Activity-guided Isolation Research Articles

Activity-guided isolation of α-amylase, α-glucosidase, and pancreatic lipase inhibitory compounds from Rhus coriaria L.

The leaves and fruits of Rhus coriaria are traditionally used in Turkey for the treatment of diabetes. The aim of the present study is to determine α-amylase, α-glucosidase, and pancreatic lipase inhibitory activities of R. coriaria leaf and fruit ethanol extracts (80%), and to isolate active compounds against these enzymes. As a result of the activity-guided isolation, the active compounds were determined as the amentoflavone, agathisflavone, and 1,2,3,4,6-penta-O-galloyl-β-glucopyranose. Agathisflavone, amentoflavone, and penta-O-galloyl-β-glucopyranose inhibited α-glucosidase with 11.4± 0.9, 11.3± 0.7, and 4.1± 0.1µM IC50 values, respectively. Furthermore, penta-O-galloyl-β-glucopyranose inhibited α-amylase with 6.32± 0.18 µMIC50 . These three compounds also significantly inhibited (P < 0.05) pancreatic lipase. The results of high-performance liquid chromatography analysis showed that penta-O-galloyl-β-D-glycopyranose was one of the main compounds in both fruit and leaf extracts. Therefore, it may be considered that R. coriaria fruit and leaf extracts can be standardized on this substance and used in the development of both medicinal products and functional food for diabetes. PRACTICAL APPLICATION: Rhus coriaria (Sumac) is one of the plants that is well known and used around the world as a spice. It is also used against diabetes traditionally. The determination of effective compounds can lead to the standardization and development of both medicinal products and functional foods for diabetes. While the fruits of the plant are used as a spice all around the world, the leaves are generally throw away; therefore, the usage of the leaves to the food and medical industry can lead to beneficial effects on the economy.

Cytotoxic Activity-Guided Isolation from Achillea monocephala, and Biological Activities of its Different Extracts

Background: The genus Achillea is one of the most important genus of the Asteraceae family and many species of Achillea are used in traditional medicine to treat several ailments. Aim: The aim of the current research was to evaluate in vitro cytotoxic activities of n-hexan, chloroform, ethyl acetate and methanol extracts and to isolate the active compounds from the extract showing the strongest cytotoxic activity. In addition to this, it was aimed to evaluate the biological activities (cytotoxic, antioxidant, anti-urease, anticholinesterase, antimicrobial) of different extracts and active compounds from Achillea monocephala. Methods and Materials: The in vitro antioxidant, cytotoxic, anti-urease, anticholinesterase and antimicrobial activities of different extracts from A. monocephala aerial parts were examined. The structures of the active compounds were determined by NMR techniques, UV, IR and LC-MS/MS analysis and their biological potential was examined. Results: The chloroform extract showed strong and selective cytotoxic activity on the cancer cell lines (MDA-MB-231, MCF-7). Besides, this extract exhibited stronger antimicrobial activity than other extracts. Therefore, through activity-guided procedures, luteolin, naringenin and 8-hydroxy-salvigenin compounds were isolated from this extract. The methanol extract showed stronger antioxidant (DPPH, ABTS, CUPRAC) and anticholinesterase activity than other extracts. The n-hexan extract exhibited the highest anti-urease activity. In this study, it was determined that the isolated compounds had a strong biological activity. Naringenin compound had stronger ABTS radical cation scavenging and ferric reducing/antioxidant power, cytotoxic and antimicrobial activity than other compounds. 8-hydroxy-salvigenin compound showed the highest urease and acetylcholinestease enzyme inhibition. Conclusion: The results of this study suggest that the extracts and isolated compounds from the A. monocephala may be used as antioxidant, cytotoxic, anti-urease, anticholinesterase and antimicrobial agents in the future.

