PubMed · 13221089
The source did not provide an abstract. Follow the original record for more information.
Explore connections, maps & timelines
J MORIN. Marsilid.. https://pubmed.ncbi.nlm.nih.gov/13221089/
Cite the original work for its findings. Save a collection to share your selection of sources.
KEEP EXPLORING
4-Epi-cis-dihydroagarofuran was isolated from the bark oil of Cedrelopsis grevei and its structure was elucidated by 1D and 2D-NMR spectroscopy.
In this paper we employ a CASSCF/AMBER quantum-mechanics/molecular-mechanics tool to map the intersection space (IS) of a protein. In particular, we provide evidence that the S1 excited-state potential-energy surface of the visual photoreceptor rhodopsin is spanned by an IS segment located right at the bottom of the surface. Analysis of the molecular structures of the protein chromophore (a protonated Schiff base of retinal) along IS reveals a type of geometrical deformation not observed in vacuo. Such a structure suggests that conical intersections mediating different photochemical reactions reside along the same intersection space. This conjecture is investigated by mapping the intersection space of the rhodopsin chromophore model 2-Z-hepta-2,4,6-trieniminium cation and of the conjugated hydrocarbon 3-Z-deca-1,3,5,6,7-pentaene.
The structures of the isomeric nucleosides 4-nitro-1-(beta-D-ribofuranosyl)-1H-indazole, C(12)H(13)N(3)O(6), (I), and 4-nitro-2-(beta-D-ribofuranosyl)-2H-indazole, C(12)H(13)N(3)O(6), (II), have been determined. For compound (I), the conformation of the glycosylic bond is anti [chi = -93.6 (6) degrees ] and the sugar puckering is C2'-exo-C3'-endo. Compound (II) shows two conformations in the crystalline state which differ mainly in the sugar pucker; type 1 adopts the C2'-endo-C3'-exo sugar puckering associated with a syn base orientation [chi = 43.7 (6) degrees ] and type 2 shows C2'-exo-C3'-endo sugar puckering accompanied by a somewhat different syn base orientation [chi = 13.8 (6) degrees ].