English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Our rigorous re-examination of the conformational properties of bastadins that comprise the isobastarane and bastarane-type macrocycle has generated some interesting new insights. We determined that these macrocycles are flexible and possess a surprising degree of reflection symmetry that generates enantiomeric conformations. The macrocycle symmetry arises from its ability to twist in a disrotatory fashion, providing one set of conformers, and then twists with the opposite disrotation to generate a corresponding set of enantiomers. Overall, the isobastarane conformations for (E,E)-bastadin 19 (1a) are complex and can access several distinct ring conformations. In contrast, the bastarane macrocycle in bastadin 5 (2) and bastadin 6 (3) maintains a similar overall shape. We postulate that the short-term stability of the (Z)-oximo amide, an uncommon configuration found in bastadins and psammaplins, is due to the existence of conformers with intramolecular hydrogen bonds involving the (Z)-oxime, and hydrogen bonding impedes oxime isomerization to the more stable (E)-oximo amide in solution. Finally, the modeling results provided insights toward understanding the different antiproliferative activity against endothelial cells as well as Ca(2+) channel modulation activities attributed to bastaranes 2 and 3 versus isobastarane 1a.

journal of natural products

Unraveling the Bastarane and Isobastarane Oximo Amide Configurations and Associated Macrocycle Conformations: Implications of Their Influence on Bioactivities