Biochemical and pharmacological characterization of novel bradykinin-related peptides (BRP) named Cd-146, Thr6-BK, fulvonin and cyphokinin isolated from the venom of the solitary wasp Cyphononyx ...fulvognathus is described.
Bradykinin (BK) and its related peptides are widely distributed in venomous animals, including wasps. In fact, we have previously purified a novel BK-related peptide (BRP) named Cd-146 and the threonine6-bradykinin (Thr6-BK) from the venom of the solitary wasp Cyphononyx fulvognathus. Further survey of this same wasp venom extract allowed the structural characterization of two other novel BRPs, named here as fulvonin and cyphokinin. Biochemical characterization performed here showed that although the high primary structure similarity observed with BK, these wasp peptides are not good substrates for angiotensin I-converting enzyme (ACE) acting more likely as inhibitors of this enzyme. In pharmacological assays, only those more structurally similar to BK, namely cyphokinin and Thr6-BK, were able to promote the contraction of guinea-pig ileum smooth muscle preparations, which was completely blocked by the B2 receptors antagonist HOE-140 in the same way as observed for BK. Only fulvonin was shown to potentiate BK-elicited smooth muscle contraction. Moreover, the 2 new wasp BRPs, namely fulvonin and cyphokinin, as well as Cd-146 and Thr6-BK, showed hyperalgesic effect in the rat paw pressure test after intraplantar injection. This effect was shown here to be due to the action of these peptides on BK receptors, since the hyperalgesia induced by both Cd-146 and fulvonin was blocked by B1 receptor antagonist, while the effect of both cyphokinin and Thr6-BK was reversed by B2 antagonist. This data give support to a better understanding of the function and targets of the kinin-related peptides widely found in several insect venoms.
Ultrasound-assisted extraction was used to investigate the polyphenolic compounds, particularly anthocyanins, present in myrtle alcoholic extracts. This type of extract is typical in the making of ...liqueurs obtained from herbs or plants, especially medicinal plants. The leaf extracts were found to contain flavonoids from the quercetin and myricetin families. Besides these, the berry extracts also showed the presence of anthocyanins, hydrolysable tannins and quinic acid. The antioxidant capacity was studied using the ORAC and TEAC methods and the polyphenol content was measured using the Folin–Ciocalteu method. The results showed that the values produced by the ORAC and TEAC methods were in agreement and that the antioxidant capacity correlated with the polyphenol content. The results showed that the leaf extracts exhibited higher antioxidant capacity than the berry extracts. The extraction method was easily implementable, and proved to be a swift method for obtaining bioactive compounds from vegetable matrices.
An alternative, efficient, and green synthetic strategy for the preparation of pharmaceutical ionic liquids using mechanochemistry (MechanoAPI‐ILs) is reported. Six new API‐ILs based on gabapentin ...and l‐glutamic acid were successfully synthesized and characterized, demonstrating that mechanochemistry is a very promising synthetic strategy. Results compare both the new and the classical approach and clearly show the advantages of the new method. This new technique is faster, solvent free, reproducible, selective, and leads to higher yields.
A solid state strategy: For the first time, mechanochemistry is used in the preparation of pharmaceutical ionic liquids (MechanoAPI‐ILs). Six new API‐ILs are successfully synthesized and characterized, demonstrating this to be a very promising synthetic strategy. The technique is faster, solvent free, reproducible, selective, and leads to higher yields compared to conventional processes
•Extracts of myrtle leaves and berries were obtained by SFE and conventional methods.•The samples were collected over a period of three years.•The antioxidant capacity was evaluated by TEAC, ORAC and ...Folin–Ciocalteu methods.•SFE extracts showed significantly higher yield and antioxidant activity.•Bioactive compounds were identified and quantified by HPLC–MS.
In this work, the antioxidant capacity of extracts of Portuguese myrtle (Myrtus communis L.) is being studied over a period of three years. The samples were leaves of myrtle collected at the flowering stage and berries sampled at an early ripened stage. Supercritical fluid extraction (SFE) extracts were obtained at 23MPa, 45°C and a CO2 flow of 0.3kgh−1 using ethanol as co-solvent with a flow rate of 0.09kgh−1. Hydrodistillation was carried out in a Clevenger type apparatus and the aqueous phase was extracted with diisopropylether having obtained what is hereby designated as liquid phase extract (LPE).
The antioxidant capacity of all the extracts was determined by using three different methods: the Folin–Ciocalteu, the Trolox Equivalent Antioxidant Capacity (TEAC) and the Oxygen Radical Absorbance Capacity (ORAC). The results show that the SFE extracts present a significantly higher antioxidant capacity. The extracts were characterized and quantified by HPLC-DAD-MS/MS methods. The bioactive compounds identified in all the extracts were phenolic acids (only in the LPE extracts), flavonoids and anthocyanins (only in the SFE extracts). The results indicate that the higher antioxidant capacity of the SFE myrtle extracts is mainly correlated with the concentration of flavonol glycosides, the myricetin-O-glycosides.
