Advancements in the field of Computer-Assisted Structure Elucidation (CASE) of Natural Products achieved in the past five years are discussed. This process starts with a dereplication procedure, supported by structure-spectrum databases. Both commercial and free products are available to support the procedure. A number of new programs,as well as advancements in existing ones, are presented. Fin...

A new antibiotic swalpamycin (1) has been isolated from the culture broth of Streptomyces sp. Y-84,30967. The antibiotic has the molecular formula of C37H56O14 and belongs to the class of 16-membered neutral macrolide antibiotics. Its structure has been elucidated by an analysis of its spectral properties. It contains a novel aglycone herein called swalpanolide.

Angolamycin (1) and two novel analogues (2 and 3) were isolated from the culture broth of a Streptomyces strain. NMR and MS analysis proved that 2 is the 18-dihydro-, while 3 is the 18-deoxo-18-dihydro derivative of angolamycin. Full experimental assignment of the 1H and the 13C NMR spectra of these compounds was obtained from 1D and 2D chemical shift correlation measurements. Compounds 2 and 3...

Elucidating the structure of complex molecules is difficult at low magnetic fields due to the overlap of different peak multiplets and second-order coupling effects. This is even more challenging for rigid molecules with small chemical shift differences and with prochiral centers. Since low-field NMR spectroscopy is sometimes presumed as restricted to the analysis of only small and simple molec...