ABSTRACT
Gas chromatography (GC) and mass spectrometry (MS) were used to determine the stereoisomeric compositions of 6,10,14-trimethylpentadecan-2-ol and 6,10,14-trimethylpentadecan-2-one in wing extracts from 17 Bicyclus butterfly species from different regions of Africa. All samples were purified using solid phase extraction (SPE). Since some species contained both alcohol and ketone, these were separated and the ketone was reduced to the alcohol before analysis as either (R)-trans-chrysanthemoyl or (S)-2-acetoxypropionyl esters. A novel asymmetric synthesis was developed for a reference mixture of (2R/S,6S,10R)-6,10,14-trimethylpentadecan-2-ol with known composition of the eight stereoisomers. The mixture then was used as the (R)-trans-chrysanthemoyl esters to correlate each of the eight gas chromatographic peaks to a specific stereoisomer of the extracted wing compounds. Seven butterfly species showed (2R,6R,10R)-configuration of the alcohol, four species contained minute amounts of alcohol too small to determine the stereochemistry, nine species showed (6R,10R)-configuration of the ketone, and one species contained minute amounts of ketone too small to determine the stereochemistry. No other stereoisomers of alcohol or ketone could be detected in the extracts, and the quantities of the compounds in the wing extracts varied from 5 to 900 ng per sample for each species.
Subject(s)
Alcohols/chemistry , Butterflies/chemistry , Terpenes/chemistry , Wings, Animal/chemistry , Alcohols/chemical synthesis , Animals , Chemistry Techniques, Synthetic , Female , Gas Chromatography-Mass Spectrometry , Male , Molecular Structure , Sex Attractants/chemistry , Solid Phase Extraction , Stereoisomerism , Terpenes/chemical synthesis , Tissue Extracts/analysis , Tissue Extracts/chemistryABSTRACT
Optimal conditions for isolation of rooster liver nuclei were studied for the purification of RNA polymerases I and II by varying the concentrations of sucrose, magnesium chloride and spermine in the isolation medium. Addition of spermine and/or magnesium chloride to the hypertonic sucrose medium was found to be advantageous for the purification. Heparin-Sepharose chromatography can be recommended for purification of RNA polymerases when used in a stepwise manner. Furthermore, gradient elution in the heparin-Sepharose chromatography was found to separate RNA polymerases I and II. RNA polymerase III was eluted with RNA polymerase I. A few minor peaks of RNA polymerase II activity were detected with gradient elution. Factors influencing the affinity of RNA polymerases towards heparin-Sepharose are discussed.
