Anti-inflammatory activity of naturally occuring diarylheptanoids - A review

Cyclic diarylheptanoids from Myrica javanica: isolation, transformation, and bioactivity evaluation

Three cyclic diarylheptanoids, myricanol (1), myricanone (2), and porson (3), were isolated from Myrica javanica (Myricaceae). As a major component, myricanol (1) was obtained from dry powdered bark and twigs (up to 1.6%). Transformation of myricanol (1) afforded 5-prenylmyricanol (4) and 5-benzylmyricanol (5) in 84.5% and 65% yields, respectively. The bioactivities of the isolated cyclic diarylheptanoids and their derivatives were investigated to determine their cytotoxicity and DPPH (2,2-diphenyl-1-picrylhydrazyl) scavenging activities. The cytotoxicity assay against murine leukaemia P-388 cells demonstrated that compounds 4 and 5 showed an almost two-fold increase in the activity of their parent molecule (1), with an IC50 value of 12 µM. Furthermore, the free radical scavenging assay showed that myricanol (1) had the highest radical scavenging activity, revealing the importance of the free phenolic group (IC50 39.3 µM).

Diarylheptanoid glycosides from Dioscorea nipponica rhizomes

A group of previously undescribed diarylheptanoids with mono/di-glucose substitution, diodiarylheptosides A-F (1-6), together with six known diarylheptanoids (7-12) were isolated from the rhizomes of Dioscorea nipponica. Their structures were established by comprehensive UV, IR, HR-ESI-MS and NMR analyses, and their absolute configurations were determined by a comparison of calculated and experimental ECD, some with optical rotations, after acid-hydrolysis. Moreover, bioassay results showed that compounds 3 and 11 exhibited stronger NO inhibitions on lipopolysaccharides-induced RAW 264.7 cells, with the IC50 values of 14.91 ± 0.62 and 12.78 ± 1.12 μM.

Recent Advances in the Synthesis of Diarylheptanoids

In the quest for synthesizing biologically important natural products, medicinal chemists embark on an endless journey. This review focuses on the reports published towards the syntheses of diarylheptanoids, classifying them into linear, tetrahydropyran, diarylether, and biphenyl categories. The synthesis methods for each class from 2013 to 2023 are discussed, providing a comprehensive overview of the advancements in the field. Representative natural product examples are highlighted for each category. The review emphasizes the importance of diarylheptanoids in the realms of chemistry and medicine, showcasing their potential as valuable compounds for medicinal and synthetic chemists.

Green Onion (Allium fistulosum): An Aromatic Vegetable Crop Esteemed for Food, Nutritional and Therapeutic Significance

In recent years, there has been a shift towards a greater demand for more nutritious and healthier foods, emphasizing the role of diets in human well-being. Edible Alliums, including common onions, garlic, chives and green onions, are staples in diverse cuisines worldwide and are valued specifically for their culinary versatility, distinct flavors and nutritional and medicinal properties. Green onions are widely cultivated and traded as a spicy vegetable. The mild, onion-like flavor makes the crop a pleasant addition to various dishes, serving as a staple ingredient in many world cuisines, particularly in Eastern Asian countries such as China, Japan and the Republic of Korea. The green pseudostems, leaves and non-developed bulbs of green onions are utilized in salads, stir-fries, garnishes and a myriad of culinary preparations. Additionally, green onions have a rich historical background in traditional medicine and diets, capturing the attention of chefs and the general public. The status of the crop as an important food, its culinary diversity and its nutraceutical and therapeutic value make it a subject of great interest in research. Therefore, the present review has examined the distribution, culinary, nutritional and therapeutic significance of green onions, highlighting the health benefits derived from the consumption of diets with this aromatic vegetable crop as a constituent.

