New diterpenoids from Sapium discolor

Computational assessment of the radical scavenging activity of cleomiscosin

Coumarinolignans such as cleomiscosin A (CMA), cleomiscosin B (CMB), and cleomiscosin C (CMC) are secondary metabolites that were isolated from diverse plant species. Cleomiscosins (CMs) have numerous interesting biological activities, including noteworthy cytotoxicity of cancer cell lines along with hepatoprotective and assumed antioxidant activities. In this present study, the antioxidant properties of three cleomiscosins were investigated with a focus on the structure-activity relationship using thermodynamic and kinetic calculations with the M06-2X/6-311++G(d,p) method. The results show that CMs, including CMA, CMB, and CMC, are weak antioxidants in apolar environments, with k overall of 7.52 × 102 to 6.28 × 104 M-1 s-1 for the HOO˙ radical scavenging reaction in the gas phase and 3.47 × 102 to 6.44 × 104 M-1 s-1 in pentyl ethanoate. Remarkably, the difference in the fusion of phenylpropanoid structure with coumarin via two ortho-hydroxyl groups (CMA and CMB) does not cause any noticeable effect on their antioxidant activity, while the presence of a methoxy substitute on the aromatic ring of phenylpropanoid units (CMC) increases the reaction rate to about 61 to 84 times faster than that of CMA. In contrast, the studied CMs exhibit a good antioxidant capacity in polar environments, with a k overall range from 4.03 × 107 to 8.66 × 107 M-1 s-1, 102-103 times faster than that of Trolox, equal to that of ascorbic acid and resveratrol. The angular fusion of the phenylpropanoid and coumarin structures, as well as the methoxy substitution on the aromatic ring of the phenylpropanoid unit of the studied CMs, do not have any considerable effect on their antioxidant activity under the studied conditions.

Cembrane diterpenoids: Chemistry and pharmacological activities

Cembrane diterpenoids (cembranoids), characterized by a 14-membered carbon ring and wide variety of functional groups, found in marine and terrestrial organisms. Many studies have shown that cembrane diterpenoids have cytotoxic and anti-inflammatory activities and are widely used in the development of new drugs. This review covered publications from 2011 to 2022 and classified the cembrane-type diterpenoids into isopropyl (ene) type, γ-lactone or unsaturated five-membered ring, δ-lactone or unsaturated six-membered ring, ε-lactone or unsaturated seven-membered ring, and other cembrane diterpenes. In addition, the biological activity and structure-activity relationship were summarized. This will provide guidance for new cembrane-type diterpenes as lead compounds to explore their potential application for treating cancer and inflammatory diseases.

3β-Palmitoyloxy-olean-12-ene analogs from Sapium lateriflorum (Euphorbiaceae): Their cytotoxic and anti-inflammatory properties and docking studies

Ten compounds, including a new anti-inflammatory acyl triterpene, 3β-palmitoyloxy-1β,11α-dihydroxy-olean-12-ene, were isolated from the bioactive organic extract prepared from the leaves of Sapium lateriflorum (syn: S. nitidum). The isolated compounds were screened for their cytotoxic activity against selected human cancer cell lines and did not display significant activity. They were also evaluated as anti-inflammatory agents in mouse models (TPA-induced edema in the ear and in a carrageenan-induced paw edema model). The results indicated that the new compound, 3β-palmitoyloxy-1β,11α-dihydroxy-olean-12-ene, was the compound with major anti-inflammatory activity similar to that of indomethacin, being the hydroxyl at C-11 important for the observed activity. The results of docking studies of the 3β-palmitoyloxy esters of olean-12-ene with NF-κB and with COX-2 receptors were consistent with possible molecular mechanisms of the anti-inflammatory activity.

