Asymmetric total synthesis of three stereoisomers of (−)-renieramycin G and their cytotoxic activities

Phytochemical compounds for treating hyperuricemia associated with gout: a systematic review

Gout is a prevalent metabolic disorder characterized by increased uric acid (UA) synthesis or decreased UA clearance from the bloodstream, leading to the formation of urate crystals in joints and surrounding tissues. Hyperuricemia (HUA), the underlying cause of gout, poses a growing challenge for healthcare systems in developed and developing countries. Currently, the most common therapeutic approaches for gouty HUA primarily involve the use of allopathic or modern medicine. However, these treatments are often accompanied by adverse effects and may not be universally effective for all patients. Therefore, this systematic review aims to provide a comprehensive outline of phytochemical compounds that have emerged as alternative treatments for HUA associated with gout and to examine their specific mechanisms of action. A systematic search was conducted to identify phytochemicals that have previously been evaluated for their effectiveness in reducing HUA. From a review of > 800 published articles, 100 studies reporting on 50 phytochemicals associated with the management of HUA and gout were selected for analysis. Experimental models were used to investigate the effects of these phytochemicals, many of which exhibited multiple mechanisms beneficial for managing HUA. This review offers valuable insights for identifying and developing novel compounds that are safer and more effective for treating HUA associated with gout.

Streamlined modular synthesis of saframycin substructure via copper-catalyzed three-component assembly and gold-promoted 6-endo cyclization

The integration of copper(I)-catalyzed three-component coupling with gold(I)-mediated 6-endo cyclization streamlines the rapid and modular assembly of the substructure of bis-tetrahydroisoquinoline (THIQ) alkaloids. The design of the key synthetic intermediate bearing a 2,3-diaminobenzofuran moiety allows both gold(I)-mediated regiocontrolled 6-endo hydroamination and temporary protection of nitrile and phenolic hydroxy groups. The synthetic strategy enabled the efficient synthesis of the substructure of saframycins bearing isoquinoline and THIQ units in just four steps from the modular assembly of the three components. We also found the unexpected involvement of a fluorescent intermediate in the cascade synthetic process.

Recent advances in the synthesis and activity of analogues of bistetrahydroisoquinoline alkaloids as antitumor agents

Ecteinascidin 743 (Et-743), also known by the trade name Yondelis®, is the pioneering marine natural product to be successfully developed as an antitumor drug. Moreover, it is the first tetrahydroisoquinoline natural product used clinically for antitumor therapy since Kluepfel, a Canadian scientist, discovered the tetrahydroisoquinoline alkaloid (THIQ) naphthyridinomycin in 1974. Currently, almost a hundred natural products of bistetrahydroisoquinoline type have been reported. Majority of these bistetrahydroisoquinoline alkaloids exhibit diverse pharmacological activities, with some family members portraying potent antitumor activities such as Ecteinascidins, Renieramycins, Saframycins, Jorumycins, among others. Due to the unique chemical structure and exceptional biological activity of these natural alkaloids, coupled with their scarcity in nature, research seeking to provide material basis for further bioactivity research through total synthesis and obtaining compound leads with medicinal value through structural modification, remains a hot topic in the field of antitumor drug R&D. Despite the numerous reviews on the total synthesis of bistetrahydroisoquinoline natural products, comprehensive reviews on their structural modification are apparently scarce. Moreover, structural modification of bioactive natural products to acquire lead compounds with improved pharmaceutical characteristics, is a crucial approach for innovative drug discovery. This paper presents an up-to-date review of both structural modification and activity of bistetrahydroisoquinoline natural products. It highlights how such alkaloids can be used as antitumor lead compounds through careful chemical modifications. This review offers valuable scientific references for pharmaceutical chemists engaged in developing novel antitumor agents based on such alkaloid modifications, as well as those with such a goal in future.

