Unravelling the Complexities of Polyoxometalates in Solution Using Mass Spectrometry: Protonation versus Heteroatom Inclusion

A route to unravel and the complexities of polyoxometalates in solution using electrospray mass spectrometry is presented. This reveals the limited speciation of the clusters in organic solvent compared to that in aqueous solution and allows the unambiguous assignment of the protonation states of the cluster as a function of heteroatom inclusion

Unravelling the Complexities of Polyoxometalates in Solution Using Mass Spectrometry: Protonation versus Heteroatom Inclusion

A route to unravel and the complexities of polyoxometalates in solution using electrospray mass spectrometry is presented. This reveals the limited speciation of the clusters in organic solvent compared to that in aqueous solution and allows the unambiguous assignment of the protonation states of the cluster as a function of heteroatom inclusion

Unravelling the Complexities of Polyoxometalates in Solution Using Mass Spectrometry: Protonation versus Heteroatom Inclusion

A route to unravel and the complexities of polyoxometalates in solution using electrospray mass spectrometry is presented. This reveals the limited speciation of the clusters in organic solvent compared to that in aqueous solution and allows the unambiguous assignment of the protonation states of the cluster as a function of heteroatom inclusion

Unravelling the Complexities of Polyoxometalates in Solution Using Mass Spectrometry: Protonation versus Heteroatom Inclusion

A route to unravel and the complexities of polyoxometalates in solution using electrospray mass spectrometry is presented. This reveals the limited speciation of the clusters in organic solvent compared to that in aqueous solution and allows the unambiguous assignment of the protonation states of the cluster as a function of heteroatom inclusion

Synthesis of Bridged Bicyclic Ethers and Fused Oxetanes from Pyran-4-ones via Tandem Solvent Trapping and Norrish Type II Cyclization¹

Polyalkyl pyran-4-ones 1a−c were irradiated in methanol or ethanol. Although the expected solvent trapping products 3 could be observed, extended irradiation times allowed exclusive formation of secondary photoproducts 4 and 5 in combined yields of 37−64%. These bicyclic compounds are believed to arise from γ-hydrogen abstraction by the excited enone chromophore of 3, followed by closure of the resulting biradical through one of two possible pathways. Moderate stereoselectivity was observed in the radical coupling to produce 4, whereas the analogous closure to 5 was completely diastereoselective. Tautomerization of the enol precursors to 5 also occurred with complete selectivity for protonation from the exo face. Overall, this process converts simple, planar heterocycles and alkanols into complex products in a single transformation

Emmyguyacins A and B: Unusual Glycolipids from a Sterile Fungus Species That Inhibit the Low-pH Conformational Change of Hemagglutinin A during Replication of Influenza Virus

Two novel glycolipids, emmyguyacin A (1a) and emmyguyacin B (1b), were isolated at concentrations of 1.51 g/L from a potato dextrose agar fermentation of a sterile fungus species. The compounds inhibit replication of influenza A virus (A/X31) in MDCK cells by inhibiting the pH-dependent conformational change of hemagglutinin A (IC50 9 μM). The structures were deduced using one- and two-dimensional NMR techniques and mass spectrometric analyses on both the parent compounds and a host of degradation products and derivatives. A novel and unusual oxalic acid ester of a monohydroxylated fatty acid (5, 17-oxalyloxydocosanoic acid) is reported. The first isolation and characterization of the fatty acid 17-hydroxydocosanoic acid (3) itself is also reported as a saponification product of 1