Pharmaceuticals (Basel)
April 2023
Chronic myeloid leukemia (CML) is a myeloproliferative disease characterized by the formation of the BCR-ABL (breakpoint cluster region-Abelson) oncoprotein. As many patients display therapeutic resistance, the development of new drugs based on semisynthetic products represents a new potential therapeutic approach for treating the disease. In this study, we investigated the cytotoxic activity, possible mechanism of action of a hybrid compound of betulinic acid (BA) and brosimine B in CML cell lines that are sensitive (K-562) and resistant (K-562R) to imatinib, in addition to evaluating lower doses of imatinib in combination with the hybrid compound.
View Article and Find Full Text PDFBackground: Foraminispora rugosa is a species reported from Brazil, Venezuela, French Guiana, Costa Rica and Cuba. It is a basidiomycete in the Ganodermataceae family. In this study, both chemical composition and cytotoxicity of the ethanolic extract of F.
View Article and Find Full Text PDFImatinib, a specific Bcr-Abl tyrosine kinase inhibitor, is the most commonly used drug in the treatment of chronic myeloid leukemia. However, optimal response is not achieved in up to 33% of patients. Therefore, development of novel therapeutic strategies for chronic myeloid leukemia is critical.
View Article and Find Full Text PDFOnychomycosis infections currently show a significant increase, affecting about 10 % of the world population. is the main agent responsible for about 80 % of the reported infections. The clinical cure for onychomycosis is extremely difficult and effective new antifungal therapy is needed.
View Article and Find Full Text PDFAnticancer Agents Med Chem
February 2021
Background: Cancer is a multifactorial disease, representing one of the leading causes of death worldwide. On a global estimate, breast cancer is the most frequently occurring cancer in women and cervical cancer, the fourth most common. Both types of cancer remain the major cause of cancer-related mortality in developing countries.
View Article and Find Full Text PDFMethicillin-resistant Staphylococcus aureus (MRSA) is a major public health concern representing about 60% of S. aureus isolated from hospitalized patients in countries such as USA and Brazil in the last years. Additionally, the ability to adhere to surfaces and the development of biofilms are important properties of pathogenic bacteria involved in medical device-associated infections, and staphylococci are recognized as the major etiologic agents in these situations.
View Article and Find Full Text PDFis an encapsulated yeast responsible for more than 180,000 deaths per year. The standard therapeutic approach against cryptococcosis is a combination of amphotericin B with flucytosine. In countries where cryptococcosis is most prevalent, 5-fluorocytosine is rarely available, and amphotericin B requires intravenous administration.
View Article and Find Full Text PDFMedical devices (indwelling) have greatly improved healthcare. Nevertheless, infections related to the use of these apparatuses continue to be a major clinical concern. Biofilms form on surfaces after bacterial adhesion, and they function as bacterial reservoirs and as resistance and tolerance factors against antibiotics and the host immune response.
View Article and Find Full Text PDFNew medicines for the treatment of bacterial biofilm formation are required. For thisreason, this study shows the in vitro activity of betulinic acid (BA), ursolic acid (UA) and their twentyderivatives against planktonic and biofilm cells (gram-positive bacterial pathogens: Enterococcusfaecalis, and ). We evaluated the antibiofilm activity(through the crystal violet method), as well as the antibacterial activity via absorbance (OD) atconcentrations of 5, 25 and 100 μM.
View Article and Find Full Text PDFPathogenic biofilms are a global health care concern, as they can cause extensive antibiotic resistance, morbidity, mortality, and thereby substantial economic loss. Scientific efforts have been made over the past few decades, but so far there is no effective treatment targeting the bacteria in biofilms. Antimicrobial peptidomimetics have been proposed as promising potential anti-biofilm agents.
View Article and Find Full Text PDFMalaria is one of the most significant infectious diseases that affect poor populations in tropical areas throughout the world. Plants have been shown to be a good source for the development of new antimalarial chemotherapeutic agents, as shown for the discovery of quinine and artemisinin derivatives. Our research group has been working with semisynthetic triterpene derivatives that show potential antimalarial activity toward different strains of Plasmodium falciparum by specifically modulating calcium pathways in the parasite.
View Article and Find Full Text PDFTrichomonas vaginalis is an extracellular parasite that binds to the epithelium of the human urogenital tract and causes the sexually transmitted infection, trichomoniasis. In view of increased resistance to drugs belonging to the 5-nitroimidazole class, new treatment alternatives are urgently needed. In this study, eight semisynthetized triterpene derivatives were evaluated for in vitro anti-T.
