Luiz Antonio Soares Romeiro

New potential AChE inhibitor candidates.

We have theoretically studied new potential candidates of acetylcholinesterase (AChE) inhibitors designed from cardanol, a non-isoprenoid phenolic lipid of cashew Anacardium occidentale nut-shell liquid. The electronic structure calculations of fifteen molecule derivatives from cardanol were performed using B3LYP level with 6-31G, 6-31G(d), and 6-311+G(2d,p) basis functions. For this study we used the following groups: methyl, acetyl, N,N-dimethylcarbamoyl, N,N-dimethylamine, N,N-diethylamine, piperidine, pyrrolidine, and N,N-methylbenzylamine. Among the proposed compounds we identified that the structures with substitution by N,N-dimethycarbamoyl, N,N-dimethylamine, and pyrrolidine groups were better correlated to rivastigmine, and represent possible AChE inhibitors against Alzheimer disease.

Synthesis and cytotoxicity screening of substituted isobenzofuranones designed from anacardic acids.

This work is part of a large program, which seeks to discover new antitumor isobenfuranones designed from anacardic acids. The synthetic strategy for the construction of the title compounds takes into consideration the use of inexpensive anacardic acids (2), the major natural cashew (Anacardium occidentale) nut-shell phenolic lipid, and features one-pot construction of fused-ring aromatic gamma-lactones, phthalides. The cytotoxicity screening in different human cancer cell lines (HL-60 leukemia, SF295 glioblastoma and MDA-MB435 melanoma) by the MTT assay showed that acyclic precursor (6), and isobenfuranones (1a and 1b) are active compounds. Interestingly, 1a exhibits significant antiproliferative effect against HL-60 cells and moderate activity against SF295 and MDA-MB435 cell lines. Analysis of mechanisms involved in the cytotoxic activity showed that active compounds were leading to DNA damage, triggering apoptosis or necrosis induction.

Discovery of LASSBio-772, a 1,3-benzodioxole N-phenylpiperazine derivative with potent alpha 1A/D-Adrenergic receptor blocking properties

We described herein the discovery of 1-(2-(benzo[d] [1,3]dioxol-6-yl)ethyl)-4-(2-methoxyphenyl) piperazine (LASSBio-772), as a novel potent and selective alpha 1A/1D adrenoceptor (AR) antagonist selected after screening of functionalized N-phenylpiperazine derivatives in phenylephrine-induced vasoconstriction of rabbit aorta rings. The affinity of LASSBio-772 for alpha 1A and alpha 1B AR subtypes was determined through displacement of [(3)H]prazosin binding. We obtained Ki values of 0.14 nM for the alpha 1A-AR, similar to that displayed by tamsulosin (K(i) = 0.13 nM) and 5.55 nM for the alpha 1B-AR, representing a 40-fold higher affinity for alpha 1A-AR. LASSBio-772 also presented high affinity (K(B) = 0.025 nM) for the alpha 1D-AR subtype in the functional rat aorta assay, showing to be equipotent to tamsulosin (K(B) = 0.017 nM).

New application of triphosgene in a convenient synthesis of 3-aryl-1,3-benzoxazine-2,4-diones from anacardic acids

In conjunction with a search program focused on utilization of cashew (Anacardium occidentale) nut shell liquid (CNSL) as starting material for the preparation of useful compounds, a convenient synthesis of novel series of 3-aryl-1,3-benzoxazine-2,4-diones was prepared from anacardic acids by using of the triphosgene.

Potential acetylcholinesterase inhibitors: molecular docking, molecular dynamics, and in silico prediction

AbstractThis paper deals with molecular modeling of new therapeutic agents for treating the Alzheimer’s disease. The therapeutic line adopted for this study is the cholinergic hypothesis. To modulate positively the cholinergic function through the inhibition of the acetylcholinesterase, a set of candidates was designed from a natural compound extracted from the cashew nutshell liquid, anacardic acid. In silico screening of this chemical library revealed a ligand that is more promising once it is correlated with an active drug through specific topological and electronic descriptors. The protein–ligand docking showed stable binding modes and the binding free energy computed for the active site of the receptor suggests that our ligand presents a potential biological response. Graphical AbstractRepresentation of the three dimensional structure of the AChE, showing the important binding sites of the Gorge and the conformation of the ligand

Effect of piplartine and cinnamides on Leishmania amazonensis, Plasmodium falciparum and on peritoneal cells of Swiss mice

