Stable Axially Chiral Isomers of Arylnaphthalene Lignan Glycosides with Antiviral Potential Discovered from Justicia procumbens

Bioactive atropisomers: Unraveling design strategies and synthetic routes for drug discovery

Atropisomerism, an expression of axial chirality caused by limited bond rotation, is a prominent aspect within the field of medicinal chemistry. It has been shown that atropisomers of a wide range of compounds, including established FDA-approved drugs and experimental molecules, display markedly different biological activities. The time-dependent reversal of chirality in atropisomers poses complexity and obstacles in the process of drug discovery and development. Nonetheless, recent progress in understanding atropisomerism and enhanced characterization methods have greatly assisted medicinal chemists in the effective development of atropisomeric drug molecules. This article provides a comprehensive review of their special design thoughts, synthetic routes, and biological activities, serving as a reference for the synthesis and biological evaluation of bioactive atropisomers in the future.

Ethnomedicinal uses, phytochemistry, and pharmacological relevance of Justicia procumbens (Oriental Water Willow) - A promising traditional plant

ETHNOPHARMACOLOGICAL RELEVANCE

Justicia procumbens L. (JP) (Oriental Water Willow, Shrimp plant, Acanthaceae) is a herbaceous plant that is commonly found in India, Taiwan, Australia, Southern China, Vietnam, and Korea. The plant has been primarily used to treat fever, asthma, edema, cough, jaundice, urinary tract infection, and sore throat, as well as for snake bites and as a fish-killer. In the present review, the reported phyto-chemical, ethno-pharmacological, biological, and toxicological studies on J. procumbens were summarized. Special focus had been given to its reported lignans, regarding their isolation, characterization, quantitative estimation, and biosynthesis.

MATERIALS AND METHODS

A survey of the literature was done using assorted databases and publishers; Scopus, Sci-Finder, Web of Science, PubMed, GoogleScholar, ScienceDirect, Wiley, Taylors&Francis, Bentham, Thieme, and Springer.

RESULTS

Currently, 95 metabolites have been separated fromJ. procumbens. Lignans and their glycosides were reported as main phyto-constituents of J. procumbens. Various methods are mentioned for quantitative estimation of these lignans. These phyto-constituents possessed wide pharmacological effectiveness, such as antiplatelet aggregation, antimicrobial, antitumor, and antiviral.

CONCLUSIONS

Many of the stated effects are harmonious with the reported traditional uses of this plant. This data could further support J. procumbens's utilization as a herbal remedy and drug lead. However, further study of J. procumbens toxicity, as well as preclinical and clinical investigation is required to ensure the safe usage of J. procumbens.

Mechanisms of Rostellularia procumbens (L.) Nees on treating chronic glomerulonephritis explored by network pharmacology, RNA-seq, and in vitro experiments

BACKGROUND

The purpose of this study was to demonstrate the in vitro anti-nephritis activity of Rostellularia procumbens (L.) Nees (R. procumbens) extract and to make a preliminary investigation of its anti-nephritis mechanism.

METHODS

A prediction network was built that describes the relationship between R. procumbens and CGN. Then, the potential targets for R. procumbens against CGN were imported into the DAVID database for Gene Ontology (GO) biological annotation analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis. A lipopolysaccharide (LPS)-stimulated rat mesangial cell HBZY-1 model in vitro was used to examine the anti-inflammatory activity of R. procumbens extract. RNA-seq was utilized to investigate differentially expressed genes (DEGs) and enriched signaling pathways between groups. Finally, qPCR was used for the validation analysis of the experimental results.

RESULTS

The results of network pharmacology showed that R. procumbens exerts its therapeutic effect on CGN through the AGE-RAGE signaling pathway in diabetic complications, PI3K-Akt, IL-17 signaling pathway, and so on. R. procumbens n-butanol extract (J-NE) can effectively relieve inflammation in HBZY-1. The results of KEGG pathway enrichment suggest that J-NE attenuated CGN was associated with the IL-17 signaling pathway, and the results of RNA-seq were consistent with network pharmacology. Targets enriched in the IL-17 signaling pathway, including Chemokine (C-C motif) ligand 7 (CCL7), Lipocalin 2 (LCN2), Chemokine (C-C motif) ligand 2 (CCL2), and Chemokine (C-X-C motif) ligand 1 (CXCL1), have been identified as crucial targets attenuating CGN by J-NE.

