Novel ethanocycloheptono [3,4,5-kl]benzo[a]xanthene induces apoptosis in BEL-7402 cells

Oxidation of BINOLs by Hypervalent Iodine Reagents: Facile Synthesis of Xanthenes and Lactones

Xanthene derivatives have broad applications in medicines, fluorescent probes, dyes, food additives, etc. Therefore, much attention was focused on developing the synthetic methods to prepare these compounds. Binaphthyl‐based xanthene derivatives were prepared through the oxidation of BINOLs promoted by the hypervalent iodine reagent iodosylbenzene (PhIO). Nine‐membered lactones were obtained through a similar oxidative reaction when iodoxybenzene (PhIO₂) was used. Additionally, one‐pot reactions of BINOLs, PhIO and nucleophiles such as alcohols and amines were also investigated to provide alkoxylated products and amides in good to excellent yields.

Xanthenes in Medicinal Chemistry - Synthetic strategies and biological activities

BACKGROUND

Xanthenes are a special class of oxygen-incorporating tricyclic compounds. Structurally related to xanthones, the presence of different substituents in position 9 strongly influences their physical and chemical properties, as well as their biological applications. This review explores the synthetic methodologies developed to obtain 9H-xanthene, 9-hydroxyxanthene and xanthene-9-carboxylic acid, as well as respective derivatives, from simple starting materials or through modification of related structures. Azaxanthenes, bioisosteres of xanthenes, are also explored. Efficiency, safety, ecological impact and applicability of the described synthetic methodologies are discussed. Synthesis of multi-functionalized derivatives with drug-likeness properties are also reported and their activities explored. Synthetic methodologies for obtaining (aza)xanthenes from simple building blocks are available, and electrochemical and/or metal free procedures recently developed arise as greener and efficient methodologies. Nonetheless, the synthesis of xanthenes through the modification of the carbonyl in position 9 of xanthones represents the most straightforward procedure to easily obtain a variety of (aza)xanthenes. (Aza)xanthene derivatives displayed biological activity as neuroprotector, antitumor, antimicrobial, among others, proving the versatility of this nucleus for different biological applications. However, in some cases their chemical structures suggest a lack of pharmacokinetic properties being associated with safety concerns, which should be overcome if intended for clinical evaluation.

Structure-Bioactivity Relationship Study of Xanthene Derivatives: A Brief Review

Over the last decades, several heterocyclic derivatives compounds have been synthesized or extracted from natural resources and have been tested for their pharmaceutical activities. Xanthene is one of these heterocyclic derivatives. These compounds consist of an oxygen-containing central heterocyclic structure with two more cyclic structures fused to the central cyclic compound. It has been shown that xanthane derivatives are bioactive compounds with diverse activities such as anti-bacterial, anti-fungal, anti-cancer, and anti-inflammatory as well as therapeutic effects on diabetes and Alzheimer. The anti-cancer activity of such compounds has been one of the main research fields in pharmaceutical chemistry. Due to this diverse biological activity, xanthene core derivatives are still an attractive research field for both academia and industry. This review addresses the current finding on the biological activities of xanthene derivatives and discussed in detail some aspects of their structure-activity relationship (SAR).