19462-13-6Relevant articles and documents
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Wallis,Fernholz
, p. 1504 (1935)
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On the importance of the pore inner cavity for the ionophoric activity of 1,3-alternate calix[4]arene/steroid conjugates
Izzo, Irene,Maulucci, Nakia,Martone, Cristina,Casapullo, Agostino,Fanfoni, Lidia,Tecilla, Paolo,De Riccardis, Francesco
, p. 5385 - 5391 (2006)
1,3-Alternate calix[4]arenes, decorated with four nonpolar 'all-trans' tetracyclic nuclei and cation-stabilizing β-methoxyethoxy appendages, were synthesized from commercially available starting materials and through straightforward functional groups tran
Naturally occurring marine steroid 24-methylenecholestane-3β,5α,6β,19-tetraol functions as a novel neuroprotectant
Leng, Tiandong,Liu, Ailing,Wang, Youqiong,Chen, Xinying,Zhou, Shujia,Li, Qun,Zhu, Wenbo,Zhou, Yuehan,Su, Xingwen,Huang, Yijun,Yin, Wei,Qiu, Pengxin,Hu, Haiyan,Xiong, Zhi-Gang,Zhang, Jingxia,Yan, Guangmei
, p. 96 - 105 (2016)
Steroids have been shown to have multiple effects on the nervous system including neuroprotective activities, and they have the potential to be used for the treatment of neurodegenerative diseases. In this current study, we tested the hypothesis that the marine steroid 24-methylenecholestane-3β,5α,6β,19-tetraol (Tetrol) has a neuroprotective effect. (1) We synthesized Tetrol through a multiple step reaction starting from hyodeoxycholic acid (HDCA). (2) We then evaluated the neuroprotective effect of Tetrol with a glutamate-induced neuronal injury model in vitro. Tetrol concentration dependently increased the survival rate of cerebellar granule neurons challenged with toxic concentration of glutamate. Consistently, Tetrol significantly decreased glutamate-induced lactate dehydrogenase (LDH) release with a threshold concentration of 2.5 μM. (3) We further evaluated the neuroprotective effect of Tetrol in a middle cerebral artery occlusion (MCAO)-induced cerebral ischemia model in rat. Tetrol, at a dose of 12 mg/kg, significantly decreased MCAO-induced infarction volume by ～50%. (4) Finally, we probed the mechanism and found that Tetrol concentration dependently attenuated N-methyl-d-aspartate (NMDA)-induced intracellular calcium ([Ca2+]i) increase with an IC50 of 7.8 ± 0.62 μM, and inhibited NMDA currents in cortical neurons with an IC50 of 10.28 ± 0.71 μM. Taken together, we have synthesized and characterized Tetrol as a novel neuroprotectant through negative modulation of NMDA receptors.
Decarboxylative alkenylation
Edwards, Jacob T.,Merchant, Rohan R.,McClymont, Kyle S.,Knouse, Kyle W.,Qin, Tian,Malins, Lara R.,Vokits, Benjamin,Shaw, Scott A.,Bao, Deng-Hui,Wei, Fu-Liang,Zhou, Ting,Eastgate, Martin D.,Baran, Phil S.
, p. 213 - 218 (2017/05/19)
Olefin chemistry, through pericyclic reactions, polymerizations, oxidations, or reductions, has an essential role in the manipulation of organic matter. Despite its importance, olefin synthesis still relies largely on chemistry introduced more than three decades ago, with metathesis being the most recent addition. Here we describe a simple method of accessing olefins with any substitution pattern or geometry from one of the most ubiquitous and variegated building blocks of chemistry: alkyl carboxylic acids. The activating principles used in amide-bond synthesis can therefore be used, with nickel- or iron-based catalysis, to extract carbon dioxide from a carboxylic acid and economically replace it with an organozinc-derived olefin on a molar scale. We prepare more than 60 olefins across a range of substrate classes, and the ability to simplify retrosynthetic analysis is exemplified with the preparation of 16 different natural products across 10 different families.
