1
|
Abstract
Abstract
Patterson search is a powerful tool for solving difficult crystal structures since it actively uses chemical information. Our program PATSEE, which attempts to combine the merits of Patterson and direct methods in order to locate a fragment with known geometry in the unit cell, has solved a large number of crystal structures during the last decade and proved to be reliable and widely applicable. We have tested PATSEE successfully on 20 structures of different size and complexity contained in a test data bank using fragments either taken from related crystal structures or calculated by force-field methods. Even structures with several torsional degrees of freedom (like those of oligopeptides) could be solved convincingly. As a result, general experiences – such as requirements for the minimum size and the accuracy of a search fragment, the reliability of the various figures of merit, the chances to locate single atoms and to tackle larger structures – were gained, which should help in finding an optimum strategy for the solution of problem structures with PATSEE.
Collapse
|
2
|
Sundberg RJ, Smith SQ. The IBOGA alkaloids and their role as precursors of anti-neoplastic bisindole Catharanthus alkaloids. THE ALKALOIDS. CHEMISTRY AND BIOLOGY 2003; 59:281-376. [PMID: 12561419 DOI: 10.1016/s0099-9598(02)59009-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/28/2023]
Affiliation(s)
- Richard J Sundberg
- Department of Chemistry, University of Virginia, Charlottesville, Va., USA
| | | |
Collapse
|