Identification of Iridoids,Flavonoids and Triterpenes from the Methanolic Extract of Melampyrum bihariense A. Kern. and the Antioxidant Activity of the Extract

Melampyrum bihariense A. Kern. (Scrophulariaceae), a plant species used in traditional medicine for the treatment of rheumatic disorders and skin infections, was investigated with regard to its antioxidant activity and identification of its bioactive chemical constituents. The crude methanolic extract of the aerial parts of M. bihariense was examined by the spectrophotometric DPPH (1,1-diphenyl-2-picrylhydrazyl) and ferric reducing antioxidant power methods. The free radical scavenging capacity (SC₅₀) of the extract was found by the DPPH method to be 27.10 mg mL⁻¹, and the ferric reducing ability equivalent to ascorbic acid at 50 mg mL⁻¹ was 0.709 μg mL⁻¹. The chemical composition of this highly effective in the methanolic extract was analysed, and the main compounds were isolated through solvent–solvent partition, and multiple chromatographic separations, including column chromatography, vacuum liquid chromatography, centrifugal planar chromatography and preparative thin-layer chromatography. The structures were established by one- and two-dimensional NMR and liquid chromatography-mass spectrometry. The iridoids aucubin (1), 8-epi-loganin (2) and mussaenoside (3), the flavones apigenin and luteolin and the triterpene acids ursolic acid and oleanolic acid were identified; components 2, 3, ursolic acid and oleanolic acid for the first time in this species. The present study reveals that M. bihariense exerts antioxidant activity, and the iridoids, flavonoids and triterpene acids may be the main bioactive constituents of its methanolic extract.

     

Investigation of antiplasmodial efficacy of lupeol and ursolic acid isolated from Ficus benjamina leaves extract

Abstract

This study emphasizes on the investigation of antiplasmodial activity of triterpenoids isolated from Ficus benjamina leaves. An unsaponified fraction of petroleum ether extract of plant leaves was subjected to silica gel column chromatography which led to the isolation of two known triterpenoids; namely ursolic acid and lupeol. These compounds were evaluated for antiplasmodial activity by schizont maturation inhibition assay using 3D7 Plasmodium strains. Both, ursolic acid and lupeol were found to exhibit significant antiplasmodial effect with an IC₅₀ value of 18?µg/ml and 3.8?µg/ml, respectively. This study further confirms the traditional role of Ficus benjamina plant in the treatment of malaria which may be attributed to ursolic acid and lupeol.     

Phytochemical analysis,antimicrobial, antioxidant and urease inhibitory potential of Cyphostemma digitatum Lam.

In this paper we report the antimicrobial, antiradical and urease inhibitory potential along with photochemical investigation of the crude extracts of Cyphostemma digitatum Lam. Phytochemical screening of both the crude (hot/cold) alcoholic and aqueous extracts of C. digitatum showed the presence of alkaloids, flavonoids, saponins, coumarins, steroids, terpenoids and tannins. The crude methanolic extract (hot/cold) exhibited good antioxidant activity, while the aqueous extract was a weak antioxidant. The crude methanolic extract was found to be more active against Bacillus subtilis, while both the extracts showed moderate antifungal potential, the methanolic crude extract showed good urease inhibitory activity compared with the aqueous crude extract.     

Two new cytotoxic furoquinoline alkaloids isolated from Aegle marmelos (Linn.) Correa

Two new cytotoxic furoquinoline alkaloids were isolated from the leaves of Aegle marmelos (Linn.) Correa; one from the total alkaloidal fraction (acid/base shake-out method) of the CHCl₃ extract and identified as 7,8-dihydroxy-4-hydrofuroquinoline and named trivially as Aegelbine-A. The other new alkaloid isolated from the pet. ether extract and identified as 4-hydro-7-hydroxy-8-prenyloxyfuroquinoline and named trivially as Aegelbine-B, together with a known alkaloid; aegeline and a known phenolic acid; ρ-hydroxybenzoic acid. The structures of all the isolated compounds were established based on 1D and 2D NMR spectroscopy and HR-ESI/MS. The cytotoxic activity of the isolated compounds was evaluated in vitro against HepG-2, PC3, A549 and MCF-7 cell lines. The obtained results revealed promising activity with structure-based relationship which is discussed briefly.     

