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Molecular Microbiology Oct 2017Elfamycins are a relatively understudied group of antibiotics that target the essential process of translation through impairment of EF-Tu function. For the most part,... (Review)
Review
Elfamycins are a relatively understudied group of antibiotics that target the essential process of translation through impairment of EF-Tu function. For the most part, the utility of these compounds has been as laboratory tools for the study of EF-Tu and the ribosome, as their poor pharmacokinetic profile and solubility has prevented implementation as therapeutic agents. However, due to the slowing of the antibiotic pipeline and the rapid emergence of resistance to approved antibiotics, this group is being reconsidered. Some researchers are using screens for novel naturally produced variants, while others are making directed, systematic chemical improvements on publically disclosed compounds. As an example of the latter approach, a GE2270 A derivative, LFF571, has completed phase 2 clinical trials, thus demonstrating the potential for elfamycins to become more prominent antibiotics in the future.
Topics: Actinomycetales; Actinomycetales Infections; Aminoglycosides; Anti-Bacterial Agents; Drug Design; Escherichia coli; Guanosine Triphosphate; Peptide Elongation Factor Tu; Peptides, Cyclic; Polyenes; Pyridones; Ribosomes; Thiazoles
PubMed: 28710887
DOI: 10.1111/mmi.13750 -
Molecules (Basel, Switzerland) Aug 2020Boron and silicon-substituted 1,3-dienes and boron and silicon-substituted alkenes and alkynes have been known for years and the last 10 years have seen a number of new... (Review)
Review
Boron and silicon-substituted 1,3-dienes and boron and silicon-substituted alkenes and alkynes have been known for years and the last 10 years have seen a number of new reports of their preparation and use in Diels-Alder reactions. This review first covers boron-substituted dienes and dienophiles and then moves on to discuss silicon-substituted dienes and dienophiles.
Topics: Alkynes; Boron; Catalysis; Cycloaddition Reaction; Models, Molecular; Polyenes; Silicon; Stereoisomerism
PubMed: 32824327
DOI: 10.3390/molecules25163740 -
Current Neuropharmacology 2021Retinoic acid, a metabolite of vitamin A, acts through either genomic or nongenomic actions. The genomic action of retinoids exerts effects on gene transcription through...
Retinoic acid, a metabolite of vitamin A, acts through either genomic or nongenomic actions. The genomic action of retinoids exerts effects on gene transcription through interaction with retinoid receptors such as retinoic acid receptors (RARα, β, and γ) and retinoid X receptors (RXRα, β, and γ) that are primarily concentrated in the amygdala, pre-frontal cortex, and hippocampal areas in the brain. In response to retinoid binding, RAR/RXR heterodimers undergo major conformational changes and orchestrate the transcription of specific gene networks. Previous experimental studies have reported that retinoic acid exerts an antiepileptogenic effect through diverse mechanisms, including the modulation of gap junctions, neurotransmitters, long-term potentiation, calcium channels and some genes. To our knowledge, there are no previous or current clinical trials evaluating the use of retinoic acid for seizure control.
Topics: Humans; Receptors, Retinoic Acid; Retinoids; Tretinoin
PubMed: 32351181
DOI: 10.2174/1570159X18666200429232104 -
International Journal of Molecular... Aug 2023Lutein, zeaxanthin, and -zeaxanthin (a steroisomer of zeaxanthin) are macular pigments. They modify the physical properties of the lipid bilayers in a manner similar to... (Review)
Review
Lutein, zeaxanthin, and -zeaxanthin (a steroisomer of zeaxanthin) are macular pigments. They modify the physical properties of the lipid bilayers in a manner similar to cholesterol. It is not clear if these pigments are directly present in the lipid phase of the membranes, or if they form complexes with specific membrane proteins that retain them in high amounts in the correct place in the retina. The high content of macular pigments in the Henle fiber layer indicates that a portion of the lutein and zeaxanthin should not only be bound to the specific proteins but also directly dissolved in the lipid membranes. This high concentration in the prereceptoral region of the retina is effective for blue-light filtration. Understanding the basic mechanisms of these actions is necessary to better understand the carotenoid-membrane interaction and how carotenoids affect membrane physical properties-such as fluidity, polarity, and order-in relation to membrane structure and membrane dynamics. This review focuses on the properties of lutein.