Recent Advances in the Total Synthesis of the Tetrahydroisoquinoline Alkaloids (2002-2020)

The tetrahydroisoquinoline (THIQ) natural products constitute one of the largest families of alkaloids and exhibit a wide range of structural diversity and biological activity. Ranging from simple THIQ natural products to complex trisTHIQ alkaloids such as the ecteinascidins, the chemical syntheses of these alkaloids and their analogs have been thoroughly investigated due to their intricate structural features and functionalities, as well as their high therapeutic potential. This review describes the general structure and biosynthesis of each family of THIQ alkaloids as well as recent advancements of the total synthesis of these natural products from 2002 to 2020. Recent chemical syntheses that have emerged harnessing novel, creative synthetic design, and modern chemical methodology will be highlighted. This review will hopefully serve as a guide for the unique strategies and tools used in the total synthesis of THIQ alkaloids, as well as address the longstanding challenges in their chemical and biosynthesis.

Synthesis and cytotoxicity of (-)-homo-renieramycin G and its derivatives

(-)-Homo-renieramycin G and its twenty derivatives were prepared from l-tyrosine methyl ester via a multi-step route. Their cytotoxicities were tested against four human cancer cell lines (A549, HeLa, KB and BGC-823). (-)-Renieramycin G and (-)-homo-renieramycin G showed comparable cytotoxicity against these four cancer cell lines, which indicated that the expansion of ring C from the six-membered 1,4-piperazinone to the seven-membered 1,4-diazepanone had no obvious impact on the cytotoxicity. Compound 42 with methyl side chain and compounds 38-41 with heterocyclic aromatic side chains at C-23 exhibited the most potent cytotoxicity with the IC₅₀ values at the level of 10^-6 M.

Renieramycin-type alkaloids from marine-derived organisms: Synthetic chemistry, biological activity and structural modification

Marine natural products are known for their diverse chemical structures and extensive bioactivities. Renieramycins, the member of tetrahydroisoquinoline family of marine natural products, arouse interests because of their strong antitumor activities and similar structures to the first marine antitumor agent ecteinascidin-743, approved by the European Union. According to the literatures, researches on the pharmacological activities of renieramycins mainly focus on their antitumor activities. In addition, by structural modification, derivatives of renieramycins show stronger antiproliferative activity and less accidental necrosis activity on cells. Nevertheless, the difficulties in extraction and separation hinder their further development. Hence, the synthetic chemistry work of renieramycins plays a key role in their further development. In this review, currently reported researches on the synthetic chemistry, pharmacological activities and structural modification of renieramycins are summarized, which will benefit future drug development and innovation.

Synthesis, antibacterial activities, and sustained perfume release properties of optically active5-hydroxy- and 5-acetoxyalkanethioamide analogues

5-Acetoxy- and 5-hydroxyalkanethioamide analogues showed high antibacterial activity against Staphylococcus aureus. Antibacterial thioamides were prepared from 5-alkyl-δ-lactones by amidation, thionation, and subsequent deacetylation. Optically active thioamides with 99% diastereomeric excesses were prepared by diastereomeric resolution using Cbz-L-proline as the resolving agent. Antibacterial thioamides were slowly lactonized by a lipase catalyst. Therefore, these thioamides are potential sustained-release perfume compounds having antibacterial properties.

Design, synthesis and cytotoxicity of novel hexacyclic saframycin-ecteinascidin analogs

Two series of novel hexacyclic skeletons and their thirty-four derivatives were prepared from l-tryptophan and l-DOPA. The cytotoxicities of these compounds were tested against four human cancer cell lines HCT-116, HepG2, BGC-823 and A2780. Compounds with the tetrahydro-β-carboline moiety in the left-half of the hexacyclic skeleton showed more potent cytotoxicity with IC50 values in the range of 10-7-10-9 M. Compound 20 with the 4-methoxybenzamide side chain showed potent cytotoxicity towards HepG2 with an IC50 value of 1.32 nM. Compounds 29 and 30 with 2-pyridine amide and (2E)-3-(3-thifluoromethyl-phenyl)acrylic amide side chains showed selective cytotoxicity towards A2780 with IC50 values of 1.73 nM and 7 nM, respectively.

Total synthesis of alkaloids using both chemical and biochemical methods

A chemoenzymatic approach to synthesize structurally complex natural alkaloids (tetrahydroisoquinoline antibiotics, indole diterpenes, and monoterpene indole alkaloids) has been reviewed.

Primary aminomethyl derivatives of kaempferol: hydrogen bond-assisted synthesis, anticancer activity and spectral properties

Primary aminomethyl derivatives of kaempferol with anticancer activity were synthesized by a combination strategy involving a hydrogen bond-assisted process.