Antioxidant activity-guided isolation of constituents from Euphorbia gaditana Coss. and their antioxidant and tyrosinase inhibitory activities

Abstract Two previously unreported compounds, 4-O-(2′′-O-galloyl-β- d -glucopyranosyl)-3,5-dihydroxyacetophenone (1) and 5-isopropyl-2-oxo-3,6-dihydropyran-4-carboxylic acid (2), along with twenty-nine known compounds (3−31) were isolated from the aerial parts of Euphorbia gaditana Coss. Their structures were elucidated based on extensive spectroscopic analysis 1D and 2D-NMR, mass spectrometry HR-ESI-MS, optical rotation [α]D, acid hydrolysis and the comparison of NMR data with those described in literature. The antioxidant activity-guided study was conducted using DPPH and CUPRAC methods started from the extracts to bioactive isolated molecules. Most of the isolates (1-31) showed a good to excellent antioxidant activity compared to the standards BHT and ascorbic acid. Furthermore, 1 and 2 exhibited a moderate tyrosinase inhibitory activity (IC50 89.78 ± 0.93 and 52.39 ± 0.69 μg/mL, respectively) compared to the standard kojic acid (IC50 25.23 ± 0.78 μg/mL).

Integrating Molecular Networking and 1H NMR Spectroscopy for Isolation of Bioactive Metabolites from the Persian Gulf Sponge Axinella sinoxea.

The geographic position, highly fluctuating sea temperatures and hypersalinity make Persian Gulf an extreme environment. Although this unique environment has high biodiversity dominated by invertebrates, its potential in marine biodiscovery has largely remained untapped. Herein, we aimed at a detailed analysis of the metabolome and bioactivity profiles of the marine sponge Axinella sinoxea collected from the northeast coast of the Persian Gulf in Iran. The crude extract and its Kupchan subextracts were tested in multiple in-house bioassays, and the crude extract and its CHCl3-soluble portion showed in vitro antibacterial activity against Methicillin-resistant Staphylococcus aureus (MRSA) and Enterococcus faecium (Efm). A molecular networking (MN)-based dereplication strategy by UPLC-MS/MS revealed the presence of phospholipids and steroids, while 1H NMR spectroscopy indicated the presence of additional metabolites, such as diketopiperazines (DKPs). Integrated MN and 1H NMR analyses on both the crude and CHCl3 extracts combined with an antibacterial activity-guided isolation approach afforded eight metabolites: a new diketopiperazine, (-)-cyclo(L-trans-Hyp-L-Ile) (8); a known diketopiperazine, cyclo(L-trans-Hyp-L-Phe) (7); two known phospholipids, 1-O-hexadecyl-sn-glycero-3-phosphocholine (1) and 1-O-octadecanoyl-sn-glycero-3-phosphocholine (2); two known steroids, 3β-hydroxycholest-5-ene-7,24-dione (3) and (22E)-3β-hydroxycholesta-5,22-diene-7,24-dione (4); two known monoterpenes, loliolide (5) and 5-epi-loliolide (6). The chemical structures of the isolates were elucidated by a combination of NMR spectroscopy, HRMS and [α]D analyses. All compounds were tested against MRSA and Efm, and compound 3 showed moderate antibacterial activity against MRSA (IC50 value 70 μg/mL). This is the first study that has dealt with chemical and bioactivity profiling of A. sinoxea leading to isolation and characterization of pure sponge metabolites.

Polycyclic meroterpenoids, talaromyolides E − K for antiviral activity against pseudorabies virus from the endophytic fungus Talaromyces purpureogenus

