Isolation and NMR Scaling Factors for the Structure Determination of Lobatolide H, a Flexible Sesquiterpene from Neurolaena lobata.

A new flexible germacranolide (1, lobatolide H) was isolated from the aerial parts of Neurolaena lobata. The structure elucidation was performed by classical NMR experiments and DFT NMR calculations. Altogether, 80 theoretical level combinations with existing 13C NMR scaling factors were tested, and the best performing ones were applied on 1. 1H and 13C NMR scaling factors were also developed for two combinations utilizing known exomethylene containing derivatives, and the results were complemented by homonuclear coupling constant (JHH) and TDDFT-ECD calculations to elucidate the stereochemistry of 1. Lobatolide H possessed remarkable antiproliferative activity against human cervical tumor cell lines with different HPV status (SiHa and C33A), induced cell cycle disturbance and exhibited a substantial antimigratory effect in SiHa cells.

Cytotoxicity, apoptosis inducing activity and Western blot analysis of tanshinone derivatives from Stachys parviflora on prostate and breast cancer cells.

Cytotoxic activities of methanolic crude extract of Stachys parviflora (Lamiaceae family) and its sub-fractions were primarily evaluated against human breast adenocarcinoma (MCF-7 and MDA-MB-231) and prostate (PC3) cell lines. The methanolic extract exhibited the highest activity, and was chosen for the isolation procedure. Four diterpenoid quinones, namely miltirone [1], tanshinone IIA [2], 1-hydroxy-tanshinone IIA [3], and cryptotanshinone [4] were isolated. Notably, this is the first report on the isolation and/or characterization of the mentioned diterpenoids from the Stachys genus. In this study, 1-hydroxy-tanshinone IIA [3] displayed the highest cytotoxicity among the isolated compounds. The mechanism of the cytotoxicity of methanolic extract and isolated compounds was further investigated by the utilization of propidium iodide staining (PI) assay. The results showed that the methanolic extract and 1-hydroxy-tanshinone IIA [3] enhanced DNA fragmentation in PC3 and MCF-7 cells. Moreover, the western blotting analysis demonstrated increasing and decreasing protein levels of Bax and Bcl2, respectively, and cleaved poly ADP-ribose polymerase (PARP). Further bioassay-guided phytochemical assessments of S. parviflora can be suggested as a promising approach for discovering potent bioactive secondary metabolites.

Antiproliferative and cytotoxic effects of sesquiterpene lactones isolated from Ambrosia artemisiifolia on human adenocarcinoma and normal cell lines.

CONTEXT: Ambrosia artemisiifolia L. (Asteraceae) contains sesquiterpene lactones as characteristic secondary metabolites. Many of these compounds exert antiproliferative and cytotoxic effects. OBJECTIVE: To isolate the sesquiterpene lactones from the aerial part of A. artemisiifolia and to elucidate their cytotoxic, antiproliferative and antibacterial effects. MATERIALS AND METHODS: The compounds were identified by one-dimensional (1D) and 2D NMR, HR-MS spectroscopy from the methanol extract. Isolated compounds were investigated for their cytotoxic and antiproliferative effects on human colonic adenocarcinoma cell lines and human embryonal lung fibroblast cell line using MTT assay. The selectivity of the sesquiterpenes was calculated towards the normal cell line. To check the effect of drug interactions between compounds and doxorubicin, multidrug-resistant Colo 320 cells were used. RESULTS: A new seco-psilostachyinolide derivative, 1,10-dihydro-1'-noraltamisin, and seven known compounds were isolated from the methanol extract. Acetoxydihydrodamsin had the most potent cytotoxic effect on sensitive (Colo205) cell line (IC50 = 7.64 µM), also the strongest antiproliferative effect on Colo205 (IC50 = 5.14 µM) and Colo320 (IC50 = 3.67 µM) cell lines. 1'-Noraltamisin (IC50 = 8.78 µM) and psilostachyin (IC50 = 5.29 µM) showed significant antiproliferative effects on the multidrug-resistant Colo320 cell line and had moderate selectivity against human embryonal lung fibroblast cell line. Psilostachyin C exhibited cytotoxic effects on Colo205 cells (IC50 = 26.60 µM). None of the isolated compounds inhibited ABCB1 efflux pump (EP; P-glycoprotein) or the bacterial EPs. DISCUSSION AND CONCLUSIONS: Acetoxydihydrodamsin, 1'-noraltamisin, and psilostachyin showed the most remarkable cytotoxic and antiproliferative activity on tumour cell lines and exerted selectivity towards MRC-5 cell line.

