Treatment of ecdysteroids with excess of TBAF in THF was shown to proceed with stereoselective oxidation at the 9alpha position of the carbon skeleton. The stereochemistry of the products was confirmed by X-ray analysis. Using this method, 9alpha-hydroxyecdysteroids were obtained in good yield. The results open a route to novel type of natural and modified steroids that are difficult to access otherwise.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1016/j.steroids.2009.10.011 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Total Synthesis and Anti-Inflammatory Activity of Tectoridin and Related Isoflavone Glucosides.
J Nat Prod
December 2024
Anti-infective Agent Creation Engineering Research Centre of Sichuan Province, School of Pharmacy, Chengdu University, Chengdu 610106, China.
The first total syntheses of four isoflavone glucosides, tectoridin (), tectoridin A (), tectorigenin 7--β-d-glucopyranosyl-12--β-d-glucopyranoside (), and isotectroigenin 7--β-d-glucopyranoside (), have been accomplished. Key steps in our synthetic approach include a regioselective halogenation reaction, followed by methanolysis to introduce the -OCH group into isoflavone frameworks and a PTC-promoted stereoselective glycosidation to establish glycosidic bonds. The synthesized isoflavone glucosides (-) and their corresponding aglycones ( and ) were evaluated for anti-inflammatory activity against nitric oxide (NO), tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and interleukin-1 β (IL-1β) in lipopolysaccharide (LPS)-induced RAW264.
View Article and Find Full Text PDFElectrochemical Dicarboxylation of Vinyl Epoxide with CO2 for the Facile and Selective Synthesis of Diacids.
Angew Chem Int Ed Engl
December 2024
East China Normal University, School of Chemistry and Molecular Engineering, 3663 N. Zhongshan Rd., 200062, Shanghai, CHINA.
We present a novel electrochemical dicarboxylation of epoxides with CO2, characterized by the cleavage of two C-O single bonds. Not only are vinyl epoxides viable, but cyclic carbonates also serve as effective substrates, facilitating the synthesis of E-configured adipic and octanedioic acids with high chemo-, regio-, and stereoselectivity. The synthetic practicality is further highlighted by the diverse functionalizations of the resulting multifunctional diacids.
View Article and Find Full Text PDFIdentification of a bacteria P450 enzyme from B. megaterium H-1 with vitamin D C-25 hydroxylation capabilities.
Enzyme Microb Technol
December 2024
College of Biomass Science and Engineering, Sichuan University, Chengdu 610065, China.
Calcidiol (25(OH)VD) and calcitriol (1α,25(OH)VD) are active vitamin D with high medicinal value, which can maintain calcium and phosphorus balance and treat vitamin D deficiency. Microbial synthesis is an important method to produce high-value-added compounds. It can produce active vitamin D through the hydroxylation reaction of P450, which can reduce the traditional chemical synthesis steps, and greatly improve the production efficiency and economic benefits.
View Article and Find Full Text PDFExploring Mycolactone-The Unique Causative Toxin of Buruli Ulcer: Biosynthetic, Synthetic Pathways, Biomarker for Diagnosis, and Therapeutic Potential.
Toxins (Basel)
December 2024
Department of Chemistry, University of Ghana, Legon-Accra P.O. Box LG56, Ghana.
Mycolactone is a complex macrolide toxin produced by , the causative agent of Buruli ulcer. The aim of this paper is to review the chemistry, biosynthetic, and synthetic pathways of mycolactone A/B to help develop an understanding of the mode of action of these polyketides as well as their therapeutic potential. The synthetic work has largely been driven by the desire to afford researchers enough (≥100 mg) of the pure toxins for systematic biological studies toward understanding their very high biological activities.
View Article and Find Full Text PDFOrganometallic Photocatalyst-Promoted Synthesis and Modification of Carbohydrates under Photoirradiation.
Chem Rec
December 2024
Qiandongnan Traditional Medicine Research & Development Center, School of Life and Health Science, Kaili University, 3 Kaiyuan Road, Qiandongnan Miao and Dong Autonomous Prefecture, Kaili, 556011, China.
Carbohydrates are natural, renewable, chemical compounds that play crucial roles in biological systems. Thus, efficient and stereoselective glycosylation is an urgent task for the preparation of pure and structurally well-defined carbohydrates. Photoredox catalysis has emerged as a powerful tool in carbohydrate chemistry, providing an alternative for addressing some of the challenges of glycochemistry.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!