Results 81 to 90 of about 18,265 (273)

Total synthesis of rupestine G and its epimers [PDF]

Royal Society Open Science, 2018
Rupestine G is a guaipyridine sesquiterpene alkaloid isolated from Artemisia rupestris L. The total synthesis of rupestine G and its epimers was accomplished employing a Suzuki reaction to build a terminal diene moiety. The diene was further elaborated into the desired
Abdullah Yusuf, Jiangyu Zhao, Bianlin Wang, Paruke Aibibula, Haji Akber Aisa, Guozheng Huang   +5 more
openaire   +3 more sources

An Efficient Solid Phase Extraction Method for Purification and Analysis of Compound‐Specific Plant Sugar Stable Hydrogen Isotope Values

Rapid Communications in Mass Spectrometry, Volume 40, Issue 2, 30 January 2026.
ABSTRACT Rationale The stable hydrogen isotope composition (δ2H) of plant compounds can serve as environmental or metabolic proxies, but interpretations are hindered by insufficient mechanistic understanding. This can be improved by analyzing the δ2H values of metabolic intermediates, such as sucrose, which is the direct substrate of cellulose and a ...
Selina Hugger, Meisha Holloway‐Phillips, Ansgar Kahmen, Daniel B. Nelson   +3 more
wiley   +1 more source

High resolution mass spectrometry in molecular structure and stereochemical studies - Effect of stereochemistry on the fragmentation of epimeric derivatives of azabicycloalkanes [PDF]

High resolution mass spectrometry in studies of stereochemistry effect on fragmentation of epimeric derivatives of ...
Burlingame, A. L., Schnoes, H. K., Smith, D. H.   +2 more
core   +1 more source

Stereochemische Entschlüsselung der Strobilurin‐PKS enthüllt die komplexe biosynthetische Logik des iterativen Aufbaus eines EZE‐Triens

Angewandte Chemie, Volume 138, Issue 4, 22 January 2026.
Die iterative Strobilurin‐PKS baut ein bemerkenswertes EZE‐Trien auf, indem es seine S‐tereoselektvität während der Synthese variiert. Die stereoselektive 2R‐Methylierung des Triketid‐Intermediats durch die C‐terminale C‐Methyltransferase‐Domäne induziert die KR‐ und DH‐Domänen ihre native Stereoselektivität umzukehren und ein Z‐konfiguriertes ...
Maurice Hauser, Jing Pang, Daowan Lai, Yunlong Sun, Hao Yao, Russell J. Cox   +5 more
wiley   +1 more source

Dietary 25 Hydroxyvitamin D3 Improved Serum Concentration Level and Alkaline Phosphatase Activity during Lactation but Had Meager Impact on Post-Farrowing Reproductive Performance in Sows

Animals
Dietary 25 hydroxyvitamin D3 (25(OH)D3) promotes serum 25(OH)D3 concentration and alkaline phosphatase activity (ALP); however, post-farrowing reproductive performance of lactating sows fed with 14-epimer of 25(OH)D3 is uncertain. This study investigated
Prester C. John Okafor, Nitipong Homwong
doaj   +1 more source

Methylene Homologues of Artemisone: An Unexpected Structure-Activity Relationship and a Possible Implication for the Design of C10-Substituted Artemisinins. [PDF]

, 2016
We sought to establish if methylene homologues of artemisone are biologically more active and more stable than artemisone. The analogy is drawn with the conversion of natural O- and N-glycosides into more stable C-glycosides that may possess enhanced ...
Ariey, Avery, Batty, Batty, Bhattacharjee, Brewer, Brewer, Campbell, Cho, Conyers, Davis, Delves, Dunay, Efferth, Espinosa, Fieschi, Ford-Moore, Genovese, Genovese, Ghose, Gordi, Gravett, Hall, Haynes, Haynes, Haynes, Haynes, Haynes, Haynes, Haynes, Haynes, Haynes, Haynes, Haynes, Haynes, Hooft van Huijsduijnen, Ilett, Ingelman, Jansen, Jiménez-Barbero, Johann-Liang, Kelter, Kim, Kinoshita, Krishna, Laclau, Li, Lubell, Ma, Ma, Marfurt, Morris, Nivière, Nontprasert, Obaldia, Palfey, Parapini, Phyo, Ramu, Ravishankar, Schmieg, Schmuck, Schmuck, Schmuck, Smith, Teyssot, Tilley, Toovey, Toovey, Toovey, Toovey, Toovey, van Agtmael, Vivas, Waknine-Grinberg, Waknine-Grinberg, Wells, Woodrow, Xu, Zhou   +79 more
core   +1 more source

General Intermediates for the Synthesis of 6-C-Alkylated DMDP-Related Natural Products

Molecules, 2013
Protected L-homoDMDP en-8 and its C-6 epimer en-7 were prepared through two different pathways starting from the vinylpyrrolidine en-9. Based on the NMR and X-ray analysis, the stereochemistry of homoDMDP at C-6 was confirmed to be consistent with ...
Chu-Yi Yu, Yue-Mei Jia, Yi-Xian Li, Mu-Hua Huang   +3 more
doaj   +1 more source

Report from the 5th international symposium on mycotoxins and toxigenic moulds : challenges and perspectives (MYTOX) held in Ghent, Belgium, May 2016 [PDF]

, 2016
The association research platform MYTOX “Mycotoxins and Toxigenic Moulds” held the 5th meeting of its International Symposium in Ghent, Belgium on 11 May 2016.[...
Audenaert, Kris, Croubels, Siska, De Saeger, Sarah   +2 more
core   +2 more sources

Synthetic Epimers of Ajmaline and Isoajmaline

Zeitschrift für Naturforschung B, 1996
Two new epimers of ajmaline (1) and isoajmaline (2) were synthesized by means of tosylation followed by hydrolysis with NaOH/CH3OH. Displacement of tosyl with hydroxyl group yielded C21 epimers of these alkaloids. The structures were identified by various spectroscopic techniques.
M. Ataullah Khan, Humaira Raees
openaire   +1 more source

Stereochemical Dissection of the Strobilurin PKS Reveals the Complex Biosynthetic Logic of Iterative EZE Triene Construction

Angewandte Chemie International Edition, Volume 65, Issue 4, 22 January 2026.
The strobilurin iterative PKS assembles a remarkable EZE triene by varying its stereoselectivity during synthesis. Stereoselective 2R‐methylation of the triketide intermediate by the C‐terminal C‐methyltransferase domain induces the KR and DH domains to invert their native stereoselectivities and produce a Z‐configured intermediate.
Maurice Hauser, Jing Pang, Daowan Lai, Yunlong Sun, Hao Yao, Russell J. Cox   +5 more
wiley   +1 more source