Identification of the 'wrong' active pharmaceutical ingredient in a counterfeit Halfan drug product using accurate mass electrospray ionisation mass spectrometry,accurate mass tandem mass spectrometry and liquid chromatography/mass spectrometry

Methodology is presented for identifying an unknown active (pharmaceutical) ingredient (AI) in a counterfeit drug product. A range of mass spectrometric techniques, i.e., accurate mass mass spectrometry, tandem mass spectrometry (MS/MS) and liquid chromatography/mass spectrometry (LC/MS), has been employed to determine the AI in a counterfeit Halfan suspension, an antimalarial drug. In particular, use of LockSpray accurate mass MS/MS allowed identification of parts of the molecule from fragments, hence limiting the number of possible elemental compositions for the nominal mass of 278 found for the AI in the counterfeit product. The analysis of the isotope pattern observed for the protonated molecule further reduced the number of possible elemental compositions. A literature search for readily commercially available compounds of molecular formula C(12)H(14)N(4)O(2)S suggested that the AI was either sulfamethazine or sulfisomidine. An LC/MS separation of those two compounds and reference MS/MS spectra obtained for sulfamethazine and sulfisomidine led to the conclusion that the AI in the counterfeit Halfan suspension is sulfamethazine, which is an antibacterial agent.     

Synthesis and structure of a dimethyl(μ-hydrido)di-platinum(II) complex

The complex [Pt₂Me₂(μ-H)(μ-dppm)₂][PF₆] (I, dppm = Ph₂PCH₂PPh₂) has been prepared and characterised by ¹H and ³¹P NMR spectroscopy and by a full molecular structure determination by X-ray methods. The complex undergoes only slow reductive elimination of methane induced by added tertiary phosphine at 70°C.     

Non-Markovian Green function for plasma turbulence

We consider the Green function appropriate for weak plasma turbulence and show that, after a sufficiently long time, it approaches the Green function for a Markovian system.     

The manipulability of the Shapley-value

The manipulation of the Shapley-value, when used as a resource allocation mechanism, is examined. First, the extent to which an individual can, by unilaterally misrepresenting his utility function, affect the value allocation in his favor, is evaluated. When all agents attempt to manipulate, a game results, whose equilibrium allocations can be described as follows. At an equilibrium, the initial allocation appears to be Pareto-efficient. Any equilibrium allocation is also an equilibrium allocation of the analogously defined Walrasian manipulation game. The true (constrained) Walrasian allocations are equilibrium allocations. Under two slight respecifications of the value, there are no other equilibrium allocations.This is a revised version of a University of Minnesota discussion paper (September 1979). The author thanks L. Hurwicz, T. Ikeda, T. Ito, J. Jordan, and particularly A. Mas-Colell for their comments. Assistance from NSF, under grant No 8006482, and from the Sloan Foundation, is gratefully acknowledged.     

Obtusallene I,a new halogenated allene from Laurencia Obtusa

Obtusallene, a new halogenated bicyclic ether with an allenic side chain, has been isolated from the red form of the alga Laurencia obtusa, and identified by spectroscopic methods and X-ray crystallography.     

Monotonicity and independence axioms

Given σ, a family ofchoice problems, subsets ofR ⁿ representing the payoff vectors (measured in von Neumann-Morgenstern utility scales) attainable by a group ofn players, asolution f on σ associates to everyS in σ a unique elementf (S) ofS. Amonotonicity axiom specifies how the solution outcome should change when the choice problem is subjected to certain geometric transformations while anindependence axiom requires, in similar circumstances, the invariance of the solution outcome. A number of such axioms are here formulated and the logical relationships among them are established.Strong monotonicity is shown to be the strongest axiom and strongly monotonic solutions are characterized.     

Ring contraction of 3-bromothiochroman-4-one: Formation of a dimeric spirothioindoxyl and vinylenethioindigo

Contrary to the literature, the reaction of 3-bromothiochroman-4-one with sodium acetate in acetic acid gives a dimeric spirothioindoxyl (whose crystal structure has been determined) which, after bromination and then heating in pyridine yields “vinylenethioindigo”.