Results 71 to 80 of about 24,198 (212)

Knoevenagel Reaction in [MMIm][MSO4]: Synthesis of Coumarins

open access: yesMolecules, 2011
The ionic liquid 1,3-dimethylimidazolium methyl sulfate, [MMIm][MSO4], together with a small amount of water (the amount taken up by the ionic liquid upon exposure to air), acts efficiently as both solvent and catalyst of the Knoevenagel condensation ...
Emilia Tojo   +2 more
doaj   +1 more source

Shedding Light on Synthetic Autocatalysis: From Conventional Closed‐Shell Chemistries to Overlooked Open‐Shell Occurrences

open access: yesChemistry – A European Journal, EarlyView.
Why add another catalyst when the product itself holds the power to catalyze its own formation? Autocatalysis in synthetic chemistry enhances reaction efficiency and uncovers novel catalytic behavior across both closed‐shell and open‐shell systems, expanding reactivity and enabling innovative design strategies.
Jaspreet Kaur, Joshua P. Barham
wiley   +1 more source

Opium trade and use during the Late Bronze Age: Organic residue analysis of ceramic vessels from the burials of Tel Yehud, Israel

open access: yesArchaeometry, EarlyView., 2022
Abstract Organic residue analysis was conducted on various vessels from burials at Tel Yehud, Israel. The analyses led to new reliable evidence for the presence of opioid alkaloids and their decomposition products. This research revitalizes a decades‐old discussion on the presence and function of the opium trade across a cultural region of utmost ...
Vanessa Linares   +5 more
wiley   +1 more source

Transport of Twelve Coumarins from Angelicae Pubescentis Radix across a MDCK-pHaMDR Cell Monolayer—An in Vitro Model for Blood-Brain Barrier Permeability

open access: yesMolecules, 2015
Angelicae Pubescentis Radix (APR), a widely used traditional Chinese medicine, is reported to have central nervous system activities. The purpose of this study was to characterize the blood-brain barrier permeability of twelve coumarins from APR ...
Yan-Fang Yang   +4 more
doaj   +1 more source

Fluorescent Diarylethenes With Polar Groups: Synthesis, Spectra, and Optical Microscopy Applications

open access: yesChemistry – A European Journal, EarlyView.
Blinking green and flashing red: photo‐switchable and photo‐activatable probes emitting green and red light were prepared and applied as bioconjugates in super‐resolution optical microscopy. ABSTRACT The use of photoactivatable fluorescent diarylethenes (fDAEs) in biology‐related light microscopy has been restricted by the lack of probes having freely ...
Kakishi Uno   +6 more
wiley   +1 more source

Synthetic Strategies for Activity‐Based Probes to Decode Ubiquitin‐Like Modifiers

open access: yesChemistry – A European Journal, EarlyView.
ABSTRACT Ubiquitin‐like proteins (Ubls) such as SUMO, NEDD8, ISG15, URM1, UFM1, FAT10, ATG8/ATG12, and FUBI are essential regulators of cellular homeostasis, controlling processes from protein stability and trafficking to immune signaling and autophagy.
Saibal Chanda   +5 more
wiley   +1 more source

Comparison of the bioactive chemical components and antioxidant activities in three tissues of six varieties of Citrus grandis ‘Tomentosa’ fruits

open access: yesInternational Journal of Food Properties, 2019
The total phenolic, flavonoid, coumarin, and volatile contents and antioxidant activities in three tissues of six Citrus grandis ‘Tomentosa’ (CGT) fruit varieties were investigated. Two flavones, 3 coumarins and 147 volatiles were identified. The exocarp
Ruiyi Fan   +3 more
doaj   +1 more source

Cytotoxicity and Apoptosis Induction of Coumarins and Carbazole Alkaloids from Clausena Harmandiana

open access: yesMolecules, 2019
Seven compounds, carbazole alkaloids (heptaphylline, 7-methoxyheptaphylline, 7-methoxymukonal) and coumarins (clausarin, dentatin, nordentatin, and xanthoxyletin), were isolated from the root bark of Clausena harmandiana.
Porntip Jantamat   +2 more
doaj   +1 more source

N‐Aryl Acridone Derivatives as Effective Catalysts for Energy Transfer Reactions

open access: yesChemistry – A European Journal, EarlyView.
Acridones derivatives have high triplet energy, are simple accessible, and could be used in challenging [2+2] ENT reactions. ABSTRACT Organic photocatalysts capable of promoting high‐energy triplet energy transfer (EnT) remain limited, particularly for demanding [2+2] photocycloaddition reactions.
Francesco Calogero   +8 more
wiley   +1 more source

Composição química e atividade biológica das folhas e frutos de Triphasia trifolia Chemical composition and biological activity of leaves and fruits of Triphasia trifolia

open access: yesQuímica Nova, 2008
The chemical composition of the essential oils from leaves and fruits of Triphasia trifolia was analyzed by GC-FID and GC-MS. The major constituents of oil obtained from leaves were sabinene (35.4%) and myrcene (34.1%), while the prevalent compounds in ...
Renata P. dos Santos   +4 more
doaj   +1 more source

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