scholarly journals Design, Synthesis, and Utility of Defined Molecular Scaffolds

Organics ◽  
2021 ◽  
Vol 2 (3) ◽  
pp. 161-273
Author(s):  
Daisuke Sato ◽  
Zhiyuan Wu ◽  
Hikaru Fujita ◽  
Jonathan S. Lindsey

A growing theme in chemistry is the joining of multiple organic molecular building blocks to create functional molecules. Diverse derivatizable structures—here termed “scaffolds” comprised of “hubs”—provide the foundation for systematic covalent organization of a rich variety of building blocks. This review encompasses 30 tri- or tetra-armed molecular hubs (e.g., triazine, lysine, arenes, dyes) that are used directly or in combination to give linear, cyclic, or branched scaffolds. Each scaffold is categorized by graph theory into one of 31 trees to express the molecular connectivity and overall architecture. Rational chemistry with exacting numbers of derivatizable sites is emphasized. The incorporation of water-solubilization motifs, robust or self-immolative linkers, enzymatically cleavable groups and functional appendages affords immense (and often late-stage) diversification of the scaffolds. Altogether, 107 target molecules are reviewed along with 19 syntheses to illustrate the distinctive chemistries for creating and derivatizing scaffolds. The review covers the history of the field up through 2020, briefly touching on statistically derivatized carriers employed in immunology as counterpoints to the rationally assembled and derivatized scaffolds here, although most citations are from the past two decades. The scaffolds are used widely in fields ranging from pure chemistry to artificial photosynthesis and biomedical sciences.

2009 ◽  
Vol 13 (04n05) ◽  
pp. 461-470 ◽  
Author(s):  
Joaquim Crusats ◽  
Zoubir El-Hachemi ◽  
Carlos Escudero ◽  
Josep M. Ribó

The formation and structure of the title aggregates are paradigms of the self-assembly of amphiphilic molecular building blocks in supramolecular chemistry. This review summarizes the research in the University of Barcelona on the homoassociation of the water soluble meso 4-sulfonatophenyl-and phenyl substituted porphyrins.


2018 ◽  
Vol 17 (1) ◽  
pp. 87-94
Author(s):  
A. B. Belov

The history of the study of infections attributed by the microbiologist and epidemiologist V.I. Tersky in 1958 as the class of human infectious diseases – «Sapronoses» is presented. Over the past 60 years in the world and especially in Russian science the knowledge that allows us to complete the development of an ecological and epidemiological theory of sapronoses infections was accumulated. This knowledge should be extended to the whole complex of biomedical sciences associated with the population pathology of biota. To solve the controversial and complex issues of the theory, terminology and classifications of population infectology, it is necessary to integrate the knowledge of specialists in various fields of research and practice in the medicine, veterinary medicine, parasitology, phytopathology and other disciplines. The ways and prospects of improving the general theory of infectology in the light of new approaches to understanding the essence of sapronoses are discussed. 


2020 ◽  
Vol 27 (8) ◽  
pp. 688-697
Author(s):  
Yu Chen ◽  
Kai Tao ◽  
Wei Ji ◽  
Pandeeswar Makam ◽  
Sigal Rencus-Lazar ◽  
...  

Supramolecular self-assembled functional materials comprised of cyclic dipeptide building blocks have excellent prospects for biotechnology applications due to their exceptional structural rigidity, morphological flexibility, ease of preparation and modification. Although the pharmacological uses of many natural cyclic dipeptides have been studied in detail, relatively little is reported on the engineering of these supramolecular architectures for the fabrication of functional materials. In this review, we discuss the progress in the design, synthesis, and characterization of cyclic dipeptide supramolecular nanomaterials over the past few decades, highlighting applications in biotechnology and optoelectronics engineering.


2021 ◽  
Vol 22 (22) ◽  
pp. 12466
Author(s):  
Mahmoud Izadi ◽  
Tayyiba Akbar Ali ◽  
Ehsan Pourkarimi

Research in biomedical sciences has changed dramatically over the past fifty years. There is no doubt that the discovery of apoptosis and autophagy as two highly synchronized and regulated mechanisms in cellular homeostasis are among the most important discoveries in these decades. Along with the advancement in molecular biology, identifying the genetic players in apoptosis and autophagy has shed light on our understanding of their function in physiological and pathological conditions. In this review, we first describe the history of key discoveries in apoptosis with a molecular insight and continue with apoptosis pathways and their regulation. We touch upon the role of apoptosis in human health and its malfunction in several diseases. We discuss the path to the morphological and molecular discovery of autophagy. Moreover, we dive deep into the precise regulation of autophagy and recent findings from basic research to clinical applications of autophagy modulation in human health and illnesses and the available therapies for many diseases caused by impaired autophagy. We conclude with the exciting crosstalk between apoptosis and autophagy, from the early discoveries to recent findings.


