Two Approaches to the Aromatic Core of the Aminonaphthoquinone Antibiotics
作者:Christopher C. Nawrat、Leoni I. Palmer、Alexander J. Blake、Christopher J. Moody
DOI:10.1021/jo400737f
日期:2013.6.7
Two complementary approaches are presented for the synthesis of the quinone chromophores of the naphthoquinone ansamycins and related natural products. The first involves the use of an improved protocol for the manganese(III) acetate mediated cyclization of 5-aryl-1,3-dicarbonyl compounds to β-naphthols, leading to the simple, scalable preparation of building blocks suitable for the synthesis of naturally
We have synthesized an analog 4 containing a cyclopropanated quinol skeleton and examined its ability to inhibit NF-κB. Surprisingly, 4 showed no remarkable NF-κB inhibitory activity as determined through expression of cyclooxygenase-2 (COX-2) in an RAW264.7 macrophage cell line.
Synthesis of the Antitumor Antibiotic LL-C10037.alpha.
作者:Peter Wipf、Yuntae Kim
DOI:10.1021/jo00092a004
日期:1994.7
(+/-)-LL-C10037 alpha and its C(4)-epimer were prepared in nine steps from 2,5-dimethoxyaniline. The concise synthetic route represents the first synthesis of this highly functionalized antitumor antibiotic and is useful for the preparation of analogs of the putative pharmacophore of the Ras farnesyltransferase inhibitor manumycin.
We have developed a highly convergent synthesis of the manumycin-type m-C7N-antibiotic nisamycin that is applicable to other members of this family of antibiotics. The synthesis features a three-step sequence to the epoxyquinol core that serves as a scaffold for the attachment of the polyene side chains. The eastern polyene side chain was constructed via a novel organozirconocene-mediated synthesis. Zirconocene methodology was also applied to the synthesis of the polyene side chains of asukamycin. The southern side chain of nisamycin was introduced via a Stille reaction that employed a vinyl bromo ketone, derived from an acid-sensitive bromo ketal. Pd-mediated coupling of the vinyl bromide with a stannyl TIPS ester gave TIPS-protected nisamycin that was readily converted to the natural product.
A new NF-κB inhibitor based on the amino-epoxyquinol core of DHMEQ
The amino-epoxyquinols 6a and 6b were synthesized as soluble derivatives of an NF-kappa B inhibitor DHMEQ (1). In spite of the opposite configuration from 1, 6b rather than 6a affected the deactivation of NF-kappa B, based on NO secretion and MALDI-TOF MS analysis. It was indicated that 6b inhibited the activation by different manner from that of 1. (C) 2010 Elsevier Ltd. All rights reserved.