Skip To Content

ACD/Labs Blog

Mikhail Elyashberg
M. Cao and co-workers described the isolation and structure elucidation of 10 new alkaloids belonging to the Daphniphyllum alkaloids family. The spectral data presented for one of the compounds, Daphmacromine A (molecular formula C25H37NO5), were used to challenge ACD/Structure Elucidator.

Mikhail Elyashberg
Wang et al isolated a novel alkaloid lycojaponicumin (molecular formula C16H21NO4) from the alkaloidal extract in a trace amount, with a unique 5/5/5/5/6 pentacyclic ring system including two fused tetrahydroisoxazole rings. The structure was elucidated by spectroscopic methods and X-ray diffraction analysis.

Mikhail Elyashberg
A recent article highlighted the isolation and structure elucidation of a new natural product Psychotripine (molecular formula C33H34N6), which exhibited a complex carbon skeleton comprised of 11 rings. We attempted the Computer-Assisted Structure Elucidation (CASE) of Psychotriptine using only the original limited and incomplete NMR data gathered from the original publication

Mikhail Elyashberg
Philip Williams and co-workers isolated a new cytotoxic peptide, Tasiamide B (molecular formula C50H74N8O12) containing the unusual amino acid-derived residue 4-amino-3-hydroxy-5-phenylpentanoic acid. The structure of the peptide was determined through a combination of 2D NMR experiments and HPLC analysis of degradation products. The experimental data was submitted to the Structure Elucidator Challenge to determine if the software could propose the same structure.

Mikhail Elyashberg
Robert Capon and co-workers identified two new nematocidal depsipeptides, identified as phoriospongins A (molecular formula C52H82N11O15Cl) and B. The structures of the phoriospongins were determined by detailed spectroscopic analysis and comparison with the previously reported sponge depsipeptide cyclolithistide A. The experimental data was submitted to the Structure Elucidator Challenge to determine if the software could propose the same structure.

Mikhail Elyashberg
Botryococcus braunii is a colonial green microalga that is known for producing various types of hydrocarbons and other types of oils. In a 1998 publication, Okada and co-workers isolated and identified two new carotenoids in their efforts to better understand the relationship between colony color and hydrocarbon production, one of which was α-botryoxanthin A (molecular formula C74H112O2).

Mikhail Elyashberg
For more than a decade, ACD/Structure Elucidator has been used by industry and academic experts to help solve some of the toughest structure problems. Using data from various analytical techniques (NMR, MS, UV, and IR) Structure Elucidator can propose chemical structures that are consistent with ALL available analytical data.

Arvin Moser
Functional groups such as allene (C=C=C) and cumulene (C=C=C=C) present an interesting challenge in an elucidation project, especially when an elucidator is not expecting them. The 13C chemical shifts for allene carbons are typically expected at 80, 200 and 100 ppm +/- ~20 ppm per shift. The confusion, or better described as bias, arises at...

Ryan Sasaki
In yesterday’s post I pointed you to an article that has become the most accessed article of all time in the Journal of Cheminformatics, co-authored by representatives of ACD/Labs. This article is a very comprehensive outline of the different approaches, developments, and successes of the development of CASE (Computer-Assisted Structure Elucidation) systems . I hope...

Arvin Moser
There are many ways to teach the process of elucidating unknown structures. Offering a student a visual guide, such as seeing firsthand a spectral dataset, can enhance the learning process and better equip the student on future work. Presented below is a typical elucidation question from a university test. The numerical values have been extracted...