Easy, efficient and versatile one-pot synthesis of Janus-type-substituted fullerenols

4-Pyridinio-1,4-Dihydropyridines as Calcium Ion Transport Modulators: Antagonist, Agonist, and Dual Action

A set of six new 4-pyridinio-1,4-dihydropyridine (1,4-DHP) compounds has been synthesized. The calcium channel modulating activity of these compounds was evaluated in an aorta vascular smooth muscle cell line (A7R5), in an isolated rat aortic ring model, and in human neuroblastoma cell lines (SH-SY5Y). The antagonistic effect of these 1,4-DHP was tested by modulating the impact of carbachol-dependent mobilization of intracellular Ca²⁺ in SH-SY5Y cells. The intracellular free Ca²⁺ concentration was measured in confluent monolayers of SH-SY5Y cells and A7R5 cells with the Ca²⁺-sensitive fluorescent indicator Fluo-4 NW. Only four compounds showed calcium channel blocking activity in SH-SY5Y and A7R5 cells as well as in the aortic ring model. Among them, compound 3 was the most active calcium channel antagonist, which had 3 times higher activity on carbachol-activated SH-SY5Y cells than amlodipine. Two of the compounds were inactive. Compound 4 had 9 times higher calcium agonist activity than the classic DHP calcium agonist Bay K8644. The intracellular mechanism for the action of compound 4 using inhibitor analysis was elucidated. Nicotinic as well as muscarinic receptors were not involved. Sarcoplasmic reticulum (ER) Ca²⁺ (SERCA) stores were not affected. Ryanodine receptors (RyRs), another class of intracellular Ca²⁺ releasing channels, participated in the agonist response evoked by compound 4. The electrooxidation data suggest that the studied compounds could serve as antioxidants in OS.

Molecular Semiconductor Surfactants with Fullerenol Heads and Colored Tails for Carbon Dioxide Photoconversion

The leaf is a prime example of a material converting waste (CO2 ) into value with maximum sustainability. As the most important constituent, it contains the coupled photosystems II and I, which are imbedded in the cellular membrane of the chloroplasts. Can key functions of the leaf be packed into soap? We present next-generation surfactants that self-assemble into bilayer vesicles (similar to the cellular membrane), are able to absorb photons of two different visible wavelengths, and exchange excited charge carriers (similar to the photosystems), followed by conversion of CO2 (in analogy to the leaf). The amphiphiles contain five dye molecules as the hydrophobic entity attached exclusively to one hemisphere of a polyhydroxylated fullerene (Janus-type). We herein report on their surfactant, optical, electronic, and catalytic properties. Photons absorbed by the dyes are transferred to the fullerenol head, where they can react with different species such as CO2 to give formic acid.