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1.
Bioorg Chem ; 146: 107283, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38513324

RESUMO

The breast cancer resistance protein (BCRP/ABCG2) transporter mediates the efflux of numerous antineoplastic drugs, playing a central role in multidrug resistance related to cancer. The absence of successful clinical trials using specific ABCG2 inhibitors reveals the urge to identify new compounds to attend this critical demand. In this work, a series of 13 magnolol derivatives was tested as ABCG2 inhibitors. Only two compounds, derivatives 10 and 11, showed partial and complete ABCG2 inhibitory effect, respectively. This inhibition was selective toward ABCG2, since none of the 13 compounds inhibited neither P-glycoprotein nor MRP1. Both inhibitors (10 and 11) were not transported by ABCG2 and demonstrated a low cytotoxic profile even at high concentrations (up to 100 µM). 11 emerged as the most promising compound of the series, considering the ratio between cytotoxicity (IG50) and ABCG2 inhibition potency (IC50), showing a therapeutic ratio (TR) higher than observed for 10 (10.5 versus 1.6, respectively). This derivative showed a substrate-independent and a mixed type of inhibition. The effect of compound 11 on the ABCG2 ATPase activity and thermostability revealed allosteric protein changes. This compound did not affect the expression levels of ABCG2 and increased the binding of the conformational-sensitive antibody 5D3. A docking study showed that 11 did not share the same binding site with ABCG2 substrate mitoxantrone. Finally, 11 could revert the chemoresistance to SN-38 mediated by ABCG2.


Assuntos
Antineoplásicos , Compostos de Bifenilo , Neoplasias da Mama , Lignanas , Humanos , Feminino , Membro 2 da Subfamília G de Transportadores de Cassetes de Ligação de ATP , Resistencia a Medicamentos Antineoplásicos , Proteínas de Neoplasias , Antineoplásicos/farmacologia , Antineoplásicos/metabolismo
2.
Food Chem ; 443: 138504, 2024 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-38309024

RESUMO

Pistacia vera shells, an abundant agricultural by-product, are a rich source of undiscovered bioactive compounds. This study employed a response surface methodology (RSM) approach to optimize the microwave-assisted extraction of antioxidants. The highest total phenolic content, and antioxidant activity were achieved under the optimized extraction conditions (20 % ethanol, 1000 W, 135 s, and solvent-to-solid ratio of 27 mL/g). The resulting extract (OPVS-E) included gallic acid derivatives, hydrolysable tannins, flavonoids, fatty acids, and anacardic acids. Remarkably, OPVS-E displayed potent inhibitory activity against α-amylase (IC50 = 2.05 µg/mL) and α-glucosidase (IC50 = 41.07 µg/mL), by far more powerful than the anti-diabetic drug acarbose, OPVS-E exhibited a strong antiradical capacity against reactive oxygen species (ROS) without causing toxicity in intestinal cells (HT29-MTX and Caco-2). These findings introduce OPVS-E as a potential novel dual-action nutraceutical ingredient, able to mitigate postprandial hyperglycemia and counteract the ROS overproduction occurring in type 2 diabetes mellitus.


Assuntos
Diabetes Mellitus Tipo 2 , Hiperglicemia , Pistacia , Humanos , Antioxidantes/farmacologia , Extratos Vegetais/farmacologia , Hiperglicemia/tratamento farmacológico , Espécies Reativas de Oxigênio , Células CACO-2
3.
Heliyon ; 10(2): e24469, 2024 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-38298717

