Optimisation of artemisinin and scopoletin extraction from Artemisia annua with a new modern pressurised cyclic solid-liquid (PCSL) extraction technique.

INTRODUCTION: Artemisia annua is a small herbaceous plant belonging to the Asteraceae family declared therapeutic by the World Health Organisation, in particular for its artemisinin content, an active ingredient at the base of most antimalarial treatments, used every year by over 300 million people. In the last years, owing to low artemisinin content, research of new ways to increase the yield of the plant matrix has led to the use of the total extract taking advantage from the synergic and stabilising effects of the other components. OBJECTIVE: In this work we evaluated and compared the content of artemisinin and scopoletin in extracts of A. annua collected in the Campania Region (southern Italy), by two different extraction processes. METHODOLOGY: Artemisia annua plants were extracted by traditional maceration (TM) in hydroalcoholic solution as a mother tincture prepared according to the European Pharmacopeia and by pressurised cyclic solid-liquid (PCSL) extraction, a new generation method using the Naviglio extractor. RESULTS: The results showed that the PCSL extraction technique is more effective than traditional methods in extracting both phytochemicals, up to 15 times more, reducing the extraction times, without using solvents or having risks for the operators, the environment and the users of the extracts. CONCLUSION: The Naviglio extractor provides extracts with an artemisinin and scopoletin content eight times higher than the daily therapeutic dose, which should be evaluated for its stability over time and biological properties for possible direct use for therapeutic purposes.

Comparative study of the antidiabetic potential of Paederia foetida twig extracts and compounds from two different locations in Malaysia.

Context: Paederia foetida L. (Rubiaceae) is an edible plant distributed in Asian countries including Malaysia. Fresh leaves have been traditionally used as a remedy for indigestion and diarrhea. Several phytochemical studies of the leaves have been documented, but there are few reports on twigs. Objective: This study investigates the enzyme inhibition of P. foetida twig extracts and compound isolated from them. In addition, in silico molecular docking of scopoletin was investigated. Materials and methods: Plants were obtained from two locations in Malaysia, Johor (PFJ) and Pahang (PFP). Hexane, chloroform and methanol extracts along with isolated compound (scopoletin) were evaluated for their enzyme inhibition activities (10,000-0.000016 µg/mL). The separation and identification of bio-active compounds were carried out using column chromatography and spectroscopic techniques, respectively. In silico molecular docking of scopoletin with receptors (α-amylase and α-glucosidase) was carried out using AutoDock 4.2. Results: The IC50 values of α-amylase and α-glucosidase inhibition activity of PFJ chloroform extract were 9.60 and 245.6 µg/mL, respectively. PFP chloroform extract exhibited α-amylase and α-glucosidase inhibition activity (IC50 = 14.83 and 257.2 µg/mL, respectively). The α-amylase and α-glucosidase inhibitory activity of scopoletin from both locations had IC50 values of 0.052 and 0.057 µM, respectively. Discussion and conclusions: Separation of PFJ chloroform extract afforded scopoletin (1), stigmasterol (2) and γ-sitosterol (3) and the PFP chloroform extract yielded (1), (2), (3) and ergost-5-en-3-ol (4). Scopoletin was isolated from this species for the first time. In silico calculations gave a binding energy between scopoletin and α-amylase of -6.03 kcal/mol.

Acute and Chronic Antihypertensive Effect of Fractions, Tiliroside and Scopoletin from Malva parviflora.

Hypertension is a disease of high prevalence and morbidity where vascular inflammation and associated oxidative stress (endothelial dysfunction) is the underlying cause of this pathology. We are reporting the antihypertensive activity of extracts and fractions of Malva parviflora in mice with chronic and acute hypertension. Also, the treatments of this plant were able to counteract the kidney inflammation and associated oxidative stress. The chronic hypertension model consisted of administration of angiotensin II (AGII) during 12 weeks, causing a sustained increase in systolic (SBP) or diastolic (DBP) pressure, with values of pharmacological constants of: ED50 = 0.038 mg/kg y Emax = 135 mmHg for SBP and ED50 = 0.046 mg/kg y Emax = 98 mmHg for DBP. The chronic hypertension caused the inflammation and lipid peroxidation in kidneys, measured by of tissue level of cytokines such as interleukin-1ß (IL-1ß), IL-6, Tumor Necrosis Factor-α (TNF-α), IL-10 and malondialdehyde, and treatments for M. parviflora were able to modulate these parameters. The chemical fractionation allowed to identify three compounds: oleanolic acid, tiliroside and scopoletin, which were tested in a model of acute hypertension. The pharmacodynamic parameters for SBP were ED50 = 0.01 and 0.12 mg/kg while Emax = 33.22 and 37.74 mmHg for scopoletin and tiliroside, respectively; whereas that for DBP data were ED50 = 0.01 and 0.02 mg/kg; with an Emax = 7.00 and 6.24 mmHg, in the same order. M. parviflora, is able to counteract the effect of chronic and acute administration of AGII, on hypertension, but also the inflammatory and oxidative damage in the kidney. The oleanolic acid, scopoletin and tiliroside are the compounds responsible for such activities.

