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Nature Chemistry Jan 2023The cis/trans geometry of olefins is known to dramatically influence the thermal and mechanical properties of polyalkenamers. Yet, polymerization methods that...
The cis/trans geometry of olefins is known to dramatically influence the thermal and mechanical properties of polyalkenamers. Yet, polymerization methods that efficiently control this parameter are scarce. Here we report the development of a stereoretentive acyclic diene metathesis polymerization that uses the reactivity of dithiolate Ru carbenes combined with cis monomers. These Ru catalysts exhibit exquisite retention of the cis geometry and tolerate many polar functional groups, enabling the synthesis of all-cis polyesters, polycarbonates, polyethers and polysulfites. The stereoretentive acyclic diene metathesis polymerization is also characterized by low catalyst loadings and tolerance towards trans impurities in the monomer batch, which should facilitate large-scale implementation. Modulation of the reaction temperature and time leads to an erosion of stereoretention, permitting a stereocontrolled synthesis of polyalkenamers with predictable cis:trans ratios. The impact of the stereochemistry of the repeating alkenes on the thermal properties is clearly demonstrated through differential scanning calorimetry and thermogravimetric analysis.
Topics: Polymerization; Polyenes; Alkenes; Temperature; Catalysis
PubMed: 36280767
DOI: 10.1038/s41557-022-01060-6 -
The Journal of Nutrition Aug 2023Adding carotenoids, particularly lutein (L) and zeaxanthin (Z), to prenatal micronutrient formulations has been promoted to enhance infant visual and neural development... (Randomized Controlled Trial)
Randomized Controlled Trial
BACKGROUND
Adding carotenoids, particularly lutein (L) and zeaxanthin (Z), to prenatal micronutrient formulations has been promoted to enhance infant visual and neural development and to maintain maternal health. Although these claims are biologically plausible, they are not yet supported by a compelling prospective trial.
OBJECTIVE
We investigated the effect of prenatal carotenoid supplementation on biomarkers of maternal and infant systemic carotenoid status.
METHODS
We randomly assigned 47 first trimester pregnant subjects by 1:1 allocation to receive standard-of-care prenatal vitamins plus a 10 mg L and 2 mg Z softgel (the Carotenoid group) or standard-of-care prenatal vitamins with a placebo softgel (the Control group) for 6-8 mo. Maternal carotenoid concentrations in the serum and skin at the end of each trimester and postpartum were measured with HPLC and resonance Raman spectroscopy, respectively. Infants' systemic carotenoid status was assessed using similar techniques but optimized for infants. Repeated measures and paired t-tests were determined, and a P value < 0.05 was considered statistically significant.
RESULTS
After supplementation, there was a statistically significant increase in maternal serum L + Z concentrations, serum total carotenoid concentrations, and skin carotenoid status (P < 0.001 for all) in the Carotenoid group relative to the Control group at all study time points. Similarly, infants whose mothers were in the Carotenoid group had a significant 5-fold increase in cord blood L + Z concentrations, over a 3-fold increase in cord blood total carotenoids, and a 38% increase in skin carotenoids compared with the Control group (P < 0.0001 for all). In addition, there was a strong positive, statistically significant correlation between postpartum maternal and infant systemic carotenoid status (P < 0.0001).
CONCLUSION
Prenatal carotenoid supplementation significantly increased maternal and infant systemic (skin and serum) carotenoid status, which may benefit pregnant women and their infants' health. This trial was registered at clinicaltrials.gov as NCT03750968.
Topics: Female; Humans; Infant; Pregnancy; Carotenoids; Dietary Supplements; Lutein; Mothers; Prospective Studies; Vitamins; Zeaxanthins
PubMed: 37247819
DOI: 10.1016/j.tjnut.2023.05.024 -
Plant Signaling & Behavior Dec 2023The cleavage of plant carotenoids leads to apocarotenoids, a group of metabolites including precursors of the hormones strigolactones (SLs) and abscisic acid, regulatory...