Juncaceae Species as Promising Sources of Phenanthrenes: Antiproliferative Compounds from Juncus maritimus Lam.

Juncaceae family represents an abundant source of phenanthrenes. In continuation of our work aiming at the isolation of biologically active compounds from Juncaceae species, Juncus maritimus Lam. was subjected to phytochemical and pharmacological investigations. The isolation process was carried out by using combined extraction and chromatographic methods. The structures of the obtained chemical compounds were elucidated by spectroscopic analysis, including HRESIMS, 1D (1H, 13C-JMOD), and 2D (1H-1H-COSY, HSQC, HMBC, NOESY) NMR spectra. Four new [maritins A-D (1-4)] and seven known phenanthrenes (5-11) were isolated from the plant, of which two (4 and 11) are phenanthrene dimers composed of effusol monomers. Maritin C (3) has an unusual 4,5-ethanophenanthrene skeleton most likely produced by biosynthetic incorporation of a vinyl group into a cyclohexadiene ring. Compounds 1-11 were tested for their antiproliferative activity on seven human tumor cell lines (HeLa, HTM-26, T-47D, A2780, A2780cis, MCF-7, KCR) and one normal cell line (MRC-5) using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The dimeric phenanthrenes showed strong antiproliferative activity against T-47D cells with IC50 values of 9.1 and 6.2 µM, respectively.

Oxidized Juncuenin B Analogues with Increased Antiproliferative Activity on Human Adherent Cell Lines: Semisynthesis and Biological Evaluation.

Phenanthrenes have become the subject of intensive research during the past decades because of their structural diversity and wide range of pharmacological activities. Earlier studies demonstrated that semisynthetic derivatization of these natural compounds could result in more active agents, and oxidative transformations are particularly promising in this regard. In our work, a natural phenanthrene, juncuenin B, was transformed by hypervalent iodine(III) reagents using a diversity-oriented approach. Eleven racemic semisynthetic compounds were produced, the majority containing an alkyl substituted p-quinol ring. Purification of the compounds was carried out by chromatographic techniques, and their structures were elucidated by 1D and 2D NMR spectroscopic methods. Stereoisomers of the bioactive derivatives were separated by chiral-phase HPLC and the absolute configurations of the active compounds, 2,6-dioxo-1,8a-dimethoxy-1,7-dimethyl-8-vinyl-9,10-dihydrophenanthrenes (1a-d), and 8a-ethoxy-1,7-dimethyl-6-oxo-8-vinyl-9,10-dihydrophenanthrene-2-ols (7a,b) were determined by ECD measurements and TDDFT-ECD calculations. The antiproliferative activities of the compounds were tested on different (MCF-7, T47D, HeLa, SiHa, C33A, A2780) human gynecological cancer cell lines. Compounds 1a-d, 4a, 6a, and 7a possessed higher activity than juncuenin B on several tumor cell lines. The structure-activity relationship studies suggested that the p-quinol (2,5-cyclohexadien-4-hydroxy-1-one) moiety has a considerable effect on the antiproliferative properties, and substantial differences could be identified in the activities of the stereoisomers.

Gerardiins A-L and Structurally Related Phenanthrenes from the Halophyte Plant Juncus gerardii and Their Cytotoxicity against Triple-Negative Breast Cancer Cells.