RESUMO

PLA/PBAT bioplastic is a commercial biodegradable plastic employed for packaging and several food and agriculture applications. In this regard, properties such as the antioxidant ability to extend food shelf life and light resistance, are of great interest in the production of packaging and mulching films, respectively. These features are obtained by developing blends with pure chemicals and/or natural products as additives. In the present work blend formulations of PLA/PBAT with a walnut shell extract rich in antioxidants were developed and evaluated for their properties in comparison with classic PLA/PBAT. Specifically, natural additives, and most importantly the production process were purposely selected to i) be green and cost-effective; ii) confer antioxidant properties; and iii) improve material performance. To this aim, a walnut shell extract (EWS) with high antioxidant activity was obtained thanks to a novel green and cost-effective microwave-assisted extraction (MAE) procedure. A response surface methodology was utilized to explore how the total phenolic content (TPC) and antioxidant activity are influenced by varying aqueous ethanol concentration, extraction time, and microwave power. The highest predicted TPC and antioxidant activity were achieved when employing the ideal conditions for Microwave-Assisted Extraction (MAE): using a mixture of 30 % ethanol in water, an irradiation time of 120 s, and a microwave power of 670 W. The optimized EWS was characterized by HPLC-MS determining qualitative and quantitative data with the identification of flavonoids, fatty acids, and anacardic acids among the main components, responsible for antioxidant activity. The resulting EWS powder was melt-mixed at 140C° and 20 RPM with the bio-based PLA/PBAT bioplastic at two different concentrations (0.5 and 1.5 w/w) by forming film specimens. All EWS-based bioplastic films showed increased antioxidant features determined by the DPPH bleaching test, TEAC, and ORAC assays. The films keep the antioxidant capacity even after 7 days of UV-accelerated aging. Remarkably, adding 1.5 % EWS boosted the bioplastic UV light resistance, reducing the abatement of molecular masses by more than 60 % without affecting mechanical properties.

4.
Int J Mol Sci ; 24(23)2023 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-38069237

RESUMO

Nowadays, there is considerable attention toward the use of food waste from food processing as possible sources of compounds with health properties, such as anticancer activity. An example is tomato processing, which is responsible for generating a remarkable amount of waste (leaves, peel, seeds). Therefore, our goal was to evaluate the potential anticancer property of tomato extracts, in particular "Datterino" tomato (DT) and "Piccadilly" tomato (PT), and to study their phytochemical composition. Liquid chromatography with tandem mass spectrometry (LC/MS-MS) results showed that these extracts are rich in alkaloids, flavonoids, fatty acids, lipids, and terpenes. Furthermore, their potential anticancer activity was evaluated in vitro by MTT assay. In particular, the percentage of cell viability was assessed in olfactory ensheathing cells (OECs), a particular glial cell type of the olfactory system, and in SH-SY5Y, a neuroblastoma cell line. All extracts (aqueous and ethanolic) did not lead to any significant change in the percentage of cell viability on OECs when compared with the control. Instead, in SH-SY5Y we observed a significant decrease in the percentage of cell viability, confirming their potential anticancer activity; this was more evident for the ethanolic extracts. In conclusion, tomato leaves extracts could be regarded as a valuable source of bioactive compounds, suitable for various applications in the food, nutraceutical, and pharmaceutical fields.


Assuntos
Alcaloides , Neuroblastoma , Eliminação de Resíduos , Solanum lycopersicum , Humanos , Sobrevivência Celular , Neuroblastoma/tratamento farmacológico , Alcaloides/química , Extratos Vegetais/química , Esteroides/análise , Sementes/química
5.
Int J Biol Macromol ; 242(Pt 3): 124968, 2023 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-37217044

RESUMO

Lignin modifying enzymes (LMEs) have gained widespread recognition in depolymerization of lignin polymers by oxidative cleavage. LMEs are a robust class of biocatalysts that include lignin peroxidase (LiP), manganese peroxidase (MnP), versatile peroxidase (VP), laccase (LAC), and dye-decolorizing peroxidase (DyP). Members of the LMEs family act on phenolic, non-phenolic substrates and have been widely researched for valorization of lignin, oxidative cleavage of xenobiotics and phenolics. LMEs implementation in the biotechnological and industrial sectors has sparked significant attention, although its potential future applications remain underexploited. To understand the mechanism of LMEs in sustainable pollution mitigation, several studies have been undertaken to assess the feasibility of LMEs in correlating to diverse pollutants for binding and intermolecular interactions at the molecular level. However, further investigation is required to fully comprehend the underlying mechanism. In this review we presented the key structural and functional features of LMEs, including the computational aspects, as well as the advanced applications in biotechnology and industrial research. Furthermore, concluding remarks and a look ahead, the use of LMEs coupled with computational framework, built upon artificial intelligence (AI) and machine learning (ML), has been emphasized as a recent milestone in environmental research.


