Absolute structural elucidation of natural products-a focus on quantum-mechanical calculations of solid-state CD spectra

Gennaro Pescitelli, T. Kurtán, Ulrich Flörke, Karsten Krohn

Research output: Contribution to journalArticle

91 Citations (Scopus)

Abstract

In this review article we examine state-of-the-art techniques for the structural elucidation of organic compounds isolated from natural sources. In particular, we focus on the determination of absolute configuration (AC), perhaps the most challenging but inevitable step in the whole process, especially when newly isolated compounds are screened for biological activity. Among the many methods employed for AC assignment that we review, special attention is paid to electronic circular dichroism (CD) and to the modern tools available for quantum-mechanics CD predictions, including TDDFT. In this context, we stress that conformational flexibility often poses a limit to practical CD calculations of solution CD spectra. Many crystalline natural products suitable for X-ray analysis do not contain heavy atoms for a confidential AC assignment by resonant scattering. However, their CD spectra can be recorded in the solid state, for example with the KCl pellet technique, and analyzed possibly by nonempirical means to provide stereochemical information. In particular, solid-state CD spectra can be compared with those calculated with TDDFT or other high-level methods, using the X-ray geometry as input. The solid-state CD/TDDFT approach, described in detail, represents a quick and reliable tool for AC assignment of natural products.

Original languageEnglish
JournalChirality
Volume21
Issue number1 E
DOIs
Publication statusPublished - 2009

Fingerprint

Dichroism
Circular Dichroism
Biological Products
Quantum theory
X ray analysis
Bioactivity
Organic compounds
Scattering
Crystalline materials
X rays
Atoms
X-Rays
Geometry
Mechanics

Keywords

  • Absolute configuration
  • Conformational analysis
  • Exciton-coupled CD
  • KCl pellet
  • Tddft calculations
  • X-ray diffractometry

ASJC Scopus subject areas

  • Organic Chemistry
  • Analytical Chemistry
  • Drug Discovery
  • Pharmacology
  • Catalysis
  • Spectroscopy

Cite this

Absolute structural elucidation of natural products-a focus on quantum-mechanical calculations of solid-state CD spectra. / Pescitelli, Gennaro; Kurtán, T.; Flörke, Ulrich; Krohn, Karsten.

In: Chirality, Vol. 21, No. 1 E, 2009.

Research output: Contribution to journalArticle

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