a bstract Anti-pseudorabies virus (PRV) activity-guided isolation of an endophytic fungus Talaromyces purpureogenus resulted in seven rare polycyclic meroterpenoids talaromyolides E–K, together with two known compounds preaustinoid and austinolide. Their structures and absolute configurations were elucidated by HRESIMS, extensive NMR spectroscopic analyses, time-dependent density functional theory (TDDFT) calculations of ECD spectra, and single crystal X-ray diffraction. Talaromyolides I and K showed a dose-dependent inhibition of PRV, of which talaromyolide K had the most potent inhibition effect rate (60.11%), blocking effect rate (53.24%) and killing effect rate (62.16%) at a concentration of 50 μg/mL. A plausible biosynthetic pathway for talaromyolides E–K was proposed. • Seven previously undescribed compounds from endophytic fungus Talaromyces purpureogenus. • Single crystal X-ray diffraction and ECD spectra were performed to establish absolute configurations. • Putative biosynthetic mechanism was proposed for the titled talaromyolides E–K. • Talaromyolide K exhibited obvious antiviral activity against pseudorabies virus.

Immunomodulatory activity-guided isolation and characterization of a novel polysaccharide from Atractylodis macrocephalae Koidz

The Rhizoma of Atractylodis macrocephala Koidz. is a traditional Chinese herbal medicine that has been widely and empirically used for unexplained recurrent spontaneous abortion. In this study, a polysaccharide from the Rhizoma of Atractylodis macrocephala Koidz., designated as RAMP2, with an absolute molecular weight of 4.354 × 103 Da was isolated and found to be composed of mannose, galacturonic acid, glucose, galactose and arabinose. The NMR results displayed that →3-β-glcp-(1→, →3,6-β-glcp-(1→, →6-β-glcp-(1→, T-β-glcp-(1→, →4-α-galpA-(1→, →4-α-galpA-6-OMe-(1→, →5-α-araf-(1→, →4,6-β-manp-(1→ and →4-β-galp-(1→ were the main linkages in RAMP2. TEM and SEM results indicated that RAMP2 was globular in structure. Furthermore, in vitro experiments on murine CD4+ T cells revealed that RAMP2 could increase the percentage of Treg cells, up-regulate Foxp3, IL-10 and IL-2 mRNA expressions and the secretion of IL-10 and IL-2. RAMP2 was further shown to increase STAT5 phosphorylation levels in Treg cells, suggesting that RAMP2 increased the number of Treg cells through IL-2/STAT5 pathway.

A novel chresdihydrochalcone from Streptomyces chrestomyceticus exhibiting activity against Gram-positive bacteria.

Microbial-derived natural products provide unique bioactivities and serve as a unique source of drug leads. In the present study, we isolated one new chresdihydrochalcone (1), one new chresphenylacetone (2), and one known streptimidone (3) from Streptomyces chrestomyceticus BCC 24770 using antibacterial activity-guided isolation and purification procedures. We determined their molecular weights using MS and HRMS and elucidated their chemical structures from their 1D and 2D NMR and electronic circular dichroism (ECD) spectra. Compound 1 showed moderate inhibitory activities against the Gram-positive bacteria Methicillin-resistant Staphylococcus aureus, Bacillus subtilis, and Micrococcus luteus. Cytotoxicity and hemolytic activity were not observed at a concentration of up to 100 μg ml-1. The specific antimicrobial activity and low toxicity of compound 1 indicate this compound to be a potential antibiotic candidate, especially as antibiotic resistance has become a significant public health threat.