Assuntos
Inteligência Artificial , Lignina , Lignina/química , Peroxidases/metabolismo , Biotecnologia , Lacase , Fenóis
6.
Bioorg Chem ; 134: 106455, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-36913880

RESUMO

Obesity is a complex disease defined as an excessive amount of body fat. It is considered a risk factor for several pathologies; therefore, there is an increasing interest in its treatment. Pancreatic lipase (PL) plays a key role in fat digestion, and its inhibition is a preliminary step in the search for anti-obesity agents. For this reason, many natural compounds and their derivatives are studied as new PL inhibitors. This study reports the synthesis of a library of new compounds inspired by two natural neolignans, honokiol (1) and magnolol (2) and bearing amino or nitro groups linked to a biphenyl core. The synthesis of unsymmetrically substituted biphenyls was achieved through an optimisation of the Suzuki-Miyaura cross-coupling reaction followed by the insertion of allyl chains, thus furnishing the O- and/or N-allyl derivatives, and finally, a sigmatropic rearrangement yielding in some cases, the C-allyl analogues. Magnolol, honokiol and the twenty-one synthesised biphenyls were evaluated for their in vitro inhibitory activity toward PL. Three compounds (15b, 16 and 17b) were more effective inhibitors than the natural neolignans (magnolol IC50 = 158.7 µM and honokiol IC50 = 115.5 µM) with IC50 of 41-44 µM. Detailed studies through kinetics suggested better inhibitory activity of the synthetic analogues compared with the natural 1 and 2. Magnolol (Ki = 614.3 µM; K'i of 140.9 µM) and the synthetic biphenyls 15b (Ki = 286.4 µM; K'i = 36.6 µM) and 16 (Ki = 176.2 µM; K'i = 6.4 µM) are mixed-type inhibitors, whereas honokiol (Ki = 674.8 µM) and 17b (Ki = 249 µM) are competitive inhibitors. Docking studies corroborated these findings, showing the best fitting for intermolecular interaction between biphenyl neolignans and PL. The above outcomes highlighted how the proposed structures could be considered interesting candidates for future studies for the development of more effective PL inhibitors.


Assuntos
Lignanas , Lignanas/química , Compostos de Bifenilo/farmacologia , Compostos de Bifenilo/química
7.
Pharmaceutics ; 15(2)2023 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-36839716

RESUMO

Colorectal cancer is one of the most diffused tumoral diseases. Since most medicaments employed for its treatment are debilitating, the use of naturally derived products, which can be effective against the mutated cells and, in addition, can reduce most inflammatory-related effects, could be extremely beneficial for the continued treatment of this disease. In this research, ethyl protocatechuate (PCAEE), a protocatechuic acid prodrug, was encapsulated in solid lipid nanoparticles (SLN) (prepared without and with Tween 80), which were characterized in terms of size, polydispersity index (PDI), zeta potential and thermotropic behavior. Encapsulation efficiency, release profile and interaction with a model of biomembrane were also assessed. The nanoparticles were tested in vitro on both healthy cells and on a model of tumoral cells. SLN prepared with Tween 80 was promising in terms of physicochemical properties (z-average of 190 nm, PDI 0.150 and zeta potential around -20 mV) and encapsulation efficiency (56%); they showed a desirable release profile, demonstrated an ability to penetrate and release the encapsulated PCAEE into a biomembrane model and were nontoxic on healthy cells. In addition, they caused a greater dose-dependent decrease in the viability of CaCo-2 cells than PCAEE alone. In conclusion, the formulation could be proposed for further studies to assess its suitability for the treatment of colorectal cancer.

8.
Molecules ; 28(2)2023 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-36677790

RESUMO

Honokiol is a natural bisphenol neolignan present in the bark of Magnolia officinalis, whose extracts have been employed in oriental medicine to treat several disorders, showing a variety of biological properties, including antitumor activity, potentially related to radical scavenging. Six bisphenol neolignans with structural motifs related to the natural bioactive honokiol were synthesized. Their chain-breaking antioxidant activity was evaluated in the presence of peroxyl (ROO•) and hydroperoxyl (HOO•) radicals by both experimental and computational methods. Depending on the number and position of the hydroxyl and alkyl groups present on the molecules, these derivatives are more or less effective than the reference natural compound. The rate constant of the reaction with ROO• radicals for compound 7 is two orders of magnitude greater than that of honokiol. Moreover, for compounds displaying quinonic oxidized forms, we demonstrate that the addition of 1,4 cyclohexadiene, able to generate HOO• radicals, restores their antioxidant activity, because of the reducing capability of the HOO• radicals. The antioxidant activity of the oxidized compounds in combination with 1,4-cyclohexadiene is, in some cases, greater than that found for the starting compounds towards the peroxyl radicals. This synergy can be applied to maximize the performances of these new bisphenol neolignans.