View Article and Find Full Text PDFIn this report, we describe the semisynthesis of two series of ursolic and betulinic acid derivatives through designed by modifications at the C-3 and C-28 positions and demonstrate their antimalarial activity against chloroquine-resistant P. falciparum (W2 strain). Structural modifications at C-3 were more advantageous to antimalarial activity than simultaneous modifications at C-3 and C-28 positions.
View Article and Find Full Text PDFBiofilm forming microorganisms substantially enhance their virulence and drug resistance causing and alternatives are need to combat this health problem. In this context, peptides are an exceptional strategy in drug design and pharmaceutical innovation due to their diverse chemical features, biological activity and biotechnological relevance. Therefore, this study proposes a comprehensive assessment of a wide range of peptides, targeting biofilms.
View Article and Find Full Text PDFBackground: Leishmaniasis reaches millions of people around the world. The control of the disease is difficult due to the restricted access to the diagnosis and medication, and low adherence to the treatment. Thus, more efficient drugs are needed and natural products are good alternatives.
View Article and Find Full Text PDFTrichomonas vaginalis is a flagellated protozoan that affects the human urogenital tract causing 276.4 million new infections a year. The parasite elicits a vaginal mucosal infiltration of immune cells, especially neutrophils which are considered to be primarily responsible for cytological change observed at the infection site as well as the major contributor in the inflammatory response against the parasite.
View Article and Find Full Text PDFPassiflora incarnata L. (Passifloraceae) has been traditionally used for treatment of anxiety, insomnia, drug addiction, mild infections, and pain. The aim of this study was to investigate the effect of a commercial extract of P.
View Article and Find Full Text PDFBackground: Chronic myeloid leukemia (CML) is currently treated with imatinib, a Bcr-Abl inhibitor. However, resistance to this drug usually develops over time. Triptolide, a diterpenoid triepoxide, has been shown active against CML cells resistant to imatinib, acting mainly on the level of Bcr-Abl transcription inhibition.
View Article and Find Full Text PDFApple juice production generates a large amount of residue comprising mainly peels, seeds, and pulp, known as apple pomace. In the global context, Brazil ranks 11th in apple production and thousands of tons of apple pomace are produced every year. This by-product is little explored, since it is a rich and heterogeneous mixture, containing interesting phytochemical groups.
View Article and Find Full Text PDFBackground: Insecticide resistance to commonly used substances demands new molecules for the chemical control of the dengue vector Aedes aegypti. Because natural product sources have been an alternative to obtain larvicidal compounds, the aim of this study was to evaluate the triterpenoids betulinic (BA) and ursolic (UA) acids and their semi-synthetic derivatives against larval Ae. aegypti.
View Article and Find Full Text PDFTreated glioblastoma multiforme (GBM) patients only survive 6 to 14months after diagnosis; therefore, the development of novel therapeutic strategies to treat gliomas remains critically necessary. Considering that phenolic compounds, like quercetin, have the potential to be used in the chemotreatment of gliomas and that some flavonoids exhibit the ability to cross the BBB, in the present study, we investigated the antitumor effect of flavonoids (including chalcones, flavones, flavanones and flavonols). Initially their activities were tested in C6 glioma cells screened using the MTT method, resulting in the selection of chalcone 2 whose feasibility was confirmed by a Trypan Blue exclusion assay in the low μM range on C6 glioma cells.
View Article and Find Full Text PDFOrg Biomol Chem
September 2015
In 1998, Hayashi and Miyaura reported the first asymmetric conjugate addition of aryl- and alkenyl-boronic acids to α,β-unsaturated ketones using chiral rhodium complexes as catalysts. During the last decade, this reaction has been developed quickly and the enantioselectivity was significantly improved with the emergence of new phosphine ligands. In addition to the methodological work, this reaction was applied as a key step in the total synthesis of natural compounds.
View Article and Find Full Text PDFGemifloxacin mesylate (GFM), chemically (R,S)-7-[(4Z)-3-(aminomethyl)-4-(methoxyimino)-1-pyrrolidinyl]-1-cyclopropyl-6-fluoro-1,4-dihydro-4-oxo-1,8-naphthyridine-3-carboxylic acid methanesulfonate, is a synthetic broad-spectrum antibacterial agent. Although many papers have been published in the literature describing the stability of fluorquinolones, little is known about the degradation products of GFM. Forced degradation studies of GFM were performed using radiation (UV-A), acid (1 mol L(-1) HCl) and alkaline conditions (0.
View Article and Find Full Text PDFEmerging yeasts are among the most prevalent causes of systemic infections with high mortality rates and there is an urgent need to develop specific, effective and non-toxic antifungal agents to respond to this issue. In this study 35 aldehydes, hydrazones and hydrazines were obtained and their antifungal activity was evaluated against Candida species (C. parapsilosis, C.
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