Understanding the Natural Products: A Profile of Ipek Suntar

Ipek Suntar's main aim was to become a pharmacist in order to explore medicine in every approach. She received her bachelor's degree from Faculty of Pharmacy, Gazi University. She obtained her master's and PhD degrees from the same institution, in Department of Pharmacognosy. “Pharmacognosy is a discipline where one can follow every step of drug discovery and development” she says. She was born in 1983. The family stayed in many different districts in Turkey, due to her father's occupation. They were always living in small districts and moving to another in every 2–3 years. Her early life passed by trying to be accepted by her schoolmates. “The best thing that I did in my childhood was studying” she says. She assumes that success is a way of acceptance. She continued to work hard in the university during graduate and postgraduate education, she almost never left the lab at the cost of being unsocial. She got married in this very busy period. Immediately after her marriage, she was awarded a project grant to conduct a part of her PhD thesis by The Scientific and Technological Research Council of Turkey (TUBITAK) to study in Europe. At the University of Wolverhampton in the United Kingdom for 6 months in the year 2009, she worked with Prof. Satyajit Sarker. “It was a very difficult but a very fruitful period for me that a foreign country provided me different perspectives” she says. She learned the importance of working together, studying much more organized and being patient. “Collaboration is essential to produce effective work if each researcher knows their responsibility and works timely and truthfully” she says. She got her PhD degree in 2011 and was assigned as an Associate Professor in 2014 in Gazi University Faculty of Pharmacy. She is still trying to do her best in the research area even with her eight-year-old daughter, coming together to the lab out of working times including the weekends and holidays. The main thing about pharmacognosy that attracted her attention was the fact that natural products (plants, animals, minerals, microorganisms, and marine sources) have been used in the treatment of many diseases for centuries and the hypothetical basis of the scientific studies on the natural products originated from the ethnobotanical reports, which provide a high success rate in the experiments. Indeed, the majority of the natural sources whose active compounds are currently employed as medicine has an ethnomedical use. Since 2005, she has been conducting in vivo and in vitro biological activity studies on natural products, revealing diverse biological effects of a wide range of plant derived compounds in various classes of chemical groups. Her research field mainly focuses on the investigation of the in vivo wound healing, anti-inflammatory, antinociceptive, anti-endometriotic, and anti-urolithiatic activities of the natural sources used in traditional medicine through biological activity-guided fractionation and isolation assays. She has published 80 scientific articles (SCI and SCI-exp. indexed) and 15 book chapters and edited one book. She is a member of Society for Medicinal Plant and Natural Product Research (GA), Phytochemical Society of Europe (PSE), and Association for Medicinal and Aromatic Plants of Southeast European Countries (AMAPSEEC). She has received many awards including Scientist Training Group Scholarships for master and doctorate programs provided by TUBITAK; Scientific Encouragement Award-2014 given by Pharmacy Academy, Association of Turkish Pharmacists; Patent Encouragement Award of Gazi University; The Best Oral/Poster Presentation Awards in scientific meetings worldwide. She has been working as Vice Dean in Faculty of Pharmacy, Gazi University since 2018. “Choose to take a part in the microenvironments in which efficient scientific discussions can be carried on. Not only one aspect, try to be faced with differences in order to enhance your vision. Always believe in yourself to produce a valuable outcome without hoping to have a motivation in your way. Your motivation will come to you spontaneously in the end when you finalize your aim.” she tells the young researchers.

A Polysaccharide-Rich Fraction Derived from Oviductus ranae with Antioxidant and Immunomodulatory Potentials

Oviductus ranae, an animal-based traditional Chinese medicinal material listed in Chinese Pharmacopeia is widely consumed as tonic, approximately twenty Oviductus ranae-related functional foods have been approved on the market by National Medical Products Administration in China. Proteins are well-defined bioconstituents in Oviductus ranae, little information is availabe on its polysaccharides. In present work, a Polysaccharide-Rich fraction (POR-3) was fractionated from Oviductus ranae based on antioxidant activity-guided isolation and its structure was partially characterized as well as its immunomodulatory potential was explored. POR-3 belonged to a heteropolysaccharide-protein fraction mainly consisted of Man, GlcN, GalA, Gal and Fuc at a molar ratio of 1: 2.28: 2.40: 3.00: 2.23 with binding proteins content of 6.42±0.16%. POR-3 possessed polydisperse property with MW of 999.586 kDa and PDI of 4.09. The UV and FT-IR analysis demonstrated that structures of POR-3 correspond with the characteristics of polysaccharide-protein complex. POR-3 elicited higher scavenging capacities against hydroxyl and DPPH radicals and exerted potent in vitro immunomodulatory activity via promoting macrophages phagocytosis and via stimulating NO production as well as appeared no proliferation on macrophages. POR-3 possesses high potentials to be consumed as a medicine or functional food with antioxidant and immune modulator properties.

