violacein

Violacein is a bacterial metabolite originally isolated from C. violaceum that has antibacterial and antiprotozoal activities.[1] [2] It is produced by C. violaceum as a purple pigment in response to N-hexanoyl homoserine lactone , a property that has been modified to create a strain of C. violaceum used in detecting quorum-sensing molecules.[3] Violacein is active against Gram-positive bacteria, including B. subtilis and S. aureus (MICs = 0.8 and 1.6 µM, respectively). It is also active against P. falciparum, including chloroquine-susceptible and -resistant strains (IC50s = 0.85 and 0.63 µM, respectively).[2] It reduces parasitemia in a mouse model of nonlethal P. chabaudi chabaudi infection when administered at a dose of 7.5 mg/kg and increases survival in a mouse model of lethal P. chabaudi chabaudi infection. Violacein permeabilizes the cytoplasmic membrane of bacterial cells but does not affect the cell wall.[1]

Deoxyviolacein is a bacterial metabolite and byproduct in the biosynthesis of the bisindole alkaloid violacein that has anticancer, antibacterial, and antifungal properties. It inhibits proliferation of hepatocellular carcinoma cells when used at concentrations ranging from 0.1 to 1 μM. Deoxyviolacein (125 μg ml) has antibacterial activity against Gram-positive bacteria, including S. aureus, B. subtilis, and B. megaterium. It also has antifungal activity against R. solani when used at a concentration of 2 mg ml.

N-Acetyltyramine 是一种群体感应抑制剂，由溶藻弧菌 M3-10 产生。N-Acetyltyramine 可以抑制C. violaceumATCC 12472 的群体感应。它可以逆转阿霉素耐药白血病 P388 细胞的耐药性。

Quorum sensing is a regulatory system used by bacteria for controlling gene expression in response to increasing cell density. Controlling bacterial infections by quenching their quorum sensing systems is a promising field of study. The expression of specific target genes, such as transcriptional regulators belonging to the LuxIR family of proteins, is coordinated by synthesis of diffusible acylhomoserine lactone (AHL) molecules. N-butyryl-L-Homocysteine thio-lactone is an analog of N-butyryl-L-homoserine lactone, the small diffusible signaling molecule involved in quorum sensing, thereby controlling gene expression and cellular metabolism. N-butyryl-L-Homocysteine thio-lactone induces violacein expression in C. violaceum mutants usually not able to produce AHLs.

Aculene D, 一种真菌代谢物，针对Chromobacterium violaceum CV026表现出群体感应(QS)抑制活性。该化合物能在亚抑制浓度下，显著削减由N-己酰基-l-高丝氨酸内酯(C6-HSL)触发的C. violaceum CV026培养物中紫罗兰素的产生。