Prediction of anti-plasmodial activity of Artemisia annua extracts:: application of 1H NMR spectroscopy and chernometrics

We describe the application of H-1 NMR spectroscopy and chemometrics to the analysis of extracts of Artemisia annua. This approach allowed the discrimination of samples from different sources, and to classify them according to anti-plasmodial activity without prior knowledge of this activity. The use of partial least squares analysis allowed the prediction of actual values for anti-plasmodial activities for independent samples not used in producing the models. The models were constructed using approximately 70% of the samples, with 30% used as a validation set for which predictions were made. Models generally explained >90% of the variance, R-2 in the model, and had a predictive ability, Q(2) of >0.8. This approach was also able to correlate H-1 NMR spectra with cytotoxicity (R-2 = 0.9, Q(2) = 0.8). This work demonstrates the potential of NMR spectroscopy and chemometrics for the development of predictive models of anti-plasmodial activity. (C) 2004 Elsevier B.V. All rights reserved.