Synthesis of the enantiomers of lasiol, an acyclic monoterpene alcohol in the mandibular gland secretion of the male ants, Lasius meridionalis.
(2S,3S)-(-)-Lasiol (2,3,6-trimethyl-5-hepten-1-ol, 1) and its antipode were synthesized from cis-4,5-dimethylcyclohexene oxide (3) by employing asymmetric cleavage of the epoxy ring with a chiral lithium amide derived from 4 to give optically active cis-4,5-dimethyl-2-cyclohexen-1-ol (5) as the key-step.
Alcohol-induced versus anion-induced states of α-chymotrypsinogen A at low pH
Characterization of conformational transition and folding intermediates is central to the study of protein folding. We studied the effect of various alcohols (trifluoroethanol (TFE), butanol, propanol, ethanol and methanol) and salts (K3FeCN6, Na2SO4, KClO4 and KCl) on the acid-induced state of α-chymotrypsinogen A, a predominantly β-sheet protein, at pH 2.0 by near-UV circular dichroism (CD), far-UV CD and 1-anilinonaphthalene-8-sulfonic acid (ANS) fluorescence measurements. Addition of alcohols led to an increase in ellipticity value at 222 nm indicating the formation of α-helical structure. The order of effectiveness of alcohols was shown to be TFE>butanol>propanol>ethanol>methanol. ANS fluorescence data showed a decrease in fluorescence intensity on alcohol addition, suggesting burial of hydrophobic patches. The near-UV CD spectra showed disruption of tertiary structure on alcohol addition. No change in ellipticity was observed on addition of salts at pH 2.0, whereas in the presence of 2 M urea, salts were found to induce a molten globule-like state as evident from the increases in ellipticity at 222 nm and ANS fluorescence indicating exposure of hydrophobic regions of the protein. The effectiveness in inducing the molten globule-like state, i.e. both increase in ellipticity at 222 nm and increase in ANS fluorescence, followed the order K3FeCN6>Na2SO4>KClO4>KCl. The loss of signal in the near-UV CD spectrum on addition of alcohols indicating disordering of tertiary structure results suggested that the decrease in ANS fluorescence intensity may be attributed to the unfolding of the ANS binding sites. The results imply that the alcohol-induced state had characteristics of an unfolded structure and lies between the molten globule and the unfolded state. Characterization of such partially folded states has important implications for protein folding.
White-Collar Crime in Modern England: Financial Fraud and Business Morality, 1845-1929.
List of tables Acknowledgments Introduction 1. The new economy: transformation of finance and opportunities for crime 2. The railway mania 3. Banking and credit fraud 4. Stock fraud 5. Company fraud: promotion 6. Company fraud: management 7. Company law and the courts 8. Business ethics and professionalization Conclusion Notes Bibliography Index.