Zanthplanispine
In a search for novel anti-inflammatory bioactive drug leads from this plant, Su at al isolated from its roots a novel tetrahydrofuran lignan named zanthplanispine, molecular formula C21H22O8.
Cascarinoid A Structure Elucidation
Gao et al isolated, amongst others, Cascarinoid A, the first example of a crotofolane diterpenoid alkaloid, molecular formula C28H31NO5.
Orbicularisine Structure Elucidation
Goudou at al described the isolation of a novel metabolite, orbicularisine, from the tropical bivalve Codakia orbicularis living in seagrass beds, molecular formula C13H10N2O5S.
Dimericbiscognienyne A Structure Elucidation
Zhao and coworkers had been studying the secondary metabolites of Biscogniauxia sp. They isolated a diisoprenyl-cyclohexane-type meroterpenoid dimer with a new skeleton, Dimericbiscognienyne A (molecular formula C32H40O6).
Ent-Kaurane-Type Diterpenoid Structure Elucidation
Yaouba et al reported the isolation and phytochemical investigation of the constituents of Aspilia pluriseta Schweinf and Aspilia mossambicensis. They isolated, identified and comprehensively investigated compound 1, molecular formula C21H30O3.
The intricacies of solving for an unknown structure using solution NMR data
Let me begin by stating my experiences with elucidations on organic molecules. I have led over 60 training sessions attended by chemists and Spectroscopists from Academia to industry around the world. Some more successful than others—this came down to expertise of the attendee. I have also conversed with dozens of chemists/Spectroscopists, experts and non-experts, at...
The Curse of Dead Data in Analytical Chemistry
This Halloween, we will explore how data “dies” and why you can’t bring it back to life. Not only that, but we will discover the secret of how you can keep your analytical data alive… forever!
Evaluation of mass spectral library search algorithms implemented in commercial software
Performance of several library search algorithms (against EI mass spectral databases) implemented in commercial software products (ACD/SpecDB, ChemStation, GC/MS Solution, and MS Search) was estimated. Test set contained 1000 mass spectra, which were randomly selected from NIST’08 (RepLib) mass spectral database. It was shown that composite (also known as identity) algorithm implemented in ms search...
Complicating NMR data interpretation
Typically, structure elucidation via NMR can be ascribed by a stepwise workflow: 1. a sample is prepared for NMR, 2. the NMR instrument is optimized for data collection, 3. NMR data is acquired, 4. the spectral data is processed, 5. the spectral data is searched/compared to an internal database for possible hits or similarities, 6....
Fitting a Molecular Formula to a Mass
With a monoisotopic mass identified from a mass spectrum, the next step is to fit a molecular formula (or elemental composition) to the unknown. For organic compounds, the starting elements of choice are Carbon, Hydrogen, Oxygen, Nitrogen and sometimes Sulfur. Information from starting material and known derivatives can also help when deciding what elements and...