Molecular and crystal structures of hemigossypolone and gossypolone

The results are given of an x-ray structural investigation of hemigossypolone isolated from the stems of a wiltinfected cotton plant and of gossypolone obtained by oxidizing gossypol.     

Molecular characteristics of subfractions of laminarin

Pacific Ocean Institute of Bioorganic Chemistry, Far Eastern Scientific Center of the Russian Academy of Sciences, Vladivostok. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 296–298, March–April, 1994.     

Multivariate calibration methods for quantification in strongly overlapping capillary electrophoretic peaks

Capillary zone electrophoresis with diode-array detection was applied to the separation of ebrotidine and its metabolites. However, three of these, which are neutral in the conditions studied, co-migrated with the electroosmotic flow signal. Therefore, strongly overlapping peaks were observed. The main aim of this study was to show the potentiality of capillary electrophoresis in combination with chemometrics. Multivariate calibration methods were applied to quantify these analytes in synthetic mixtures. The results obtained using partial least squares (PLS) were in agreement with actual values, with an overall prediction error of 9.7%.     

A concise route to (-)-kainic acid

A concise route to (-)-kainic acid from enantiopure (+)-cis-4-carbobenzoxyamino-2-cyclopentenol has been devised by employing concurrent Chugaev syn-elimination and intramolecular ene reaction as the key step.     

Soft agonist receptor interactions: Theoretical and experimental simulation of the active site of the receptor of sweet molecules

The structure-activity relationship of sweet molecules is chosen as an example to illustrate a mechanistic approach of soft agonist-receptor interactions. It is shown that an essentially geometric model of the receptor site can explain the activity of most sweet molecules, both rigid and flexible. The relevant conformations of flexible molecules in solution are extracted from a combination of NMR data and of energy calculations. A possible experimental simulation of the receptor environment in solution is illustrated by the complex of a dipeptide sweetener with a crown-ether.