An integrated approach of homogenization-ultrasound-assisted extraction followed by high-speed countercurrent chromatography for rapidly preparative separation naphthoquinones and diarylheptanes from Juglands mandshurica Maxim. exocarp

This research investigated the effectiveness of an integrated method for the extraction and separation of naphthoquinones and diarylheptanes from exocarp of Juglands mandshurica Maxim. (namely, green walnut husks). The target compounds were obtained by ultra-turrax homogenization (UTH) coupled with ultrasound-assisted extraction (UAE) technology followed by high-speed countercurrent chromatography (HSCCC). The UTH-UAE extraction method achieved higher efficiency with 2.49- and 2.36-fold to those by UAE, and 1.39- and 1.34-fold to those by UTH in a short time. HSCCC was adopted for further separation and purification; six target compounds, namely, regiolone (RE), juglone (JU), myricatomento-genin (MG), galleon (GA), 2-oxatrycyclo[13.2.2.13,7]eicosa-3,5,7(20),15,17,18-hexaen-10-16-diol (OE), and juglanin A (JA), were separated with more than 95.37% purities and more than 84.71% final recovery rates, respectively. In this study, the integrated strategy of extraction and separation could get high purity compounds quickly, which would provide time and solvent saved method for the natural products separation from plants.

Diarylheptanoids/sorafenib as a potential anticancer combination against hepatocellular carcinoma: the p53/MMP9 axis of action

Hepatocellular carcinoma (HCC) is a serious and potentially fatal form of cancer associated with liver damage. New anticancer drugs are increasingly needed due to the increasing number of cancer cases every year. In this study, diarylheptanoids (DAH) from Alpinia officinarum were examined for their antitumor activity against DAB-induced HCC in mice, as well as their ability to reduce liver damage. Assays for cytotoxicity were conducted using MTT. The DAB-induced HCC Swiss albino male mice were given DAH and sorafenib (SOR) either as single treatments or in combination, and the effects on tumour development and progression were monitored. Malondialdehyde (MDA) and total superoxide dismutase (T-SOD) were evaluated along with biomarkers of liver enzymes (AST, ALT, and GGT). The apoptosis-related gene (CASP8), the apoptosis-related gene (p53), the anti-inflammatory genes (IL-6), the migration-related gene matrix metalloprotease-9 (MMP9), and the angiogenesis-related gene vascular endothelial growth factor (VEGF) were assessed using qRT-PCR in the hepatic tissue. As a final step, DAH and SOR were docked with CASP8 and MMP9 via molecular docking to propose potential mechanisms of action. Our results revealed that the combination of DAH and SOR has a potent inhibitory effect on the growth and viability of the HepG2 cell line. The outcomes demonstrated that DAH and SOR-treated HCC-bearing mice displayed a reduction in the tumour burden and liver damage as demonstrated by (1) parameters of repaired liver function; (2) low levels of hepatic MDA; (3) elevated levels of hepatic T-SOD; (4) p53, IL-6, CASP8, MMP9, and VEGF downregulation; and (5) enhanced hepatic structure. The best results were revealed in mice that were co-treated with DAH (given orally) and SOR (given intraperitoneally). The docking study also proposed that both DAH and SOR could inhibit CASP8 and MMP9's oncogenic activities and had a high affinity for these enzymes. In conclusion, according to study findings, DAH enhances SOR antiproliferative and cytotoxic effects and identifies their molecular targets. Furthermore, the results revealed that DAH was able to boost the anticancer effects of the drug SOR and reduce liver damage caused by HCC in mice. This suggests that DAH could be a potential therapeutic agent against liver cancer.

Evaluation of the Chemical Stability, Membrane Permeability and Antiproliferative Activity of Cyclic Diarylheptanoids from European Hornbeam (Carpinus betulus L.)

