Enzymatic Formation of Indole-Containing Unnatural Cyclic Polyprenoids by Bacterial Squalene:Hopene Cyclase
摘要:
[GRAPHICS]Two indole-containing substrate analogues, in which a C-20 isoprene unit is connected to indole (3-(geranylgeranyl)indole and 3-(farnesyldimethylallyl)indole), were synthesized and tested for enzymatic cyclization by squalene:hopene cyclase from Alicyclobacillus acidocaidarius. Interestingly, 3-(geranylgeranyl)indole was not a substrate for the bacterial squalene cyclase, while 3-(farnesyldimethylallyl)indole was efficiently converted to a 2:1 mixture of unnatural novel products.
Enzymatic Formation of Indole-Containing Unnatural Cyclic Polyprenoids by Bacterial Squalene:Hopene Cyclase
摘要:
[GRAPHICS]Two indole-containing substrate analogues, in which a C-20 isoprene unit is connected to indole (3-(geranylgeranyl)indole and 3-(farnesyldimethylallyl)indole), were synthesized and tested for enzymatic cyclization by squalene:hopene cyclase from Alicyclobacillus acidocaidarius. Interestingly, 3-(geranylgeranyl)indole was not a substrate for the bacterial squalene cyclase, while 3-(farnesyldimethylallyl)indole was efficiently converted to a 2:1 mixture of unnatural novel products.
The structure of hippospongic acid A was reinvestigated and new evidence supporting the revised structure previously proposed was obtained. The structure, including absolute configuration, was established by the enantioselective synthesis.
Titanium-Mediated Dehydroxylative Cross-Coupling of Allylic Alcohols with Electron-Deficient Olefins
作者:Liangcai Yao、Jiajing Bao、Yun Wang、Jinghan Gui
DOI:10.1021/acs.orglett.4c00061
日期:2024.2.16
Herein we report a Ti(III)-mediated dehydroxylative cross-couplingreaction of allylicalcohols with electron-deficient olefins. This reaction is amenable to various synthetically versatile allylicalcohols, including geraniol and farnesol, providing a general method for dehydroxylative C–C bond formation. We demonstrated the reaction’s utility by simplifying the syntheses of eight useful building
Synthesis of (6E)-8-Thia- and (14E)-13-Thia-2,3-oxidosqualene: Inhibitors of 2,3-Oxidosqualene-Lanosterol Cyclase
作者:Yi Feng Zheng、Allan C. Oehlschlager、Peter G. Hartman
DOI:10.1021/jo00098a048
日期:1994.9
Synthesis of (6E)-8-thia-2,3-oxidosqualene (22) and (14E)-13-thia-2,3-oxidosqualene (34) as inhibitors of 2,3-oxidosqualene-lanosterol cyclase are reported. Synthesis of 22 required the stereospecific generation of a vinyl sulfide. This was achieved by a new coupling of a benzenethiosulfonate (15) and a lithiated vinyl iodide (18). Synthesis of 34 involved similar coupling of benzenethiosulfonate 29 with lithium reagent obtained from vinyl iodide 33. The required (E)-vinyl iodides 18 and 33 were prepared by zirconium-catalyzed carboalumination of 4-pentyn-1-ol, (16) and 2,6-dimethyl-2(E),6(E)-dien-10-yne (32) respectively. Both 22 and 34 inhibited 2,3-oxidosqualene-lanosterol cyclase from Candida albicans with IC50 values of 0.68 and 45 mu M, respectively.
Enantioselective total synthesis and absolute stereostructure of hippospongic acid A
A compound having the structure proposed for hippospongic acid A, a triterpene that specifically inhibits gastrulation of starfish embryos, was synthesized enantioselectively. The synthetic compound was not identical to the natural product. Comparison of the NMR spectra of the natural and synthetic compounds led us to propose an alternative structure, which was confirmed by enantioselective synthesis. The present synthesis established that the natural product has the (R)-configuration. (C) 2001 Elsevier Science Ltd. All rights reserved.
Enzymatic formation of pyrrole-containing novel cyclic polyprenoids by bacterial squalene:hopene cyclase
A convergent synthesis provided two pyrrole-containing squalene analogues, in which a C(20) isoprene unit is connected to pyrrole, 2-(geranylgeranyl)pyrrole and 2-(farnesyldimethylallyl)pyrrole. When incubated with recombinant squalene:hopene cyclase from Alicyclobacillus acidocaldarius, 2-(farnesyldimethylallyl)pyrrole wits enzymatically converted to a 10: 1 mixture of a tricyclic and a bicyclic unnatural novel polyprenoids, whereas 2-(geranylgeranyl)pyrrole was not a substrate for the enzyme. (c) 2006 Elsevier Ltd. All rights reserved.