Species in the Juncaceae accumulate different types of secondary metabolites, among them phenanthrenes and 9,10-dihydrophenanthrenes in substantial amounts. These compounds have chemotaxonomic significance and also possess interesting pharmacological activities. The present study has focused on the isolation, structure determination, and pharmacological investigation of phenanthrenes from Juncus gerardii. Twenty-six compounds, including 23 phenanthrenes, have been isolated from a methanol extract of this plant. Twelve compounds, the phenanthrenes gerardiins A-L (1-12), were obtained as new natural products. Eleven phenanthrenes [effusol (13), dehydroeffusol (14), effususin A (15), compressin A, 7-hydroxy-2-methoxy-1-methyl-5-vinyl-9,10-dihydrophenanthrene, juncusol, 2-hydroxy-7-hydroxymethyl-1-methyl-5-vinyl-9,10-dihydrophenanthrene, 2,7-dihydroxy-5-formyl-1-methyl-9,10-dihydrophenanthrene, effususol A, 2,7-dihydroxy-5-hydroxymethyl-1-methyl-9,10-dihydrophenanthrene, and jinflexin C], 1-O-p-coumaroyl-3-O-feruloyl-glycerol, and the flavones apigenin and luteolin were isolated for the first time from this plant. The cytotoxicity of the 23 isolated phenanthrenes in both mouse (4T1) and human (MDA-MB-231) triple-negative breast cancer cells and in a nontumor (D3, human cerebral microvascular endothelial) cell line was tested using an MTT viability assay. The results obtained showed that the dimeric compounds gerardiins I (9), J (10), K (11), and L (12), derived biogenetically from effusol and dehydroeffusol, were cytotoxic to both tumor and nontumor cell lines, while the monomeric compounds exerted no or very low cytotoxicity. Impedance measurements were consistent with the results of the MTT assays performed.

Pigments of the Moss Paraleucobryum longifolium: Isolation and Structure Elucidation of Prenyl-Substituted 8,8'-Linked 9,10-Phenanthrenequinone Dimers.

In a search for new secondary metabolites from mosses, leucobryns A-E, axially chiral 9,10-phenanthrenequinone dimers, were isolated from Paraleucobryum longifolium (1-5), together with diosmetin triglycoside. Leucobryns B (2) and C (3) were proved to be homodimeric atropodiastereomers containing both axial and central chirality elements, while leucobryns D (4) and E (5) were found to be heterodimeric atropodiastereomers containing central chirality in only one of the two monomeric units. Axial chirality of the compounds was determined by ECD measurements and sTDA ECD calculations, while the central chirality elements were assigned by TDDFT-SOR calculations. Leucobryns represent the first 9,10-phenanthrenequinone dimers, the monomers of which are linked through their C-8 atoms. Leucobryns B-E contain an uncommon C10 monoterpenoid side chain, in which isoprenoid units are joined by 3,4 linkages. Leucobryns A and B exhibited weak antiproliferative activity against several human cancer cell lines.

Antiproliferative Phenanthrenes from Juncus tenuis: Isolation and Diversity-Oriented Semisynthetic Modification.

The occurrence of phenanthrenes is limited in nature, with such compounds identified only in some plant families. Phenanthrenes were described to have a wide range of pharmacological activities, and numerous research programs have targeted semisynthetic derivatives of the phenanthrene skeleton. The aims of this study were the phytochemical investigation of Juncus tenuis, focusing on the isolation of phenanthrenes, and the preparation of semisynthetic derivatives of the isolated compounds. From the methanolic extract of J. tenuis, three phenanthrenes (juncusol, effusol, and 2,7-dihydroxy-1,8-dimethyl-5-vinyl-9,10-dihydrophenanthrene) were isolated. Juncusol and effusol were transformed by hypervalent iodine(III) reagent, using a diversity-oriented approach. Four racemic semisynthetic compounds possessing an alkyl-substituted p-quinol ring (1-4) were produced. Isolation and purification of the compounds were carried out by different chromatographic techniques, and their structures were elucidated by means of 1D and 2D NMR, and HRMS spectroscopic methods. The isolated secondary metabolites and their semisynthetic analogues were tested on seven human tumor cell lines (A2780, A2780cis, KCR, MCF-7, HeLa, HTB-26, and T47D) and on one normal cell line (MRC-5), using the MTT assay. The effusol derivative 3, substituted with two methoxy groups, showed promising antiproliferative activity on MCF-7, T47D, and A2780 cell lines with IC50 values of 5.8, 7.0, and 8.6 µM, respectively.

Synthesis and In Vitro Antitumor Activity of Naringenin Oxime and Oxime Ether Derivatives.

