Harnessing the Potential of Electron Donor-Acceptor Complexes and N-Centered Radicals: Expanding the Frontiers of Isoquinoline Derivative Synthesis

Research on synthesizing nitrogen-containing heterocyclic scaffolds is important because these structures are commonly found in Nature, such as in the alkaloids' family. In our study, we propose a new method to synthesize the isoquinoline core using an electron donor-acceptor (EDA) complex strategy. Our mechanistic investigations have confirmed that our synthesis process operates through an EDA mechanism, which is not extensively discussed in the literature, particularly regarding its applications on alkynyl substrates. This EDA strategy has proven to be a simple and straightforward way to produce isoquinoline scaffolds and their derivatives without the need for metal catalysts.

Synthesis of Isoquinolines and Related Heterocycles under Visible-Light Conditions

Visible-light catalysis is now widely acknowledged as a potent approach for efficiently constructing various types of frameworks, particularly bioactive compounds, with high yields. However, there is still a strong need for further advancements in these methods because certain delicate compounds cannot be synthesized due to structural sensitivity. In this context, a seamless reaction pathway toward 6-membered ring nitrogen-containing heterocycles is presented here, offering access to isoquinoline derivatives and related heterocycles.

PSL Chemical Biology Symposia Third Edition: A Branch of Science in its Explosive Phase

This symposium is the third PSL (Paris Sciences & Lettres) Chemical Biology meeting (2016, 2019, 2023) held at Institut Curie. This initiative originally started at Institut de Chimie des Substances Naturelles (ICSN) in Gif-sur-Yvette (2013, 2014), under the directorship of Professor Max Malacria, with a strong focus on chemistry. It was then continued at the Institut Curie (2015) covering a larger scope, before becoming the official PSL Chemical Biology meeting. This latest edition was postponed twice for the reasons that we know. This has given us the opportunity to invite additional speakers of great standing. This year, Institut Curie hosted around 300 participants, including 220 on site and over 80 online. The pandemic has had, at least, the virtue of promoting online meetings, which we came to realize is not perfect but has its own merits. In particular, it enables those with restricted time and resources to take part in events and meetings, which can now accommodate unlimited participants. We apologize to all those who could not attend in person this time due to space limitation at Institut Curie.

Photoredox synthesis of 6- and 7-membered ring scaffolds via N-centered radicals

N-Containing heterocycles are important scaffolds due to their ubiquitous presence in bioactive compounds. Their synthesis has been considered as an important research field. In this work we report the access to 6- and 7-membered rings via a photoinduced strategy. To our knowledge, this work represents the first exemple of photo-induced 7-endo-trig cyclization with N-centered radicals.

Polycyclic nitrogen heterocycles as potential thymidine phosphorylase inhibitors: synthesis, biological evaluation, and molecular docking study

New polycyclic heterocycles were synthesised and evaluated as potential inhibitors of thymidine phosphorylase (TP). Inspired by the pharmacophoric pyrimidinedione core of the natural substrate, four series have been designed in order to interact with large empty pockets of the active site: pyrimidoquinoline-2,4-diones (series A), pyrimidinedione linked to a pyrroloquinoline-1,3-diones (series B and C), the polycyclic heterocycle has been replaced by a pyrimidopyridopyrrolidinetetraone (series D). In each series, the tricyclic nitrogen heterocyclic moiety has been synthesised by a one-pot multicomponent reaction. Compared to 7-DX used as control, 2d, 2l, 2p (series A), 28a (series D), and the open intermediate 30 showed modest to good activities. A kinetic study confirmed that the most active compounds 2d, 2p are competitive inhibitors. Molecular docking analysis confirmed the interaction of these new compounds at the active binding site of TP and highlighted a plausible specific interaction in a pocket that had not yet been explored.

Silver-catalyzed tandem cycloisomerization/hydroarylation reactions and mechanistic investigations for an efficient access to 1,2-dihydroisoquinolines

A combination of AcOH and Ag catalyst induced an efficient tandem reaction to form 1,2-dihydroisoquinoline derivatives. Highly functionalized multiheterocyclic scaffolds are accessible straightforwardly using readily available starting materials.