Identification of Iridoids,Flavonoids and Triterpenes from the Methanolic Extract of Melampyrum bihariense A. Kern. and the Antioxidant Activity of the Extract

Melampyrum bihariense A. Kern. (Scrophulariaceae), a plant species used in traditional medicine for the treatment of rheumatic disorders and skin infections, was investigated with regard to its antioxidant activity and identification of its bioactive chemical constituents. The crude methanolic extract of the aerial parts of M. bihariense was examined by the spectrophotometric DPPH (1,1-diphenyl-2-picrylhydrazyl) and ferric reducing antioxidant power methods. The free radical scavenging capacity (SC₅₀) of the extract was found by the DPPH method to be 27.10 mg mL^?1, and the ferric reducing ability equivalent to ascorbic acid at 50 mg mL^?1 was 0.709 μg mL^?1. The chemical composition of this highly effective in the methanolic extract was analysed, and the main compounds were isolated through solvent–solvent partition, and multiple chromatographic separations, including column chromatography, vacuum liquid chromatography, centrifugal planar chromatography and preparative thin-layer chromatography. The structures were established by one- and two-dimensional NMR and liquid chromatography-mass spectrometry. The iridoids aucubin (1), 8-epi-loganin (2) and mussaenoside (3), the flavones apigenin and luteolin and the triterpene acids ursolic acid and oleanolic acid were identified; components 2, 3, ursolic acid and oleanolic acid for the first time in this species. The present study reveals that M. bihariense exerts antioxidant activity, and the iridoids, flavonoids and triterpene acids may be the main bioactive constituents of its methanolic extract.     

Antioxidant,antimicrobial and urease inhibiting activities of methanolic extracts from Cyphostemma digitatum stem and roots

Cyphostemma digitatum stem and roots extracts were investigated for antioxidant, antimicrobial, urease inhibition potential and phytochemical analysis. Phytochemical screening of the roots and stem extract revealed the presence of secondary metabolites including flavonoids, alkaloids, coumarins, saponins, terpenoids, tannins, carbohydrates/reducing sugars and phenolic compounds. The methanolic extracts of the roots displayed highest antioxidant activity (93.518%) against DPPH while the crude methanolic extract of the stem showed highest antioxidant activity (66.163%) at 100 μg/mL concentration. The methanolic extracts of both stem and roots were moderately active or even found to be less active against the selected bacterial and fungal strains (Tables S2 and S3). The roots extract (methanol) showed significant urease enzyme inhibition activity (IC₅₀ = 41.2 ± 0.66; 0.2 mg/mL) while the stem extract was found moderately active (IC₅₀ = 401.1 ± 0.58; 0.2 mg/mL) against thiourea (IC₅₀ = 21.011; 0.2 mg/mL).     

New alkaloids from the leaves of Evodia rutaecarpa

One new indole alkaloid (1) and one new indole alkaloidal glycoside (2), together with nine known alkaloids (3–11), were isolated from the leaves of Evodia rutaecarpa. Their structures were determined on the basis of spectroscopic and chemical methods. Compound 4 exhibited potent activity against Pseudomonas aeruginosa with an MIC value of 7.13 μg/ml.     

Bioactive compounds and antioxidant capacity of Chuquiraga jussieui J.F.Gmel from the highlands of Ecuador

Abstract

Chuquiraga jussieui J.F.Gmel is grown between 3000 and 5000 meters above sea level throughout the Andean region of Ecuador and used by the indigenous populations of the Andes for medicinal purposes. Here, we determined the total phenolic, flavonoids, vitamin C and carotenoids content of the leaves and flowers of Ch. jussieui J.F.Gmel from different highlands of Ecuador as well as the capacity of a crude methanolic extract from the both parts of the plant to scavenge free radicals and protect red blood cell membranes from lipid oxidation. The leaves showed a high bioactive compound content in comparison to the flowers. The crude extract from the leaves proved to be more effective than the flowers in reducing iron and scavenging the DPPH, O₂^? and H₂O₂ radicals, as well as in protecting cellular membrane against lipid oxidation, demonstrating that Ch. jussieui J.F.Gmel represents an important source of bioactive compounds with relevant healthy properties.     

