keyword
https://read.qxmd.com/read/38728657/short-formal-syntheses-of-lycorine-and-congeners-using-a-5-endo-trig-6-endo-trig-radical-cyclization-sequence
#1
JOURNAL ARTICLE
Shen Tan, Samir Z Zard, Le Nhan Pham, Michelle L Coote, Martin G Banwell, Ping Lan, Lorenzo V White
Here, we report a practical route to medicinally interesting lycorine congeners alongside formal syntheses of various lycorine-type natural products, including lycorine itself. The efficiency of our strategy derives from a back-to-back 5 -endo-trig /6 -endo-trig radical cyclization sequence, which we systematically studied both experimentally and computationally. The results of our work will facilitate future development of urgently needed antiviral therapeutics based on lycorine.
May 10, 2024: Organic Letters
https://read.qxmd.com/read/38728656/rapid-access-to-tigliane-ingenane-and-rhamnofolane-diterpenes-from-a-lathyrane-precursor-via-biomimetic-skeleton-transformation-strategy
#2
JOURNAL ARTICLE
Neng Wang, Lin-Xi Wan, Xiaohuan Li, Jin-Bu Xu, Feng Gao
Bioinspired skeleton transformation of a tricyclic lathyrane-type Euphorbia diterpene was conducted to efficiently construct a tetracyclic tigliane diterpene on a gram scale via a key aldol condensation. The tigliane diterpene was then respectively converted into naturally rare ingenane and rhamnofolane diterpenes through a semipinacol rearrangement and a visible-light-promoted regioselective cyclopropane ring-opening reaction. This work provides a concise strategy for high-efficiency access to diverse polycyclic Euphorbia diterpene skeletons from abundant lathyrane-type natural products and paves the way for biological activity investigation of naturally rare molecules...
May 10, 2024: Journal of Natural Products
https://read.qxmd.com/read/38728614/inhibitory-nitric-oxide-production-and-cytotoxic-activities-of-phenolic-compounds-from-gnetum-montanum-markgr
#3
JOURNAL ARTICLE
Hieu Ngo Van, Cong Pham Van, Trang Vu Thi, Duc Ngo Viet, Tai Bui Huu, Dat Nguyen Tien, Minh Bui Quang, Anh Le Tuan, Tinh Phung Thi, Dan Nguyen Van, Hoan Vu Xuan, Anh Hoang Le Tuan
One new compound, styrene dimer-type listeanol-4- O - α -ʟ-rhamnopyranosyl-(1→4)- β -ᴅ-glucopyranoside ( 1 ), and four known compounds namely listeanol ( 2 ), isorhapotigenin ( 3 ), genetifolin E ( 4 ), gnetifolin K ( 5 ) were isolated from the methanolic extract from the aerial part of the Gnetum montanum Markgr. in Viet Nam. Their chemical structures were determined by modern spectroscopic methods (NMR and HR-ESI-MS) and comparison with those of published data. These compounds were evaluated for their anti-inflammatory and cytotoxic activities...
May 10, 2024: Natural Product Research
https://read.qxmd.com/read/38728607/letter-to-the-editor-on-in-vitro-in-silico-study-of-hypoglycaemic-potential-of-pterocarpus-marsupium-heartwood-extract
#4
JOURNAL ARTICLE
Samiha Khan Chetona
The Short Communication "In vitro & in silico study of hypoglycemic potential of Pterocarpus marsupium heartwood extract" published in Natural Product Research is praised for its depth of inquiry and exploration of hypoglycemic and antioxidant properties. However, there are areas for refinement, such as clearer definitions of key terms related to type 2 diabetes mellitus, updated literature review, improved organization and contextualization of the Results and Discussion section, and a more balanced discussion of the study's implications...
May 10, 2024: Natural Product Research
https://read.qxmd.com/read/38728594/engineering-built-in-electric-field-microenvironment-of-cqds-g-c-3-n-4-heterojunction-for-efficient-photocatalytic-co-2-reduction
#5
JOURNAL ARTICLE
Yun Xu, Weidong Hou, Kai Huang, Huazhang Guo, Zeming Wang, Cheng Lian, Jiye Zhang, Deli Wu, Zhendong Lei, Zheng Liu, Liang Wang
Graphitic carbon nitride (CN), as a nonmetallic photocatalyst, has gained considerable attention for its cost-effectiveness and environmentally friendly nature in catalyzing solar-driven CO2 conversion into valuable products. However, the photocatalytic efficiency of CO2 reduction with CN remains low, accompanied by challenges in achieving desirable product selectivity. To address these limitations, a two-step hydrothermal-calcination tandem synthesis strategy is presented, introducing carbon quantum dots (CQDs) into CN and forming ultra-thin CQD/CN nanosheets...