New xylofuranosyl and glucopyranosyl nucleoside phosphoramidates were synthesized as potential mimetics of nucleoside 5′-monophosphates. Their access involved
-glycosylation of uracil and ...2-acetamido-6-chloropurine with 5′/6′-azido-1,2-di-
-acetyl glycosyl donors and subsequent Staudinger-phosphite reaction of the resulting azido nucleosides. The coupling of the purine derivative with the pyranosyl donor furnished N
- and N
-linked nucleosides in 1:1 ratio, whereas with the furanosyl donor, the N
-nucleoside was the major regioisomer formed. When using uracil, only 5′/6′-azido N
-linked nucleosides were obtained. The purine 5′/6′-azido nucleosides were converted into corresponding phosphoramidates in good yields. The antiproliferative effects of the nucleoside phosphoramidates and those of the azido counterparts on cancer cells were evaluated. While the nucleoside phosphoramidates did not show significant activities, the purine 5′/6′-azido nucleosides displayed potent effects against K562, MCF-7 and BT474 cell lines. The 5′-azidofuranosyl N
and N
-linked purine nucleosides exhibited highest activity towards the chronic myeloid leukemia cell line (K562) with GI
values of 13.6 and 9.7 μM, respectively. Among pyranosyl nucleosides, the N
-linked nucleoside was the most active compound with efficacy towards all cell lines assayed and a highest effect on K562 cells (GI
=6.8 μM). Cell cycle analysis of K562 and MCF-7 cells showed that the most active compounds cause G2/M arrest.
Euptox A, from Ageratina adenophora juice, is a toxin associated with the plant's resistance to infections, invasiveness and traditional use in cancer treatment. We used FTIR spectroscopy and protein ...profiling of cell lines to study the impact of euptox A on human cells, to clarify its mechanism of action in a top-down approach.
Euptox A was extracted from the juice of A. adenophora. Its stability in the gastrointestinal tract was evaluated, as the compound/juice is generally taken orally. Cytotoxicity was determined in HeLa, Caco-2 and MCF7 cells, and the mechanism of action analyzed by protein and metabolite profiles using electrophoresis and FTIR spectroscopy.
Euptox A resisted gastrointestinal digestion and was the most cytotoxic component of the extract for all cell lines tests. Euptox A-treated HeLa cells showed changes in protein profile, especially on 40S ribosomal protein S8 (RP), generally associated with cancer cells. FTIR profiles of treated cells diverged in the same metabolites as cells treated with cisplatin, both in metabolite directed analysis and in multivariate analysis (principal component analysis).
In conclusion, euptox A in this top-down study showed a cellular impact that suggests a strong potential against cancer, acting on cancer targeted cellular characteristics.
•Euptox A induced changes in protein and metabolic profiles of HeLa cells.•Decrease in ribosomal protein suggests counteraction of carcinogenesis.•FTIR data indicate euptox A to induce apoptosis similarly to drug cisplatin.•Euptox A cellular action suggests specificity for cancer treatment.
Herein we report novel hybrid compounds based on valproic acid and DNA-alkylating triazene moieties, 1, with therapeutic potential for glioblastoma multiforme chemotherapy. We identified hybrid ...compounds 1d and 1e to be remarkably more potent against glioma and more efficient in decreasing invasive cell properties than temozolomide and endowed with chemical and plasma stability. In contrast to temozolomide, which undergoes hydrolysis to release an alkylating metabolite, the valproate hybrids showed a low potential to alkylate DNA. Key physicochemical properties align for optimal CNS penetration, highlighting the potential of these effective triazene based-hybrids for enhanced anticancer chemotherapy.
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•Multitarget approach for glioma treatment combining aryltriazenes and HDAC inhibitors.•Key physicochemical properties suitable to ensure BBB penetration.•Enhanced and selective cytotoxic action on glioma cell lines compared to the drug Temozolomide.•Triazene-based hybrids improved cytotoxicity is unrelated to DNA alkylation.
