120-08-1Relevant articles and documents
Lamellarins as inhibitors of P-glycoprotein-mediated multidrug resistance in a human colon cancer cell line
Plisson, Fabien,Huang, Xiao-Cong,Zhang, Hua,Khalil, Zeinab,Capon, Robert J.
, p. 1616 - 1623 (2012)
Chemical analysis of a Didemnum sp. (CMB-01656) collected during scientific Scuba operations off Wasp Island, New South Wales, yielded five new lamellarins A1 (1), A2 (2), A3 (3), A4 (4) and A5 (5) and eight known lamellarins C (6), E (7), K (8), M (9), S (10), T (11), X (12) and χ (13). Analysis of a second Didemnum sp. (CMB-02127) collected during scientific trawling operations along the Northern Rottnest Shelf, Western Australia, yielded the new lamellarin A6 (14) and two known lamellarins G (15) and Z (16). Structures were assigned to 1-16 on the basis of detailed spectroscopic analysis with comparison to literature data and authentic samples. Access to this unique library of natural lamellarins (1-16) provided a rare opportunity for structure-activity relationship (SAR) investigations, probing interactions between lamellarins and the ABC transporter efflux pump P-glycoprotein (P-gp) with a view to reversing multidrug resistance in a human colon cancer cell line (SW620 Ad300). These SAR studies, which were expanded to include the permethylated lamellarin derivative (17) and a series of lamellarin-inspired synthetic coumarins (19-24) and isoquinolines (25-26), successfully revealed 17 as a promising new non-cytotoxic P-gp inhibitor pharmacophore. Copyright
Psoralen and coumarin photochemistry in HSA complexes and DMPC vesicles
Chen,Rinco,Popov,Vuong,Johnston, Linda J.
, p. 31 - 37 (2006)
The photochemistry and photophysics of several psoralens and coumarins have been examined in human serum albumin (HSA) complexes and dimyristoylphosphatidylcholine (DMPC) vesicles. Fluorescence spectroscopy indicates that there are multiple binding sites with polarities that are intermediate between those of acetonitrile and water for the substrates complexed to HSA. In the case of the 6,7-dimethoxycoumarin-HSA complex, laser flash photolysis experiments provide evidence for the formation of radical cation in addition to triplet. Radical cations are not detected for other coumarin-HSA complexes, either due to a lower yield of formation or to rapid reaction of an initial radical cation with adjacent amino acids. Fluorescence spectra for coumarins indicate that they are primarily solubilized in the polar headgroup region in DMPC vesicles. Consistent with this, radical cations generated by photoionization are detected in transient experiments. For dimethoxycoumarins the radical cation is long-lived, indicating rapid exit from the vesicle and decay in the aqueous phase. However, 4,5′,8- trimethylpsoralen and 7-ethoxy-4-hexadecylcoumarin radical cations are much shorter-lived, presumably due to rapid decay by electron recombination in the vesicle. The results for both HSA complexes and vesicles indicate that radical ions may play a role in psoralen and coumarin photochemistry in a cellular environment.
Cascade synthesis of 3-alkenylcoumarins by palladium-catalyzed reaction of phenols and ethyl propiolate
Kitamura, Tsugio,Tatemoto, Kotaro,Sakai, Mariko,Oyamada, Juzo
, p. 705 - 707 (2012)
A highly effective cascade process giving 3-alkenylcoumarins is furnished by a series of reactions involving palladaarylation of ethyl propiolate with phenols, intramolecular transesterification to 3-coumarylpalladium species, its alkyne insertion, and protonation. [Pd(OAc)2(dppe)] is an effective catalyst for the synthesis of 3-alkenylcoumarins from phenols and ethyl propiolate.
A Convenient Synthesis of a Simple Coumarin from Salicylaldehyde and Wittig Reagent (I): A Synthesis of Methoxy- and Hydroxycoumarins
Harayama, Takashi,Katsuno, Keiko,Nishioka, Hiromi,Fujii, Masako,Nishita, Yoshitaka,et al.
, p. 613 - 622 (1994)
Reaction of methoxy- and hydroxysalicylaldehydes (1) with phosphorane in diethylaniline under reflux gave only coumarins (3) in high yields except for 3-methoxysalicylaldehyde (1b).It was clarified that methoxy group(s) at C4 and C6 on 1 facilitated the formation of 3.
13C NMR SPECTRA AND STRUCTURE OF BUNGEIDIOL AND ITS TRASFORMATION PRODUCTS
Abyshev, A. Z.,Zmeikov, V. P.
, p. 270 - 276 (1982)
The results are given of a study of the 13C NMR spectra of the new terpenoid coumarin bungeidiol (I) and of the products of its transformation (II) and (III) and some model compounds (IV-VII).On the basis of the results obtained from these 13C NMR spectra and with the use of additive contributions depending on the nature and positions of various substituents (hydroxy and methoxy groups) in the aromatic ring, the structure (I) has been confirmed and a complete assignmant of the signals of all the carbon atoms both in the coumarin ring and in the aliphatic part of the molecule of (I) has been made.
Anchimerically Assisted Selective Cleavage of Acid-Labile Aryl Alkyl Ethers by Aluminum Triiodide and N, N-Dimethylformamide Dimethyl Acetal
Sang, Dayong,Yue, Huaxin,Zhao, Zhengdong,Yang, Pengtao,Tian, Juan
, p. 6429 - 6440 (2020/07/14)
Aluminum triiodide is harnessed by N,N-dimethylformamide dimethyl acetal (DMF-DMA) for the selective cleavage of ethers via neighboring group participation. Various acid-labile functional groups, including carboxylate, allyl, tert-butyldimethylsilyl (TBS), and tert-butoxycarbonyl (Boc), suffer the conditions intact. The method offers an efficient approach to cleaving catechol monoalkyl ethers and to uncovering phenols from acetal-type protecting groups such as methoxymethyl (MOM), methoxyethoxymethyl (MEM), and tetrahydropyranyl (THP) chemoselectively.
Escoparone chemical whole synthetic method
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Paragraph 0032; 0042-0044; 0045; 0055-0057, (2019/05/15)
The invention discloses escoparone chemical whole synthetic method, which belongs to the technical field of chemical synthesis, escoparone chemical full-synthetic method is 2, 4, 5 - trimethoxybenzaldehyde de-methyl generating 4 - dihydroxy - 5 - methoxybenzaldehyde; 4 - dihydroxy - 5 - methoxy benzaldehyde with malonic acid to generate the cyclization reaction to produce the 3 - carboxyl scopolamine lactone; 3 - carboxyl scopolamine lactone by microwave auxiliary decarboxylative generating scopolamine lactone; scopolamine lactone by methylation get escoparone, aims to solve the low efficiency of the plant extract, the disadvantage of low yield and the synthetic yield is low, high cost, is not suitable for the industrial application of the shortcomings.
