Publications by authors named "Frade R"

In this study were synthesized non-Michael acceptor cyclopentenones (CP) from biomass derivative furfural as anticancer agents. Cyclic enones, both from natural sources and synthetic analogues, have been described as cytotoxic agents. Most of these agents were unsuccessful in becoming valuable therapeutic agents due to toxicity problems derived from unselective critical biomacromolecule alkylation.

View Article and Find Full Text PDF

Unlabelled: There are several sites in which the human body core temperature can be estimated and used to identify febrile states in a threat of pandemic situations at high-populational-traffic places (e.g. airports, ports, universities, schools, public buildings).

View Article and Find Full Text PDF

The development of metal-organic frameworks (MOFs) enclosing active pharmaceutical ingredients is of considerable interest, as their use in controlled drug release and delivery is very promising. Although nalidixic acid is an antibiotic with a broad spectrum of biological applications, effective mainly against Gram-negative infections, its oral bioavailability is low due to a poor solubility and slow dissolution. Herein, we report new metal-organic frameworks (BioMOFs) comprising nalidixic acid and divalent magnesium and manganese ions.

View Article and Find Full Text PDF

Hybrid compounds may play a critical role in the context of the malaria eradication agenda, which will benefit from therapeutic tools active against the symptomatic erythrocytic stage of Plasmodium infection, and also capable of eliminating liver stage parasites. To address the need for efficient multistage antiplasmodial compounds, a small library of 1,2,4,5-tetraoxane-8- aminoquinoline hybrids, with the metabolically labile C-5 position of the 8-aminoquinoline moiety blocked with aryl groups, was synthesized and screened for antiplasmodial activity and metabolic stability. The hybrid compounds inhibited development of intra-erythrocytic forms of the multidrug-resistant Plasmodium falciparum W2 strain, with EC values in the nM range, and with low cytotoxicity against mammalian cells.

View Article and Find Full Text PDF

The first general protocol for the preparation of symmetric triarylmethanes bearing secondary anilines by ytterbium-catalyzed Friedel-Crafts reaction of hetero(aryl) aldehydes and secondary anilines is reported. Mechanistic studies indicated that the iminium ion intermediate is the electrophilic partner. The reaction is greatly accelerated by high pressure (9 kbar) and showed a broad substrate scope on the hetero(aryl) aldehyde.

View Article and Find Full Text PDF

Iminoboronates have been utilized to successfully install azide and alkyne bioorthogonal functions on proteins, which may then be further reacted with their bioorthogonal counterparts. These constructs were also used to add polyethylene glycol (PEG) to insulin, a modification which has been shown to be reversible in the presence of fructose. Finally, iminoboronates were used to assemble a folic acid/paclitaxel small-molecule/drug conjugate in situ with an IC50  value of 20.

View Article and Find Full Text PDF

A diversity-oriented library of s-triazine-based hybrids was screened for activity against the chloroquine-resistant Plasmodium falciparum W2 strain. The most striking result was sub-micromolar activity against cultured erythrocytic-stage parasites of hybrid molecules containing one or two 8-aminoquinoline moieties. These compounds were not clearly toxic to human cells.

View Article and Find Full Text PDF

Sophorolipids (SLs) are glycolipid biosurfactants, produced as a mixture of several compounds by some nonpathogenic yeast. In the current study, separation of individual SLs from mixtures with further evaluation of their surface properties and biologic activity on MDA-MB-321 breast cancer cell line were investigated. SLs were biosynthesized by Starmerella bombicola in a culture media supplemented with borage oil.

View Article and Find Full Text PDF

Folic acid targeting by functionalization of the terminal γ-carboxylic acid is one of the most important strategies to selectively deliver chemotherapeutics and dyes to cancer cells which overexpress folate receptors. However, conjugation of folic acid is limited by its unique solubility and by selectivity issues imposing the need for expensive preparative reverse-phase chromatographic purification to isolate γ-folate conjugates. Herein is provided a novel synthetic tool for the synthesis of new folic acid conjugates with excellent γ-purity based on strain-promoted alkyne-azide cycloadditions with a γ-folate-cyclooctyne conjugate 3.

View Article and Find Full Text PDF

Herein we present the synthesis of fluorescent 2-acetylbenzeneboronic acids that undergo B-N promoted conjugation with lysozyme and N-(2-aminoethyl) folic acid (EDA-FA), generating conjugates that are selectively recognized and internalized by cancer cells that over-express folic acid receptors.