Assuntos
Antioxidantes , Lignanas , Antioxidantes/farmacologia , Antioxidantes/química , Lignanas/farmacologia , Lignanas/química , Fenóis/farmacologia , Compostos de Bifenilo/química , Sequestradores de Radicais Livres/farmacologia , Radicais Livres
9.
Molecules ; 27(18)2022 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-36144620

RESUMO

Skin is the first human barrier that is daily exposed to a broad spectrum of physical and chemical agents, which can increase reactive oxygen species (ROS) and lead to the formation of topical disorders. Antioxidant molecules, such as benzo[k,l]xanthene lignans (BXL), are ideal candidates to eliminate or minimize the effects of ROS. Herein, we aimed to formulate BXL-loaded solid lipid nanoparticles (SLN-BXL) to improve the bioavailability and interaction with the skin, and also to investigate the protective impact against intracellular ROS generation in HFF-1 in comparison with the drug-free situation. SLN-BXL were formulated using the PIT/ultrasonication method, and then were subjected to physicochemical characterizations, i.e., average size, zeta potential (ZP), polydispersity index (PDI), encapsulation efficiency (%EE), thermotropic behavior, and interaction with a biomembrane model. The results show a mean size around 200 nm, PDI of 0.2, and zeta potential of about -28 mV, with values almost unchanged over a period of three months, while the EE% is ≈70%. Moreover, SLN-BXL are able to deeply interact with the biomembrane model, and to achieve a double-action release in mildly hydrophobic matrices; the results of the in vitro experiments confirm that SLN-BXL are cell-safe and capable of attenuating the IL-2-induced high ROS levels. In conclusion, based on our findings, the formulation can be proposed as a candidate for a preventive remedy against skin disorders induced by increased levels of ROS.


Assuntos
Lignanas , Nanopartículas , Antioxidantes/farmacologia , Portadores de Fármacos , Humanos , Interleucina-2 , Lignanas/farmacologia , Lipídeos/química , Lipossomos , Nanopartículas/química , Tamanho da Partícula , Espécies Reativas de Oxigênio , Xantenos
10.
Membranes (Basel) ; 12(6)2022 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-35736322

RESUMO

Benzo[k,l]xanthene lignans are a group of rare natural products belonging to the class of polyphenols with promising biological activities and are studied as potential chemotherapeutic agents. The lipophilic character of a xanthene core makes these molecules difficult to be used in an aqueous medium, limiting their employment in studies for pharmaceutical applications. To overcome this problem, a drug-delivery system which is able to improve the stability and bioavailability of the compound can be used. In this study, a bioactive benzoxanthene lignan (BXL) has been included in SLN. Unloaded and BXL-loaded SLN have been prepared using the Phase Inversion Temperature method and characterized in terms of size, zeta potential, entrapment efficiency and stability. Differential scanning calorimetry was used to evaluate the thermotropic behavior and ability of SLN to act as carriers for BXL. A biomembrane model, represented by multilamellar vesicles, was used to simulate the interaction of the SLN with the cellular membrane. Unloaded and loaded SLN were incubated with the MLV, and their interactions were evaluated through variations in their calorimetric curves. The results obtained suggest that SLN could be used as a delivery system for BXL.

