Copper and iron interactions with angiotensin-converting enzyme inhibitors. A study by fast-atom bombardment tandem mass spectrometry

Fast atom bombardment, combined with high-energy collision-induced tandem mass spectrometry, has been used to investigate gas-phase metal-ion interactions with captopril, enalaprilat and lisinopril, all angiotensin-converting enzyme inhibitors.Suggestions for the location of metal-binding sites are presented. For captopril, metal binding occurs most likely at both the sulphur and the nitrogen atom. For enalaprilat and lisinopril, binding preferably occurs at the amine nitrogen. Copyright 1999 John Wiley & Sons, Ltd.     

Energy relations in the case of impact action on a rod

Time changes are analyzed of internal energy of a uniform free rod of constant cross section which is loaded at one end by an arbitrary time-variable force.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 7, pp. 96–101, July, 1972.     

Synthesis and mass spectra of some phosphadipeptides

Conclusions The mass-spectrometric fragmentation of several phosphadipeptides has been investigated. The mass spectra show peaks which are unequivocally related to the sequence of amino acid residues in the molecule, as well as peaks which correspond to the C-terminal amino acids. These peaks can be utilized for the massspectrometric identification of metabolites of the compounds studied.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 5, pp. 1138–1144, May, 1978.     

Physangulidines A, B, and C: three new antiproliferative withanolides from Physalis angulata L

Bioassay-directed fractionation of the whole plant of Physalis angulata L. afforded three new antiproliferative withanolides with an unusual carbon framework: physangulidines A (1), B (2), and C (3). Structures of the three isomeric withanolides were determined by a combination of HRMS, NMR spectroscopic, and X-ray crystallographic methods. Each has shown significant antiproliferative activity against DU145 prostate cancer cells. Physangulidine A (1) was further tested against a wide range of additional cancer cell lines and found to exhibit significant antiproliferative activity.     

Mechanism of reducing effective dry friction under shock and vibration effects (to theory of technogenic seismic sources)

A simple mechanical model illustrates that even very weak vibration or shock impacts can cause a significant displacement of bodies in contact by dry friction. The model is studied using the concepts of effective friction coefficients under vibration and elements of the vibrational displacement theory. The results are compared with those of earlier and new experiments. Their application to the theory of man-made earthquakes and the problem of increasing oil recovery from petroliferous layers through vibration effects is discussed.