Benzoxanthenone Lignans Related to Carpanone, Polemanone, and Sauchinone: Natural Origin, Chemical Syntheses, and Pharmacological Properties.

Medicinal plants from the genus Saururus are commonly used to treat inflammatory pathologies. They contain numerous bioactive compounds, notably the polycyclic lignan sauchinone from the species Saururus chinensis. An in-depth analysis of benzoxanthenone lignans related to sauchinone, and the analogous products carpanone and polemannones, has been carried out. The review reports the product's isolation, biosynthetic pathway, and chemical strategies to synthesize benzoxanthenones via liquid- and solid-phase syntheses. The metabolic and pharmacokinetic properties of sauchinone are discussed. At the pharmacological level, sauchinone is a potent blocker of the production of pro-inflammatory mediators, such as nitric oxide and prostaglandin E2, and an efficient antioxidant agent. The properties of sauchinone can be exploited to combat multiple pathologies, such as liver injuries, renal dysfunction, osteoarthritis, inflammatory bowel disease, ulcerative colitis, and cancers. The capacity of the natural product to inhibit tumor cell proliferation and to reduce migration/invasion of cancer cells and the development of metastases is underlined, together with the regulation of the epithelial-mesenchymal transition and immune checkpoints. Altogether, the review offers a complete survey of the chemical and biochemical properties of sauchinone-type benzoxanthenones.