Naringenin is one of the most abundant dietary flavonoids exerting several beneficial biological activities. Synthetic modification of naringenin is of continuous interest. During this study our aim was to synthesize a compound library of oxime and oxime ether derivatives of naringenin, and to investigate their biological activities. Two oximes and five oxime ether derivatives were prepared; their structure has been elucidated by NMR and high-resolution mass spectroscopy. The antiproliferative activity of the prepared compounds was evaluated by MTT assay against human leukemia (HL-60) and gynecological cancer cell lines isolated from cervical (HeLa, Siha) and breast (MCF-7, MDA-MB-231) cancers. Tert-butyl oxime ether derivative exerted the most potent cell growth inhibitory activity. Moreover, cell cycle analysis suggested that this derivative caused a significant increase in the hypodiploid (subG1) phase and induced apoptosis in Hela and Siha cells, and induced cell cycle arrest at G2/M phase in MCF-7 cells. The proapoptotic potential of the selected compound was confirmed by the activation of caspase-3. Antioxidant activities of the prepared molecules were also evaluated with xanthine oxidase, DPPH and ORAC assays, and the methyl substituted oxime ether exerted the most promising activity.

Less Cytotoxic Protoflavones as Antiviral Agents: Protoapigenone 1'-O-isopropyl ether Shows Improved Selectivity Against the Epstein-Barr Virus Lytic Cycle.

Protoflavones, a rare group of natural flavonoids with a non-aromatic B-ring, are best known for their antitumor properties. The protoflavone B-ring is a versatile moiety that might be explored for various pharmacological purposes, but the common cytotoxicity of these compounds is a limitation to such efforts. Protoapigenone was previously found to be active against the lytic cycle of Epstein-Barr virus (EBV). Further, the 5-hydroxyflavone moiety is a known pharmacophore against HIV-integrase. The aim of this work was to prepare a series of less cytotoxic protoflavone analogs and study their antiviral activity against HIV and EBV. Twenty-seven compounds, including 18 new derivatives, were prepared from apigenin through oxidative de-aromatization and subsequent continuous-flow hydrogenation, deuteration, and/or 4'-oxime formation. One compound was active against HIV at the micromolar range, and three compounds showed significant activity against the EBV lytic cycle at the medium-low nanomolar range. Among these derivatives, protoapigenone 1'-O-isopropyl ether (6) was identified as a promising lead that had a 73-times selectivity of antiviral over cytotoxic activity, which exceeds the selectivity of protoapigenone by 2.4-times. Our results open new opportunities for designing novel potent and safe anti-EBV agents that are based on the natural protoflavone moiety.

Sesquiterpene Lactones and Flavonoids from Psephellus pyrrhoblepharus with Antiproliferative Activity on Human Gynecological Cancer Cell Lines.

Multistep chromatographic separations of the chloroform extract of the Turkish endemic plant Psephellus pyrrhoblepharus (Boiss.) Wagenitz (syn. Centaurea pyrrhoblephara Boiss.) resulted in the isolation of six guaianolid-type sesquiterpenes, chlorojanerin (1), 19-deoxychlorojanerin (2), 15-hydroxyjanerin (3), aguerin B (4), cynaropicrin (5), eleganin (6); three flavonoids, apigenin, 6-methoxyluteolin and jaceosidine; two glycosides, benzyl-1-O-ß-d-glucoside and 3(Z)-hexenyl-1-O-ß-d-glucoside; and the coumarin scopoletin. The structures were established by the interpretation of their ESI-MS and 1D and 2D NMR data including 1H-NMR, JMOD, 1H,1H-COSY, HSQC, HMBC, and NOESY experiments. All compounds were isolated for the first time from P. pyrrhoblepharus. Compounds 1-6, the isolated flavonoids and scopoletin were evaluated for their antiproliferative activities on human gynecological cancer cell lines (SiHa, HeLa, and MDA-MB-231 cells) using the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. Chlorojanerin (1), 19-deoxychlorojanerin (2), aguerin B (4), cynaropicrin (5), eleganin (6) were shown to have noteworthy effects on all of the tested cell lines, while apigenin, jaceosidine, and 6-methoxyluteolin were moderately active on HeLa cells. The highest activities were demonstrated by the chlorine-containing derivatives chlorojanerin (1) and 19-deoxychlorojanerin (2) with IC50 values of 2.21 and 2.88 µM, respectively, against the triple negative breast cancer model MDA-MB-231 cells.

Antispasmodic Activity of Prenylated Phenolic Compounds from the Root Bark of Morus nigra.

