Structural determination of salsolins A and B, new antioxidant polyoxygenated triterpenes from Salsola baryosma, by 1D and 2D NMR spectroscopy

Phytochemical profiling of Salsola tetragona Delile by LC-HR/MS and investigation of the antioxidant, anti-inflammatory, cytotoxic, antibacterial and anti-SARS-CoV-2 activities

This study aimed to investigate the phytochemical composition and biological activity of Salsola tetragona Delile. (Amaranthaceae), a medicinal plant. The study evaluated the antioxidant potential of the crude extract and five fractions of S. tetragona using DPPH•, ABTS•+, CUPRAC, and metal chelating assays. The anti-inflammatory activity was determined using a protein denaturation assay, and the antibacterial activity was determined by the Minimum inhibitory concentrations (MICs) for the growth of Escherichia coli and Staphylococcus aureus strains. The MTT test and an in vitro scratch assay evaluated the effects on cell viability and cell migration. The potential anti-SARS-CoV-2 activity was assessed by analyzing the effects on the interaction between ACE2 and Spike protein. The bioactive compounds present in the plant were identified using LC-HR/MS analysis. The crude hydromethanolic extract (STM) and five fractions of S. tetragona, n-hexane (STH), dichloromethane (STD), ethyl acetate (STE), n-butanol (STB), and aqueous (STW) showed significant antioxidant activity in four different tests. In the anti-inflammatory assay, the ethyl acetate fraction exhibited significantly higher activity than Aspirin® (IC50 = 13 ± 5 µg/mL). The crude extract and its fractions showed positive antibacterial activity with similar MICs. In the cytotoxicity assay against the breast cancer cell line MCF7, the dichloromethane fractions (STD) were very effective and demonstrated superiority over the other fractions (IC50 = 98 µg/mL). Moreover, the potential of the extract and fractions as anti-SARS-CoV-2, the ethyl acetate, and dichloromethane fractions demonstrated important activity in this test. LC-HR/MS analysis identified 16 different phenolic compounds, Eleven of which had not been previously reported in the genus Salsola. The results suggest that the extracts of S. tetragona have the potential to become new sources for developing plant-based therapies for managing a range of diseases.

The old world salsola as a source of valuable secondary metabolites endowed with diverse pharmacological activities: a review

Salsola is an important genus in the plant kingdom with diverse traditional, industrial, and environmental applications. Salsola species are widely distributed in temperate regions and represent about 45% of desert plants. They are a rich source of diverse phytochemical classes, such as alkaloids, cardenolides, triterpenoids, coumarins, flavonoids, isoflavonoids, and phenolic acids. Salsola spp. were traditionally used as antihypertensive, anti-inflammatory, and immunostimulants. They attracted great interest from researchers as several pharmacological activities were reported, including analgesic, antipyretic, antioxidant, cytotoxic, hepatoprotective, contraceptive, antidiabetic, neuroprotective, and antimicrobial activities. Genus Salsola is one of the most notorious plant genera from the taxonomical point of view. Our study represents a comprehensive review of the previous phytochemical and biological research on the old world Salsola secies. It is designed to be a guide for future research on different plant species that still belong to this genus or have been transferred to other genera.

Isolation of New Constituents from Whole Plant of Salsola imbricata Forssk. of Saudi Origin

This work describes the first report of the known glycosidic constituents β-sitosterol-3-O-β-d-glucoside-6'-palmitate (1), β-sitosterol-3-O-β-d-glucoside (2), momor-cerebroside I (3), phytolacca cerebroside (4), 1,2-di-O-palmitoyl-3-O-(6-sulfoquinovopyranosyl)-glycerol (5), isorhamnetin-3-robinobioside (6), and isorhamnetin-3-rutinoside (7) from the plant Salsola imbricata Forssk. grown in the eastern region of Saudi Arabia. The structures of the isolated compounds were elucidated from extensive 1D and 2D nuclear magnetic resonance (NMR), gas chromatography-mass spectrometry (GC-MS), liquid chromatography-mass spectrometry (LC-MS), and chemical analyses. Compound 1 is reported for the first time from the Amaranthaceae family. In addition to the isolated and identified fatty alcohols, compounds 3, 4, 5, and 6 are also reported for the first time from the genus Salsola. The findings of this study suggest a contribution of the isolated compounds to the various biological activities reported for this plant.