11.
RSC Chem Biol ; 3(6): 614-647, 2022 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-35755186

RESUMO

Laccases are a class of multicopper oxidases that catalyse the one-electron oxidation of four equivalents of a reducing substrate, with the concomitant four-electron reduction of dioxygen to water. Typically, they catalyse many anabolic reactions, in which mostly phenolic metabolites were subjected to oxidative coupling. Alternatively, laccases catalyse the degradation or modification of biopolymers like lignin in catabolic processes. In recent years, laccases have proved valuable and green biocatalysts for synthesising compounds with therapeutic value, including antitumor, antibiotic, antimicrobial, and antioxidant agents. Further up to date applications include oxidative depolymerisation of lignin to gain new biomaterials and bioremediation processes of industrial waste. This review summarizes selected examples from the last decade's literature about the laccase-mediated synthesis of biologically active natural products and their analogues; these will include lignans and neolignans, dimeric stilbenoids, biflavonoids, biaryls and other compounds of potential interest for the pharmaceutical industry. In addition, a short section about applications of laccases in natural polymer modification has been included.

12.
Molecules ; 27(8)2022 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-35458679

RESUMO

Inulin is considered a dietary fiber and represents a noteworthy ingredient for food biofortification due to its health effects and its neutral taste. The aim of the work was the evaluation of the quality of pasta produced using whole-meal flours of two ancient Sicilian landraces (Senatore Cappelli-CAP and Timilia-TIM) fortified with two types of inulin (long-chain topinambur inulin IT and low-chain chicory inulin IC), at two different levels of substitution (2 and 4%) to evaluate its possible effect on α-amylase inhibition. The color indices L* and a* were mainly influenced by cultivars, while IT improved the sensory attributes, mainly the elasticity sensation, and influenced less the other sensory attributes: adhesiveness, color, odor, taste, and Over Quality Score for both landraces. The cooking quality was linked mainly to the landrace used, due to the very different gluten matrix of CAP and TIM. IC and IT showed promising α-Amy inhibitory activity with comparable IC50 values of 0.45 ± 0.04 and 0.50 ± 0.06 mg/mL. The enrichment of spaghetti with inulin with an inhibitory effect on α-amylase determined the hypoglycemic properties of pasta, thus lowering the corresponding IC50 value.


Assuntos
Inulina , alfa-Amilases , Culinária , Farinha/análise , Inulina/farmacologia , Polimerização , Triticum
13.
Bioorg Chem ; 117: 105458, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34736132

RESUMO

Type 2 Diabetes mellitus is a chronic disease considered one of the most severe global health emergencies. Chlorogenic acid (1) has been shown to delay intestinal glucose absorption by inhibiting the activity of α-glucosidase (α-Glu) and α-amylase (α-Amy). In the present work, eleven chlorogenic acid amides have been synthesized and evaluated for their antioxidant properties (as DPPH and ORAC) and inhibition activity towards the two enzymes and, with the aim to obtain dual-action antidiabetic agents. The two most promising hypoglycemic compounds, bearing a tertiary amine function on an alkyl chain (8) and a benzothiazole scaffold (11), showed IC50 values lower than that of (1) (45.5 µM α-Glu; 105.2 µM α-Amy). Amides 8 and 11 were by far more potent α-Glu inhibitors than the antidiabetic drug acarbose (IC50 = 268.4 µM) and about twice less active toward α-Amy than acarbose (IC50 = 34.4 µM). Kinetics experiments on amides 8 and 11 indicated these compounds as mixed-type inhibitors of α-Glu with K'i values of 13.3 and 6.3 µM, respectively. The amylase inhibition occurred with a competitive mechanism in the presence of 8 (Ki = 79.7 µM) and with a mixed-type mechanism with 11 (Ki = 19.1 µM; K'i = 93.6 µM). Molecular docking analyses supported these results, highlighting the presence of additional binding sites in both enzymes. Fluorescence experiments confirmed the grater affinity of amides 8 and 11 towards the two enzymes respect to (1). Moreover, a significant enhancement in acarbose efficacy was observed when inhibition assays were performed adding acarbose and amide 11. The above outcomes pinpointed the benzothiazole-based amide 11 as a promising candidate for further studies on type 2 diabetes treatment, both alone or combined with acarbose.