View Article and Find Full Text PDF

Magnetic ionic liquids (MILs) are new solvents with an interesting broad of applications however their toxicity is still an open issue. In this paper we report the toxicity of [C(8)MIM] and [Choline-C(n)] based magnetic ionic liquids assessed in two human cell lines: normal skin fibroblasts (CRL-1502) and colorectal adenocarcinoma cells (CaCo-2), acquiring this last characteristics of human enterocytes after differentiation. The results showed that [CoCl(4)] and [MnCl(4)] are more prone to generate cytotoxicity.

View Article and Find Full Text PDF

The switch of human melanoma cell phenotype from non to highly tumorigenic and metastatic is triggered by the increase of procathepsin L secretion, which modifies the tumour microenvironment. The aim of the present study was to identify components involved in the regulation of procathepsin L secretion in melanoma cells. We focused on Rab family members, i.

View Article and Find Full Text PDF

Ionic liquids enclose a large number of molecular structures consisting of a cation and an anion. Their physical state and their chemical properties can be tuned by different combination of the ions and a large number of ionic liquids have already been reported. Toxicity of ionic liquids is a subject of great importance concerning their likely use as greener solvents and new materials for a broad number of potential applications.

View Article and Find Full Text PDF

A novel dirhodium complex (Rh(2)(L-PheAla)(2)(OAc)(2) is reported with strong activity towards human colon adenocarcinoma cells. Its effect was not accompanied by generation of reactive oxygen species (ROS) neither by activation of caspase-3.

View Article and Find Full Text PDF
Article Synopsis
  • The study focuses on isolating, identifying, and synthesizing two natural compounds that inhibit the NF-κB signaling pathway, derived from the iso-tanapartholide family.
  • A crucial step in the synthesis involved an oxidative cleavage reaction that effectively produced the natural products without using protective groups.
  • Biological tests on the synthesized compounds confirmed their action at a late stage of the NF-κB signaling pathway, providing valuable insights into their function.
View Article and Find Full Text PDF

The RB18A/MED1 human gene, also named TRAP220, DRIP205 and PBP, encodes for a single 205 kDa component, which interacts with nuclear receptors and transcription factors. RB18A/MED1 chromosome localization on locus 17q12-q21.1 suggests its involvement in human cancers.

View Article and Find Full Text PDF

We previously demonstrated that the switch from non- to highly tumorigenic phenotype of human melanoma cells is directly related to procathepsin L secretion, which increased cell resistance to complement-mediated cell lysis. Involvement of procathepsin L secretion in tumor growth was clearly demonstrated by three different strategies: (1) inhibition of secreted procathepsin L activity; (2) increase of procathepsin L secretion; and (3) inhibition of procathepsin L secretion. This latter strategy was triggered by intracellular expression of anti-human cathepsin L single-chain variable fragment (ScFv).

View Article and Find Full Text PDF

Overexpression of cathepsin L, a cysteine protease, and consequently procathepsin L secretion switch the phenotype of human melanoma cells to highly tumorigenic and strongly metastatic. This led us to identify the DNA regulatory sequences involved in the regulation of cathepsin L expression in highly metastatic human melanoma cells. The results of the present study demonstrated the presence of regulatory sequences in the 3' region downstream of the cathepsin L gene and in the 3'- and 5'-flanking regions of GC/CCAAT sites of its promoter.

View Article and Find Full Text PDF

It is well established that CD21 activation on human B cell surface triggers B cell proliferation. We previously demonstrated that CD21 activation also triggers tyrosine phosphorylation of two components, p95 and p120, both interacting with SH2 domains of the p85 subunit of PI 3-kinase. We successively identified p95 as the nucleolin and the first signal transduction pathway specifically triggered by CD21 activation, i.

View Article and Find Full Text PDF

Cathepsin L, a cysteine protease, is overexpressed in human tumor cells and plays a major role in melanoma progression. Our aim was herein to identify molecular mechanisms, which contribute to its overexpression. We found that cathepsin L protein expression correlated with mRNA level in tumor cells.

View Article and Find Full Text PDF

Human cell lines are often infected by mycoplama strains. We have demonstrated that when infected by Mycoplasma fermentans, human B lymphoma cell proliferation increased strongly. These infected B cells expressed a p45 kDa protein which interacted with the intracellular domain of CD21, the EBV/C3d receptor.

View Article and Find Full Text PDF

RB18A (TRAP220/DRIP205) is a cofactor of transcription. We herein demonstrated that RB18A downregulated p53 and upregulated MDM2 promoters. These RB18A regulations, not modified by p53wt expression, were inhibited by mutant p53 (p53mut) expression, which directly interacts with RB18A D5 domain.

View Article and Find Full Text PDF