Breastfeeding practices and complementary feeding in Ecuador: implications for localized policy applications and promotion of breastfeeding: a pooled analysis

Background

Best practices in breastfeeding are often not followed despite appropriate levels of knowledge and positive attitudes regarding the benefits of human milk. For many reasons, some women do not initiate breastfeeding, suspend breastfeeding early, or initiate complementary feeding earlier than recommended. Usual measurement methods use large sample surveys at a national scale, which are not well suited for monitoring sub-national differences.

Methods

In order to understand how local infant feeding practices could influence policy and promotion practices, we apply data pooling methodology to analyse breastfeeding patterns in different Ecuadorian settings: Cumbayá parish, located near Quito, the Ecuadorian capital; the city of Macas and rural surroundings in the Amazon basin province of Morona Santiago; and the province of Galapagos. Surveys were conducted independently between August 2017 and August 2018; while they are representative of each respective setting, sampling designs and survey methods differ, but the same demographic information and data based on standard breastfeeding indicators established by the World Health Organization (WHO) were collected. In order to account for differences in the different settings, the design effect of each survey was considered in the analysis.

Results

Significant differences were found in breastfeeding practices between the suburban Cumbayá parish near Quito and Galapagos on one hand, and urban and rural parts of Morona Santiago, on the other. The rates of early breastfeeding initiation and age-appropriate breastfeeding are significantly higher in urban and rural Morona Santiago then in Cumbayá or Galapagos, while the rate of exclusive breastfeeding is highest in rural parts of Morona Santiago. No significant differences were found in complementary feeding practices between Cumbayá and Galapagos, but there are with urban and rural Morona Santiago. Initiation of breastfeeding in the first hour after birth occurs in only 36.2% of cases in Cumbayá but in 75.4% of cases in urban Morona.

Conclusions

Differences among regions reflect specific opportunities and barriers to practices related to promoting optimal infant health and nutrition. Consequently, regional or local conditions that often are not apparent in national-level data should orient policies and promotion activities in specific populations.

2nd PSL Chemical Biology Symposium (2019): At the Crossroads of Chemistry and Biology

Chemical Biology is the science of designing chemical tools to dissect and manipulate biology at different scales. It provides the fertile ground from which to address important problems of our society, such as human health and environment.

Overweight, obesity, and food consumption in Galapagos, Ecuador: a window on the world

BACKGROUND

In order to understand why rates of overweight and obesity are so high in the Ecuadorian province of Galapagos, this study analyzes changes in household food expenditures and perceptions and practices related to food consumption patterns. Galapagos is understood as an unusual but not unique case because conditions there graphically illustrate trends observed in communities and countries worldwide. A mixed methods approach was employed: a quantitative component was based on expenditures for foods classified according to the NOVA system, and a qualitative component utilized focus group discussions, key informant interviews, and structured observations.

RESULTS

Galapagos residents increased consumption of processed and ultra-processed foods and decreased consumption of unprocessed and minimally processed foods. Perceived barriers to healthy diets include price, availability, and quality of fresh produce, as well as easy access to industrialized processed and ultra-processed foods.

CONCLUSIONS

Changes in consumption patterns represent both local conditions and global trends; in that sense, the factors that affect Galapagos residents are not unique. Hence, these findings help elucidate processes observed in communities around the world.

The double burden of chronic malnutrition and overweight and obesity in Ecuadorian mothers and children, 1986-2012

BACKGROUND:

The simultaneous presence of undernutrition and over-nutrition represents a paradox in global public health and is of increasing concern in Ecuador, where chronic malnutrition and overweight and obesity occur in the context of demographic and epidemiologic transitions. Two overlapping trends are present in Ecuador; while levels of stunting have decreased slowly in the past three decades, increasing proportions of children <5 years and women of reproductive age suffer from overweight and obesity.

AIM:

To analyze stunting and overweight and obesity in children <5 and their mothers aged from 15 to 49 years in the context of demographic and household characteristics between 1986 and 2012.