Assuntos
Acarbose/farmacologia , Amidas/farmacologia , Antioxidantes/farmacologia , Ácido Clorogênico/farmacologia , Diabetes Mellitus Tipo 2/tratamento farmacológico , Inibidores de Glicosídeo Hidrolases/farmacologia , Hipoglicemiantes/farmacologia , Acarbose/química , Amidas/síntese química , Amidas/química , Animais , Antioxidantes/síntese química , Antioxidantes/química , Compostos de Bifenilo/antagonistas & inibidores , Ácido Clorogênico/síntese química , Ácido Clorogênico/química , Diabetes Mellitus Tipo 2/metabolismo , Relação Dose-Resposta a Droga , Inibidores de Glicosídeo Hidrolases/síntese química , Inibidores de Glicosídeo Hidrolases/química , Hipoglicemiantes/síntese química , Hipoglicemiantes/química , Simulação de Acoplamento Molecular , Estrutura Molecular , Pâncreas/enzimologia , Picratos/antagonistas & inibidores , Saccharomyces cerevisiae/enzimologia , Relação Estrutura-Atividade , Suínos , alfa-Amilases/antagonistas & inibidores , alfa-Amilases/metabolismo , alfa-Glucosidases/metabolismo
14.
J Nat Prod ; 84(3): 654-665, 2021 03 26.
Artigo em Inglês | MEDLINE | ID: mdl-33646787

RESUMO

Obesity, now widespread all over the world, is frequently associated with some chronic diseases. Thus, there is a growing interest in the prevention and treatment of obesity. To date, the only antiobesity drug is orlistat, a natural product-derived pancreatic lipase (PL) inhibitor with some undesired side effects. In the last decades, many natural compounds or derivatives have been evaluated as potential PL inhibitors, and natural polyphenols are among the most promising for possible exploitation as antiobesity agents. However, few studies have been devoted to isoflavones. In this work, we report a study on the PL inhibitory properties of a small library of semisynthetic isoflavone derivatives together with the natural leads daidzein (1), genistein (2), and formononetin (3). In vitro lipase inhibition assay showed that 2 is the most promising PL inhibitor. Among synthetic isoflavones, the hydroxylated and brominated derivatives were more potent than their natural leads. Detailed studies through fluorescence measurements and kinetics of lipase inhibition showed that 2 and the bromoderivatives 10 and 11 have the greatest affinity for PL. Docking studies corroborated these findings highlighting the interactions between isoflavones and the enzyme, confirming that hydroxylation and bromination are useful modifications.


Assuntos
Inibidores Enzimáticos/farmacologia , Isoflavonas/farmacocinética , Lipase/antagonistas & inibidores , Inibidores Enzimáticos/síntese química , Hidroxilação , Isoflavonas/síntese química , Simulação de Acoplamento Molecular , Estrutura Molecular , Pâncreas/enzimologia
15.
Int J Mol Sci ; 21(18)2020 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-32967305

RESUMO

Rapid and efficient analyses of copper ions are crucial to providing key information for Cu2+ in living cells because of their biological importance. In this study, we reported one new turn-off fluorescent sensor for Cu2+ with a benzo[k,l]xanthene core, which served as an efficient cation sensor for copper ion over a wide range of other cations (Na+, K+, Ag+, Hg2+, Cd2+, Co2+, Ni2+, Zn2+, Mg2+, and Fe3+) owing to the catechol group in the aromatic core. The sensor showed selectivity for Cu2+ over other ions; the logKß for Cu2+ binding to compound 1 had a value of 13.265. In the presence of Cu2+, sensor 1 provided significant fluorescence decrement; Co2+, and Ni2+ caused a fluorescence decrement when employed at a higher concentration than Cu2+, while Na+, K+, Hg2+, Cd2+, Zn2+, and Mg2+ metal ions produced only minor changes in fluorescence intensity. Fluorescence experiments demonstrate that compound 1 may have an application as a fluorescent probe for detecting Cu2+ with a limit of detection of 0.574 µM.


Assuntos
Cobre/análise , Corantes Fluorescentes/química , Corantes Fluorescentes/síntese química , Limite de Detecção , Espectrometria de Fluorescência
16.
Bioorg Chem ; 104: 104190, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32919130