Antioxidant activity-guided isolation of usnic acid and diffractaic acid compounds from lichen genus Usnea sp.

Antioxidant activity-guided isolation of usnic acid and diffractaic acid compounds from lichen genus Usnea sp.

Antiproliferative and Antiplasmodial Investigation of Alphitonia excelsa and Arcangelesia flava

Alphitonia excelsa (Rhamnaceae) and Arcangelesia flava (Menispermaceae) are utilized by locals in Samar island for medicinal purposes. Extracts from twigs of A. excelsa exhibited antiproliferative activity against the A2780 human ovarian cancer cell line, while a stem extract of A. flava had potent activity in an antimalarial screen against the drug-resistant Plasmodium falciparum Dd2 strain. Extracts of A. excelsa and A. flava were subjected to activity-guided isolation using column chromatography (silica gel and ODS) and HPLC. A. excelsa yielded betulinic acid (1) as its antiproliferative component, while A. flava gave palmatine (2) and jattrorrhizine (3) as its antiplasmodial components. These compounds were identified based on the comparison of their spectral data [nuclear magnetic resonance (NMR) and mass spectroscopy (MS)] with literature values. The IC50 value of betulinic acid against A2780 cells was determined to be 20.6 μM. Both palmatine and jatrorrhizine had strong growth inhibitory activity against P. falciparum Dd2, with IC50 values of 0.41 μM and 0.43 μM, respectively.

Anti-Inflammatory Effects of Fermented Bark of Acanthopanax sessiliflorus and Its Isolated Compounds on Lipopolysaccharide-Treated RAW 264.7 Macrophage Cells.

The fermentation was carried out on the bark of Acanthopanax sessiliflorus (AS). Acanthopanax species have been used in traditional medicine as tonics, sedatives, and antispasmodics. An activity-guided isolation of the fermented bark of A. sessiliflorus (FAS) yielded several phytochemicals: acanthoside D (1), acanthoside B (2), daucosterol (3), protocatechuic acid (4), chlorogenic acid methyl ester (5), ciwujiatone (6), syringaresinol (7), farnesol (8), 3,4-dicaffeoylquinic acid (9), and falcarindiol (10). HPLC analysis showed that content of lignan glycoside (1) was decreased and 4 and 7 were increased after fermentation. Anti-inflammatory activities on FAS showed the decrease of nitric oxide (NO) production, and inhibitory activities of iNOS and COX-2, proinflammatory cytokines (IL-6 and tumor necrosis factor-α), and collagenase. The aglycone, syringaresinol (7), which was increased through fermentation showed enhanced activity than 1. Thus, FAS may have the potential to treat inflammatory disorders, such as arthritis.

Herbicidal Polyketides and Diketopiperazine Derivatives from Penicillium viridicatum.

Herbicidal activity-guided isolation from the fermentation extract of Penicillium viridicatum had obtained two herbicidal series of polyketides (1-7) and diketopiperazine derivatives (8-11), especially including three novel polyketides (1-3). The structures and absolute configurations of new polyketides 1-3 were elucidated by extensive spectroscopic analyses, as well as comparisons between measured and calculated ECD spectra. Novel polyketides 1-3 and known 4, all bearing the heptaketide skeleton with a trans-fused decalin ring of 8-CH3 substitution, could significantly inhibit the radicle growth of Echinochloa crusgalli seedlings with a dose-dependent relationship. Especially at the concentration of 10 μg/mL, 1-4 exhibited the inhibition rates with 81.5% ± 2.0, 76.4% ± 0.8, 79.6% ± 1.1, and 80.0 ± 1.8%, respectively, even better than the commonly used synthetic herbicide of acetochlor with 76.1 ± 1.4%. Further greenhouse bioassay revealed that 4 showed pre-emergence herbicidal activity against E. crusgalli with the fresh-weight inhibition rate of 74.1% at a dosage of 400 g ai/ha, also better than acetochlor, while the other isolated metabolites (5-11) exhibited moderate herbicidal activities. The structure-activity differences of isolated polyketides indicated that the heptaketide skeleton, characterized by a trans-fused decalin ring with 8-CH3 substitution, should be the key factor of their herbicidal activities, which could give new insights for the bioherbicide developments.