Genus Salsola: Chemistry, Biological Activities and Future Prospective-A Review

The genus Salsola L. (Russian thistle, Saltwort) includes halophyte plants and is considered one of the largest genera in the family Amaranthaceae. The genus involves annual semi-dwarf to dwarf shrubs and woody tree. The genus Salsola is frequently overlooked, and few people are aware of its significance. The majority of studies focus on pollen morphology and species identification. Salsola has had little research on its phytochemical makeup or biological effects. Therefore, we present this review to cover all aspects of genus Salsola, including taxonomy, distribution, differences in the chemical constituents and representative examples of isolated compounds produced by various species of genus Salsola and in relation to their several reported biological activities for use in folk medicine worldwide.

Biological activities of Agave by-products and their possible applications in food and pharmaceuticals

Agave leaves are considered a by-product of alcoholic beverage production (tequila, mezcal and bacanora) because they are discarded during the production process, despite accounting for approximately 50% of the total plant weight. These by-products constitute a potential source of Agave extracts rich in bioactive compounds, such as saponins, phenolic compounds and terpenes, and possess different biological effects, as demonstrated by in vitro and in vivo tests (e.g. antimicrobial, antifungal, antioxidant, anti-inflammatory, antihypertensive, immunomodulatory, antiparasitic and anticancer activity). Despite their positive results in biological assays, Agave extracts have not been widely evaluated in food systems and pharmaceutical areas, and these fields represent a potential route to improve the usage of Agave plants as food additives and agents for treating medical diseases. © 2017 Society of Chemical Industry.

Previously undescribed fridooleanenes and oxygenated labdanes from the brown seaweed Sargassum wightii and their protein tyrosine phosphatase-1B inhibitory activity

Previously undescribed fridooleanene triterpenoids 2α-hydroxy-(28,29)-frido-olean-12(13), 21(22)-dien-20-propyl-21-hex-4'(Z)-enoate, 2α-hydroxy-(28,29)-frido-olean-12(13), 21(22)-dien-20-prop-2(E)-en-21-butanoate and oxygenated labdane diterpenoids 2α-hydroxy-8(17), (12E), 14-labdatriene, 3β, 6β, 13α-tri hydroxy 8(17), 12E, 14-labdatriene were purified from the ethyl acetate-methanol and dichloromethane fractions of the air-dried thalli of Sargassum wightii (Sargassaceae), a brown seaweed collected from the Gulf-of-Mannar of Penninsular India. Inhibitory potential of Δ12 oleanenes towards protein tyrosine phosphatase-1B, the critical regulator of insulin-receptor activity were found to be significantly greater (IC50 0.1 × 10-2 and 0.09 × 10-2 mg/mL, respectively) than the standard sodium metavanadate (IC50 0.31 × 10-2 mg/mL). Fridooleanene triterpenoids displayed greater antioxidant activities (IC50DPPH 0.16-0.18 mg/mL) than the commercially available antioxidants, butylated hydroxytoluene and α-tocopherol (IC50DPPH 0.25 and 0.63 mg/mL, respectively). In general, the oxygenated labdane diterpenoids displayed significantly lesser antioxidant and tyrosine phosphatase-1B inhibitory properties than those exhibited by the fridooleanenes. Bioactivities of the titled compounds were primarily determined by the electronic and lipophilic parameters and not by the steric descriptors. Molecular docking simulations and kinetic studies were employed to describe the tyrosine phosphatase-1B inhibitory mechanism. The previously undescribed fridooleanene triterpenoids might be used as potential anti-hyperglycaemic pharmacophore leads to reduce the risk of elevated postprandial glucose levels.

A New Cardenolide and Other Compounds from Salsola tetragona

One new cardenolide, 3- O-β-D-allopyranosylcoroglaucigenin (salsotetragonin) (1), was isolated from the aerial parts of Salsola tetragona Delile with four known cardenolides (2–5), two known flavonoids (6–7), three known phenolic compounds (8–10) and two known fatty acids (11–12). Their structures were identified by spectroscopic analyses and by comparison of their spectral data with those reported in the literature. Compounds 1–5, 7, 10 and 12 were isolated from the genus Salsola for the first time. This is the first report on cardenolides identified in the Amaranthaceae family.

New Isorhamnetin Derivatives from Salsola imbricata Forssk. Leaves with Distinct Anti-inflammatory Activity

BACKGROUND

Salsola imbricata Forssk. is a shrub widely growing in Egypt, used as a camel food, traditionally, used as anti-inflammatory agent. Literature survey showed no report about the anti-inflammatory activity of S. imbricata.

AIM OF THE STUDY

This work was designed to study the phenolic constituents and to provide evidence for the traditional use of S. imbricata as an anti-inflammatory agent.