METHODS:

This study compares data from nationally-representative surveys conducted in Ecuador in 1986, 2004, and 2012, each of which collected information on children <5 and mothers aged 15-49 years.

RESULTS:

The prevalence of chronic malnutrition in children <5 decreased at different rates among Ecuadorians who differ in terms of residence, socioeconomic status, and mothers' level of education, while overweight and obesity increased dramatically in the same period.

CONCLUSION:

Chronic malnutrition in children <5 and overweight in children <5 and mothers 15-49 years represent a double burden of malnutrition in Ecuador. The phenomena differ in their effects, and, while the prevalence of stunting is declining in Ecuador as it is in many parts of the world, the problem of overweight and obesity has emerged in dramatic fashion, and currently represents an extraordinary challenge to public health.

Visible light amination/Smiles cascade: access to phthalazine derivatives

We report the synthesis of various phthalazines via a new cascade reaction, initiated by visible light photocatalysis, involving a radical hydroamination reaction followed by a radical Smiles rearrangement. Phthalazine derivatives are obtained in high yields and from a broad scope readily accessible ortho-alkynylsulfonohydrazone precursors. The mild photoredox conditions ensure an excellent functional group tolerance. Application of this strategy to a one-pot protocol starting from the corresponding carbonyl compounds, and subsequent functionalization allow the rapid synthesis of structurally diverse structures.

The double burden of undernutrition and excess body weight in Ecuador

BACKGROUND

Ecuador's current nutrition policies have not taken adequate notice of the double burden of malnutrition and continue to focus on stunting and to a lesser extent on overweight, without addressing the simultaneous presence of undernutrition, micronutrient deficiencies, and overweight or obesity (OW/OB).

OBJECTIVE

The aim of this article was to describe the prevalence and distribution of undernutrition (stunting, anemia, and zinc deficiency), overweight, and obesity in Ecuador to explore the evolving double burden of malnutrition at the national, household, and individual levels and to discuss whether current public health policies are addressing the double burden.

DESIGN

Data from the 2012 Ecuadorian National Health and Nutrition Survey (ENSANUT-ECU) was used to estimate the dual burden of malnutrition at the national, household, and individual levels in children <5 y old, school-aged children, and women of reproductive age.

RESULTS

In 13.1% of households, mothers with excess body weight coexist with a stunted child <5 y old. Moreover, among households with overweight or obese mothers, 12.6% have an anemic child and 14% have a zinc-deficient child. At the individual levels, the coexistence of OW/OB and stunting, anemia, or zinc deficiency was found in 2.8%, 0.7%, and 8.4% of school-aged children, respectively. In addition, 8.9% and 32.6% of women aged 12-49 y have excess body weight and anemia or zinc deficiency, respectively.

CONCLUSIONS

This article shows the coexistence of high rates of undernutrition and OW/OB at the individual, household, and national levels in Ecuador. Although integrated approaches to address the emerging double burden are required, public health policies to date have not responded adequately.

Silver versus Gold Catalysis in Tandem Reactions of Carbonyl Functions onto Alkynes: A Versatile Access to Furoquinoline and Pyranoquinoline Cores

An efficient and versatile tandem process of acetalization and cycloisomerization reactions has been developed for the reactions of 1-alkynyl-2-carbonylquinoline substrates. The reaction occurs thanks to Au(I) and Ag(I) catalysis. Silver(I) catalysis has been extensively studied (11 different silver species) on a broad range of quinoline derivatives (variation of alkyne substituent, of carbonyl function and of nucleophiles), leading to a variety of furoquinoline and pyranoquinoline moieties. An insight is given for the presumed mechanism along with DFT-B3 LYP/6-31G** calculations to address the 6-endo and 5-exo regioselectivities observed.

Acridine and acridone derivatives, anticancer properties and synthetic methods: where are we now?

