Synthesis of Substituted 3(2H)-Furanones Using …

The naturally produced N-acylhomoserine lactones showed a strong non-linear concentration dependent influence on violacein production in C. violaceum with a maximum at 3.7*10-8 M with HHL. Apart from the N-acylhomoserine lactones only one furanone (emoxyfurane) was found to simulate N-acylhomoserine lactone activity and induce violacein formation. The most effective substances acting negatively both on growth and quorum sensing were analogs and intermediates in synthesis of the butenolides from Streptomyces antibioticus.

Synthesis of 4-Halo-3(2H)-furanones Using …

Gold-Catalyzed Synthesis of Furans and Furanones …

Asymmetric synthesis of furanones - ScienceDirect

All bioassays were conducted by DM under the supervision of HB. RB and US assessed the structure-function relationship of the furanones and RB with DM drafted the manuscript. JG performed all synthesis of the natural analogs of Streptomyces antibioticus furanones. US supervised the work of JG and provided the structures and the sterical comparison of the furanones.

Synthesis of 3-mercapto-2(5H)-furanones via reaction …

The complete set of furanone analogs and derivatives illustrated in Figure were tested for activation and inhibition of the quorum sensing system of C. violaceum CV026, as demonstrated before for compound 3.31 in Figure . For comparison with the natural inducers, the long chain DHL (compound 23) was included as test compound. The data are summarized in Table . Synthesized furanones or intermediates from synthesis, which were not soluble in water, were not tested for biological activities and are not listed in Table . Activation of quorum sensing gives the effect on violacein production at 10-4 M in the absence of HHL (Column 1); 0 means no violacein compared to the blank, 1 is equal to the effect of 3.7*10-8 M HHL. Activation of the CV026 violacein formation was negative for all furanones, except for #12, which resulted in a slight stimulation. Effects on growth are seen in the change in turbidity at 10-2 M (Column 2); 1 is equal to the control with no additions. Some furanones were toxic at 10-2 M. Turbidity dropped to 40 to 60 % of the control in the presence of 10-2 M of the compounds 3.31, 3.32, 4.31, 4.32, 3.51, 13, 18, 19 or 22. Some compounds induced an increase in absorption compared to the control (3.01, 3.02, 12, DHL). It may be that these were degraded by CV026 and stimulated growth by acting as additional carbon source. For two activators, #12 and the long chain DHL, this increase in absorption was partially due to the simultaneous induction of violacein formation as the assays turned purple. Inhibition was tested at a compound concentration of 10-4 M in the presence of either 3.7*10-8 M HHL (column 3) or 10-6 M HHL (column 4); setting the effect of these concentrations to 1 in the absence of the added compound. All furanones including compound DHL (see also Fig. ) inhibited violacein formation at 10-4 M in the presence of optimum HHL concentration (column 3). The inhibition ranged from a few percent for #19, 15, 8 and 11, to 70 to 80% for #3.01, 4.01, 3.11, 3.31 and 12. Interestingly, the same experiment at an elevated HHL concentration of 10-6 M (column 4) resulted in different inhibitory effects for some furanones; it could both be larger (e.g. #3.22, 4.22, or 3.02) or smaller (e.g. #3.41, 3.01, or 4.51) compared to the ones shown in column 3. Enhanced expression gives the effect on violacein production by 10-5 M furanones at a suboptimal HHL concentration of 4.6*10-9 M, (Column 5); 1 is equal to the control lacking an addition. These data indicate whether a compound acted cooperatively with HHL present at a suboptimal concentration (4.6*10-9 M) and enhanced expression of violacein. Obviously quite a few furanones acted synergistically with limiting HHL and stimulated violacein formation.

"Total synthesis of the natural furanones " by Zhiwen …

As the regulation of many bacterial processes is governed by quorum sensing systems, the finding of natural and synthetic furanones acting as agonists or antagonists suggests an interesting tool to control and handle detrimental AHL induced effects.

Synthesis of 4-substituted-3(2H)-furanones with ..

Cell to cell signaling systems in Gram-negative bacteria rely on small diffusible molecules such as the N-acylhomoserine lactones (AHL). These compounds are involved in the production of antibiotics, exoenzymes, virulence factors and biofilm formation. They belong to the class of furanone derivatives which are frequently found in nature as pheromones, flavor compounds or secondary metabolites. To obtain more information on the relation between molecular structure and quorum sensing, we tested a variety of natural and chemically synthesized furanones for their ability to interfere with the quorum sensing mechanism using a quantitative bioassay with Chromobacterium violaceum CV026 for antagonistic and agonistic action. We were looking at the following questions:

Effects of natural and chemically synthesized furanones …

In recent years, furan-2(5H)-ones have attracted considerable attention as synthetic target. This subunit is present in a large number of natural products, which display a wide range of biological activities, and is present in a number of drugs with diverse biological activities, such as antifungal, antibacterial and anti-inflammatory. It can also be used as synthetic intermediate. This review describes recent synthetic methodologies for preparation of furan-2(5H)-ones, as well as their application in the total synthesis of natural products with this subunit.