Topics: Lutein; Zeaxanthins; Membranes; Carotenoids; Lipid Bilayers
PubMed: 37629129
DOI: 10.3390/ijms241612948 -
Molecules (Basel, Switzerland) Aug 2021This paper presents the results of the first part of testing a novel electrospun fiber mat based on a unique macromolecule: polyisobutylene (PIB). A PIB-based compound...
This paper presents the results of the first part of testing a novel electrospun fiber mat based on a unique macromolecule: polyisobutylene (PIB). A PIB-based compound containing zinc oxide (ZnO) was electrospun into self-supporting mats of 203.75 and 295.5 g/m that were investigated using a variety of techniques. The results show that the hydrophobic mats are not cytotoxic, resist fibroblast cell adhesion and biofilm formation and are comfortable and easy to breathe through for use as a mask. The mats show great promise for personal protective equipment and other applications.
Topics: Biofilms; Cell Adhesion; Cells, Cultured; Fibroblasts; Humans; Materials Testing; Nanofibers; Polyenes; Polymers; Zinc Oxide
PubMed: 34500639
DOI: 10.3390/molecules26175207 -
Molecules (Basel, Switzerland) Jan 2023The goal of this review is to provide an overview of the current findings on the major carotenoids and their content in pumpkin products and by-products. The content of... (Review)
Review
The goal of this review is to provide an overview of the current findings on the major carotenoids and their content in pumpkin products and by-products. The content of total carotenoids and the composition of carotenoids in pumpkins depend mainly on the species and cultivar, pedoclimatic conditions, the part of the plant (pulp, peel or seed), extraction procedures and the type of solvent used for extraction. The major carotenoids identified in pumpkins were β-carotene, α-carotene, lutein and zeaxanthin. β-Carotene is the major carotenoid in most pumpkin species. The number and content of total carotenoids are higher when minor carotenoids and ester forms are considered. The use of carotenoids in the development of functional foods has been the topic of many versatile studies in recent years, as they add significant value to foods associated with numerous health benefits. In view of this, pumpkin and pumpkin by-products can serve as a valuable source of carotenoids.
Topics: beta Carotene; Cucurbita; Carotenoids; Lutein; Functional Food
PubMed: 36677916
DOI: 10.3390/molecules28020858 -
Frontiers in Endocrinology 2023The association between dietary carotenoid intake and Soluble Klotho (S-Klotho) levels among the elderly population requires further evaluation. The purpose of this...
OBJECTIVES
The association between dietary carotenoid intake and Soluble Klotho (S-Klotho) levels among the elderly population requires further evaluation. The purpose of this study is to evaluate the relationship between the dietary carotenoid intake and the S-Klotho plasma levels in older adults.
METHODS
Eligible participants aged 60 years or above were selected from the National Health and Nutrition Examination Surveys (NHANES) data, collected between 2007 and 2016. The consumption of carotenoids was determined through two 24-hour dietary recall assessments. Moreover, the S-Klotho levels in the serum were measured using an Enzyme-Linked Immuno-Sorbent Assay (ELISA).
RESULTS
A total of 5,056 participants were included in the study having a median total carotenoid intake of 9775.25 μg (95% confidence interval (CI): 8971.30-10579.21) and a median S-Klotho concentration of 815.59 pg/mL (95% CI: 802.59-828.60). The multivariable regression analysis showed that a single standard deviation increase in total carotenoid intake was significantly associated with an 8.40 pg/mL increase in S-Klotho levels (95% CI: 0.48-16.31). When the carotenoids were divided into quartiles, participants in the third ((4963.5μg/day,11662.5μg/day]) and fourth quartiles ((11662.5μg/day,377178μg/day]) showed higher S-Klotho levels compared to those in the first quartile. Among carotenoid subtypes, increased intake of α-carotene, β-carotene, and lutein with zeaxanthin was associated with elevated S-Klotho levels. These observed associations between carotenoid subtypes and S-Klotho levels remained consistent across male participants, having a normal weight, and a moderate physical activity based on stratified analysis.
CONCLUSION
The total carotenoid intake was positively related to plasma levels of S-Klotho in the elderly population, particularly for α-carotene, β-carotene, and lutein with zeaxanthin. However, further research is needed to confirm these findings and explore the underlying mechanisms behind this relationship.