2011 ◽  
Author(s):  
◽  
Drew A. Fowler

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT REQUEST OF AUTHOR.] Supramolecular chemistry, in its simplest and broadest description, is the chemistry of intermolecular interactions or chemistry of the noncovalent bond. Supramolecular chemistry is rooted in discoveries, such as the chlorine clathrate found in 1810 by Sir Humphry Davy, and concepts, such as coordination chemistry (1893-Werner) and the lock-and-key concept (1894-Fischer). The broad definition of supramolecular chemistry can be applied to a vast subject range including naturally occurring assemblies, such as proteins and the double helix of DNA. Today, a key interest of supramolecular chemists is the design of functional multi-component systems constructed from smaller molecular building blocks. This research focuses specifically on the supramolecular chemistry of a family of macrocycles called calixarenes, specifically the pyrogallol derivatives pyrogallol[4]arenes. Due to the bowl-like shape of the macrocycles and the presence of 12 upper-rim hydroxyls, pyrogallol[4]arenes have been found to exhibit a number of interesting supramolecular properties. The following dissertation contains the description of advances that have been made using these macrocycles. This work illustrates the expansion of a project dealing with the cocrystallization, and encapsulation of fluorescent reporter molecules with a variety of pyrogallol[4]arenes in different solvent systems. The description of a number of crystal structures that is offered will illustrate how, through thoughtful experimentation, the successful design of a new host molecular capsule was carried out and broadened to include a number of guest molecules. The target molecules have also been expanded from the fluorescent reporters to a variety of possible targets molecules. The solid-state structures discussed include multiple cocrystals of gabapentin, an active pharmaceutical ingredient, and structures containing the organometallic sandwich complex ferrocene.


1961 ◽  
Vol 2 (2) ◽  
pp. 73-105 ◽  
Author(s):  
John R. W. Small

It is generally accepted that history is an element of culture and the historian a member of society, thus, in Croce's aphorism, that the only true history is contemporary history. It follows from this that when there occur great changes in the contemporary scene, there must also be great changes in historiography, that the vision not merely of the present but also of the past must change.


1962 ◽  
Vol 11 (02) ◽  
pp. 137-143
Author(s):  
M. Schwarzschild

It is perhaps one of the most important characteristics of the past decade in astronomy that the evolution of some major classes of astronomical objects has become accessible to detailed research. The theory of the evolution of individual stars has developed into a substantial body of quantitative investigations. The evolution of galaxies, particularly of our own, has clearly become a subject for serious research. Even the history of the solar system, this close-by intriguing puzzle, may soon make the transition from being a subject of speculation to being a subject of detailed study in view of the fast flow of new data obtained with new techniques, including space-craft.


2020 ◽  
Vol 5 (1) ◽  
pp. 6-11 ◽  
Author(s):  
Laurence B. Leonard

Purpose The current “specific language impairment” and “developmental language disorder” discussion might lead to important changes in how we refer to children with language disorders of unknown origin. The field has seen other changes in terminology. This article reviews many of these changes. Method A literature review of previous clinical labels was conducted, and possible reasons for the changes in labels were identified. Results References to children with significant yet unexplained deficits in language ability have been part of the scientific literature since, at least, the early 1800s. Terms have changed from those with a neurological emphasis to those that do not imply a cause for the language disorder. Diagnostic criteria have become more explicit but have become, at certain points, too narrow to represent the wider range of children with language disorders of unknown origin. Conclusions The field was not well served by the many changes in terminology that have transpired in the past. A new label at this point must be accompanied by strong efforts to recruit its adoption by clinical speech-language pathologists and the general public.


Crisis ◽  
2020 ◽  
pp. 1-6
Author(s):  
Mohammed Madadin ◽  
Ritesh G. Menezes ◽  
Maha A. Alassaf ◽  
Abdulaziz M. Almulhim ◽  
Mahdi S. Abumadini ◽  
...  

Abstract. Background: Medical students are at high risk of suicidal ideation. Aim: We aimed to obtain information on suicidal ideation among medical students in Dammam located in the Eastern Province of Saudi Arabia. Method: This cross-sectional study was conducted at the College of Medicine affiliated with Imam Abdulrahman Bin Faisal University in the Eastern Province of Saudi Arabia. Suicidal ideation in the past 12 months was assessed based on responses to four questions in the depression subscale of the General Health Questionnaire 28 (GHQ-28). In addition, data were collected to examine the association of suicidal ideation with various factors. Results: We found that 1 in 3 medical students in the study had suicidal ideation in the past 12 months, while around 40% had lifetime suicidal ideation. Suicidal ideation was associated with feelings of parental neglect, history of physical abuse, and dissatisfaction with academic performance. Limitations: The cross-sectional nature of this study limits its ability to determine causality regarding suicidal ideation. Conclusion: These rates are considerably high when compared with rates from studies in other countries around the world. This study provides a reference in the field of suicidology for this region of Saudi Arabia.


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