Rubescins I and J, further limonoid derivatives from the stem bark of Trichilia rubescens (Meliaceae).

Two new tetranorterpenoid derivatives named rubescins I (1) and J (2), were isolated along with six known compounds including rubescin D (3), lichexanthone (4), scopoletin (5), scopoletin O-glycoside (6), ß-sitosterol (7) and stigmasterol (8) from the stem bark of Trichilia rubescens (Meliaceae). The structures of the compounds were determined by means of MS, different NMR and by comparison with related data reported in the literature.

In Vivo Use of 1D and 2D 1H NMR to Examine the Glycosylation of Scopoletin in Duboisia myoporoides Cell Suspensions.

Cell suspensions initiated from Duboisia myoporoides-a shrub belonging to the Solanaceae family and being a rich source of tropane alkaloids-previously showed their ability to glycosylate scopoletin into scopolin, which represent coumarins showing health benefits. To investigate the time course of this glycosylation reaction, an in vivo NMR approach was developed using a perfusion system in an 8-mm NMR tube and 1H NMR with 1D and 2D (TOCSY and NOESY) experiments. The time course of metabolic changes could therefore be followed without any labeling.

Nutritional composition, antioxidant activity and isolation of scopoletin from Senecio nutans: support of ancestral and new uses.

Continuing with our study characterising Senecio nutans Sch. Bip., we have isolated and identified a simple coumarin, scopoletin, that could be relevant for the biological properties of the species related with the ancestral medical uses. This is the first report of scopoletin from S. nutans. In addition, the extract was analysed for its antioxidant activity using the ABTS and FRAP method as well as providing the first nutritional analyses of this plant from northern Chile highlands.

[Chemical constituents from petroleum ether fraction of Swertia chirayita and their activities in vitro].

The present work is to study the chemical constituents from petroleum ether fraction of Tibetan medicine Swertia chirayita by column chromatography and recrystallization. The structures were identified by physical and chemical properties and spectral data as swerchirin (1), decussatin (2), 1,8-dihydroxy-3,5,7-trimethoxyxanthone (3), 1-hydroxy-3,5,7,8-tetramethoxyxanthone (4), bellidifolin (5), 1-hydroxy-3, 7-dimethoxyxanthone (6), methylswertianin (7), 1-hydroxy-3,5-dimethoxyxanthone (8), erythrodiol (9), oleanolic acid (10), gnetiolactone (11), scopoletin (12), sinapaldehyde (13), syringaldehyde (14), and ß-sitosterol (15). Compounds 3, 4, 9, 11-14 were isolated from S. chirayita for the first time. Compounds 9 and 12 were firstly isolated from the genus Swertia. The cytotoxic activities of compounds 1, 2, 5, 7 and 8 against human pancreatic cancer cell lines SW1990 and BxPC-3,and the protective effects of these compounds against hydrogen peroxide (H2O2)-induced oxidative stress in human endothelium-derived EA.hy926 were investigated in vitro. The results showed no obvious effect at the high concentration of 50 µmol•L⁻¹.

Antipsychotic-like activity of scopoletin and rutin against the positive symptoms of schizophrenia in mouse models.

In an earlier report, we demonstrated an antipsychotic-like activity of a methanolic extract of Morinda citrifolia Linn fruit in mouse models and postulated the contribution of its bioactive principles, scopoletin and rutin. Moreover, the antidopaminergic activities of scopoletin and rutin were reported in isolated vas deferens preparations. In the present study, scopoletin and rutin were assessed for antipsychotic-like activity using apomorphine-induced climbing behavior and methamphetamine-induced stereotypy in mice. The results of this study revealed that scopoletin and rutin (0.05, 0.1, 0.5, and 1 mg/kg, p.o.) had a "U-shaped" dose-dependent effect on climbing and stereotyped behaviors induced by apomorphine and methamphetamine, respectively, in mice. A significant reduction in climbing and stereotyped behaviors caused by scopoletin and rutin was observed only at a dose 0.1 mg/kg. This study suggests that scopoletin and rutin can alleviate positive symptoms of schizophrenia only at a specific dose. Further studies evaluating the effects of scopoletin and rutin on animal models for negative symptoms of schizophrenia are required for a novel drug discovery in the treatment of neuropsychiatric diseases.