Black mulberry is a widely acknowledged ancient traditional medicine. Its extract and constituents have been reported to exert various bioactivities including antimicrobial, hypotensive, analgesic etc. effects. While black mulberry preparations are also used as antispasmodic agents in folk medicine, no related studies are available on its isolated constituents. Through an extensive chromatographic purification, seven phenolic compounds were isolated from the methanol extract of Morus nigra root bark, including morusin (1), kuwanon U (2), kuwanon E (3), moracin P (4), moracin O (5), albanol A (6), and albanol B (7). A complete NMR signal assignment of moracin P and O was achieved, and related literature errors confusing the identity of moracin derivatives are hereby clarified. Compounds 2, 5 and 7 were identified as strong antispasmodic agents on isolated rat ileum and tracheal smooth muscles, while compound 3, a methoxy derivative of 2, was inactive. Moracin O (5) inhibited the ileal and tracheal smooth muscle contractions with Emax values of 85% and 302 mg, respectively. Those actions were superior as compared with papaverine. Our findings demonstrate that prenylated arylbenzofurans, geranylated flavonoids and Diels-Alder adducts from Morus nigra are valuable antispasmodic agents. Compounds 2, 5 and 7 are suggested as marker compounds for quality control of antispasmodic mulberry preparations. Moracin O (5) is a new lead compound for related drug development initiatives.

Rhodiosin and herbacetin in Rhodiola rosea preparations: additional markers for quality control?

Context: Rhodiola rosea L. (Crassulaceae) is well-known to contain flavonoids such as the herbacetin derivative rhodiosin. However, flavonoids are not typically used in quality control. Objective: This study analyses two flavonoids of R. rosea rhizomes and roots for their potential as analytical markers. Materials and methods: Two constituents were isolated from ethanolic extracts via HPLC, identified via NMR and quantified via RP-HPLC. Presence and content variation was investigated according to extraction (solvent and repetitions), drying (temperature and duration) and sample origin (homogenously cultivated plants of different provenance, commercial samples). Results: Rhodiosin was identified as a main flavonoid, accompanied by 10-fold lower concentrated herbacetin. Both compounds were best extracted with 70-90% ethanol, but were also detectable in more aqueous extracts. Different drying conditions had no effect on the flavonoid content. These two flavonoids were consistently identified in rhizome and root extracts of over 100 R. rosea samples. Rhizomes tend to contain less flavonoids, with average ratios of rosavins to flavonoids of 1.4 (rhizomes) and 0.4 (roots). Provenance differences were detected in the range (rhodiosin plus herbacetin) of 760-6300 µg/mL extract corresponding to a maximum of approximately 0.5-4.2% (w/w) in the dry drug. Conclusions: For the first time, two main flavonoids present in R. rosea were quantified systematically. Rhodiosin and herbacetin can be detected simultaneously to phenylpropenoids or salidroside in authentic samples, influenced by the plant part examined and the plant origin. Rhodiosin and herbacetin may serve as additional marker to guarantee a consistent content of R. rosea products.

Diterpenoids from Euphorbia dulcis with Potassium Ion Channel Inhibitory Activity with Selective G Protein-Activated Inwardly Rectifying Ion Channel (GIRK) Blocking Effect.

Nine new (1-9) and two known (10, 11) jatrophane diterpenoids were isolated from the methanol extract of Euphorbia dulcis. The structure elucidation of the compounds was performed by means of extensive spectroscopic analysis, including HRESIMS, 1D (1H, JMOD), and 2D (HSQC, HMBC, 1H-1H-COSY, NOESY) NMR experiments. The absolute configuration of compound 1 was determined by single-crystal X-ray diffraction. The electrophysiological effects of compounds 1-11 and the five diterpenoids (12-16) previously isolated from Euphorbia taurinensis were investigated on stable transfected HEK-GIRK1/4 (Kir3.1/3.4) and HEK-hERG (Kv11.1) cell lines using automated patch-clamp equipment. The majority of the diterpenoids showed significant blocking activity on GIRK channels (60.8-88.7% at 10 µM), while compounds 1, 2, 9-11, 13, and 14 exerted notable inhibitory effects even at 1 µM concentration. None of the jatrophane diterpenoids interfered with the function of hERG proteins; however, compound 14 remarkably hampered K+ flow through hERG channels. These selective activities suggest that jatrophane diterpenoids may represent a group of potential lead compounds for the development of novel therapeutic agents against atrial fibrillation.

Bioactivity-Guided Investigation of the Anti-Inflammatory Activity of Hippophae rhamnoides Fruits.

