Evaluation of some biological activities of Abelia triflora R Br (Caprifoliaceae) constituents

Purpose: To investigate the antioxidant, anti-inflammatory, antidiabetic,  cardiovascular and cytotoxic activities of the leaf extract and major compounds isolated from Abelia triflora R. Br. (Caprifoliaceae)Methods: The chloroform soluble fraction of A. triflora leaves was subjected to several column chromatographic separations to isolate its constituents.  Anti-inflammatory and antioxidant activities were determined in terms of the ability to inhibit NF-kB, iNOS activity and lipoxygenase enzyme, and to decrease oxidative stress in HepG2 cells. Antidiabetic and cardiovascular activities were determined by screening for peroxisome proliferator-activated receptor alpha (PPARα) and PPARɣ agonistic activities. In vitro cytotoxic activity was determined against a set of four human cancer cell lines (SK-MEL, KB, BT-549, SK-OV-3) and two  non-cancerous kidney cell lines (LLC-PK1 and VERO). Cell viability was measured by neutral red assay.Results: Three triterpene acids were isolated from the chloroform fraction namely; ursolic acid (4), 2, 3-dihydroxy ursolic acid (5) and 2, 3, 21-trihydroxy ursolic acid (6). The results showed that ursolic acid exhibited potent inhibition of lipoxygenase enzyme and iNOS (inducible nitric oxide synthase) activity with IC50 (half-maximal inhibitory concentration) value of 13.0 μg/mL, compared to parthenolide positive standard (IC50, 0.3μg/mL); furthermore, it inhibited NF-kB (nuclear factor-kappa B) with IC50 of 25.0 μg/mL, compared to parthenolide (positive standard, (IC50, 0.5 μg/mL). Also, ursolic acid possessed the highest cytotoxic effect against the three cell lines, SK-MEL (IC50, 14.5 μg/mL), BT-549 (IC50, 16.0 μg/mL) and SK-OV-3 (IC50, 12.5 μg/mL). Only 2,3-dihydroxy ursolic acid activated PPARɣ (1.5-fold at 25 μM), compared to rosiglitazone (positive standard, 3.7 fold at 10 μM)Conclusion: Among the investigated compounds, ursolic acid exhibited the highest anti-inflammatory and cytotoxic activities, while 2,3-dihydroxy ursolic acid demonstrated antidiabetic activity via activation of PPARɣ.Keywords: Abelia triflora, Anti-inflammatory, Antidiabetic, Cardiovascular activity, Antioxidant, Cytotoxi

A cost-effective o-toulidine-based Schiff base as an efficient sorbent for metal ion uptake from aqueous and soil samples: Synthesis, antimicrobial, and acute toxicity analyses

Heavy metals create serious health problems, so the practical implementation and development of low-cost sorbent materials to remove heavy metals from the ecosystem is a worldwide issue. The purpose of this study is to find a low-cost ligand that has the potential to adsorb heavy metals from aqueous and soil samples and also has biological potential. For this, a Schiff base, dimeric o-toluidine (SBL), has been synthesized through condensation, characterized by spectroscopic analysis, and had its biological activities measured. We also studied its adsorption efficiency through a batch technique to remove Zn(II), Co(II), and Cu(II) from aqueous and soil samples under different conditions such as metal ion concentration, pH, contact time, and SBL concentration. The adsorption potential of SBL was analyzed by the Langmuir and Freundlich adsorption isotherms. The values of correlation coefficients revealed that the Freundlich isotherm elucidated results that were more appropriable than the Langmuir model. Adsorption equilibrium was established in 90 min for aqueous samples and in 1,440 min for soil samples. For the maximum adsorption of all metals, the optimum pH was 8, and it showed a capacity to remove 77 to 95 percent of metals from the samples. The maximum adsorption capacity (qmax) of SBL were 75.75, 62.50, and 9.17 mg g-1 in the case of Cu(II), Zn(II), and Co(II) ions, respectively, from aqueous samples and 10.95, 64.10, and 88.49 mg g-1 in the case of Zn(II), Cu (II), and Co(II), respectively, from soil samples. The effectiveness of SBL in the sorption of the selected metals was found to be Cu+2 > Zn+2 > Co+2 for aqueous samples and Co+2 > Cu+2 > Zn+2 for soil samples. The antimicrobial activity of SBL was also investigated. The results revealed that SBL showed moderate inhibitory activity against Staphylococcus dysentria, C. albican, and Aspergillus niger, whereas it exhibited weak activity against S. aureus, P. aureginosa, K. pneumoniae, P. vulgaris, and E.coli when compared to Fluconazole and Ciprofloxacin as the standard. Acute toxicity of the synthesized compound was measured through its daily oral administration with various doses ranging from 0.1 to 1,000 mg/kg of the mice’s body weights. Even at the dose of 1,000 mg/kg, the SBL showed no mortality or any type of general behavioral change in the treated mice. Based on preparation cost, metal removal capacity, toxicity, and antimicrobial activities, SBL is an excellent sorbent and should be studied at pilot scale levels

