70424-09-8Relevant articles and documents
Isolation of 2-Alkyl-4-quinolones with Unusual Side Chains from a Chinese Pseudomonas aeruginosa Isolate
Li, Jianye,Sun, Weiwei,Saalim, Muhammad,Wei, Guixiang,Zaleta-Pinet, Diana A.,Clark, Benjamin R.
supporting information, p. 2294 - 2298 (2020/07/14)
Chemical investigation of a Pseudomonas aeruginosa strain isolated from Hebei, China, led to the isolation of a suite of quinolones, quinolone-N-oxides, and phenazines, the structures of which were elucidated by detailed spectroscopic analysis. Most notable among the secondary metabolites isolated was an unprecedented 4-quinolone containing an S-methyl group in the side chain and a new derivative including a phenyl ring in the side chain, which expand significantly the variety of structural motifs found in the quinolones and raise interesting questions about their biosynthesis.
Lepadins I-K, 3- O-(3′-Methylthio)acryloyloxy-decahydroquinoline Esters from a Bahamian Ascidian Didemnum sp. Assignment of Absolute Stereostructures
ómarsdóttir, Sesselja,Wang, Xiao,Liu, Hong-Bing,Duggan, Brendan M.,Molinski, Tadeusz F.
, p. 13670 - 13677 (2018/11/10)
Three decahydroisoquinoline alkaloids, lepadins I-K, were isolated from a specimen of Didemnum sp. collected in the Bahamas. The structures of the new compounds were assigned by an integrated analysis of MS, IR, and 1H, 13C, and 2D NMR spectra. Like previously reported lepadins, the structures of the new compounds contain a decahydroquinoline heterocyclic core in lepadin I, and a new variation, an octahydroquinoline in lepadin J, but differ from earlier reported compounds by acylation of the 3-hydroxyl group by a rare 3′-methylthioacrylate. The absolute configuration of lepadin I was solved by interpretation of NOE measurements, and exciton coupled circular dichroism (ECCD) of the corresponding N-p-bromobenzoyl derivative. The latter constitutes a general method for determination of absolute configuration of the entire lepadin family. The configuration of the remote side-chain secondary carbinol was solved by the modified Mosher's esters method. Lepadin I inhibited butyrylcholineesterase (BuChE, IC50 3.1 μM), but only weakly inhibited acetylcholineesterase (AChE) (10% at 100 μM).
The Synthesis and Absolute Configuration of the Novel Ichthyotoxic Diacylglycerols, Umbraculumin A and Umbraculumin C
Medeiros, Edna Faria De,Herbert, John M.,Taylor, Richard J. K.
, p. 2725 - 2730 (2007/10/02)
The total syntheses of umbraculumin A 1 and umbraculumin C 2 in homochiral form are described.Noteworthy steps involve (i) the preparation of the key Z,E-acid 10 by organolithium addition to pyrylium salts, (ii) the use of the 4-methoxyphenylmethyl protecting group for the preparation of 1,2-diacyl glycerols and its removal using trifluoroacetic acid-anisole without significant acyl migration (DDQ removal having proved inefficient) and (iii) a new procedure for the stereoselective preparation of (Z)- and (E)-3-methylthiopropenoic acid.