According to modern ethnobotanical records, the fruit of Hippophae rhamnoides is effective in the treatment of different allergic symptoms. In order to obtain pharmacological evidence for this observation, the fruit was investigated for anti-inflammatory activity using in vivo animal models. Aqueous and 70% MeOH extracts were tested in 48/80-induced rat paw edema assay after oral administration, and it was found that the 70% MeOH extract (500 mg/kg) reduced significantly edema volume (0.660 ± 0.082 mL vs. control 0.935 ± 0.041 mL). Extracts of different parts of the fruit (pulp, peel, seed) were investigated in the same assay, and the peel extract was shown to exhibit maximum edema-reducing effect (0.470 ± 0.124 mL vs. control 0.920 ± 0.111 mL). This extract was used to elucidate the mode of action. Different inflammation inducers (serotonin, histamine, dextran, bradykinin, and carrageenan) were applied in the rat paw model, but the extract inhibited only the compound 48/80 elicited inflammation. The active extract was then fractionated by solvent-solvent partitioning and chromatographic methods with the guidance of the 48/80-induced anti-inflammatory assay, and the main compounds responsible for the activity were identified as ursolic acid and oleanolic acid. Our data suggest that the activity is most probably based on a membrane stabilizing effect caused by the inhibition of degranulation of mast cells. Moreover, previously unknown 2,5-bis-aryl-3,4-dimethyltetrahydrofuran lignans, nectandrin B, fragransin A2, and saucernetindiol were isolated and identified from H. rhamnoides for the first time.

Bioactive Segetane, Ingenane, and Jatrophane Diterpenes from Euphorbia taurinensis.

A novel segetane (1: ) and jatrophane diterpene (2: ), together with five known diterpenoids possessing segetane (3: ), jatrophane (4: ), and ingenane skeletons (5 - 7: ), were isolated from the methanol extract of Euphorbia taurinensis All. The structure elucidation of the compounds was performed by means of extensive spectroscopic analysis, including HRESIMS and 1D (1H, J-modulated spin-echo carbon experiment) and 2D (HSQC, HMBC, COSY, NOESY) NMR experiments. The multidrug resistance reversing and cytotoxic effects of five diterpenes (1, 4:  - 7: ) were studied on the L5178 mouse lymphoma cell line using rhodamine 123 accumulation and the MTT cell viability assay. Segetane and jatrophane diterpenes had no cytotoxic activity on the sensitive parent and multidrug resistance cells, while ingenane diterpenes showed a cytotoxic effect on both cell lines. Ingenanes 6: and 7: and segetane 1: demonstrated the remarkable multidrug resistance modulating effect at 20 µM.

Phenanthrenes from Juncus Compressus Jacq. with Promising Antiproliferative and Anti-HSV-2 Activities.

Juncaceae species are rich sources of phenanthrenes. The present study has focused on the isolation and structure determination of biologically active components from Juncus compressus. Eleven compounds (nine phenanthrenes and two flavonoids) have been isolated from the plant by the combination of different chromatographic methods. Two compounds (compressins A (Compound 1) and B (Compound 2)) are novel natural products, while seven phenanthrenes (effusol (Compound 3), effususol (Compound 4), juncusol (Compound 5), 2-hydroxy-1-methyl-4-oxymethylene-5-vinyl-9,10-dihydrophenanthrene (Compound 6), 7-hydroxy-1-methyl-2-methoxy-5-vinyl-9,10-dihydrophenanthrene (Compound 7), effususin A (Compound 8), and dehydroeffusol (Compound 9)), and two flavonoids (apigenin (Compound 10) and luteolin (Compound 11) were isolated for the first time from the plant. Compressin B (Compound 2) is a dimeric phenanthrene, in which two juncusol monomers (Compound 5) are connecting through their C-3 atoms. The structure elucidation of the isolated compounds was carried out using 1D, 2D NMR spectroscopic methods and HR-MS measurements. In vitro investigation of the antiproliferative effect of the phenanthrenes on two cervical (HeLa and SiHa) and an ovarian human tumor cell line (A2780) revealed that compounds have remarkable antiproliferative activity, mainly on the HeLa cell line. Moreover, juncusol (Compound 5) proved to possess significant antiviral activity against the herpes simplex 2 virus (HSV-2).

Antiproliferative and cytotoxic activities of furocoumarins of Ducrosia anethifolia.