Acridine derivatives are interesting chemotherapeutic agents that were first used as antibacterial and antiparasite agents. In this review we wish to concentrate our attention on the anticancer properties of acridines used in clinics since the 1970's. Based on recent results, an outlook on antitumour acridine chemotherapy will be proposed. The biological activity of acridines is mainly attributed to the planarity of these aromatic structures, which can intercalate within the double-stranded DNA structure, thus interfering with the cellular machinery. Recent understanding of the mode of action of acridines leads to continuous and exciting research in this heterocyclic family. Indeed, biological targets such as topoisomerases I and II, telomerase/telomere and protein kinases emerge and allow the design of novel acridine-based patterns. This review further pinpoints the latest progress in the development of anticancer agents based on naturally occurring and synthetic acridines (e.g. acridones, pyridoacridines); for this matter in vitro/in vivo studies and clinical trial results will be discussed. The DNA-affinic property of acridine is also useful to vectorise drugs into cell nuclei and some applications in hypoxia-selective treatment, platinum or N-mustard derived conjugates will be reported. Some other properties including inhibition of multidrug resistance or potential impact on Alzheimer disease will be treated. It is noteworthy that the position and the nature of the substituent on the heterocyclic core are determinants for the biological property and selectivity observed. So, we wish also to disclose a summary of recent synthetic methodologies developed for acridine synthesis.

An Efficient and Simple Aminobenzannulation Reaction: Pyrrolidine as a Trigger for the Synthesis of 1-Amino-acridines

[reaction: see text] A new aminobenzannulation methodology has been developed and applied successfully to the synthesis of 1-amino-acridines. The key and last step goes through an enamine intermediate that was detected in some cases. When pyrrolidine and powdered 4 A molecular sieves were used, the enamine synthesis and the aminobenzannulation step took place subsequently, whereas for other secondary amines, neutral Al(2)O(3) or PtCl(2) catalysis was necessary.

Aminoglycoside-derived cationic lipids as efficient vectors for gene transfection in vitro and in vivo

BACKGROUND

Cationic lipids are at present very actively investigated for gene transfer studies and gene therapy applications. Basically, they rely on the formation of DNA/lipid aggregates via electrostatic interactions between their cationic headgroup and the negatively charged DNA. Although their structure/activity relationships are not well understood, it is generally agreed that the nature of the positive headgroup impacts on their transfection activity. Thus, we have directed our efforts toward the development of cationic lipids with novel cationic moieties. In the present work, we have explored the transfection potential of the lipophilic derivatives of the aminoglycoside kanamycin A. Indeed, aminoglycosides, which are natural polyamines known to bind to nucleic acids, provide a favorable scaffold for the synthesis of a variety of cationic lipids because of their structural features and multifunctional nature.

METHODS AND RESULTS

We report here the synthesis of a cationic cholesterol derivative characterized by a kanamycin A headgroup and of its polyguanidinylated derivative. The amino-sugar-based cationic lipid is highly efficient for gene transfection into a variety of mammalian cell lines when used either alone or as a liposomal formulation with the neutral phospholipid dioleoylphosphatidylethanolamine (DOPE). Its polyguanidinylated derivative was also found to mediate in vitro gene transfection. In addition, colloidally stable kanamycin-cholesterol/DOPE lipoplexes were found to be efficient for gene transfection into the mouse airways in vivo.

CONCLUSIONS

These results reveal the usefulness of cationic lipids characterized by headgroups composed of an aminoglycoside or its guanidinylated derivative for gene transfection in vitro and in vivo.

Incidence and outcomes of total hip arthroplasty among U.S. Army aviators

Among Army aviators, the incidence of total hip arthroplasty (THA) is unknown. This study analyzes the incidence and aeromedical disposition of THA among Army aviators. The U.S. Army Epidemiology Data Register was queried for a 10-year period from calendar year 1987 to 1996. The aviators selected for this study cohort were all qualified and on active flight status before undergoing THA. Data collected included age, gender, diagnoses, and aeromedical dispositions. There were 214,003 aviator-years of observation. Eleven aviators underwent 14 THAs. The overall incidence of THA was 0.05 per 1,000 aviator-years of observation. Of the 11 aviators who underwent THA during the study period, 4 received aeromedical suspension from flying duties (36%). THA is a rare medical event among Army aircrew members. Most are able to return to full flying duties with a waiver. Aircrew members younger than 50 years with THA are more likely to be suspended from aviation duties.