May 10, 2024: Advanced Science (Weinheim, Baden-Wurttemberg, Germany)
https://read.qxmd.com/read/38728575/elevating-fetal-hemoglobin-recently-discovered-regulators-and-mechanisms
#6
JOURNAL ARTICLE
Gerd A Blobel, Eugene Khandros
It has been known for over half a century that humans produce different forms of hemoglobin, a tetramer of α- and β-like hemoglobin chains, throughout ontogeny. The switch from fetal to adult hemoglobin occurs around the time of birth when erythropoiesis shifts from the fetal liver to the bone marrow. Naturally, diseases caused by defective adult β-globin genes, such as sickle cell disease and β-thalassemia manifest themselves as production of fetal hemoglobin fades. Reversal of this developmental switch has been a major goal to treat these diseases and has been a driving force to understand its underlying molecular biology...
May 10, 2024: Blood
https://read.qxmd.com/read/38728462/the-concept-of-folic-acid-supplementation-and-its-role-in-prevention-of-neural-tube-defect-among-pregnant-women-prisma
#7
REVIEW
Fikadu Seyoum Tola
Folic acid is the synthetic form of vitamin B9, found in supplements and fortified foods, while folate occurs naturally in foods. Folic acid and its derivatives are extremely important in the synthesis of nucleic acids (DNA and ribose nucleic acid [RNA]) and different proteins. It acts as a coenzyme for the transfer of 1 carbon in the biosynthesis of purine, pyrimidine, and amino acids. Folic acid is critically important in rapidly proliferating tissues, including fetus and trophoblastic tissue to prevent neural tube defect (NTD)...
May 10, 2024: Medicine (Baltimore)
https://read.qxmd.com/read/38728443/direct-a-hydroxy-acid-loading-onto-a-bacterial-thiotemplate-assembly-line-via-a-multienzyme-gateway
#8
JOURNAL ARTICLE
Jonas Fiedler, Felix Trottmann, Keishi Ishida, Ishida-Ito Mie, Christian Hertweck
Various nonribosomal peptide synthetases (NRPS) create structural and functional diversity by incorporating a-hydroxy acids into peptide backbones. Trigonic acid, an unusual cyclopropanol-substituted hydroxy acid, is the source of the molecular warhead of malleicyprol, a critical virulence factor of human and animal pathogens of the Burkholderia pseudomallei (BP) group. The process of selecting and loading this building block remained enigmatic as the NRPS module designated for this task is noncanonical. Using a combination of bioinformatics, mutational analyses, targeted metabolomics, and in vitro biochemical assays, we show that two trans-acting enzymes are required to load this central building block onto the modular assembly line...
May 10, 2024: Angewandte Chemie
https://read.qxmd.com/read/38728351/spatial-variability-and-source-analysis-of-soil-heavy-metals-a-case-study-of-the-key-planting-area-of-special-agricultural-products-in-cangxi-county-china
#9
JOURNAL ARTICLE
Ziwei Feng, Wende Chen, Yichen Meng, Haixia Lu, Xinyi Shi, Jiajun Zhang
Heavy metal pollution in farmland soil represents a considerable risk to ecosystems and human health, constituting a global concern. Focusing on a key area for the cultivation of special agricultural products in Cangxi County, we collected 228 surface soil samples. We analyzed the concentration, spatial distribution, and pollution levels of six heavy metals (Cr, Cu, Pb, Ni, Zn, and Hg) in the soil. Moreover, we investigated the sources and contribution rates of these heavy metals using Principal Component Analysis/Absolute Principal Component Scores (PCA/APCS) and Positive Matrix Factorization (PMF) models...
2024: PloS One
https://read.qxmd.com/read/38728344/quantitative-analysis-of-the-impact-of-climate-variability-and-human-activities-on-grassland-productivity-of-the-qilian-mountain-national-park-china
#10
JOURNAL ARTICLE
Qiang Li, Guoxing He, Degang Zhang, Xiaoni Liu
To quantitatively analyze the impact of climate variability and human activities on grassland productivity of China's Qilian Mountain National Park, this study used Carnegic-Ames-Stanford Approach model (CASA) and Integrated Vegetation model improved by the Comprehensive and Sequential Classification System (CSCS) to assess the trends of grassland NPP from 2000 to 2015, the residual trend analysis method was used to quantify the impact of human activities and climate change on the grassland based on the NPP changes...