CONTEXT: Phytochemical and pharmacological data on Ducrosia anethifolia (DC.) Boiss. (Apiaceae), an Iranian medicinal plant, are scarce; however, furocoumarins are characteristic compounds of D. anethifolia. OBJECTIVE: Our experiments identify the secondary metabolites of D. anethifolia and assess their antitumor and anti-multidrug resistance activities. MATERIALS AND METHODS: Pure compounds were isolated from the extract of aerial parts of the plant by chromatographic methods. Bioactivities were tested on multidrug resistant and sensitive mouse T-lymphoma cell lines. The inhibition of the cancer MDR efflux pump ABCB1 was evaluated by flow cytometry (at 2 and 20 µM). A checkerboard microplate method was applied to study the interactions of furocoumarins and doxorubicin. Toxicity was studied using normal murine NIH/3T3 fibroblasts. RESULTS: Thirteen pure compounds were isolated, nine furocoumarins namely, pabulenol (1), (+)-oxypeucedanin hydrate (2), oxypeucedanin (3), oxypeucedanin methanolate (4), (-)-oxypeucedanin hydrate (5), imperatorin (6), isogospherol (7), heraclenin (8), heraclenol (9), along with vanillic aldehyde (10), harmine (11), 3-hydroxy-α-ionone (12) and 2-C-methyl-erythrytol (13). Oxypeucedanin showed the highest in vitro antiproliferative and cytotoxic activity against parent (IC50 = 25.98 ± 1.27, 40.33 ± 0.63 µM) and multidrug resistant cells (IC50 = 28.89 ± 0.73, 66.68 ± 0.00 µM), respectively, and exhibited slight toxicity on normal murine fibroblasts (IC50 = 57.18 ± 3.91 µM). DISCUSSION AND CONCLUSIONS: Compounds 2, 3, 5, 7, 10-13 were identified for the first time from the Ducrosia genus. Here, we report a comprehensive in vitro assessment of the antitumor activities of D. anethifolia furocoumarins. Oxypeucedanin is a promising compound for further investigations for its anticancer effects.

Three New Iridoid Glycosides from the Aerial Parts of Asperula involucrata.

Three new iridoid glycosides, named involucratosides A - C (1 - 3), were isolated from the H2 O subextract of crude MeOH extract prepared from the aerial parts of Asperula involucrata along with a known iridoid glycoside (adoxoside), three flavone glycosides (apigenin 7-O-ß-glucopyranoside, luteolin 7-O-ß-glucopyranoside, apigenin 7-O-rutinoside) as well as two phenolic acid derivatives (chlorogenic acid and ferulic acid 4-O-ß-glucopyranoside). Their chemical structures were established by UV, IR, 1D- (1 H, 13 C and JMOD) and 2D- (COSY, HSQC, HMBC and NOESY) NMR experiments and HR-ESI-MS. In addition, the crude extract, subextracts and isolates were evaluated for their xanthine oxidase inhibitory and antioxidant activities in in vitro tests. This is the first report on the chemical composition and bioactivities of A. involucrata.

Phenanthrenes from Juncus inflexus with Antimicrobial Activity against Methicillin-Resistant Staphylococcus aureus.

The present study has focused on an investigation of the antibacterial effects of Juncus inflexus and the isolation and identification of its active compounds. Eleven phenanthrenes were isolated from a methanolic extract of the roots. Four compounds (jinflexins A-D, 1-4) are new natural products, while seven phenanthrenes [juncuenins A (5), B (6), and D (8), juncusol (7), dehydrojuncuenins A (9) and B (11), and dehydrojuncusol (10)] were isolated for the first time from the plant. Jinflexin D (4) is a dimer with an unprecedented heptacyclic ring system. The absolute configurations of the new compounds were determined by TDDFT-ECD calculations, and their enantiomeric purity was checked by chiral HPLC analysis. Extracts of different polarity (n-hexane, dichloromethane, and ethyl acetate) were evaluated for their antimicrobial effects against methicillin-resistant Staphylococcus aureus, extended-spectrum ß-lactamase (ESBL)-producing Citrobacter freundii, Escherichia coli, Enterobacter cloacae, Klebsiella pneumoniae, multiresistant Acinetobacter baumannii, and Pseudomonas aeruginosa. The MIC values of the isolated compounds were determined by a microdilution method. Jinflexin B (2), juncusol (7), juncuenin D (8), and dehydrojuncuenin B (11) showed significant activity (MIC value range 12.5-100 µg/mL) against MRSA strains.