Mass spectrometry-guided discovery of new analogs of bicyclic phosphotriester salinipostin and evaluation of their monoacylglycerol lipase inhibitory activity.

Natural products containing the highly unusual phosphotriester ring are known to be potent serine hydrolase inhibitors. The long-chain bicyclic enol-phosphotriester salinipostins (SPTs) from the marine actinomycete Salinispora have been identified as selective antimalarial agents. A potential regulatory function has been suggested for phosphotriesters based on their structural relationship with actinomycete signaling molecules and the prevalence of spt-like biosynthetic gene clusters across actinomycetes.

Identification of Tricyclic Guanidino Compounds from the Tetrodotoxin-Bearing Newt .

The biosynthesis of the potent neurotoxin tetrodotoxin (TTX, ) is still unresolved. We used MS-guided screening and nuclear magnetic resonance analyses including long-range HSQMBC to characterize two novel skeletal tricyclic guanidino compounds, Tgr-288 ( and ) and Tgr-210 (), from the TTX-bearing newt, . The presence of these compounds in toxic newts is congruent with a previously proposed pathway for TTX biosynthesis in terrestrial organisms that includes a monoterpene precursor and the production of structurally diversified guanidino compounds.

Energy Efficient Control of Ultrafast Spin Current to Induce Single Femtosecond Pulse Switching of a Ferromagnet.

New methods to induce magnetization switching in a thin ferromagnetic material using femtosecond laser pulses without the assistance of an applied external magnetic field have recently attracted a lot of interest. It has been shown that by optically triggering the reversal of the magnetization in a GdFeCo layer, the magnetization of a nearby ferromagnetic thin film can also be reversed via spin currents originating in the GdFeCo layer. Here, using a similar structure, it is shown that the magnetization reversal of the GdFeCo is not required in order to reverse the magnetization of the ferromagnetic thin film.

Structures of -Hydroxy-Type Tetrodotoxin Analogues and Bicyclic Guanidinium Compounds Found in Toxic Newts.

The biosynthesis of tetrodotoxin (TTX, ), a potent neurotoxin widely distributed in marine and terrestrial metazoans, remains unresolved. A significant issue has been identifying intermediates and shunt products associated with the biosynthetic pathway of TTX. We investigated TTX biosynthesis by screening and identifying new TTX-related compounds from and .

Band transport across a chain of dopant sites in silicon over micron distances and high temperatures.

Macroscopic manifestations of quantum mechanics are among the most spectacular effects of physics. In most of them, novel collective properties emerge from the quantum mechanical behaviour of their microscopic constituents. Others, like superconductivity, extend a property typical of the atomic scale to macroscopic length scale.