Neuroligin (NLG), a postsynaptic adhesion molecule, is involved in the formation of synapses by binding to a cognate presynaptic ligand, neurexin. Here we report that neuroligin-1 (NLG1) undergoes ectodomain shedding at the juxtamembrane stalk region to generate a secreted form of NLG1 and a membrane-tethered C-terminal fragment (CTF) in adult rat brains in vivo as well as in neuronal cultures. Pharmacological and genetic studies identified ADAM10 as the major protease responsible for NLG1 shedding, the latter being augmented by synaptic NMDA receptor activation or interaction with soluble neurexin ligands. NLG1-CTF was subsequently cleaved by presenilin/γ-secretase. Secretion of soluble NLG1 was significantly upregulated under a prolonged epileptic seizure condition, and inhibition of NLG1 shedding led to an increase in numbers of dendritic spines in neuronal cultures. Collectively, neuronal activity-dependent proteolytic processing of NLG1 may negatively regulate the remodeling of spines at excitatory synapses.

The first asymmetric total synthesis of lepenine has been accomplished. The synthesis features a tethered intramolecular Diels-Alder reaction, an intramolecular Mannich reaction, and a Diels-Alder reaction between an ortho-quinone monoketal and ethylene, resulting in stereoselective construction of the unique hexacyclic system.

An efficient deborylthiolation of aryl- and alkenylborons with thiosulfonates has been achieved under mild conditions using a copper catalyst. All steps of the experimental process were free from unpleasant odors. The mild reaction conditions as well as ready availability of boron compounds and thiosulfonates enabled easy access to an array of sulfides, including those bearing sensitive functional groups.

A facile synthetic method for unsymmetrical tertiary phosphine oxides is reported. Sequential treatment of phosphonodithioic acid S,S-di(p-tolyl) esters with two Grignard reagents enabled the stepwise introduction of different carbon substituents on the phosphorus atom. The chemical stability of dithioesters and monosubstituted thioesters has enhanced the utility of this method, rendering a wide range of organophosphorus compounds easily available.