Synthesis, characterisation and crystal structure of a novel pyridyl urea macrocycle

A novel pyridyl urea based macrocycle has been synthesised and fully characterised including a single crystal X-ray structure determination. The synthetic approach first involves the reaction of benzyloxycarbonylaminopropyl-3-isocyanate with t-butyl 2-[(2-aminopyridin-3-yl)oxy]acetate resulting in a coupling product. After deprotection of the amine and acid moieties and coupling subsequent coupling in the presence of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC), a macrocycle is formed. The structures of the compounds were confirmed by mass spectrometry and NMR spectroscopy. The X-ray crystal structure of the macrocycle reveals as expected a non-binding conformation with an intramolecular hydrogen bond between the urea NH and the pyridyl nitrogen

X-ray crystallographic and validated HPTLC analysis of the biomarker chromone glucoside (schumanniofioside A) isolated from Acalypha fruticosa growing in Saudi Arabia

A chromone glucoside 2-methyl-5,7-dihydroxychromone 5-O-β-D-glucopyranoside (schumanniofioside A, compound 1) was isolated from the methanol extract of Acalypha fruticosa. The structure of compound 1 was fully assigned based on nuclear magnetic resonance (NMR) (1H, 13C and 2D) spectra and electrospray ionization mass spectrum (ESI-MS) in addition to X-ray Crystallography. The molecules were packed in the crystal structure by eight intermolecular OH⋯O and CH⋯O interactions. The structure of compound 1 belongs to monoclinic, P21, a = 9.1989 (4) Å, b = 4.6651 (2) Å, c = 20.4042 (7) Å, β = 97.862 (3)°, V = 867.31 (6) Å3, Z = 2, wRref (F2) = 0.101, T = 100 K. Thus, the bond angles, bond lengths and absolute structure of compound 1 were confirmed by its X-ray structure. A validated HPTLC method was developed for the quantitative analysis of compound 1 in chloroform and methanol extracts of A. fruticosa. It was found to furnish a compact and sharp band of compound 1 at Rf = 0.13 ± 0.005 using chloroform, methanol and glacial acetic acid [17:3:0.5 (v/v/v)] as mobile phase. The LOD and LOQ for compound 1 were found to be 17.86 and 54.13 ng/band, respectively. Compound 1 was found in both chloroform and methanol extracts of the plant (0.03% w/w and 0.31% w/w, respectively). The proposed HPTLC method can be used for the further analysis of schumanniofioside A in different plant extracts, herbal formulations and biological samples as well as in process quality control

A Comparative Analysis of Polysaccharides and Ethanolic Extracts from Two Egyptian Sweet Potato Cultivars, Abees and A 195: Chemical Characterization and Immunostimulant Activities

Sweet potato (Ipomoea batatas (L.) Lam.) belongs to family Convolvulaceae. The plant is distributed worldwide and consumed, especially for its edible tubers. Many studies have proved that the plant has variable biological activities such as antidiabetic, anti-cancer, antihypertensive, antimicrobial, and immunostimulant activities. The roots of sweet potatoes are rich in valuable phytochemical constituents that vary according to the flesh color. Our investigation focused on the chemical profiling of two Egyptian sweet potato cultivars, Abees and A 195, using UPLC-QTOF and the analysis of their polysaccharide fractions by GC-MS. Furthermore, we assessed the immunostimulant properties of these extracts in immunosuppressed mice. The study revealed that sweet potato roots contain significant concentrations of phenolic acids, including caffeoylquinic, caffeic, caffeoyl-feruloyl quinic, and p-coumaric acids, as well as certain flavonoids, such as diosmin, diosmetin, and jaceosidin, and coumarins, such as scopoletin and umbelliferone. Moreover, polysaccharides prepared from both studied cultivars were analyzed using GC-MS. Further biological analysis demonstrated that all the tested extracts possessed immunostimulant properties by elevating the level of WBCs, IL-2, TNF, and IFN-γ in the immunosuppressed mice relative to the control group with the highest values in polysaccharide fractions of A195 (the ethanolic extract showed a higher effect on TNF and IFN-γ, while its polysaccharide fraction exhibited a promising effect on IL-2 and WBCs). In conclusion, the roots of the Egyptian sweet potato cultivars Abees and A 195 demonstrated significant immunostimulant activities, which warrants further investigation through clinical studies

