Anti-inflammatory Limonoids From Cortex Dictamni

Abstract

The root barks of perennial herb Dictamnus dasycarpus (Cortex Dictamni) were reported to be rich in anti-inflammation activity constituents, limonoids. Then, the investigation of anti-inflammation therapeutic limonoids from this plant was developed in the present study. Through the combination of various chromatographies isolation, six new limonoids, named dictamlimonol A (1), dictamlimonoside B (2), and dictamlimonols C-F (3-6), along with seven known ones (7-13), were obtained. Their structures were ascertained based on the extensive spectroscopic methods and ECD data analysis. Among them, compound 1 was the first 7,19-epoxy limonoid found in natural products. The anti-inflammatory effects of all limonoids were evaluated in lipopolysaccharide (LPS)-treated RAW 264.7 cell lines. Compounds 5, 7-11, and 13 were found to inhibit LPS-induced nitric oxide (NO) production. Moreover, dictamlimonol D (5), fraxinellone (11), and dasylactone A (13) were found to reduce the LPS-induced expressions of interleukin-6 (IL-6), tumor necrosis factor (TNF-α), inducible nitric oxide synthase (iNOS), nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), and cyclooxygenase-2 (COX-2) at the protein levels in a dose-dependent manner. These findings support that the administration of Cortex Dictamni may be beneficial for inflammation.

Dictamnine is an effective anti‐anaphylactoid compound acting via the MrgX2 receptor located on mast cells

“…Cortex dictamni is a traditional Chinese medicine used to treat diseases such as skin inflammation, rubella, eczema, rheumatism, and gynecologic inflammations (Chen et al, 2020). Previous phytochemical studies have revealed that limonoids and quinoline alkaloids are the main characteristic constituents of C. dictamni (Gao et al, 2020a).…”

New 12,23-Epoxydammarane Type Saponins Obtained from Panax notoginseng Leaves and Their Anti-Inflammatory Activity

“…Its molecular formula, C 47 H 78 O 17 ( m / z 913.51648 [M − H] − ; calcd. for C 47 H 77 O 17 , 913.51553) was measured on the negative-ion ESI-Q-Orbitrap MS. d -glucose and d -xylose were detected in its acid hydrolysis product by HPLC analysis [ 9 ]. The 1 H and 13 C NMR ( Table 1 ) spectra showed signals for eight methyl groups at δ 0.82, 0.94, 1.01, 1.11, 1.31, 1.51, 1.68, and 1.83 (3H each, all s, H 3 -19, 18, 29, 30, 28, 21, 26, and 27), three oxygenated methines at δ 3.37 (1H, dd, J = 4.5, 11.5 Hz, H-3), 3.67 (1H, m, H-12), and 4.86 (1H, dd, J = 8.0, 10.0 Hz, H-23), one tri-substituted olefin group at δ 5.55 (1H, d, J = 8.0 Hz, H-24), two β- d -glucopyranosyl moieties at δ 4.97 (1H, d, J = 8.0 Hz, H-1′) and 5.12 (1H, d, J = 8.0 Hz, H-1″), and one β- d -xylopyranosyl group at δ 4.99 (1H, d, J = 7.5 Hz, H-1‴), which suggested that notoginsenoside NL-I ( 1 ) was a dammarane-type triterpene saponin.…”

“…Acid Hydrolysis of 1 and 2 : Compounds 1 and 2 were hydrolyzed by 1M HCl and aqueous layers were obtained by using the reported method [ 9 ]. As the results shown, d -glucose and d -xylose were detected in their acid hydrolysate.…”

Sudachinoid- and Ichangensin-Type Limonoids from Citrus junos Downregulate Pro-Inflammatory Cytokines

“…Many studies have reported the chemical properties and pharmacological activities of limonoids, including their structure–activity relationship [ 27 ]. Recently, the anti-inflammatory activities of limonoids and limonoid glucosides were reported [ 28 ]. Therefore, we sought to determine the effects of the limonoids isolated from C. junos seeds on inflammatory responses using two in vitro models, RAW 264.7 mouse macrophage cells and HT-29 colon epithelial cells, which can simulate the characteristics of intestinal epithelial cells in IBD.…”