Anti-Amyloidogenic Effects of Asarone Derivatives From Perilla frutescens Leaves against Beta-Amyloid Aggregation and Nitric Oxide Production.

Alzheimer’s disease (AD) is a progressive, neurodegenerative brain disorder associated with loss of memory and cognitive function. Beta-amyloid (Aβ) aggregates, in particular, are known to be highly neurotoxic and lead to neurodegeneration. Therefore, blockade or reduction of Aβ aggregation is a promising therapeutic approach in AD. We have previously reported an inhibitory effect of the methanol extract of Perilla frutescens (L.) Britton (Lamiaceae) and its hexane fraction on Aβ aggregation. Here, the hexane fraction of P. frutescens was subjected to diverse column chromatography based on activity-guided isolation methodology. This approach identified five asarone derivatives including 2,3-dimethoxy-5-(1E)-1-propen-1-yl-phenol (1), β-asarone (2), 3-(2,4,5-trimethoxyphenyl)-(2E)-2-propen-1-ol (3), asaronealdehyde (4), and α-asarone (5). All five asarone derivatives efficiently reduced the aggregation of Aβ and disaggregated preformed Aβ aggregates in a dose-dependent manner as determined by a Thioflavin T (ThT) fluorescence assay. Furthermore, asarone derivatives protected PC12 cells from Aβ aggregate-induced toxicity by reducing the aggregation of Aβ, and significantly reduced NO production from LPS-stimulated BV2 microglial cells. Taken together, these results suggest that asarone derivatives derived from P. frutescens are neuroprotective and have the prophylactic and therapeutic potential in AD.

Plant therapy in the Peruvian Amazon (Loreto) in case of infectious diseases and its antimicrobial evaluation.

The plant species reported here are used in contemporary phytotherapies by native and neo-urban societies from the Iquitenian surroundings (district of Loreto, Peruvian Amazon) for ailments related to microbial infections. Inhabitants of various ethnic origins were interviewed and 81 selected extracts were evaluated for their antimicrobial properties against a panel of 36 sensitive and multi-resistant bacteria or yeast. Medicinal plant researches in the Peruvian Amazon are now significant, but none of them has focused on an exhaustive listing of identified species tested on so many microbes with standardized experiments (to obtain MIC value). The aim of the study was to inventory the plants used against infections in the Loreto, an Amazonian region of Peru. It led to the new identification of secondary metabolites in two plant species. Ethnographic survey was carried out using "participant-observation" methodology and focus on bioprospecting of antimicrobial remedies. Selected plant extracts and antimicrobial drugs were tested in vitro with agar dilution method on 35 bacteria strains and 1 yeast to evaluate their Minimal Inhibitory Concentration (MIC). Microdilution methods using 96-well microtiter plates were used for the determination of MIC from isolated compounds, and cytotoxicity in HepG2 cells from some selected extracts were also evaluated. Activity-guided isolation and identification of compounds were performed by various chromatographic methods and structural elucidations were established using HRMS and NMR spectroscopy. This study outlined antimicrobial activities of 59 plant species from 33 families (72 single plant extracts and 2 fermented preparations), 7 mixtures, and one insect nest extract against 36 microorganisms. Of the 59 species analysed, 12 plants showed relevant antibacterial activity with MIC ≤0.15mg/mL for one or several of the 36 micro-organisms (Aspidosperma excelsum, Brosimum acutifolium, Copaifera paupera, Erythrina amazonica, Hura crepitans, Myrciaria dubia, Ocotea aciphylla, Persea americana, Spondias mombin, Swartzia polyphylla, Virola pavonis, Vismia macrophylla). Examination by bioautography of E. amazonica, M. dubia and O. aciphylla extracts allowed the phytochemical characterization of antimicrobial fractions and compounds. This study suggested an a posteriori correlation of the plant extract antimicrobial activity with the chemosensory cues of the drugs and attested that those chemosensory cues may be correlated with the presence of antimicrobial compounds (alkaloids, tannins, saponosids, essential oil, oleoresin …). It also led to the first isolation and identification of three secondary metabolites from E. amazonica and M. dubia.