Genus Sapium (Euphorbiaceae): A review on traditional uses, phytochemistry, and pharmacology

ETHNOPHARMACOLOGICAL RELEVANCE

Genus Sapium, belonging to Euphorbiaceae family, has a wide distribution in Asia and in temperate and tropical regions of Africa and America. The various parts of Sapium species have been used in traditional Chinese herbal medicine for the treatment of edema, skin-related diseases, bacterial infections, cancers, diabetes, and other ailments.

AIM OF THE STUDY

A comprehensive and updated review on the phytochemistry, pharmacology, and traditional medicinal uses of Sapium has been summarized and discussed to facilitate further exploitation of the therapeutic values of Sapium species.

MATERIALS AND METHODS

The relevant information of Sapium species was collected by scientific search engines including Elsevier, Google Scholar, Scifinder, and CNKI (China national knowledge infrastructure), and Master's dissertations and Summon from Shandong University Library.

RESULTS

Phytochemical studies revealed that approximately 259 compounds including terpenoids, phenylpropanoids, flavonoids, tannins, steroids, alkaloids, etc. have been isolated and identified from Sapium species, among which terpenoids, phenylpropanoids and tannins are the main constituents. Pharmacological in vitro and in vivo studies revealed that the extracts and pure compounds possessed significant antibacterial, antiinflammatory, antioxidant, antihypertensive effects, cytotoxicity, antidiabetic, molluscicidal effects. Terpenoids, phenylpropanoids, tannins, flavonoids, and alkaloids may be responsible for these activities.

CONCLUSIONS

The traditional uses, phytochemistry, and pharmacology described in this article demonstrated that the plants of Sapium genus possess many different types of compounds exhibiting wide range of biological activities, and they have high medicinal value and potential in the treatment of a variety of diseases. Detailed phytochemical studies have been conducted on only twelve species in the literature. More wide-ranging studies are still needed to explore this genus. Most of the existing bioactivity-related studies were implemented on crude extracts. More in-depth studies are necessary to reveal the links between the traditional uses and bioactivity in the future.

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

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 IC₅₀ values of 1.7-15.3 μM.

Advances in the chemistry and pharmacological potential of coumarinolignans

Coumarinolignans (CLs) are a group of non-conventional lignans having coumarins and phenyl propanes as two C₆C₃ units linked commonly through a dioxane bridge. The research findings during Jan 2008-May 2018 on this group of secondary metabolites describing their occurrence, structural characteristics, large-scale preparation, synthesis, derivatives, pharmacological activities, and structure-activity relationship are presented in this review. Around 38 CLs have been isolated from 40 plant species belonging to 20 different families during the review period. Reports on the syntheses of CL derivatives are also discussed. The majority of the reported CLs have shown potential anti-inflammatory activities, especially against pro-inflammatory cytokines. The other pharmacological effects exhibited by CLs such as hepatoprotective, anticancer, etc., are also covered in this review comprehending the lacunae in their development into drugs. This article is a continuation of our earlier work on coumarinolignans (Begum SA, Sahai M, Ray AB (2010) Non-conventional lignans: coumarinolignans, flavonolignans, and stilbenolignans. In: Kinghorn AD, Falk H, Kobayashi J (eds) Progress in the chemistry of organic natural products, Springer, Verlag/Wien, p 1-70).

Cytotoxic diterpenoids from Pteris ensiformis

Phytochemistry investigation on Pteris ensiformis led to the isolation of a new ent-kaurane diterpenoid, ent-kaurane-6β,16α-diol-3-one (1), along with five known diterpenoids (2-6) and three known sesquiterpenes (7-9). Their structures were established by means of spectroscopic methods. The ethanol extract and the isolated compounds (1-9) were evaluated for their antitumor activity against three cancer cell lines.

Diterpenoids of terrestrial origin

This review covers the isolation and chemistry of diterpenoids from terrestrial as opposed to marine sources and includes labdanes, clerodanes, pimaranes, abietanes, kauranes, cembranes and their cyclization products. The literature from January to December, 2015 is reviewed.