysis on the β-lactones and thermogravimetric analyses on the polymers also confirm the chemical modification of the products.