2024: PloS One
https://read.qxmd.com/read/38728298/controlled-aerobic-oxidative-dimerization-of-hydroxystilbenoids-by-chromium-catalysis
#11
JOURNAL ARTICLE
Shota Nagasawa, Yudai Itagaki, Yusuke Sasano, Yoshiharu Iwabuchi
Aerobic oxidative dimerization of hydroxystilbenoids is described. A Cr-salen complex catalyzed the dimerization of hydroxystilbenoids in 1,1,1,3,3,3-hexafluoroisopropanol to form compounds comprising a natural product-like scaffold (quadrangularin) or its precursor depending on the aromatic substituents. The addition of a catalytic amount of scandium triflate [Sc(OTf)3 ] to the reaction system altered the reaction outcome to give a different natural product-like compound, a pallidol-type dimer.
May 10, 2024: Organic Letters
https://read.qxmd.com/read/38728176/dynamic-simulation-research-on-microprofile-control-mechanism-of-foam-in-fractured-media-based-on-level-set-method
#12
JOURNAL ARTICLE
Fei Wang, Zhihao Yu, Juan Chen, Yi Yu, Hailong Chen
Fractured reservoirs are an important source of oil and gas energy. After depletion of production, the production capacity of this reservoir decreases rapidly. Effective profile control is needed to improve the sweep efficiency and reservoir heterogeneity. Foam can solve such problems, but its profile control mechanism is not fully understood. Based on this, this paper uses the level set method to study the microscale control mechanism of foam in fractured media. The results show that artificial fractures and high-permeability microfractures are tighter than natural fractures, the Jamin effect of foam is stronger, and the secondary foaming ability is better...
May 10, 2024: Langmuir: the ACS Journal of Surfaces and Colloids
https://read.qxmd.com/read/38728013/conjugated-linoleic-acid-metabolite-impact-in-colorectal-cancer-a-potential-microbiome-based-precision-nutrition-approach
#13
JOURNAL ARTICLE
Adriana González, Asier Fullaondo, Javier Rodríguez, Cristina Tirnauca, Iñaki Odriozola, Adrian Odriozola
Colorectal cancer (CRC) is the second most deadly and the third most diagnosed cancer in both sexes worldwide. CRC pathogenesis is associated with risk factors such as genetics, alcohol, smoking, sedentariness, obesity, unbalanced diets, and gut microbiota dysbiosis. The gut microbiota is the microbial community living in symbiosis in the intestine, in a dynamic balance vital for health. Increasing evidence underscores the influence of specific gut microbiota bacterial species on CRC incidence and pathogenesis...
May 10, 2024: Nutrition Reviews
https://read.qxmd.com/read/38727951/conservation-and-upgradation-of-indigenous-cholistani-cattle-breed-of-pakistan-a-pathway-to-sustainable-livestock
#14
REVIEW
Umer Farooq, Musadiq Idris, Haroon Rashid
Pakistan is endowed with many established indigenous zebu Bos indicus type (humped) cattle breeds including Sahiwal, Red Sindhi, Bhagnari and Cholistani. Amongst these indigenous cattle breeds, Sahiwal and Red Sindhi have extensively been navigated and hence these two are acclaimed as internationally recognized breeds. However, research work on Cholistani cattle breed actually initiated in 2010 and has attained a steady pace. This breed was a new entrant in Livestock Census of Pakistan since 2006. Cholistani is a hardy, tick-resistant, adaptable cattle breed being reared under pastoral nomadism of the Cholistan desert, Pakistan...
May 10, 2024: Tropical Animal Health and Production
https://read.qxmd.com/read/38727941/a-social-ecological-approach-for-identifying-and-mapping-ecosystem-service-trade-offs-and-conservation-priorities-in-peri-urban-areas
#15
JOURNAL ARTICLE
Zheyi Xia, Jiasi Huang, Yuwen Huang, Kui Liu, Runmiao Zhu, Zhen Shen, Chengcheng Yuan, Liming Liu
Considering both ecological and social dimensions in the assessment of ecosystem services (ESs) can facilitate acceptable and inclusive management strategies, especially in peri-urban areas characterized by intricate human-ecosystem interactions. A limited body of research, however, has mapped the plural values of ESs and their different types of trade-offs in such areas. This research aimed to execute an interdisciplinary analysis of the biophysical and social values of ESs in peri-urban Shanghai, China, through a social-ecological approach that integrates spatial biophysical assessment with participatory mapping...