RESUMO

Interactions of two newly synthesized and six previously reported benzoxanthene lignans (BXLs), analogues of rare natural products, with DNA/RNA, G-quadruplex and HSA were evaluated by a set of spectrophotometric methods. Presence/absence of methoxy and hydroxy groups on the benzoxanthene core and minor modifications at C-1/C-2 side pendants - presence/absence of phenyl ring and presence/absence of methoxy and hydroxy groups on phenyl ring - influenced the fluorescence changes and the binding strength to double-stranded (ds-) and G-quadruplex structures. In general, compounds without phenyl ring showed stronger fluorescence changes upon binding than phenyl-substituted BXLs. On the other hand, BXLs with an unsubstituted phenyl ring showed the best stabilization effects of G-quadruplex. Circular dichroism spectroscopy results suggest mixed binding mode, groove binding and partial intercalation, to ds-DNA/RNA and end-stacking to top or bottom G-tetrads as the main binding modes of BXLs to those targets. All compounds exhibited micromolar binding affinities toward HSA and an increased protein thermal stability. Moderate to strong antiradical scavenging activity was observed for all BXLs with hydroxy groups at C-6, C-9 and C-10 positions of the benzoxanthene core, except for derivative bearing methoxy groups at these positions. BXLs with unsubstituted or low-substituted phenyl ring and one derivative without phenyl ring showed strong growth inhibition of Gram-positive Staphylococcus aureus. All compounds showed moderate to strong tumor cell growth-inhibitory activity and cytotoxicity.


Assuntos
Antineoplásicos/farmacologia , DNA Tumoral Circulante/química , Lignanas/farmacologia , RNA Neoplásico/química , Albumina Sérica Humana/química , Xantenos/farmacologia , Antineoplásicos/síntese química , Antineoplásicos/química , Proliferação de Células/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Escherichia coli K12/citologia , Escherichia coli K12/efeitos dos fármacos , Humanos , Lignanas/síntese química , Lignanas/química , Estrutura Molecular , Salmonella enterica/citologia , Salmonella enterica/efeitos dos fármacos , Staphylococcus aureus/citologia , Staphylococcus aureus/efeitos dos fármacos , Relação Estrutura-Atividade , Células Tumorais Cultivadas , Xantenos/síntese química , Xantenos/química
17.
Molecules ; 25(14)2020 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-32708865

RESUMO

The ethyl acetate extract of the commercial tannin Tan'Activ QS-SOL (from Schinopsis lorentzii wood), employed for the production of red wine, was subjected to chromatography on Sephadex LH-20, providing nine fractions (A-1-A-9), which were estimated for total phenols content (GAE), antioxidant activity (DPPH, ORAC), and hypoglycemic activity (α-glucosidase and α-amylase inhibition). All the fractions were analyzed by means of HPLC/ESI-MS/MS and 1H-NMR to identify the principal active constituents. Fractions A-1 and A-3 showed the highest antioxidant activity and gallic acid (1), pyrogallol (3), eriodictyol (6), catechin (12), and taxifolin (30) were identified as the major constituents. The highest α-glucosidase and α-amylase inhibitory activity was observed in fractions A-7-A-9 containing condensed (9', 15, 18, 19, 23, and 27) hydrolysable tannins (13 and 32) as well as esters of quinic acid with different units of gallic acid (5, 11, 11', 14, and 22). This last class of gallic acid esters are here reported for the first time as α-glucosidase and α-amylase inhibitors.


Assuntos
Antioxidantes/farmacologia , Inibidores de Glicosídeo Hidrolases/farmacologia , Hipoglicemiantes/farmacologia , Taninos/química , Anacardiaceae/química , Antioxidantes/química , Inibidores de Glicosídeo Hidrolases/química , Humanos , Hipoglicemiantes/química , Espectrometria de Massas , Fenóis/química , Fenóis/farmacologia , Extratos Vegetais/química , Espectroscopia de Prótons por Ressonância Magnética , Taninos/farmacologia , Madeira/química , alfa-Amilases/antagonistas & inibidores , alfa-Amilases/química , alfa-Glucosidases/efeitos dos fármacos
18.
J Agric Food Chem ; 68(12): 3806-3816, 2020 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-32096635

RESUMO

The development of genetically modified (GM) crops speeds up the obtainment of novel varieties with improved agronomic characteristics. However, the risk evaluation of the use of GMs is mandatory before their release in the market. In this paper, an untargeted and comprehensive nuclear magnetic resonance-based metabolomic study was carried out on the peel and flesh of a transgenic lemon clone (E23) expressing the chit42 gene and exhibiting an increased tolerance to some pathogenic fungi and on its wild type. Results highlighted a substantial equivalence of the metabolomics profile of the transgenic clone compared to the wild type. In addition, an enhanced response of the E23 clone toward fungal pathogens affecting the postharvest management in lemon was evidenced. These results confirm the potential of genetic engineering for the punctual modification of specific agronomic traits without altering the whole pattern of metabolites and open new perspectives for a more sustainable and effective management of specific postharvest diseases in citrus.