Topics: Male; Aged; Humans; Middle Aged; Antioxidants; Lutein; beta Carotene; Nutrition Surveys; Zeaxanthins; Carotenoids; Aging
PubMed: 37955004
DOI: 10.3389/fendo.2023.1283722 -
Frontiers in Endocrinology 2023The thyroid hormones play a pivotal role in various physiological processes, including growth, metabolism regulation, and reproduction. While non-modifiable factors are... (Review)
Review
The thyroid hormones play a pivotal role in various physiological processes, including growth, metabolism regulation, and reproduction. While non-modifiable factors are known to impact thyroid function, such as genetics and age, nutritional factors are also important. Diets rich in selenium and iodine are conventionally acknowledged to be beneficial for the production and release of thyroid hormones. Recent studies have suggested a potential link between beta-carotene, a precursor to vitamin A (retinol), and thyroid function. Beta-carotene is known for its antioxidant properties and has been shown to play a role in the prevention of various clinical conditions such as cancer and cardiovascular and neurological diseases. However, its impact on thyroid function is still unclear. Some studies have suggested a positive association between beta-carotene levels and thyroid function, while others have found no significant effect. Conversely, the hormone produced by the thyroid gland, thyroxine, enhances the conversion of beta-carotene to retinol. Furthermore, vitamin A derivatives are being explored as potential therapeutic options for thyroid malignancies. In this review, we highlight the mechanisms through which beta-carotene/retinol and thyroid hormones interact and review the findings of clinical studies examining the association between beta-carotene consumption and thyroid hormone levels. Our review underscores the need for further research to clarify the relationship between beta-carotene and thyroid function.
Topics: Thyroid Gland; beta Carotene; Vitamin A; Thyroid Hormones; Physiological Phenomena
PubMed: 37305054
DOI: 10.3389/fendo.2023.1089315 -
Oxidative Medicine and Cellular... 2022Tissue and organ ischemia can lead to cell trauma, tissue necrosis, irreversible damage, and death. While intended to reverse ischemia, reperfusion can further aggravate... (Review)
Review
Tissue and organ ischemia can lead to cell trauma, tissue necrosis, irreversible damage, and death. While intended to reverse ischemia, reperfusion can further aggravate an ischemic injury (ischemia-reperfusion injury, I/R injury) through a range of pathologic processes. An I/R injury to one organ can also harm other organs, leading to systemic multiorgan failure. A type of carotenoid, lycopene, has been shown to treat and prevent many diseases (e.g., rheumatoid arthritis, cancer, diabetes, osteoporosis, male infertility, neurodegenerative diseases, and cardiovascular disease), making it a hot research topic in health care. Some recent researches have suggested that lycopene can evidently ameliorate ischemic and I/R injuries to many organs, but few clinical studies are available. Therefore, it is essential to review the effects of lycopene on ischemic and I/R injuries to different organs, which may help further research into its potential clinical applications.
Topics: Antioxidants; Carotenoids; Humans; Ischemia; Lycopene; Male; Reperfusion; Reperfusion Injury
PubMed: 36246396
DOI: 10.1155/2022/9309327 -
Plant Signaling & Behavior Dec 2023Photosynthetic organisms biosynthesize various carotenoids, a group of light-absorbing isoprenoid pigments that have key functions in photosynthesis, photoprotection,... (Review)
Review
Photosynthetic organisms biosynthesize various carotenoids, a group of light-absorbing isoprenoid pigments that have key functions in photosynthesis, photoprotection, and phototaxis. Microalgae, in particular, contain diverse carotenoids and carotenoid biosynthetic pathways as a consequence of the various endosymbiotic events in their evolutionary history. Carotenoids such as astaxanthin, diadinoxanthin, and fucoxanthin are unique to algae. In microalgae, carotenoids are concentrated in the eyespot, a pigmented organelle that is important for phototaxis. A wide range of microalgae, including chlorophytes, euglenophytes, ochrophytes, and haptophytes, have an eyespot. In the chlorophyte , carotenoid layers in the eyespot reflect light to amplify the photosignal and shield photoreceptors from light, thereby enabling precise phototaxis. Our recent research revealed that, in contrast to the β-carotene-rich eyespot of , the euglenophyte relies on zeaxanthin for stable eyespot formation and phototaxis. In this review, we highlight recent advancements in the study of eyespot carotenoids and phototaxis in these microalgae, placing special emphasis on the diversity of carotenoid-dependent visual systems among microalgae.
Topics: Carotenoids; Microalgae; Phototaxis; Terpenes; beta Carotene
PubMed: 37724547
DOI: 10.1080/15592324.2023.2257348