O-Methylviridicatin is a natural derivative of the alkaloid mycotoxin Viridicatin produced by several species of Penicillium. The scaffold of quinolin-2(1H)-one is a useful structural motif found in many natural products. In particular, derivatives of 4-arylquinolinones have attracted attention for their anticancer/antiviral activities. O-Methylviridicatin is a fungal metabolite that can inhibit the tumor necrosis factor alpha (TNFα)-induced replication of HIV.
O-Methylviridicatin is soluble in ethanol, methanol, DMSO and DMF but is practically insoluble in water.
During a high-throughput, cell-based, virus-free assay screening system, 15,000 fungal extracts were screened and the metabolite 3-O-Methylviridicatin was shown to be an inhibitor of cytokine tumour necrosis factor alpha (TNFα)-induced replication of HIV. This factor activates transcription of the provirus in both T-cells and macrophages. It blocked TNF- α activation of the HIV long terminal repeat (LTR) in a HeLa-based system (IC50 =5 µM), and inhibited HIV replication in OM-10.1 cell line, which are HL-60 promyelocytes infected with HIV-1, which is a model of TNF-α-induced chronic infection (IC50 =2.5µM)(Heguy et al, 1998).
The synthesis of O-Methylviridicatin and its several analogs have shed insights into the development of new anti-inflammatory agents. In particular, 4-phenyl-3-methylthioquinolinone had an enhanced ability to inhibit TNF-α-secretion (Sun et al, 2015).
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