Coumarinolignoids and Taraxerane Triterpenoids from Sapium discolor and Their Inhibitory Potential on Microglial Nitric Oxide Production

Abstract

Seventeen compounds, including three new pairs of coumarinolignoid enantiomers, (7′S,8′S)-sapiumins A−C (1a−3a) and (7′R,8′R)sapiumins A−C (1b−3b), six new taraxerane triterpenoids, sapiumic acids A−F (4−9), and five known taraxerane triterpenoids (10−14), were isolated from an ethanol extract prepared from the stems and leaves of Sapium discolor. The structures of 1−9 and their relative configurations were determined by spectroscopic data analysis, and the absolute configurations of the coumarinolignoids 1a/1b−3a/3b and triterpenoids 6−9 were assigned using experimental and calculated ECD data. Compounds 1a/1b−3a/3b are the first coumarinolignoids to be reported from the genus Sapium. Among all the isolates, compounds 1b, 2a/2b, 3a/3b, and 6−9 inhibited nitric oxide production in lipopolysaccharide-stimulated BV-2 microglial cells, with IC 50 values of 1.7−15.3 μM.C oumarinolignoids are a class of natural products in which a phenylpropanoid unit is linked to a coumarin moiety through a 1,4-dioxane bridge. 1 These substances are relatively rare and exhibit a wide variety of biological properties, such as anti-inflammatory, antioxidant, and hepatoprotective effects. 2−4 Taraxeranes, a type of triterpenoids derived biosynthetically from oleananes, 5 display cytotoxic and allelopathic activities. 6−8 Both coumarinolignoids and taraxerane triterpenoids occur in plants in the family Euphorbiaceae. 9−12 Sapium discolor (Champ. ex Benth.) Muell. Arg., which is distributed widely in southern mainland China, is a tree or shrub belonging to the family Euphorbiaceae. 13 The root bark and leaves of this plant have long been used in folk medicine to treat snakebites, allergic dermatitis, and eczema. 13,14 Previous phytochemical research has indicated the presence of four diterpenoids and other constituents in this species. 15,16 In an ongoing search for antineuroinflammatory agents from folk medicines, 17,18 the EtOAc-soluble fraction of a 95% aqueous EtOH extract of S. discolor was shown to inhibit the production of nitric oxide (NO) in lipopolysaccharide (LPS)-stimulated BV-2 microglial cells. Thus, a bioassay-guided phytochemical study of the active fractions led to the isolation of three new pairs of coumarinolignoid enantiomers, (7′S,8′S)-sapiumins A−C (1a−3a) and (7′R,8′R)-sapiumins A−C (1b−3b), and six new taraxerane triterpenoids, sapiumic acids A−F (4−9), along with five known taraxeranes (10−14). This is the first report of the isolation of coumarinolignoids from the genus Sapium. Herein, we report the isolation, structural elucidation, and NO inhibitory effects of the new compounds.

Stewartiacids A–N, C-23 carboxylated triterpenoids from Chinese Stewartia and their inhibitory effects against ATP-citrate lyase and NF-κB

“…In turn, the ROE correlations of H 3 -24/H 3 -25, H 3 -25/H-11, H 3 -26/H-11, H 3 -28/H-18, and H 3 -29/H-18 suggested these protons to be β-oriented in 11. Meanwhile, the magnitude of J H-7′/H-8′ (10.4 Hz) indicated a trans configuration of the dioxane ring, 27 and the ROE correlation between H-8′ and H-11 supported their β-orientation. The ROE correlation between H-2′ and the methoxy group also confirmed the latter to be located at C-3′.…”

Assessment of antioxidant and xanthine oxidase inhibitory activity of Triadica cochinchinensis stem bark

“…On the other hand, alkaloids were absent in this extract. Recent studies on the chemistry of T. cochinchinensis have shown the occurrence of terpenoids from the leaf and stem, including diterpenoids and triterpenoids (Liu et al, 2015;Zhang et al, 2018). In addition, coumarinolignoids and lignoids also were reported from the same parts of this plant (Zang et al, 2018;Zhang et al, 2019).…”

“…Recently, the plant has been reported to contain diterpenoids, phenolics, triterpenoids, coumarinolignoids, and lignoids from leaf and stem parts. Their biological activities include anticancer activity and nitric oxide inhibition in BV-2 microglial cells induced by lipopolysaccharide (Liu et al, 2015;Zhang et al, 2018;Zhang et al, 2019). In this study, the antioxidant and…”

Monofloral Triadica Cochinchinensis Honey Polyphenols Improve Alcohol-Induced Liver Disease by Regulating the Gut Microbiota of Mice

“…Recent studies have found that triadica cochinchinensis tree contains Coumarinolignoids (coumarin), which has anti-inflammatory, antioxidant, and hepatoprotective effects. It also contains taraxeranes, which have cytotoxic and allelopathic effects (19). Qinpiting and ent-kaurane-3-oxo-16a, 17-diol in the stems and leaves of triadica cochinchinensis tree have a significant inhibitory effect on the release of NO from BV-2 microglia activated by LPS.…”