MATERIALS AND METHODS

The in vitro anti-inflammatory activity of the total aqueous methanol extract and some isolated compounds were investigated in RAW 264.7 macrophage cells using nitric oxide assay. All chemical structures were identified on the basis of electrospray ionization-mass spectrometry, one- and two-dimension nuclear magnetic resonance.

RESULTS

Nine phenolic compounds, among them two new natural products; isorhamnetin-3-O-β-D-glucuronyl (1'''→4'') glucuronide (1) and its dimethyl ester; isorhamnetin-3-O-β-D-di glucuronate dimethyl ester (2), two isorhamnetin glycosides: Isorhamnetin-3-O-β-D-galactopyranoside (3), isorhamnetin-3-O-β-D-glucopyranoside (4), and isorhamnetin (5). In addition, an alkaloidal phenolic; trans N-feruloyl tyramine (6), three phenolic acids: Isovanillic acid (7), ferulic acid (8), and p-hydroxy benzoic acid (9) were isolated from salsola imbricata leaves. All compounds were isolated and identified for the first time from this plant except compound (6). The extract and the tested compounds showed distintict anti-inflammatory activities with no toxicity on RAW 264.7 macrophage cells.

CONCLUSION

The extract and the tested compounds showed distintict anti-inflammatory activities with no toxicity on RAW 264.7 macrophage cells.

SUMMARY

Investigation of the chemical constituents of the leaves of Salsola imbricata led to isolation of two new isorhamnetin derivatives: isorhamnetin.3-O-β-D.glucuronyl (1'"→") glucuronide (1) and its dimethyl ester (2), together with seven known phenolic compounds. The extract and the tested compounds showed distintict anti-inflammatory activities with no toxicity on RAW 264.7 macrophage cells. Abbreviations used: PC: Paper chromatography, MPLC : Medium Pressure Liquid Chromatography, HMBC: Heteronuclear multiple bond correlation, HMQC: Heteronuclear single quantum correlation, NMR: Nuclear magnetic resonance.

Amelioration of adriamycin-induced cardiotoxicity by Salsola kali aqueous extract is mediated by lowering oxidative stress

OBJECTIVES

To assess the cardioprotective effect of the Salsola kali aqueous extract against adriamycin (ADR)-induced cardiotoxicity in male Swiss albino mice.

METHODS

The aqueous extract of S. kali was phytochemically screened by traditional methods for different classes and further evaluated for antioxidant activity in vitro. In vivo, cardioprotective evaluation of the extract was designed to have four groups of mice: (1) control group (distilled water, orally; normal saline, intraperitoneally (i.p.)); (2) ADR group (15 mg/kg, i.p.); (3) aqueous S. kali extract (200 mg/kg, orally); and (4) ADR + S. kali group. ADR (5 mg/kg) was injected three times over 2 weeks while S. kali was orally administered daily for 3 weeks (1 week before and 2 weeks during ADR treatment). Cardioprotective properties were assessed using biochemical and histopathological approaches.

RESULTS

ADR caused a significant increase in serum enzymes (lactate dehydrogenase, creatine phosphokinase, aspartate aminotransferase, and alanine aminotransferase). Myocardial levels of malondialdehyde, nitric oxide, and reduced glutathione, as well as the activities of superoxide dismutase and catalase increased while the activities of glutathione peroxidase and glutathione S-transferase declined. Histopathological examination of heart sections revealed that ADR caused myofibrils loss, necrosis and cytoplasmic vacuolization.

DISCUSSION

Pretreatment with S. kali aqueous extract normalized serum and antioxidant enzymes minimized lipid peroxidation and cardiac damage. These results have suggested that the extract has antioxidant activity, indicating that the mechanism of cardioprotection during ADR treatment is mediated by lowering oxidative stress.

Potent anti-platelet constituents from Centaurea iberica

New naturally occurring nitrogenous compounds 1 and 2, along with a new dimeric lignan glucoside 3, have been isolated from the ethyl acetate soluble fraction of Centaurea iberica. Their structures have been elucidated through spectroscopic techniques. All the isolated compounds showed significant platelet aggregation inhibition.

Triterpenoids

This review covers the isolation and structure determination of triterpenoids including squalene derivatives, protostanes, lanostanes, holostanes, cycloartanes, dammaranes, euphanes, tirucallanes, tetranortriterpenoids, lupanes, oleananes, friedelanes, ursanes, hopanes, isomalabaricanes and saponins; 574 references are cited.