Isochlorogenic Acid Glucosides from the Arabian Medicinal Plant <i>Artemisia sieberi</i> and Their Antimicrobial Activities

A phytochemical investigation of the stems of the Arabian plant Artemisia sieberi afforded three new isochlorogenic acid derivatives, namely isochlorogenic acid A-3′-O-β-glucopyranoside (1), isochlorogenic acid A-3′-O-β-glucopyranoside methyl ester (2), and isochlorogenic acid C-3′-O-β-glucopyranoside (3), obtained along with thirteen known secondary metabolites belonging to distinct structural classes. The structures of the new metabolites were elucidated by modern spectroscopic techniues based on high-resolution mass spectrometry (HR-ESIMS) and 1D/2D nuclear magnetic resonance (NMR). All isolated compounds were tested for their potential antimicrobial activity against four different bacterial strains (Bacillus subtilis, Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa), in addition to a fungal strain (Candida tropicalis), The results were expressed as the diameter of the clear zone (in millimetres) around each well. Compounds 1 and 3 (isochlorogenic acid A-3′-O-β-glucopyranoside and isochlorogenic acid C-3′-O-β-glucopyranoside, respectively) displayed remarkable antifungal effect and potent antibacterial activities against B. subtilis and S. aureus, respectively. 3α,4α-10β-trihydroxy-8α-acetyloxyguaian-12,6α-olide (6) and angelicoidenol 2-O-β-d-glucopyranoside (9) emerged as interesting dual antibacterial (selective on P. aeruginosa)/antifungal agents

Phytochemical analysis of Anvillea garcinii leaves: identification of garcinamines F-H and their antiproliferative activity

Anvillea garcinii is a medicinal plant used in the Arab region for intestinal diseases, lung and liver diseases, digestive problems, and as an antidiabetic agent. Repeated chromatographic purifications of A. garcinii leaves led to the isolation of three undescribed guaiane sesquiterpene derivatives, named garcinamines F–H, characterized by the presence of an amino acid unit, along with five known sesquiterpene lactones (garcinamines B–E and 9-hydroxyparthenolide). The structures of the new compounds were established using spectroscopic (1D and 2D NMR) and spectrometric methods (ESIMS). Garcinamine H possesses a double bond at the D1,10 position, a structural feature rarely reported in guaianolide-type sesquiterpenes. The antiproliferative activity of the isolated sesquiterpenes was screened against three different cancer cell lines, and 9-hydroxyparthenolide and garcinamines C and D displayed significant effects against lung carcinoma (A549), colon carcinoma (LoVo), and breast carcinoma (MCF7) cell lines

Penicillactonin and preaustinoid C, lactone-containing metabolites from a hot spring sediment Penicillium sp

Phytochemical investigation of Penicillium sp. RO-11 strain, collected from the sediments of a hydrothermal spring located in the southwestern area of Saudi Arabia, afforded, along with previously isolated compounds, the undescribed polyketides penicillactonin (1), penipyranicin D (4) and isopyrenulin B (5) and the undescribed meroterpenoid preaustinoid C (7). The structures of these compounds were elucidated based on data from mass spectrometry, 1D and 2D NMR, and comparison between experimental and calculated ECD spectra. Penicillactonin and preaustinoid C bring unprecedented structural features, for which a biosynthetic rationale is proposed, further extending the chemodiversity associated to Penicillium fungi. Preaustinoid C showed significant activity against LPS-induced NO production and selective effect on IL-2 and IFN-γ gene regulation in activated Jurkat cells