Three crystal forms of the steroid 20-hydroxyecdysone were identified by single-crystal X-ray diffraction analysis: a solvent-free modification, a methanol solvate hydrate and a trihydrate. The structure of a closely related steroid, polypodine B (the 5,20-dihydroxy derivative of ecdysone), was determined in its monohydrate form. Since the unit-cell volume of unsolvated 20-hydroxyecdysone was found to be considerably smaller than that of ecdysone [Huber & Hoppe (1965). Chem. Ber. 98, 2403-2424], a new structure determination of ecdysone was performed, which confirmed the unexpected difference between the unit-cell volumes. The crystals of ecdysone and 20-hydroxyecdysone are isostructural, while the mixed solvate of 20-hydroxyecdysone is homostructural with the hydrate of polypodine B. A detailed analysis of the hydrogen-bond networks in these closely related crystal pairs highlights their packing similarities, demonstrates the role of solvent molecules, and explains the unexpectedly small cell volume of 20-hydroxyecdysone.
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http://dx.doi.org/10.1107/s0108768102005608 | DOI Listing |
Pharmaceutics
December 2024
Department of Pharmacy, Faculty of Health and Medical Science, University of Copenhagen, Universitetsparken 2, DK-2100 Copenhagen, Denmark.
: This study aims to broaden the knowledge on co-amorphous phospholipid systems (CAPSs) by exploring the formation of CAPSs with a broader range of poorly water-soluble drugs, celecoxib (CCX), furosemide (FUR), nilotinib (NIL), and ritonavir (RIT), combined with amphiphilic phospholipids (PLs), including soybean phosphatidylcholine (SPC), hydrogenated phosphatidylcholine (HPC), and mono-acyl phosphatidylcholine (MAPC). : The CAPSs were initially prepared at equimolar drug-to-phospholipid (PL) ratios by mechano-chemical activation-based, melt-based, and solvent-based preparation methods, i.e.
View Article and Find Full Text PDFPharmaceutics
November 2024
Department of Chemistry and Biochemistry, Faculty of Agriculture, University of Belgrade, Nemanjina 6, 11080 Belgrade, Serbia.
New tributyltin(IV) complexes containing the carboxylate ligands 3-(4-methyl-2-oxoquinolin-1(2H)-yl)propanoic acid () and 2-(4-methyl-2-oxoquinolin-1(2H)-yl)acetic acid () have been synthesized. Their structures have been determined by elemental microanalysis, FT-IR and multinuclear NMR (H, C and Sn) spectroscopy and X-ray diffraction study. A solution state NMR analysis reveals a four-coordinated tributyltin(IV) complex in non-polar solvents, while an X-Ray crystallographic analysis confirms a five-coordinated trigonal-bipyramidal geometry around the tin atom due to the formation of 1D chains.
View Article and Find Full Text PDFPolymers (Basel)
December 2024
Engineering Research Center of Technical Textiles, Ministry of Education, College of Textiles, Donghua University, Shanghai 201620, China.
Smart fibers with tunable luminescence properties, as a new form of visual output, present the potential to revolutionize personal living habits in the future and are receiving more and more attention. However, a huge challenge of smart fibers as wearable materials is their stretching capability for seamless integration with the human body. Herein, stretchable thermochromic fluorescent fibers are prepared based on self-crystallinity phase change, using elastic polyurethane (PU) as the fiber matrix, to meet the dynamic requirements of the human body.
View Article and Find Full Text PDFInsects
December 2024
Institute of Environment and Ecology, School of Environment and Safety Engineering, Jiangsu University, Zhenjiang 212013, China.
The melon fruit fly, (Coquillett) (Diptera: Tephritidae), is a notorious pest, posing a significant threat to a wide range of fruits and vegetables, leading to substantial agricultural losses worldwide. With growing concerns over chemical pesticide resistance and environmental safety, plant-based insecticides have emerged as eco-friendly and economically sustainable alternatives. In this context, the present study delves into the insecticidal potential of extracts against .
View Article and Find Full Text PDFInt J Mol Sci
December 2024
College of Food Science and Engineering, Jilin University, Changchun 130062, China.
Flavonoids derived from plants in the citrus family can have an alleviating effect on allergic asthma. The aim of this study was to provide insights into the mechanisms by which these compounds exert their effects on allergic asthma by combining theoretical and practical approaches. Aurantii Fructus Immaturus flavonoids (AFIFs) were obtained by solvent extraction and were determined by high performance liquid chromatography (HPLC).
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