Four cyclic diarylheptanoids-carpinontriols A (1) and B (2), giffonin X (3) and 3,12,17-trihydroxytricyclo [12.3.1.12,6]nonadeca-1(18),2(19),3,5,14,16-hexaene-8,11-dione (4)-were isolated from Carpinus betulus (Betulaceae). Chemical stability of the isolated diarylheptanoids was evaluated as a function of storage temperature (-15, 5, 22 °C) and time (12 and 23 weeks). The effect of the solvent and the pH (1.2, 6.8, 7.4) on the stability of these diarylheptanoids was also investigated. Compounds 2 and 4 showed good stability both in aqueous and methanolic solutions at all investigated temperatures. Only 2 was stable at all three studied biorelevant pH values. Degradation products of 1 and 3 were formed by the elimination of a water molecule from the parent compounds, as confirmed by ultrahigh-performance liquid chromatography-high-resolution tandem mass spectrometry (UHPLC-HR-MS). The permeability of the compounds across biological membranes was evaluated by the parallel artificial membrane permeability assay (PAMPA). Compound 3 possesses a logPe value of -5.92 ± 0.04 in the blood-brain barrier-specific PAMPA-BBB study, indicating that it may be able to cross the blood-brain barrier via passive diffusion. The in vitro antiproliferative activity of the compounds was investigated against five human cancer cell lines, confirming that 1 inhibits cell proliferation in A2058 human metastatic melanoma cells.

Metabolomics and Transcriptomics Reveal that Diarylheptanoids Vary in Amomum tsao-ko Fruit Development

Amomum tsao-ko is an important spice and medicinal plant that has received extensive attention in recent years for its high content of bioactive constituents with the potential for food additives and drug development. Diarylheptanoids are major and characteristic compounds in A. tsao-ko; however, the biochemical and molecular foundation of diarylheptanoids in fruit is unknown. We performed comparative metabolomics and transcriptomics studies in the ripening stages of A. tsao-ko fruit. The chemical constituents of fruit vary in different harvest periods, and the diarylheptanoids have a trend to decrease or increase with fruit development. GO enrichment analysis revealed that plant hormone signaling pathways including the ethylene-activated signaling pathway, salicylic acid, jasmonic acid, abscisic acid, and response to hydrogen peroxide were associated with fruit ripening. The biosynthetic pathways including phenylpropanoid, flavonoids, and diarylheptanoids biosynthesis were displayed in high enrichment levels in ripening fruit. The molecular networking and phytochemistry investigation of A. tsao-ko fruit has isolated and identified 10 diarylheptanoids including three new compounds. The candidate genes related to diarylheptanoids were obtained by coexpression network analysis and phylogenetic analysis. Two key genes have been verified to biosynthesize linear diarylheptanoids. This integrative approach provides gene regulation and networking associated with the biosynthesis of characteristic diarylheptanoids, which can be used to improve the quality of A. tsao-ko as food and medicine.

Design and synthesis optimization of novel diimide indoles derivatives for ameliorating acute lung injury through modulation of NF-κB signaling pathway

Acute lung injury (ALI) is a common respiratory disease caused by local or systemic inflammatory reaction. Based on the natural 7-chain diaryl anti-inflammatory framework, a series of diimide indoles derivatives were designed by combining curcumin and indole in this study. The synthesis of diimide compounds was extended using dichloromethane (DCM) as solvent and 1,1'-carbonyldiimidazole (CDI) and sodium hydride (NaH) as double activators, and a total of 40 diimide-indole derivatives were obtained. The results of in vitro anti-inflammatory activity showed that most compounds could inhibit the production of interleukin-6 (IL-6) better than curcumin and indomethacin. Among the compounds, the IC₅₀ of compound 11f on IL-6 reached 1.05 μM with no obvious cytotoxic side effects. Mechanistically, compound 11f could block the expression of NF-κB P65 phosphorylation, and nuclear translocation of P65. The acute toxicity tests in-vivo also showed no obvious toxicity in mice after the intragastric administration of 1000 mg/kg. In addition, the compound 11f could significantly inhibit the LPS-induced inflammatory response in mice and reduce the number of neutrophils and wet/dry lung weight ratio, thereby alleviating ALI. These results indicated that the novel diimide indoles were promising anti-inflammatory agents for the treatment of ALI.

Screening of Antioxidant, Antibacterial, Anti-Adipogenic, and Anti-Inflammatory Activities of Five Selected Medicinal Plants of Nepal

Introduction

Herbal products have been widely used for the treatment of diseases throughout the ages. In this research, we investigated antioxidant, antibacterial, anti-adipogenic, and anti-inflammatory activities of methanolic extracts of five ethnomedicinally important plants; namely, Alnus nepalensis, Dryopteris sparsa, Artocarpus lacucha, Litsea monopetala, and Lyonia ovalifolia.