The cleavage of plant carotenoids leads to apocarotenoids, a group of metabolites including precursors of the hormones strigolactones (SLs) and abscisic acid, regulatory and signaling molecules. Zaxinone is a recently discovered apocarotenoid growth regulator that improves growth and suppress SL biosynthesis in rice (). To test if zaxinone also counteracts the growth regulatory effects of SLs in rice, we co-supplied zaxinone and the synthetic SL analog -GR24 to the rice SL-deficient ( mutant. Results showed that co-application of GR24 and zaxinone still rescued phenotype, indicating that zaxinone and GR24 act independently in regulating root and shoot growth and development in rice.
Topics: Oryza; Abscisic Acid; Carotenoids; Lactones
PubMed: 36855265
DOI: 10.1080/15592324.2023.2184127 -
International Journal of Molecular... Apr 2021is a novel and major fungal pathogen that has triggered several outbreaks in the last decade. The few drugs available to treat fungal diseases, the fact that this yeast... (Review)
Review
is a novel and major fungal pathogen that has triggered several outbreaks in the last decade. The few drugs available to treat fungal diseases, the fact that this yeast has a high rate of multidrug resistance and the occurrence of misleading identifications, and the ability of forming biofilms (naturally more resistant to drugs) has made treatments of infections highly difficult. This review intends to quickly illustrate the main issues in identification, available treatments and the associated mechanisms of resistance, and the novel and alternative treatment and drugs (natural and synthetic) that have been recently reported.
Topics: Antifungal Agents; Azoles; Candida; Candidiasis; Drug Resistance, Fungal; Drug Therapy, Combination; Echinocandins; Humans; Mycology; Polyenes; Treatment Failure
PubMed: 33922907
DOI: 10.3390/ijms22094470 -
The Journal of Nutrition Oct 2023Carotenoids are plant pigments with light filtering and antioxidant properties that deposit in human tissues, including retina and skin. Descriptive characteristics and...
BACKGROUND
Carotenoids are plant pigments with light filtering and antioxidant properties that deposit in human tissues, including retina and skin. Descriptive characteristics and covariates of carotenoid status in macula and skin have been examined in adults; however, similar studies in children are limited. Thus, this study aimed to delineate how factors of age, sex, race, weight status, and dietary carotenoid intake relate to macular and skin carotenoids in children.
METHODS
Children (7-13 y, N = 375) completed heterochromatic flicker photometry to assess macular pigment optical density (MPOD). Participants underwent anthropometrics to measure weight status (BMI percentile [BMI%]), and parent/guardian provided demographic information. Subsample data were available for skin carotenoids (N = 181), assessed using reflection spectroscopy, and dietary carotenoids (N = 101) using the Block Food Frequency Questionnaire. Relationships between skin and macular carotenoids were assessed using partial Pearson's correlations controlling for age, sex, race, and BMI%. Relationships between dietary carotenoids and macular and skin carotenoids were assessed using stepwise linear regression including age, sex, race, and BMI% in the model.
RESULTS
Mean MPOD was 0.56 ± 0.22 and skin carotenoid score was 282 ± 94.6. There was no significant correlation between MPOD and skin carotenoids (r = 0.02, P = 0.76). BMI% was negatively associated with skin (stdβ = -0.42, P < 0.001), but not macular carotenoids (stdβ = -0.04, P = 0.70). Neither MPOD nor skin carotenoids were associated with age, sex, or race (all P > 0.10). MPOD was positively associated with energy-adjusted reported lutein + zeaxanthin intake (stdβ = 0.27, P = 0.01). Skin carotenoids were positively associated with energy-adjusted reported carotenoid intake (stdβ = 0.26, P = 0.01).
CONCLUSIONS
The mean MPOD values in children were higher than what has been reported in adult populations. Previous studies in adult samples report an average MPOD of 0.21. Although macular and skin carotenoids were not related, they were associated with dietary carotenoids relevant to the respective tissues; however, skin carotenoids may be more susceptible negative influence from higher weight status.
Topics: Adult; Humans; Child; Macular Pigment; Lutein; Zeaxanthins; Macula Lutea; Retina
PubMed: 37315793
DOI: 10.1016/j.tjnut.2023.06.006 -
Analytical Chemistry Oct 2022Dinoflagellate-derived polyketides are typically large molecules (>1000 Da) with complex structures, potent bioactivities, and high toxicities. Their discovery suffers...
