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<p>A robust system for automatic processing and
assignment of raw 13C and 1H NMR data DP4-AI has been developed and integrated
into our computational organic molecule structure elucidation workflow.
Starting from a molecular structure with undefined stereochemistry or other
structural uncertainty, this system allows for completely automated structure
elucidation. Methods for NMR peak picking using objective model selection and
algorithms for matching the calculated 13C and 1H NMR shifts to peaks in noisy
experimental NMR data were developed. DP4-AI achieved a 60-fold increase in
processing speed, and near-elimination of the need for scientist time, when
rigorously evaluated used a challenging test set of molecules. DP4-AI
represents a leap forward in NMR structure elucidation and a step-change in the
functionality of DP4. It enables high-throughput analyses of databases and
large sets of molecules, which were previously impossible, and paves the way
for the discovery of new structural information through machine learning. This
new functionality has been coupled with an intuitive GUI and is available as
open-source software at https://github.com/KristapsE/DP4-AI.</p>
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Pentacyclic triterpenoid, betulinic acid (1) and phenolic, p-hydroxybenzoic acid (2), had been isolated for the first time from the stem bark of Vitex pubescens Vahl. The structure of compounds 1 and 2 was determined based on the interpretation of spectroscopic data including UV, IR, NMR (1H-NMR, 13C-NMR, HMQC, HMBC, COSY) and MS, as well as by comparison with those reported data.
Synthesis of secondary alcohols compound from safrole and methyleugenol has been achieved through conversion of allyl group to alcohol.The reaction of safrole and methyleugenol with mercuric acetate in aqueous tetrahydrofuran, followed by in situ reduction of the mercurial intermediate by alkaline sodium borohydride produced secondary alcohol namely safryl alcohol (71.25%) and methyleugenil alcohol (65.56%). The structure elucidation of these products were analyzed by FTIR, 1H-NMR, 13C-NMR and MS. Keywords: Secondary alcohols; safrole; methyleugenol
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A facile synthetic protocols were employed to prepare process-related impurities associated with the synthesis of pemetrexed disodium heptahydrate, Alimta. The research work is described for the development of the novel synthetic methods and their structure elucidation of Pemetrexed glutamide, N-methyl pemetrexed, and N-methyl pemetrexed glutamide impurities. The listed impurities were deduced through spectral analysis such as 1H-NMR, 13CNMR, and HRMS. The target compounds can be used as the reference substances for the quality control.
Database Independent Automated Structure Elucidation of Organic Molecules Based on IR, 1H NMR, 13C NMR, and MS Data