Antimalarial and cytotoxic activities of pregnene-type steroidal alkaloids from Holarrhena pubescens roots

The phytochemical investigation of an alkaloidal extract of Holarrhena pubescens roots led to the isolation and identification of a new pregnene-type alkaloid, mokluangin D (1), together with nine known steroidal alkaloids (2–10). The structure of the new metabolite was determined on the basis of spectroscopic analyses including 1D- and 2D-NMR spectroscopy and mass spectrometry. Compounds 3 and 4 showed potent antimalarial activity against Plasmodium falciparum K1 stain with IC₅₀ values of 1.2 and 2.0 μM, respectively, and showed weak cytotoxic activity against the NCI-H187 cell line with IC₅₀ values of 27.7 and 30.6 μM, respectively. The substituent groups at C-3 and the carbonyl group at C-18 are important for the activity against the P. falciparum K1 stain.     

New alkaloids from Phoebe grandis (Nees) Merr

The alkaloidal extract of the leaves of Phoebe grandis (nees) merr. have provided two new minor alkaloids; phoebegrandine D (1), a proaporphine-tryptamine dimer, and phoebegrandine E (2), an indoloquinolizidine. This is the first report on the occurrence of an indoloquinolizidine in the Phoebe species. The crude extract also exhibited antiplasmodial activity (IC50<8 microg mL-1). The structures of the novel compounds were elucidated by spectroscopic methods, notably 2D NMR and HRMS.     

Triterpene Acids from the Leaves of Planchonella Duclitan (Blanco) Bakhuizan

From the methanolic extract of the leaves of Planchonella duclitan, 2α,3α,19α,23‐tetrahydroxy‐13,27‐cyclours‐11‐en‐28‐oic acid (1), myrianthic acid (2), 2‐hydroxyursolic acid (3), ursolic acid (4), pomolic acid (5), rotundic acid (6), and jacoumaric acid (7) were isolated, and their structures were elucidated on the basis of their spectroscopic analysis. Among them, compound 1 was a new cyclopropyl ursane‐type triterpene acid. Additionally, compounds 4 and 7 showed significant cytotoxicity toward human colorectal carcinoma cell line HT29 and human breast carcinoma cell line MCF‐7 with IC₅₀ values ranging from 5.8 ± 1.4 to 6.5 ± 1.9 μM.     

Antioxidant and Anticholinesterase Activities of Extracts and Phytochemicals of Syzygium antisepticum Leaves

Bioassay-guided separation of young leaves extracts of Syzygium antisepticum (Blume) Merr. & L.M. Perry led to the isolation of four triterpenoids (betulinic acid, ursolic acid, jacoumaric acid, corosolic acid) and one sterol glucoside (daucosterol) from the ethyl acetate extract, and three polyphenols (gallic acid, myricitrin, and quercitrin) from the methanol (MeOH) extract. The MeOH extract of S. antisepticum and some isolated compounds, ursolic acid and gallic acid potentially exhibited acetylcholinesterase activity evaluated by Ellman’s method. The MeOH extract and its isolated compounds, gallic acid, myricitrin, and quercitrin, also strongly elicited DPPH radical scavenging activity. In HEK-293 cells, the MeOH extract possessed cellular antioxidant effects by attenuating hydrogen peroxide (H₂O₂)-induced ROS production and increasing catalase, glutathione peroxidase-1 (GPx-1), and glutathione reductase (GRe). Furthermore, myricitrin and quercitrin also suppressed ROS production induced by H₂O₂ and induced GPx-1 and catalase production in HEK-293 cells. These results indicated that the young leaves of S. antisepticum are the potential sources of antioxidant and anticholinesterase agents. Consequently, S. antisepticum leaves are one of indigenous vegetables which advantage to promote the health and prevent diseases related to oxidative stress.     