Abstract Context: Plants of the Piperaceae family produce piplartine that was used to synthesize the cinnamides. Objective: To assess the effects of piplartine (1) and cinnamides (2–5) against the protozoa responsible for malaria and leishmaniasis, and peritoneal cells of Swiss mice. Materials and methods: Cultures of Leishmania amazonensis, Plasmodium falciparum-infected erythrocytes, and peritoneal cells were incubated, in triplicate, with different concentrations of the compounds (0 to 256 μg/mL). The inhibitory concentration (IC50) in L. amazonensis and cytotoxic concentration (CC50) in peritoneal cell were assessed by the MTT method after 6 h of incubation, while the IC50 for P. falciparum-infected erythrocytes was determined by optical microscopy after 48 or 72 h of incubation; the Selectivity Index (SI) was calculated by CC50/IC50. Results: All compounds inhibited the growth of microorganisms, being more effective against P. falciparum after 72 h of incubation, especially for the compounds 1 (IC50 = 3.2 μg/mL) and 5 (IC50 = 6.6 μg/mL), than to L. amazonensis (compound 1 = 179.0 μg/mL; compound 5 = 106.0 μg/mL). Despite all compounds reducing the viability of peritoneal cells, the SI were <10 to L. amazonensis, whereas in the cultures of P. falciparum the SI >10 for the piplartine (>37.4) and cinnamides 4 (>10.7) and 5 (= 38.4). Discussion and conclusion: The potential of piplartine and cinnamides 4 and 5 in the treatment of malaria suggest further pre-clinical studies to evaluate their effects in murine malaria and to determine their mechanisms in cells of the immune system.

Síntese de análogo de brassinoesteróide a partir de vespertilina

In the last years, several research groups have been working on the synthesis of new steroidal plant hormones called brassinosteroids (BS), which promote plant growth and better crops. Many synthetic targets and applications of these compounds and their analogues have been described in the literature. From Solanum species of the Distrito Federal, we isolated the steroidal alkaloid solasodine, which was then converted into our starting material, vespertiline. By functionalization of rings A and B, we have synthesized a new analogue of BS, with a 2a,3a-dihydroxy-6-one structure, typical of the naturally occurring BS castasterone, the immediate biosynthetic precursor of brassinolide.

Induction of apoptosis in Ehrlich ascites tumour cells via p53 activation by a novel small-molecule MDM2 inhibitor – LQFM030

The activation of the p53 pathway through the inhibition of MDM2 has been proposed as a novel therapeutic strategy against tumours. A series of cis‐imidazoline analogues, termed nutlins, were reported to displace the recombinant p53 protein from its complex with MDM2 by binding to MDM2 in the p53 pocket, and exhibited an antitumour activity both in vitro and in vivo. Thus, the purpose of this study was to evaluate the antitumour properties of LQFM030 (2), a nutlin analogue created by employing the strategy of molecular simplification.

Characterization of cytotoxic activity of compounds derived from anacardic acid, cardanol and cardol in oral squamous cell carcinoma

Background Cancer is the second leading cause of death worldwide, and oral cancer ranks tenth among all types [1]. Chemotherapy, radiotherapy and surgery are current therapeutic options; however these are not fully efficient. Permanent functional impairment and aesthetic scars are frequent [2]. In this scenario, it is crucial to find therapeutic alternatives, including those derived from the flora, which currently provides about 1/3 of all new medicines. Anacardic acids, cardanols and cardols are the main constituents of the cashew nut shell liquid (herein referred to as “LCC”) and together, account for 90% of its composition. The liquid is an industrial byproduct, with low economic value prior to processing. The nut, the proper fruit from the plant Anacardium occidentale, is edible. Anacardic acids, cardols and cardanols are made of a phenolic ring connected to a long side chain (usually C15H31-n) that can bear several to none insaturations. Additionally, a methyl group can be found in the phenolic ring [3]. Apart from current industrial uses, it has been demonstrated that some of these compounds may exert microbicide and antioxidative activities. Anacardic acid has been shown to be cytotoxic to lung, liver and gastric tumor cells through epigenetic mechanisms by inhibiting histone acetyltransferases (HATs) [4] and in a capase-independent manner [5]. However, given the possible molecular diversity obtained from LCC constituents, not all distinct LCC derivatives have yet been fully analyzed or characterized. Aim The aim of the present study was to screen for compounds with cytotoxic activity in oral cancer cells and characterize the observed effect.

Synthesis and structure–activity relationships of novel arylpiperazines as potent antagonists of α1-adrenoceptor

Arylpiperazines 2-11 were synthesized, and their biological profiles at α1-adrenergic receptors (α1-ARs) assessed by binding assays in CHO cells expressing human cloned subtypes and by functional experiments in isolated rat vas deferens (α1A), spleen (α1B), and aorta (α1D). Modifications at the 1,3-benzodioxole and phenyl phamacophoric units resulted in the identification of a number of potent compounds (moderately selective with respect to the α1b-AR), in binding experiments. Notably, compound 7 (LDT451) showed a subnanomolar pKi of 9.41 towards α1a-AR. An encouragingly lower α1B-potency was a general trend for all the series of compounds, which showed α1A/D over α1B selectivity in functional assays. If adequately optimized, such peculiar selectivity could have relevance for a potential LUTS/BPH therapeutic application.