Assuntos
Citrus/genética , Frutas/genética , Doenças das Plantas/genética , Plantas Geneticamente Modificadas/genética , Botrytis/isolamento & purificação , Citrus/microbiologia , Resistência à Doença , Frutas/microbiologia , Penicillium/isolamento & purificação , Doenças das Plantas/microbiologia , Plantas Geneticamente Modificadas/microbiologia
19.
Molecules ; 25(3)2020 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-32046220

RESUMO

Honokiol (2) is a natural bisphenol neolignan showing a variety of biological properties, including antitumor activity. Some studies pointed out 2 as a potential anticancer agent in view of its antiproliferative and pro-apoptotic activity towards tumor cells. As a further contribution to these studies, we report here the synthesis of a small library of bisphenol neolignans inspired by honokiol and the evaluation of their antiproliferative activity. The natural lead was hence subjected to simple chemical modifications to obtain the derivatives 3-9; further neolignans (12a-c, 13a-c, 14a-c, and 15a) were synthesized employing the Suzuki-Miyaura reaction, thus obtaining bisphenols with a substitution pattern different from honokiol. These compounds and the natural lead were subjected to antiproliferative assay towards HCT-116, HT-29, and PC3 tumor cell lines. Six of the neolignans show GI50 values lower than those of 2 towards all cell lines. Compounds 14a, 14c, and 15a are the most effective antiproliferative agents, with GI50 in the range of 3.6-19.1 µM, in some cases it is lower than those of the anticancer drug 5-fluorouracil. Flow cytometry experiments performed on these neolignans showed that the inhibition of proliferation is mainly due to an apoptotic process. These results indicate that the structural modification of honokiol may open the way to obtaining antitumor neolignans more potent than the natural lead.


Assuntos
Compostos Benzidrílicos/síntese química , Compostos Benzidrílicos/farmacologia , Compostos de Bifenilo/química , Proliferação de Células/efeitos dos fármacos , Lignanas/síntese química , Lignanas/farmacologia , Fenóis/síntese química , Fenóis/farmacologia , Antineoplásicos/química , Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Ensaios de Seleção de Medicamentos Antitumorais/métodos , Células HCT116 , Células HT29 , Humanos , Lignanas/química , Células PC-3
20.
Food Chem ; 313: 126099, 2020 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-31927321

RESUMO

Diabetes mellitus is a metabolic disorder characterized by hyperglycemia, which can be counteracted by inhibition of α-glucosidase and α-amylase, both involved in the carbohydrate metabolism. Fourteen C-glucosidic ellagitannins and three galloylated glucoses were studied as potential α-glucosidase and α-amylase inhibitors. Most of the compounds were found to be moderate inhibitors of α-amylase, but potent inhibitors of α-glucosidase, showing low-micromolar IC50 values, far lower than that of the antidiabetic drug acarbose. This selectivity can be an advantage for their possible application as functional food ingredients with anti-diabetic properties because strong α-amylase inhibition generally causes undesired side effects. The best inhibitors were selected for further studies. Intrinsic fluorescence measurements confirmed their high affinity towards α-glucosidase, highlighting a static quenching mechanism. Circular dichroism measurements and kinetics of inhibition indicated that the most active C-glucosidic ellagitannin roburin D (RobD) is a competitive inhibitor, whereas α-pentagalloylglucose (α-PGG) acts as a mixed-type inhibitor.


Assuntos
Taninos Hidrolisáveis/química , Hipoglicemiantes/química , alfa-Amilases/metabolismo , alfa-Glucosidases/metabolismo , Dicroísmo Circular , Glucosídeos/química , Taninos Hidrolisáveis/metabolismo , Hipoglicemiantes/metabolismo , Concentração Inibidora 50 , Cinética , Espectrometria de Fluorescência , alfa-Amilases/antagonistas & inibidores , alfa-Glucosidases/química
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