Effects of Viola mandshurica on Atherosclerosis and Hepatic Steatosis in ApoE[Formula: see text] via the AMPK Pathway.

Atherosclerosis was previously thought to be a disease that primarily involves lipid accumulation in the arterial wall. In this report, we investigated the effect of Viola mandshurica W. Becker (V. mandshurica) water extract on atherosclerosis in apolipoprotein E deficient (ApoE[Formula: see text]) mice. The administration of V. mandshurica to high-fat diet-fed mice reduced body weight, liver weight, and serum levels of lipids (total cholesterol, low-density lipoprotein-cholesterol, triglycerides), glucose, alanine transaminase, and aspartate transaminase. Histopathologic analyses of the aorta and liver revealed that V. mandshurica attenuated atherosclerotic lesions and reduced lipid accumulation, inflammatory responses and fatty acid synthesis. V. mandshurica also increased phosphorylation of adenosine monophosphate-activated protein kinase (AMPK), thereby reducing acetyl-CoA carboxylase (ACC) in liver tissue and inhibiting sterol regulatory element-binding protein 1c (SREBP-1c). V. mandshurica reduced protein expression levels of adhesion molecules (intercellular adhesion molecule-1, vascular cell adhesion molecule-1, and E-selectin) as well as ACC, fatty acid synthase, and SREBP-1c. In addition, quantitative analysis of V. mandshurica by high-performance liquid chromatography revealed the presence of esculetin and scopoletin. Esculetin and scopoletin reduced adhesion molecules in human aortic smooth muscle cells. Our results indicate that the anti-atherosclerotic effects of V. mandshurica may be associated with activation of the AMPK pathway. Therefore, AMPK-dependent phosphorylation of SREBP-1c by V. mandshurica may be an effective therapeutic strategy for combatting atherosclerosis and hepatic steatosis.

Benzofuran glycosides and coumarins from the bark of Streblus indicus (Bur.) Corner.

Two pairs of rare benzofuran glucoside epimers, indicuses A and B and indicuses C and D, three biogenetically related compounds indicuses E-G, and one coumarin indicus H, as well as 11 known compounds, were isolated from the bark of Streblus indicus (Bur.) Corner. The structures of indicuses A-H were elucidated by NMR and MS data, as well as by CD. (S)-Marmesinin exhibited moderate antimicrobial activity in vitro against Bacillus subtilis and Saccharomyces cerevisiae. 7,8-Dihydroxy-3-(3-methyl-2-butenyl) coumarin, umbelliferone, and scopoletin displayed strong cytotoxic activity in vitro against human bladder carcinoma cell line EJ. The structure-activity relationships indicate that hydroxylation at C-7 in the cytotoxic compounds is crucial to their activities.

Study on quality standards for Chimonanthus nitens.

Chimonanthus nitens Oliv. is a commonly used traditional Chinese medicine. Terpenoids, flavonoids, and coumarins are usually considered its main bioactive ingredients. Thus, qualitative and quantitative analyses of these compounds are crucial in quality control studies of Chimonanthus nitens. In this study, five compounds were identified by double-development thin layer chromatography (TLC) and the content of four compounds was determined by high performance liquid chromatography; the detection wavelength was set to 344 nm and the column temperature was 40°C. All calibration curves showed good linear regression (R2 > 0.9995). The average recoveries ranged from 97.06 to 104.44%. The RSD was below 4.2%. Four compounds remained stable over 24 h and the relative standard deviation (RSD) of the precision of their measurement was less than 1.5%. The developed method was reproducible, sensitive, and simple, and could be used for quality control of Chimonanthus nitens.

Scopoletin, an active principle of tree tobacco (Nicotiana glauca) inhibits human tumor vascularization in xenograft models and modulates ERK1, VEGF-A, and FGF-2 in computer model.