Dinoflagellate-derived polyketides are typically large molecules (>1000 Da) with complex structures, potent bioactivities, and high toxicities. Their discovery suffers three major bottlenecks: insufficient bioavailability, low-yield cultivation of producer organisms, and production of multiple highly related analogues by a single strain. Consequently, the biotechnological production of therapeutics or toxicological standards of dinoflagellate-derived polyketides is also hampered. Strategies based on sensitive and selective techniques for chemical prospection of dinoflagellate extracts could aid in overcoming these limitations, as it allows selecting the most interesting candidates for discovery and exploitation programs according to the biosynthetic potential. In this work, we assess the combination of data-dependent liquid chromatography coupled with high-resolution tandem mass spectrometry (LC-HRMS) and molecular networking to screen polyol polyketides. To demonstrate the power of this approach, we selected dinoflagellate since it is commonly used as a biotechnological model and produces amphidinols, a family of polyol-polyene compounds with antifungal and antimycoplasmal activity. First, we screened families of compounds with multiple hydroxyl groups by examining MS profiles that contain sequential neutral losses of water. Then, we clustered MS spectra by molecular networking to facilitate the dereplication and discovery of amphidinols. Finally, we used the MS fragmentation behavior of well-characterized luteophanol D as a model to propose a structural hypothesis of nine novel amphidinols. We envision that this strategy is a valuable approach to rapidly monitoring toxin production of known and unknown polyol polyketides in dinoflagellates, even in small culture volumes, and distinguishing strains according to their toxin profiles.
Topics: Antifungal Agents; Dinoflagellida; Polyenes; Polyketides; Polymers; Water
PubMed: 36190828
DOI: 10.1021/acs.analchem.2c02185 -
Brazilian Journal of Biology = Revista... 2022Today, sweet corn is considered an important vegetable due to its high sugar content and low starch content. Cluster analysis and variance analysis showed that hybrids...
Today, sweet corn is considered an important vegetable due to its high sugar content and low starch content. Cluster analysis and variance analysis showed that hybrids had variations in yield indices. GB, DE and GS hybrids had similar performance on indices. SE hybrid that has significant performance on zeaxanthin. Biplot showed that fructose, glucose, sucrose and potassium had stability value on hybrids. All the hybrids had the best performance on fructose, glucose, sucrose and potassium factors. Factor biplot positively correlated with yield indices, including calcium, iron, zinc, magnesium, α-Carotene, 9Z-β-Carotene, phosphorus, and β-carotene. On the other hand, there is a positive correlation with fructose, glucose, potassium, lutein, sucrose, β-Cryptoxanthin, and zeaxanthin. So, to evaluate or increase lutein and zeaxanthin, the other parameters like sugar content (fructose, glucose, and sucrose) are important factors and have an effect together. Factor analysis and biplot showed that ME hybrid had a maximum performance on the first factor of yield indices. Also, the second factor of yield indices had a maxi-mum effect on NO hybrids. SE hybrids had maximum performance in zeaxanthin and GS hybrid had maximum performance in zinc, phosphorus, and iron. The dry matter had stability on DB hybrid.
Topics: Fructose; Glucose; Iron; Lutein; Phosphorus; Potassium; Sucrose; Sugars; Zea mays; Zeaxanthins; Zinc; beta Carotene
PubMed: 36102376
DOI: 10.1590/1519-6984.265735 -
Microbial Cell Factories Jan 2020Using an established CRISPR-Cas mediated genome editing technique for streptomycetes, we explored the combinatorial biosynthesis potential of the auroramycin...
Using an established CRISPR-Cas mediated genome editing technique for streptomycetes, we explored the combinatorial biosynthesis potential of the auroramycin biosynthetic gene cluster in Streptomyces roseosporous. Auroramycin is a potent anti-MRSA polyene macrolactam. In addition, auroramycin has antifungal activities, which is unique among structurally similar polyene macrolactams, such as incednine and silvalactam. In this work, we employed different engineering strategies to target glycosylation and acylation biosynthetic machineries within its recently elucidated biosynthetic pathway. Auroramycin analogs with variations in C-, N- methylation, hydroxylation and extender units incorporation were produced and characterized. By comparing the bioactivity profiles of five of these analogs, we determined that unique disaccharide motif of auroramycin is essential for its antimicrobial bioactivity. We further demonstrated that C-methylation of the 3, 5-epi-lemonose unit, which is unique among structurally similar polyene macrolactams, is key to its antifungal activity.