From bench to counter: Discovery and validation of a peony extract as tyrosinase inhibiting cosmeceutical

The anti-melanogenic principle of peony (Paeonia officinalis subsp. officinalis) seeds was elucidated via activity-guided isolation. Resveratroloside (trans-resveratrol-4′-O-beta-d-glucopyranoside) was found to be the main metabolite of P. officinalis subsp. officinalis seeds and its tyrosinase inhibiting activity was confirmed via an enzymatic assay. Furthermore, the in vitro activity and the therapeutic window were studied employing the murine melanoma cell line B16F10. The results from the conducted stability assay and the high content of resveratroloside in the seeds (i.e. 10.4% dw) motivated us to push the extract forward to an in vivo tolerance assay. A clinical study with forty Caucasian participants proofed a good skin-tolerance with high moisture effect and reduction of pores.

Antiplasmodial activity of triterpenes isolated from the methanolic leaf extract of Combretum racemosum P. Beauv.

Combretum racemosum showed activity in previous ethnopharmacological investigations of some Combretum species used in malaria treatment in parts of West Africa. This study aimed at confirming the antimalarial potential of this plant by an activity-guided isolation of its active principles. A crude methanolic leaf extract of Combretum racemosum and fractions thereof obtained by partition with chloroform and n-butanol were investigated for antiplasmodial activity against chloroquine-sensitive (D10) and chloroquine-resistant (W2) strains of Plasmodium falciparum. Repeated chromatographic separations were conducted on the chloroform fraction to isolate bioactive compounds for further tests on antiplasmodial activity. The characterization of the isolated substances was performed by applying NMR- and MS-techniques (ESI-MS, HR-ESIMS, 1D and 2D NMR). The chloroform fraction (D10: IC50 = 33.8 ± 1.5 μg/mL and W2: IC50 = 27.8 ± 2.9 μg/mL) exhibited better antiplasmodial activity than the n-butanol fraction (D10: IC50 = 78.1 ± 7.3 μg/mL and W2: IC50 = 78 ± 15 μg/mL) as well as the methanolic raw extract (D10: IC50 = 64.2 ± 2.7 μg/mL and W2: IC50 = 65.8 ± 14.9 μg/mL). Thus, the focus of the phytochemical investigation was laid on the chloroform fraction, which led to the identification of four ursane-type (19α-hydroxyasiatic acid (1), 6β,23-dihydroxytormentic acid (4), madecassic acid (8), nigaichigoside F1 (10)) and four oleanane-type (arjungenin (2), combregenin (5), terminolic acid (7), arjunglucoside I (11)) triterpenes, as well as abscisic acid (9). Compounds 1 and 2, 4 and 5, 7 and 8 as well as 10 and 11 were isolated as isomeric mixtures in fractions CR-A, CR-C, CR-E and CR-H, respectively. All isolated compounds and mixtures exhibited moderate to low activity, with madecassic acid being most active (D10: IC50 = 28 ± 12 μg/mL and W2: IC50 = 17.2 ± 4.3 μg/mL). This paper reports for the first time antiplasmodial principles from C. racemosum and thereby gives reason to the traditional use of the plant.