Methods

We investigated the DPPH free radical scavenging potential, sensitivity of selected bacterial strains towards the extracts using a disc diffusion assay, anti-inflammatory activity in RAW-264.7 cells, and anti-adipogenic activity by the ORO assay in 3T3-L1 preadipocytes.

Results and discussion

The extract of A. nepalensis showed significant antioxidant activity (IC₅₀=4.838 µg/mL), followed by A. lacucha, L. monopetala, and L. ovalifolia, exhibiting comparable IC₅₀ values to that of ascorbic acid (IC₅₀=5.063 µg/mL). Alnus nepalensis also showed good antibacterial activity in disc diffusion methods, with remarkable zones of inhibition in A. baumannii (14.66 mm) and P. mirabilis (15.50 mm) bacterial species. In addition, A. nepalensis was found to increase adipogenesis in 3T3-L1 cells, evidenced by increased lipid deposition in differentiated 3T3-L1 cells. A similar pattern of increased adipogenesis was observed on treatment with L. ovalifolia extracts. On the other hand, A. lacucha effectively reduced lipid deposition in 3T3-L1 cells at 100 µg/mL (75.18±6.42%) by inhibiting adipogenesis, showing its potential use in the management of obesity. Furthermore, A. lacucha 100 µg/mL (15.91±0.277 µM) and L. monopetala 75 µg/mL (12.52±0.05 µM) and 100 µg/mL (11.77±0.33 µM) significantly inhibited LPS-induced nitric oxide production in RAW 264.7 cells. Also, A. nepalensis and L. ovalifolia inhibited NO production significantly, endorsing their anti-inflammatory potential.

Conclusion

The findings from these in-vitro studies suggest that the selected five plants possess remarkable antioxidant, antibacterial, anti-adipogenic, and anti-inflammatory activities. This study opens the door to conduct further advanced in-vivo experiments to find possible lead compounds for the development of valuable therapeutic agents for common health problems.

Synthesis, structural elucidation, DNA binding, cleavage, AChE and BuChE cholinesterase efficiencies of metal complexes with 1,10-phenanthroline scaffold

A series of metal complexes containing a 1,10-phenanthroline scaffold [ML] (L-1,10-Phenanthroline derivative comprises conjugated aromatic core and electron withdrawing -NO₂ group); M = Cu(II), Zn(II), Co(II), and Zn(II) ions were designed and synthesized to obtain effective anti-cholinesterase efficiencies of metal chelates. Analytical and spectroscopic studies were used to determine the structural features. An octahedral structure with moderate distortion was attributed to the above metal chelates based on spectroscopic data. S. aureus, A. niger, C. albicans, B.subtilis, A. flavus, and E. coli were used to test the antibacterial efficacy of the synthesized ligands and metal complexes. Using agarose gel electrophoresis, the DNA fragmentation proficiency of prepared metal complexes was tested on pUC 18 DNA. The distorted octahedral geometry of the copper(II) complex to DNA (K_b = 4.11 × 10⁵ M^-1) is stronger than that of ethidium bromide (EB) to DNA (K_b = 3.3 × 10⁵ M^-1) and other metal complexes, respectively. The synthesized 1,10-phenanthroline derivative had the best inhibitory effects against acetylcholinesterase and butyrylcholinesterase, with IC₅₀ values of 0.45 and 3.6 M, respectively, which were lower than the reference molecules. Our experimental results may contribute to the development of new drug molecules particularly in the treatment of neurological disorders including glaucoma, Alzheimer's disease and diabetes. The actions of inhibitors on the glycosidase enzyme help to delay the breakdown and release of sugar molecules into the bloodstream, and they can be used as therapeutic factors in the treatment of diabetes.

