The use of small organic molecules as catalysts has gained increasing importance recently. These substances, the so-called organocatalysts, present a lot of advantages, like being less toxic, less polluting, and more economically viable than the organometallic catalysts that dominate asymmetric synthesis. This work intends to briefly show some classic works and recent publications, explaining the advantages of organocatalysis and the different types of compounds used in this field, as well as their course of action.
26 November 2018 in Current Topics in Medicinal Chemistry
Background: Leishmaniasis is a neglected public health problem caused by several protozoanspecies of the genus Leishmania. The therapeutic arsenal for treating leishmaniasis is quite limited, raising concerns about the occurrence of resistant strains. Furthermore, most of these drugs were developed more than 70 years ago and suffer from poor efficacy and safety and are not well adapted to the needs of patients. Therefore, research on novel natural or synthetic compounds with antiparasitic activity is urgently needed. In this paper, we evaluated the effect and the mechanism of action of naphthotriazolyl-4-oxoquinolines on promastigotes and intracellular amastigotes of Leishmania amazonensis. Materials and Methods: The naphthotriazolyl-4-oxoquinoline derivatives were obtained in good to moderate yields via the [3+2] cycloaddition reaction between 1,4-naphtoquinone and azido-4- oxoquinoline derivatives. HMPA at 100°C was established as the best solvent and temperature condition for this reaction. The structures of the compounds were confirmed by spectral analyses (infrared spectroscopy, one- and two-dimensional ¹H and ¹³C NMR spectroscopy, and high-resolution mass spectrometry). The compounds exhibited promising activities with IC50 values ranging from 0.7 to 2.0 µM against intracellular amastigotes of Leishmania amazonensis. The most selective compound was the Npentyl- substituted derivative, which showed a Selectivity Index (SI) of 8.6, making it less toxic than pentamidine (SI 4.5). Results: Our results demonstrated that all compounds, except the N-propyl-substituted derivative, induce ROS production by parasites early in the culture. As a proof of concept, we demonstrated that the most selective compound was able to interfere with sterol biosynthesis in L. amazonensis. Conclusion: The naphthotriazolyl-4-oxoquinoline derivatives were obtained in good to moderate yields. These conjugates have potent in vitro antileishmanial activity involving at least two different mechanisms of action, making them promising lead compounds for the development of new therapeutic alternatives for leishmaniasis.
18 March 2020 in Current Topics in Medicinal Chemistry
4-Oxoquinoline derivatives constitute an important family of biologically important substances, associated with different bioactivities, which can be synthesized by different synthetic methods, allowing the design and preparation of libraries of substances with specific structural variations capable of modulating their pharmacological action. Over the last years, these substances have been extensively explored by the scientific community in efforts to develop new biologically active agents, with greater efficiency for the treatment of a variety of diseases. Viral infections have been one of the targets of these studies, although to a lesser extent than other diseases such as cancer and bacterial infections. Nevertheless, the literature provides examples that corroborate with the fact that these substances may act on different pharmacological targets in different viral pathogens. This review provides a compilation of some of the major studies published in recent years showing the discovery and/or development of new antiviral oxoquinoline agents, highlighting, whenever possible, their mechanisms of action.
Background: Breast cancer is a major cause of death among women worldwide. Treatment for breast cancer involves the surgical removal of cancer tissue, followed by chemotherapy. Although the treatment is efficient, especially when the cancer is detected early, recurrence is common and is often resistant to the previous treatment. Therefore, a constant search for efficient and novel drugs for the treatment of breast cancer is mandatory. Recently, triazole derivatives have shown promising effects against different types of cancer, revealing these molecules as putative anticancer drugs. Experimental: We have synthesized a series of naphthotriazolyl-4-oxoquinoline derivatives and tested their activity against a human breast cancer cell line. Among the compounds tested, we identified a molecule that killed the human breast cancer cell line MCF-7 with minimal effects on its noncancer counterpart, MCF10A. This effect was seen after 24 hours of treatment and persisted for additional 24 hours after treatment withdrawal. After 1 hour of treatment, the compound, here named 12c, promoted a decrease in cell glucose consumption and lactate production. Moreover, the cells treated with 12c for 1 hour showed diminished intracellular ATP levels with unaltered mitochondrial potential and increased reactive oxygen species production. Additionally, apoptosis was triggered after treatment with the drug for 1 hour. All of these effects are only observed with MCF-7 cells, and not MCF10A. These data show that 12c has selective activity against breast cancer cells and is a potential candidate for a novel anticancer drug. Results and Conclusion: The naphthotriazolyl-4-oxoquinoline derivatives were obtained in good to moderate yields, and one of them, 12c, exhibited strong and selective antitumor properties. The antitumor mechanism involves inhibition of glycolysis, diminished intracellular ATP levels, induction of ROS production and triggering of apoptosis. These effects are all selective for cancer cells, since noncancer cells are unaffected, and these effects can only be attributed to the whole molecule, as different pharmacophoric groups did not reproduce these effects.
Background: The increased survival provided by the access, development, and evolution of antiretroviral drugs (ARV) greatly increased the life expectancy of people living with HIV (PWH). This has also led to an increased occurrence of diseases or morbidities related to aging. In individuals with multiple comorbidities, the simultaneous use of multiple medications, also known as polypharmacy, is common, and rational use of medications is essential. This study aims to describe the pharmacotherapeutic profile, estimate the prevalence of polypharmacy and identify factors associated with polypharmacy in a cohort of adult PWH from a referral unit in Rio de Janeiro, Brazil. Methods: Cross-sectional study including PWH on ARV who received at least one medical prescription (outpatient/hospitalized) in 2019. We described the proportion of prescribed medications according to ARV and Anatomical Therapeutic Chemical (ATC) classes stratified by age (< 50 vs. ≥50 years). Polypharmacy was defined as ≥ 5 medications prescribed beyond ARV. Logistic regression models assessed demographic and clinical factors associated with polypharmacy. Results: A total of 143,306 prescriptions of 4547 PWH were analyzed. Median age was 44.4 years (IQR:35.4–54.1) and 1615 (35.6%) were ≥ 50 years. A total of 2958 (65.1%) participants self-identified as cisgender man, 1365 (30.0%) as cisgender woman, and 224 (4.9%) as transgender women. Most self-declared Black/Pardo (2582; 65.1%) and 1984 (44.0%) completed elementary education or less. Median time since HIV diagnosis was 10.9 years (IQR:6.2–17.7). Most frequently prescribed concomitant medications were nervous system (64.8%), antiinfectives for systemic use (60.0%), alimentary tract and metabolism (45.9%), cardiovascular system (40.0%) and respiratory system (37.1%). Prevalence of polypharmacy was 50.6% (95%CI: 49.2–52.1). Model results indicated that being older, self-identify as cisgender woman, having less education and longer time since HIV diagnosis increased the odds of polypharmacy. Conclusions: We found high rates of polypharmacy and concomitant medication use in a cohort of PWH in Brazil. Targeted interventions should be prioritized to prevent interactions and improve treatment, especially among individuals using central nervous system and cardiovascular medications, as well as certain groups such as cisgender women, older individuals and those with lower education. Standardized protocols for continuous review of patients’ therapeutic regimens should be implemented.