May 10, 2024: Ambio
https://read.qxmd.com/read/38727781/natural-derived-acetophenones-chemistry-and-pharmacological-activities
#16
REVIEW
Hamid Ahmadpourmir, Homayoun Attar, Javad Asili, Vahid Soheili, Seyedeh Faezeh Taghizadeh, Abolfazl Shakeri
Acetophenones are naturally occurring phenolic compounds which have found in over 24 plant families and also fungi strains. They are exist in both free or glycosides form in nature. The biological activities of these compounds have been assayed and reported including cytotoxicity, antimicrobial, antimalarial, antioxidant and antityrosinase activities. Herein, we review the chemistry and biological activity of natural acetophenone derivatives that have been isolated and identified until January 2024. Taken together, it was reported 252 acetophenone derivatives in which the genera Melicope (69) and Acronychia (44) were the principal species as producers of acetophenones...
May 10, 2024: Natural Products and Bioprospecting
https://read.qxmd.com/read/38727754/influence-of-land-use-change-on-habitat-quality-a-case-study-of-coal-mining-subsidence-areas
#17
JOURNAL ARTICLE
Yedong Chen, Jiang Chang, Zixuan Li, Li Ming, Cankun Li
Revealing the spatiotemporal evolution characteristics and key driving processes behind the habitat quality is of great significance for the scientific management of production, living, and ecological spaces in resource-based cities, as well as for the efficient allocation of resources. Focusing on the largest coal-mining subsidence area in Jiangsu Province of China, this study examines the spatiotemporal evolution of land use intensity, morphology, and functionality across different time periods. It evaluates the habitat quality characteristics of the Pan'an Lake area by utilizing the InVEST model, spatial autocorrelation, and hotspot analysis techniques...
May 10, 2024: Environmental Monitoring and Assessment
https://read.qxmd.com/read/38727720/modular-access-to-chiral-amines-via-imine-reductase-based-photoenzymatic-catalysis
#18
JOURNAL ARTICLE
Bin Chen, Renjie Li, Jianqiang Feng, Beibei Zhao, Jiawei Zhang, Jinhai Yu, Yuanyuan Xu, Zhongqiu Xing, Yue Zhao, Binju Wang, Xiaoqiang Huang
The development of catalysts serves as the cornerstone of innovation in synthesis, as exemplified by the recent discovery of photoenzymes. However, the repertoire of naturally occurring enzymes repurposed by direct light excitation to catalyze new-to-nature photobiotransformations is currently limited to flavoproteins and keto-reductases. Herein, we shed light on imine reductases (IREDs) that catalyze the remote C(sp3 )-C(sp3 ) bond formation, providing a previously elusive radical hydroalkylation of enamides for accessing chiral amines (45 examples with up to 99% enantiomeric excess)...
May 10, 2024: Journal of the American Chemical Society
https://read.qxmd.com/read/38727521/exploring-a-non-comfort-zone-central-chirality-generating-macrocyclizations
#19
REVIEW
Kuan Zheng, Ran Hong
Macrocyclization reactions that are capable of stereoselectively co-creating one or more stereogenic centers have become useful strategies for the effective syntheses of structurally and functionally diverse organic molecules. This JOCSynopsis summarizes the recent progress in the field of natural product and analogue syntheses, including both bioinspired and non-bioinspired macrocyclic disconnections. Selected examples are organized on the basis of the sources of the asymmetric inductions.
May 10, 2024: Journal of Organic Chemistry
https://read.qxmd.com/read/38727398/na-3-mnti-po-4-3-c-nanofiber-free-standing-electrode-for-long-cycling-life-sodium-ion-batteries
#20
JOURNAL ARTICLE
Debora Maria Conti, Claudia Urru, Giovanna Bruni, Pietro Galinetto, Benedetta Albini, Vittorio Berbenni, Alessandro Girella, Doretta Capsoni
Self-standing Na3 MnTi(PO4 )3 /carbon nanofiber (CNF) electrodes are successfully synthesized by electrospinning. A pre-synthesized Na3 MnTi(PO4 )3 is dispersed in a polymeric solution, and the electrospun product is heat-treated at 750 °C in nitrogen flow to obtain active material/CNF electrodes. The active material loading is 10 wt%. SEM, TEM, and EDS analyses demonstrate that the Na3 MnTi(PO4 )3 particles are homogeneously spread into and within CNFs. The loaded Na3 MnTi(PO4 )3 displays the NASICON structure; compared to the pre-synthesized material, the higher sintering temperature (750 °C) used to obtain conductive CNFs leads to cell shrinkage along the a axis...
May 5, 2024: Nanomaterials
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