Antigonon leptopus: a potent biological source for extermination of fish bacterial pathogens Providencia and Aeromonas

This study pertains to the phytochemical components and the biological properties of the weed, Antigonon leptopus Hook. & Arn. (AUT/PUS/064). Phytochemical screening of methanolic leaf extract of A. leptopus revealed the presence of saponin, phenolic compounds, tannins, flavonoids, alkaloids, fixed oils and amino acids. Accordingly, 12 phytochemical components were analysed and characterised by GC–MS. Antibacterial activity was evaluated against fish and clinical pathogens. Fish pathogens, Providencia vermicola (MTCC 5578) and Aeromonas hydrophila (MTCC 646) were more sensitive to the methanolic leaf extract than clinical pathogens. A useful information was obtained from the phytochemistry of A. leptopus leaves, which would pave way to further applications to treat fish diseases and for utility in the pharmaceutical field.     

New Adenosine Derivatives from Aizoon canariense L.: In Vitro Anticholinesterase,Antimicrobial, and Cytotoxic Evaluation of Its Extracts

Aizoaceae is a large succulent family characterized by many psychoactive species. Aizoon canariense L., a wild neglected plant traditionally used in gastrointestinal ailments, has been the subject of a limited number of phytochemical and biological studies. Therefore, herein, we investigated the in vitro cytotoxic, antimicrobial, and anticholinesteraseactivity of the aerial parts of A. canariense L. and analyzed the phytochemical compositions of the lipoidal and alkaloidal fractions. Petroleum ether extract showed the presence of behenic and tricosylic acid, while an in-depth investigation of the alkaloidal fraction revealed the identification of new adenine based alkaloids (1–5), which were isolated and identified for the first time from Aizoon canariense L. Their structures were elucidated based on extensive spectroscopic analyses. The alkaloidal extract showed a powerful cytotoxic effect (IC₅₀ 14–28 μg/mL), with the best effect against colon carcinoma, followed by liver and breast carcinomas. The alkaloidal extract also had a potent effect against Candida albicans and Escherichia coli, with minimum inhibitory concentrations (MIC) values of 312.5 and 625 µg/mL. The in vitro anticholinesterase activity was potent, with IC₅₀ < 200 ng/mL for the tested extracts compared with 27.29 ± 0.49 ng/mL for tacrine.     

Isolation and antiproliferative activity of triterpenoids and fatty acids from the leaves and stem of Turraea vogelii Hook. f. ex benth

Chloroform extract from the leaves of Turraea vogelii Hook f. ex Benth demonstrated cytotoxic activity against a chronic myelogenous leukemia cell, K-562 with IC₅₀ of 14.27 μg/mL, while chloroform, ethyl acetate and methanol extracts from the stem of the plant inhibited K-562 cells growth with IC₅₀ of 19.50, 24.10 and 85.40 μg/mL respectively. Bioactive chloroform extract of Turraea vogelii leaves affords two triterpenoids: oleana-12,15,20-trien-3β-ol (1), and oleana-11,13-dien-3β,16α,28-triol (2), with six fatty esters, ethyl hexaeicos-5-enoate (3), 3-hydroxy-1,2,3-propanetriyltris(tetadecanoate) (4), 1,2,3-propanetriyl(7Z,7′Z,7′′Z)tris(-7-hexadecenoate) (5), 1,2,3-propanetriyl(5Z,5′Z,5′′Z)tris(-5-hexadecenoate) (6), 1,2,3-propanetriyltris(octadecanoate) (7), and 2β-hydroxymethyl tetraeicosanoate (8). Tetradecane (9), four fatty acids: hexadecanoic acid (10), tetradecanoic acid (11), (Z)-9-eicosenoic acid (12), and ethyl tetradec-7-enoate (13) were isolated from chloroform extract of Turraea vogelii stem. 1,2,3-propanetriyltris(heptadecanoate) (14), (Z)-9-octadecenoic acid (15) and (Z)-7-tetradecenoic acid (16) were isolated from ethyl acetate extract while (Z)-5-pentadecenoic acid (17) was obtained from methanol extract of the plant stem. Compounds 1, 2, 5, 6, 11, 12, 15, 16 and 17 exhibited pronounced antiproliferative activity against K-562 cell lines.     