Topics: Anti-Bacterial Agents; Antifungal Agents; Biosynthetic Pathways; CRISPR-Cas Systems; Gene Editing; Metabolic Engineering; Methicillin-Resistant Staphylococcus aureus; Microbial Sensitivity Tests; Polyenes; Streptomyces
PubMed: 31906943
DOI: 10.1186/s12934-019-1274-y -
International Journal of Molecular... Apr 2023Natural bioactive compounds have recently emerged as a current strategy for Alzheimer's disease treatment. Carotenoids, including astaxanthin, lycopene, lutein,... (Review)
Review
Natural bioactive compounds have recently emerged as a current strategy for Alzheimer's disease treatment. Carotenoids, including astaxanthin, lycopene, lutein, fucoxanthin, crocin and others are natural pigments and antioxidants, and can be used to treat a variety of diseases, including Alzheimer's disease. However, carotenoids, as oil-soluble substances with additional unsaturated groups, suffer from low solubility, poor stability and poor bioavailability. Therefore, the preparation of various nano-drug delivery systems from carotenoids is a current measure to achieve efficient application of carotenoids. Different carotenoid delivery systems can improve the solubility, stability, permeability and bioavailability of carotenoids to a certain extent to achieve Alzheimer's disease efficacy. This review summarizes recent data on different carotenoid nano-drug delivery systems for the treatment of Alzheimer's disease, including polymer, lipid, inorganic and hybrid nano-drug delivery systems. These drug delivery systems have been shown to have a beneficial therapeutic effect on Alzheimer's disease to a certain extent.
Topics: Humans; Alzheimer Disease; Nanoparticle Drug Delivery System; Carotenoids; Lycopene; Lutein
PubMed: 37108814
DOI: 10.3390/ijms24087652 -
Journal of Global Antimicrobial... Jun 2022In this study, we examined the toxicities, including poisoning and overdoses, with polyene, azole, flucytosine and echinocandin antifungals reported to the Swiss... (Observational Study)
Observational Study
OBJECTIVES
In this study, we examined the toxicities, including poisoning and overdoses, with polyene, azole, flucytosine and echinocandin antifungals reported to the Swiss National Poison Centre.
METHODS
An observational cross-sectional study on antifungals was performed based on reports between 1995 and 2016 to Tox Info Suisse. Patient demographic and clinical characteristics were summarised among all reported calls, stratified by age group. In secondary analyses, we evaluated cases with clinical follow-up information.
RESULTS
In total, 149 cases were reported to the National Poison Centre during the study period, of which 49 (32.9%) were male and 91 (61.1%) were female, and 95 (63.8%) were adults and 54 (36.2%) were children (age ≤16 years). The most frequently reported drug class was azoles (136; 91.3%). In 31 cases (20.8%) reported by treating physicians, further clinical follow-up information was available. Nearly one-half of these patients were asymptomatic (15/31; 48.4%). In 11 patients (35.5%) among those with symptoms, the symptoms of toxicity were categorised with a strong causality to the respective antifungal. Clinical findings caused by triazoles were effects in the gastrointestinal tract, hallucinations and predelirium state. Clinical findings caused by polyenes were mostly minor symptoms with infusion-related effects or hypokalaemia. The severity was categorised as minor in 6 (54.5%) of 11 cases and as moderate in 5 cases (45.5%).
CONCLUSION
Despite high administered doses, no severe or fatal cases occurred within the study period. Although various toxicities can occur with antifungal administration and overdoses, they showed a favourable safety profile.
Topics: Adolescent; Adult; Antifungal Agents; Azoles; Child; Cross-Sectional Studies; Echinocandins; Female; Humans; Male; Polyenes
PubMed: 34896339
DOI: 10.1016/j.jgar.2021.11.010