Antioxidant and cytotoxic activity of three Turkish marine-derived fungi

Abstract Background Marine-derived fungi are appraised as a favorable source for discovering new bioactive secondary metabolites. In the last few decades researchers have concentrated on marine-derived fungi to obtain new and pharmaceutically active bioactive secondary metabolites with therapeutic potential. Objective In this study three marine-derived fungi were isolated and identified from marine invertebrates and investigated with regard to their antioxidant and cytotoxic activities. Materials and methods DPPH, SO, NO, and ABTS assays were used for monitoring free radical scavenging activity, and the MTT assay was used for testing cytotoxic activity against HCT-116 colon cancer cells. Results According to the obtained results Malassezia restricta extract was shown to have the highest antioxidant and cytotoxic activities compared to the other tested fungi strains. Conclusion This study is the first report about the antioxidant and cytotoxicity activity of Acremonium sclerotigenum, Aspergillus flavus, and M. restricta. This serves as a valuable preliminary study for activity-guided isolation of secondary metabolites.

The Ameliorative Effects of the Ethyl Acetate Extract of Salicornia europaea L. and Its Bioactive Candidate, Irilin B, on LPS-Induced Microglial Inflammation and MPTP-Intoxicated PD-Like Mouse Model.

Hyperactivation of microglia, the resident innate immune cells of the central nervous system, exacerbates various neurodegenerative disorders, including Parkinson's disease (PD). Parkinson's disease is generally characterized by a severe loss of dopaminergic neurons in the nigrostriatal pathway, with substantial neuroinflammation and motor deficits. This was experimentally replicated in animal models, using neurotoxins, i.e., LPS (lipopolysaccharides) and MPTP (1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine). Salicornia europaea L. (SE) has been used as a dietary supplement in Korea and Europe for several years, due to its nutritional and therapeutic value. In this study, we intend to investigate the antineuroinflammatory and anti-PD-like effects of the bioactive fraction/candidate of the SE extract. Initially, we screened various fractions of SE extract using an in vitro antioxidant assay. The optimal fraction was investigated for its in vitro antineuroinflammatory potential in LPS-stimulated BV-2 microglial cells and in vivo anti-PD-like potential in MPTP-intoxicated mice. Subsequently, to identify the potential candidate responsible for the elite therapeutic potential of the optimal fraction, we conducted antioxidant activity-guided isolation and purification; the bioactive candidate was structurally characterized using nuclear magnetic resonance spectroscopy and chromatographic techniques and further investigated for its in vitro antioxidative and antineuroinflammatory potential. The results of our study indicate that SE-EA and its bioactive candidate, Irilin B, effectively alleviate the deleterious effect of microglia-mediated neuroinflammation and promote antioxidative effects. Thus, they exhibit potential as therapeutic candidates against neuroinflammatory and oxidative stress-mediated PD-like neurodegenerative complications.

Antiproliferative steroidal glycosides from rhizomes of Polygonatum sibiricum

Screening assays showed that total glycoside-rich fraction (TG) of rhizomes of Polygonatum sibiricum unveiled remarkable anti-proliferative activities against three cancer cell lines (A549, HepG2, and Caco2). Activity-guided isolation of TG afforded seven undescribed steroidal glycosides (polygonosides 1–7), along with 24 known glycosides. Their structures were established by 1D and 2D NMR spectroscopic analyses, high-resolution mass spectrometry, and chemical evidence. The isolated steroidal glycosides were tested for their antiproliferative activities against A549, HepG2, and Caco2 cells. Compounds 8, 10, 11, and 16 possessed stronger anticancer activities against A549 cells than the positive control Bay (25.8 μM), with IC50 values ranging from 5.8 to 24.2 μM. Compound 10 reduced the expression of Blc-2 and pro-caspase3 and increased the production of Bax as determined by western blotting. Molecular docking experiment suggested that 10 bound stably to the BH3-binding groove of the Bcl-2 protein by hydrogen bond interactions. These compounds could be candidates for anticancer agents with cytotoxic activity.