We recently reported the antineovascularization effect of scopoletin on rat aorta and identified its potential anti-angiogenic activity. Scopoletin could be useful as a systemic chemotherapeutic agent against angiogenesis-dependent malignancies if its antitumorigenic activity is investigated and scientifically proven using a suitable human tumor xenograft model. In the present study, bioassay-guided (anti-angiogenesis) phytochemical investigation was conducted on Nicotiana glauca extract which led to the isolation of scopoletin. Further, anti-angiogenic activity of scopoletin was characterized using ex vivo, in vivo and in silico angiogenesis models. Finally, the antitumorigenic efficacy of scopoletin was studied in human colorectal tumor xenograft model using athymic nude mice. For the first time, an in vivo anticancer activity of scopoletin was reported and characterized using xenograft models. Scopoletin caused significant suppression of sprouting of microvessels in rat aortic explants with IC50 (median inhibitory concentration) 0.06µM. Scopoletin (100 and 200mg/kg) strongly inhibited (59.72 and 89.4%, respectively) vascularization in matrigel plugs implanted in nude mice. In the tumor xenograft model, scopoletin showed remarkable inhibition on tumor growth (34.2 and 94.7% at 100 and 200mg/kg, respectively). Tumor histology revealed drastic reduction of the extent of vascularization. Further, immunostaining of CD31 and NG2 receptors in the histological sections confirmed the antivascular effect of scopoletin in tumor vasculature. In computer modeling, scopoletin showed strong ligand affinity and binding energies toward the following angiogenic factors: protein kinase (ERK1), vascular endothelial growth factor A (VEGF-A), and fibroblast growth factor 2 (FGF-2). These results suggest that the antitumor activity of scopoletin may be due to its strong anti-angiogenic effect, which may be mediated by its effective inhibition of ERK1, VEGF-A, and FGF-2.

Antimicrobial compounds from root, stem bark and seeds of Melia volkensii.

Three compounds, toosendanin (1), kulactone (2) and scopoletin (3), were isolated from either the root bark and/or the stem bark of Melia volkensii. Their structures were determined on the basis of spectroscopic data generated and by comparison with data from the literature. 1 and 2, isolated for the first time from M. volkensii, exhibited significant (p < 0.05) activity against Escherichia coli with minimum inhibitory concentration of 12.5 µg/mL, close to that of neomycin (6.25 µg/mL). The compounds also exhibited high activity against Aspergillus niger (MIC 6.25 µg/mL compared to 2.5 µg/mL for clotrimazole). Dichloromethane and methanol seed, hexane stem bark and methanol root bark extracts exhibited activities towards Escherichia coli, Staphylococcus aureus, Aspergillus niger and Plasmodium falciparum, respectively. Antimicrobial activity of the plant towards A. niger, P. falciparum and S. aureus is reported for the first time in the current work.

Two new phenylpropanoids from Micromelum integerrimum.

AIM: To investigate the chemical and bioactive constituents from the stems and leaves of Micromelum integerrimum. METHOD: The chemical constituents were isolated and purified by silica gel, Sephadex LH-20, and HPLC. Their structures were mainly elucidated on the basis of extensive 1D- and 2D-NMR spectroscopy and mass spectrometry. Their cytotoxicity and antimicrobial activities were tested by the SRB and turbidimetric methods, respectively. RESULTS: Two new phenylpropanoids and two known coumarins were obtained, and their structures were identified as microintegerrin A (1), microintegerrin B (2), scopoletin (3), and scopolin (4). All of the compounds were tested for their cytotoxicity against three cancer cell lines (HeLa, A549, and BGC-823) and for antimicrobial activity against the fungus Candida albicans and the bacterium Staphylococcus aureus. CONCLUSION: Two new phenylpropanoids 1 and 2 were isolated and identified from the stems and leaves of M. intgerrimum. None of the compounds showed cytotoxic or antimicrobial activity at the tested concentration of 20 µg·mL(-1).

Antioxidant and anticancer constituents from the leaves of Liriodendron tulipifera.

Sixteen compounds were extracted and purified from the leaves of Liriodendron tulipifera. These compounds include aporphines, oxoaporphine, coumarin, sesquiterpene lactone, benzenoids, cyclitol and steroids. (+)-Norstephalagine (2) (an aporphine) and scopoletin (8) (a coumarin) were isolated from Liriodendron tulipifera leaves from the first time. The identified compounds were screened for their antiradical scavenging, metal chelating and ferric reducing power activities. The results have showed that these compounds have antioxidative activity. The study has also examined the chemopreventive property of the isolated compounds against human melanoma cells A375. The results shown that (-)-anonaine (1), (-)-liridinine (3), (+)-lirinidine (6), lysicamine (7) and epitulipinolide diepoxide (9) significantly inhibited the proliferation of melanoma cells. These results revealed that these compounds have antioxidative activity and chemopreventive activity in skin melanoma cells.

[Study on the chemical constituents from ethyl acetate extract of Micromelum falcatum].

OBJECTIVE: To study the chemical constituents from ethyl acetate extract of Micromelum falcatum. METHODS: The constituents were separated and purified by silica gel, Sephadex LH-20 and HPLC. Their structures were elucidated by spectral analysis (NMR, MS). RESULTS: Ten compounds were isolated and identified as micropubescin (1), phebalosin (2), scopoletin (3), citrubuntin (4), thamnosmonin (5), hopeyhopin (6), arnottinin (7), casegravol (8), 2-methoxy-5-hydroxy cinnamate (9), threo-syringoylglycerol (10). CONCLUSION: Compounds 1 - 10 are obtained from this plant for the first time.