This study focused on the biodegradation of an azo dye (Acid Red 14, AR14) in two anaerobic–aerobic sequencing batch reactors (SBRs) treating synthetic textile wastewater, operated with aerobic ...granular sludge under different hydrodynamic regimens. The aim was to investigate the fate of the anaerobic AR14 breakdown products (aromatic amines) during the SBRs’ aerobic reaction phase. Specifically, liquid chromatography coupled with electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS) was used for structural characterization of AR14 biodegradation metabolites, their molecular formulas being confirmed by accurate mass measurements. Nineteen molecules potentially related to AR14 were detected in the SBRs, and their relative abundances were followed along the aerobic stage of treatment cycles. The two SBRs shared most of the identified compounds but with differences in their metabolite profiles. Biodecolorization through AR14 anaerobic azo bond reduction was confirmed by the identification of the aromatic amine 4-amino-naphthalene-1-sulfonic acid, which was further aerobically biodegraded, involving deamination and hydroxylation of the aromatic ring. The other aromatic amine (1-naphthol-2-amino-4-sulfonic acid) was not detected, being suggested to undergo autoxidation reactions forming dimeric, stable products. A different AR14 biodegradation pathway was observed when nitrate was added to the feed, a new intermediate product being detected (naphthalene-1-sulfonate).
Abacavir is a nucleoside reverse transcriptase inhibitor marketed since 1999 for the treatment of infection with the human immunodeficiency virus type 1 (HIV). Despite its clinical efficacy, abacavir ...administration has been associated with serious and sometimes fatal toxic events. Abacavir has been reported to undergo bioactivation in vitro, yielding reactive species that bind covalently to human serum albumin, but the haptenation mechanism and its significance to the toxic events induced by this anti-HIV drug have yet to be elucidated. Abacavir is extensively metabolized in the liver, resulting in inactive glucuronide and carboxylate metabolites. The metabolism of abacavir to the carboxylate involves a two-step oxidation via an unconjugated aldehyde, which under dehydrogenase activity isomerizes to a conjugated aldehyde. Concurrently with metabolic oxidation, the two putative aldehyde metabolites may be trapped by nucleophilic side groups in proteins yielding covalent adducts, which can be at the onset of the toxic events associated with abacavir. To gain insight into the role of aldehyde metabolites in abacavir-induced toxicity and with the ultimate goal of preparing reliable and fully characterized prospective biomarkers of exposure to the drug, we synthesized the two putative abacavir aldehyde metabolites and investigated their reaction with the α-amino group of valine. The resulting adducts were subsequently stabilized by reduction with sodium cyanoborohydride and derivatized with phenyl isothiocyanate, leading in both instances to the formation of the same phenylthiohydantoin, which was fully characterized by NMR and MS. These results suggest that the unconjugated aldehyde, initially formed in vivo, rapidly isomerizes to the thermodynamically more stable conjugated aldehyde, which is the electrophilic intermediate mainly involved in reaction with bionucleophiles. Moreover, we demonstrated that the reaction of the conjugated aldehyde with nitrogen bionucleophiles occurs exclusively via Schiff base formation, whereas soft sulfur nucleophiles react by Michael-type 1,4-addition to the α,β-unsaturated system. The synthetic phenylthiohydantoin adduct was subsequently used as standard for LC-ESI-MS monitoring of N-terminal valine adduct formation, upon modification of human hemoglobin in vitro with the conjugated abacavir aldehyde, followed by reduction and Edman degradation. The same postmodification strategy was applied to investigate the products formed by incubation of abacavir with rat liver cytosol, followed by trapping with ethyl valinate. In both instances, the major adduct detected corresponded to the synthetic phenylthiohydantoin standard. These results suggest that abacavir metabolism to the carboxylate(s) via aldehyde intermediate(s) could be a factor in the toxic events elicited by abacavir administration. Furthermore, the availability of a reliable and fully characterized synthetic standard of the abacavir adduct with the N-terminal valine of hemoglobin and its easy detection in the model hemoglobin modifications support the usefulness of this adduct as a prospective biomarker of abacavir toxicity in humans.
Duloxetine (DUL), an antidepressant drug, has been detected in surface water and wastewater effluents, however, there is little information on the formation of its transformation products (TPs). In ...this work, hydrolysis, photodegradation (UV irradiation) and chlorination experiments were performed on spiked distillated water, under controlled experimental conditions to simulate abiotic processes that can occur in the environment and wastewater treatment plants (WWTPs). Eleven TPs, nine from reaction with UV light and two from chlorine contact, were formed and detected by ultra-high performance liquid chromatography coupled to quadrupole time-of-flight mass spectrometry, and nine of them had their chemical structures elucidated upon analyses of their fragmentation patterns in MS/MS spectra. The formation and degradation of the TPs were observed. The parent compound was completely degraded after 30 min in photodegradation and after 24 hr in chlorination. Almost all TPs were completely degraded in the experiments. The ecotoxicity and mutagenicity of the TPs were predicted based on several in silico models and it was found that a few of these products presented more ecotoxicity than DUL itself and six TPs showed positive mutagenicity. Finally, wastewater samples were analyzed and DUL and one TP, possibly formed by chlorination process, were detected in the effluent, which showed that WWTP not only did not remove DUL, but also formed a TP.
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