Cytotoxic arylbenzofuran and stilbene derivatives from the twigs of Artocarpus heterophyllus

Stilbenes: Source plants, chemistry, biosynthesis, pharmacology, application and problems related to their clinical Application-A comprehensive review

Stilbenes are some of the important phenolic compounds originating from plant families like Vitaceae, Leguminaceae, Gnetaceae, and Dipterocarpaceae. Structurally, they have a C6-C2-C6 skeleton, usually with two isomeric forms. Stilbenes are biosynthesized due to biotic and abiotic stresses such as microbial infections, high temperatures, and oxidation. This review aims to provide a comprehensive overview of stilbenes' botanical sources, chemistry, biosynthetic pathways, pharmacology, and clinical applications and challenges based on up-to-date data. All included studies were collected from PubMed, ScienceDirect, Google Scholar, and CNKI, and the presented data from these indexed studies were analyzed and summarized. A total of 459 natural stilbene compounds from 45 plant families and 196 plant species were identified. Pharmacological studies also show that stilbenes have various activities such as anticancer, antimicrobial, antioxidant, anti-inflammatory, anti-degenerative diseases, anti-diabetic, neuroprotective, anti-aging, and cardioprotective effects. Stilbene synthase (STS) is the key enzyme involved in stilbene biosynthetic pathways. Studies on the therapeutic application of stilbenes pinpoint that challenges such as low bioavailability and isomerization are the major bottlenecks for their development as therapeutic drugs. Although the medicinal uses of several stilbenes have been demonstrated in vivo and in vitro, studies on the development of stilbenes deserve more attention in the future.

Prenylated coumarins from the fruits of Artocarpus heterophyllus with their potential anti-inflammatory and anti-HIV activities

A phytochemical investigation on the fruits of Artocarpus heterophyllus led to the isolation and characterisation of a new prenylated coumarin, artoheteronin (1), together with six known analogues (2-7). The chemical structure of 1 was elucidated using extensive spectral methods and the known compounds (2-7) were identified by comparing their spectral data with those reported in the literature. All known compounds (2-7) were isolated from the genus Artocarpus for the first time. The anti-inflammatory and anti-HIV activities of all isolated prenylated coumarins (1-7) were assessed in vitro. As a result, compounds 1-7 displayed notable inhibitory effects against nitric oxide (NO) production induced by lipopolysaccharide in mouse macrophage RAW 264.7 cells in vitro with the IC₅₀ values in range of 0.58 ± 0.06 to 6.29 ± 0.12 μM. Meanwhile, compounds 1-7 exhibited notable anti-HIV-1 reverse transcriptase (RT) activities possessing EC₅₀ values in the range of 0.18 to 9.12 µM.

Synthesis and biological activity of new bisbenzofuran-imidazolium salts

A series of novel bisbenzofuran-imidazolium salts were designed and prepared. The in vitro antitumor activity of these derivatives was evaluated against a panel of human tumor cell lines (A549, HL-60, MCF-7, SMMC-7721 and SW480). Results demonstrated that 2-methyl-benzimidazole ring and substitution of the imidazolyl-3-position with a 4-methoxyphenacyl or 2-naphthylacyl substituent were important for promoting cytotoxic activity. Notably, compound 23 was found to be the most potent compound with IC₅₀ values of 0.64-1.47 μM against five human tumor cell lines, and exhibited higher selectivity to MCF-7 and SW-480 cell lines with IC₅₀ values 15.3-fold and 9.1-fold lower than DDP.

Natural source, bioactivity and synthesis of benzofuran derivatives

Benzofuran compounds are a class of compounds that are ubiquitous in nature. Numerous studies have shown that most benzofuran compounds have strong biological activities such as anti-tumor, antibacterial, anti-oxidative, and anti-viral activities. Owing to these biological activities and potential applications in many aspects, benzofuran compounds have attracted more and more attention of chemical and pharmaceutical researchers worldwide, making these substances potential natural drug lead compounds. For example, the recently discovered novel macrocyclic benzofuran compound has anti-hepatitis C virus activity and is expected to be an effective therapeutic drug for hepatitis C disease; novel scaffold compounds of benzothiophene and benzofuran have been developed and utilized as anticancer agents. Novel methods for constructing benzofuran rings have been discovered in recent years. A complex benzofuran derivative is constructed by a unique free radical cyclization cascade, which is an excellent method for the synthesis of a series of difficult-to-prepare polycyclic benzofuran compounds. Another benzofuran ring constructed by proton quantum tunneling has not only fewer side reactions, but also high yield, which is conducive to the construction of complex benzofuran ring systems. This review summarizes the recent studies on the various aspects of benzofuran derivatives including their important natural product sources, biological activities and drug prospects, and chemical synthesis, as well as the relationship between the bioactivities and structures.

Two new 2-arylbenzofurnan derivatives from the leaves of Morus alba

Two new 2-arylbenzofuran derivatives, moracinfurol A and B (1-2), and ten known compounds (3-12) were isolated from the leaves of Morus alba. Their structures were determined on the basis of spectroscopic analysis including 1D, 2D NMR and HR-ESI-MS. All of the 2-arylbenzofuran derivatives were evaluated for cytotoxicity against A549 cells. Some cytotoxic 2-arylbenzofuran derivatives might induce autophagy characterized by the accumulation of LC-3 Ⅱ.