[Lethal effects of scopoletin and bisdemethoxycurcumin against Tetranychus cinnabarinus Boisd. (Acari: Tetranychidae): a simulation study].

By using slide-dip bioassay method under laboratory condition, an investigation was made on the lethal effects of scopoletin, bisdemethoxycurcumin (BDMC), and their combination at an optimal mass ratio (7:6) of scopoletin to BDMC against the adult females of Tetranychus cinnabarinus Boisd. A time-dose mortality model (TDM) was established, which passed the Hosmer-Lemeshow test. The sensitivity of the adult females to the concentration change of the acaricides was in the sequence of scopoletin > optimal mass ratio of scopoletin to BDMC > BDMC. The peak mortality of the female adults was found at 32, 28 and 32 h after treated with BDMC, scopoletin, and their combination at the optimal mass ratio, respectively. The values of the LC50 and LC90 at 48 h after treated with BDMC, scopoletin, and their combination at the optimal mass ratio were 0.3324, 0.2035 and 0.2195 mg x mL(-1), and 2.1198, 0.9521 and 1.1617 mg x mL(-1), and the median lethal time (LT50) of BDMC, scopoletin, and their combination at the optimal mass ratio was 7.4, 6.0 and 6.1 h at the concentration 1.0 mg x mL(-1), and 6.4, 4.8 and 5.0 h at the concentration 2.0 mg x mL(-1), respectively. The acaricidal activity and time-dose response of the optimal combination of scopoletin and BDMC were closer to those of scopoletin, suggesting a synergistic acaricidal activity of the combination of scopoletin and BDMC, which was worthy to be developed for application.

[Chemical constituents of Rhododendron seniavinii].

OBJECTIVE: To study the chemical constituents of Rhododendron seniavinii. METHOD: Compounds were isolated from the aqueous extract of the leaves of R. seniavinii by using Sephadex LH-20, ODS open column chromatography and other means. Their structures were elucidated according to spectral data and physiochemical properties. RESULT: Thirteen compounds were isolated from R. seniavinii and identified as 5-methoxydehydroconiferyl alcohol (1), dehydroconiferyl alcohol (2), (-)-syringaresinol (3), (-)-lyoniresinol (4), (+)-lyoniresinol 3alpha-O-beta-D-glucopyranoside (5), (-)-lyoniresinol 3alpha-O-beta-D-glucopyranoside (6), 3,4,5-trimethoxyphenyl-1-O-beta-D-glucopyranoside (7), nikoenoside (8), 3,5,7-trihydroxychromone-3-0-alpha-L-rhamnopyranoside (9), 3,4,5-trimethoxyphenol (10), scopoletin (11), scopolin (12) and quercitrin (13). CONCLUSION: Compounds 1-12 were obtained from this plant for the first time.

Inhibition effects of isolated compounds from Artemisia rubripes Nakai of the classical pathway on the complement system.

The study evaluated the anticomplement activity from isolated compounds from Artemisia rubripes Nakai from South Korea on the classical pathway. In the previous works, Artemisia rubripes chloroform extracts showed inhibitory activity against complement system. The chromatographic separation of a chloroform chloride extract of Artemisia rubripes led to the isolation of three compounds. Their structures were characterized to be scopoletin (1), 11,(13)-triene-6,12-olide (2), and 1ß,6α-dihydroxy-4(15)-eudesmene (3) by spectroscopic data. This is the first report of anticomplement activity of isolated compounds from Artemisia rubripes.

Cytotoxic fraction from Artemisia sacrorum Ledeb. against three human cancer cell lines and separation and identification of its compounds.

Artemisia sacrorum Ledeb. was extracted by 95% ethanol and water, respectively. By partitioning the 95% ethanol extract successively with different solvents and separating the water extract by macroporous resin, nine separate parts were obtained. According to the results of in vitro experiments, the CH2Cl2 (dichloromethane) fraction showed the most pronounced cytotoxic activity against HepG2, HT-29 and MCF-7 cells, with EC50 values 122.35, 49.76 and 28.51 µg mL⁻¹, respectively, at 48 h. Following this, the compounds of the CH2Cl2 fraction were separated and identified. Ten compounds were isolated from A. sacrorum Ledeb. and identified by spectral analysis. Four compounds, including acacetin, were isolated for the first time from A. sacrorum Ledeb.