Antioxidant effects of diarylheptanoids from two Curcuma species

ABSTRACTSFive linear diarylheptanoids (1-5), including a new one (1), were isolated from the rhizomes of Curcuma kwangsiensis S. G. Lee et C. F. Liang, while four linear diarylheptanoids (6-9) and four cyclic diarylheptanoids (10-13) were isolated from the roots of Curcuma aromatica Salisb. Using the model of H₂O₂-induced PC12 cells, the antioxidant effects of these thirteen diarylheptanoids from these two traditional Chinese medicines from Curcuma genus of Zingiberaceae family were investigated. As result, they produced different efficiency on damaged cell viability, ROS, LDH, SOD, CAT, and GSH-Px, which were the six indexes related to oxidative stress. Further, the correlation between these six bio-indexes and 53 selected molecular descriptors of diarylheptanoids was determined by PLS regression analysis.

Identifying of Anti-Thrombin Active Components From Curcumae Rhizoma by Affinity-Ultrafiltration Coupled With UPLC-Q-Exactive Orbitrap/MS

Recent studies concerning products that originate from natural plants have sought to clarify active ingredients, which both explains the mechanisms of the function and aids in quality control during production. As a traditional functional plant, Curcumae Rhizoma (CR) has been proven to be effective in promoting blood circulation and removing blood stasis. However, the components that play a role in its huge compound library are still unclear. The present study aimed to develop a high-throughput screening method to identify thrombin inhibitors in CR and validate them by in vitro and in vivo experiments. The effect of CR on thrombin in HUVECs cells was determined by ELISA, then an affinity-ultrafiltration-UPLC-Q-Exactive Orbitrap/MS approach was applied. Agatroban and adenosine were used as positive and negative drugs respectively to verify the reliability of the established method. The in vitro activity of the compounds was determined by specific substrate S-2238. The in vivo effect of the active ingredients was determined using zebrafish. Molecular docking was used to understand the internal interactions between compounds and enzymes. ELISA results showed that CR had an inhibitory effect on thrombin. The screening method established in this paper is reliable, by which a total of 15 active compounds were successfully identified. This study is the first to report that C7, 8, and 11 have in vitro thrombin-inhibitory activity and significantly inhibit thrombosis in zebrafish models at a safe dose. Molecular docking studies were employed to analyze the possible active binding sites, with the results suggesting that compound 16 is likely a better thrombin inhibitor compared with the other compounds. Based on the affinity-ultrafiltration-UPLC-Q-Exactive Orbitrap/MS approach, a precisely targeted therapy method using bio-active compounds from CR might be successfully established, which also provides a valuable reference for targeted therapy, mechanism exploration, and the quality control of traditional herbal medicine.

Natural Products & Bioactivity Inspired Synthetic Pursuits Interfacing with Carbohydrates: Ongoing Journey with C-Glycosides

Natural products, remains the most important source for the discovery of new drugs for the treatment of human diseases. This has inspired the synthetic community to design and develop mimics of natural products either to answer important questions in biology or to explore their therapeutic potentials. Glycosides present themselves abundantly in nature, right from the cell surface receptors to natural products of any origin. The O-Glycosides are hydrolytically less stable compared to C-glycosides and this feature has presented a great opportunity for drug discovery. The discovery of Dapagliflozin, an SGLT inhibitor and C-glucoside, for the treatment of diabetes is one such example. Aryl acyl-anion chemistry has been explored for the synthesis of 2-deoxy-C-aryl furanoside/pyranoside/septanosides. Besides success, the studies have provided valuable insight into the natural propensities of the architectural framework for the cascade to furan derivatives. The aryl acyl-anion chemistry has also enabled the synthesis of biologically active diaryl heptanoids. Inspired from sucesss of Dapagliflozin, new analogues have been synthesized with pyridine and isocoumarin heterocycle as the proximal ring. C-glucosides of isoliquiritigenin have been synthesized for the first time and evaluated as an efficient aldose reductase inhibitor. The synthesis and evaluation of acyl-C-β-D-glucosides and benzyl-C-β-D-glucoside as glucose-uptake promoters has revealed promise in small molecules. The concept of building blocks has been used to obtain natural oxylipins, D-xylo and L-xylo-configured alkane tetrols and novel lipophilic ketones with erythro/threo configured trihydroxy polar head-group as possible anti-mycobacterial agents.