Echinophora tenuifolia L. branches phytochemical profile and antiproliferative activity on human cancer cell lines

Abstract

The methanolic extract of Echinophora tenuifolia L. branches and its fractions were evaluated for their in vitro cell growth inhibitory activity on different human cancer cell lines (C32, LoVo and SKBr3) and the normal BJ fibroblasts. All tested samples were effective against the melanoma cell line C32, with IC₅₀ values ranging from 22.8?±?0.8 to 78.7?±?1.2?μg/mL, the antiproliferative activity of the dichloromethane fraction being significantly higher. This fraction was also effective against the LoVo adenocarcinoma cell line, with an IC₅₀ value of 53.0?±?2.1?μg/mL. The ethyl acetate and dichloromethane fractions showed the highest lipid peroxidation inhibitory activity, verified by means of the β-carotene bleaching test. The phytochemical profiles of E. tenuifolia branches extract were established by means of GC-MS and HPTLC. Overall, branches of E. tenuifolia L. could represent a rich source of bioactive compounds, potentially useful in the pharmaceutical field.     

In vitro anti-oxidant potential of new metabolites from Hypericum oblongifolium (Guttiferae)

Phytochemical investigations on Hypericum oblongifolium led to the isolation of a flavone named folicitin (1) and a bicyclic conjugated lactone, folenolide (2) from the ethyl acetate fraction of methanolic extract. Both metabolites were characterised as new compounds based on detailed spectroscopic analyses. In vitro anti-oxidant potential of both the compounds was evaluated by the DPPH radical scavenging assay. Compound 1 exhibited significant antioxidant activity while compound 2 was found inactive.     

Polar constituents of <Emphasis Type="Italic">Ligustrum vulgare</Emphasis> L. and their effect on lipoxygenase activity

The present work summarizes results of isolation and identification of polar constituents of the methanolic extract of Ligustrum vulgare L. leaves and of the evaluation of inhibiting activity of selected isolates on rat lung cytosol fraction lipoxygenase. Six different compounds were isolated from the ethylacetate and butanol portions of the methanolic extract (hydroxytyrosol and its glucoside, ligustroflavon, oleuropein, acteoside, echinacoside). The inhibitory activity of oleuropein, echinacoside and the water infusion of Ligustrum vulgare leaves tested on LOX was expressed as IC₅₀. Kinetic parameters (K _M, V _max) and type of inhibition were determined. As the most effective in competitive inhibition of LOX, oleuropein was proved.     

Antileishmanial diterpenoid alkaloids from Aconitum spicatum (Bruhl) Stapf

The crude extracts of tubers of Aconitum spicatum (Bruhl) Stapf were investigated for in vitro antileishmanial activity against Leishmania major. The dichloromethane extract at pH 2.5 showed antileishmanial activity with IC₅₀ value of 27.10 ± 0.0 μg/mL. Chromatographic purification of the dichloromethane extract led to isolation of three C-19 norditerpenoid alkaloids indaconitine (1), chasmaconitine (2) and ludaconitine (3). Compounds 3 and 2 showed antileishmanial activity with IC₅₀ = 36.10 ± 3.4 and 56.30 ± 2.1 μg/mL, respectively. Compound 1 was less effective (IC₅₀ > 100 μg/mL). The cytotoxicity of compounds 1, 2 and 3 studied against MCF7, HeLa and PC3 cancer cell lines and 3T3 normal fibroblast cell line did not show cytotoxicity at 30 μM.     

A new triterpene and protective effect of Periploca somaliensis Browicz fruits against CCl4-induced injury on human hepatoma cell line (Huh7)

The potential hepatoprotective effect of the methanolic extract of Periploca somaliensis Browicz fruits, its different fractions (n-hexane, chloroform and n-butanol) and the major isolated compound ursolic acid was evaluated using the human hepatoma cell line (Huh7) based on the changes in the activity of aspartate aminotransferase, alanine transaminase, glutathione and superoxide dismutase. Each sample was tested at three different concentrations (1000, 100 and 10 μg/mL). All tested samples exhibited a potent concentration-independent cytoprotective effect relative to silymarin as a reference standard. Chromatographic fractionation of the chloroform-soluble fraction of the methanol extract of P. somaliensis Browicz fruits afforded two known triterpenes, namely ursolic acid, and 11α,12α-epoxy-3β-hydroxy-olean-13β,28-olide, and a newly discovered one, namely 3β-hydroxy-urs-11-en-13β,28-olide. The structures of the isolated compounds were elucidated by the analysis of 1D and 2D NMR spectral data.