CONCLUSION

R. procumbens is a promising pharmacological candidate for the treatment of CGN in the present era.

Recent Progress in Cyclic Aryliodonium Chemistry: Syntheses and Applications

Hypervalent aryliodoumiums are intensively investigated as arylating agents. They are excellent surrogates to aryl halides, and moreover they exhibit better reactivity, which allows the corresponding arylation reactions to be performed under mild conditions. In the past decades, acyclic aryliodoniums are widely explored as arylation agents. However, the unmet need for acyclic aryliodoniums is the improvement of their notoriously low reaction economy because the coproduced aryl iodides during the arylation are often wasted. Cyclic aryliodoniums have their intrinsic advantage in terms of reaction economy, and they have started to receive considerable attention due to their valuable synthetic applications to initiate cascade reactions, which can enable the construction of complex structures, including polycycles with potential pharmaceutical and functional properties. Here, we are summarizing the recent advances made in the research field of cyclic aryliodoniums, including the nascent design of aryliodonium species and their synthetic applications. First, the general preparation of typical diphenyl iodoniums is described, followed by the construction of heterocyclic iodoniums and monoaryl iodoniums. Then, the initiated arylations coupled with subsequent domino reactions are summarized to construct polycycles. Meanwhile, the advances in cyclic aryliodoniums for building biaryls including axial atropisomers are discussed in a systematic manner. Finally, a very recent advance of cyclic aryliodoniums employed as halogen-bonding organocatalysts is described.

The efficient synthesis and biological evaluation of justicidin B

A facile new synthetic method for the preparation of a Type-A 1-arylnaphthalene lactone skeleton was developed and used to synthesise justicidin B and several derivatives. Key synthesis steps included Hauser-Kraus annulation of a phthalide intermediate and Suzuki-Miyaura cross coupling between a triflated naphthalene lactone intermediate and various potassium organotrifluoroborates. With two exceptions, the derivatives showed significant inhibitory effect on lipopolysaccharide (LPS)-induced nitric oxide (NO) production in mouse macrophages. Moreover, several compounds, including justicidin B, had marked cytotoxicity towards six human tumour cell lines.

Chemistry and Biological Activities of Naturally Occurring and Structurally Modified Podophyllotoxins

Plants containing podophyllotoxin and its analogues have been used as folk medicines for centuries. The characteristic chemical structures and strong biological activities of this class of compounds attracted attention worldwide. Currently, more than ninety natural podophyllotoxins were isolated, and structure modifications of these molecules were performed to afford a variety of derivatives, which offered optimized anti-tumor activity. This review summarized up to date reports on natural occurring podophyllotoxins and their sources, structural modification and biological activities. Special attention was paid to both structural modification and optimized antitumor activity. It was noteworthy that etoposide, a derivative of podophyllotoxin, could prevent cytokine storm caused by the recent SARS-CoV-2 viral infection.

Survey of natural products reported by Asian research groups in 2021

The new natural products reported in 2021 in peer-reviewed articles in journals with good reputations were reviewed and analyzed. The advances made by Asian research groups in the field of natural products chemistry in 2021 were summarized. Compounds with unique structural features and/or promising bioactivities originating from Asian natural sources were discussed based on their structural classification.

Neritriterpenols A-G, euphane and tirucallane triterpenes from Euphorbia neriifolia L. and their bioactivity

Euphorbia neriifolia L. is widely distributed in India, Thailand, and China and has been used to treat diseases such as rotten sores and asthma as well as for its antidiabetic and anticancer effects. In this study, seven undescribed triterpenes, including six euphanes, neritriterpenols A-B and D-G, and a tirucallane, neritriterpenol C, together with four known triterpenes, were isolated from ethanolic extracts of E. neriifolia stems. Their structures with absolute configurations were determined through detailed spectroscopic data, including 1D and 2D NMR data analyses, single-crystal X-ray diffraction analysis, ECD spectra, and DP4+ NMR data calculations as well as Mo₂(OAc)₄-induced ECD analysis. Furthermore, preliminarily evaluation of the anti-inflammatory and anti-proliferative effects of the isolated triterpenes leads to the structure-activity relationship (SAR) studies implying that the unsaturated functional group at the end of the C17 side chain on euphane-type triterpenes may be correlated with the increase of anti-inflammatory and anti-proliferative activities.