Pentasaccharide resin glycosides from Ipomoea pes-caprae

Pescapreins XXI-XXX (1-10), pentasaccharide resin glycosides, together with the known pescapreins I-IV and stoloniferin III were isolated from the aerial parts of Ipomoea pes-caprae (beach morning-glory). The pescapreins are macrolactones of simonic acid B, partially esterified with different fatty acids. The lactonization site of the aglycone, jalapinolic acid, was located at C-2 or C-3 of the second saccharide moiety. Their structures were established by a combination of spectroscopic and chemical methods. Compounds 1-10 were evaluated for their potential to modulate multidrug resistance in the human breast cancer cell line MCF-7/ADR. The combined use of these new compounds at a concentration of 5 μg/mL increased the cytotoxicity of doxorubicin by 1.5-3.7-fold.     

Antioxidants from the bark of Burkea africana, an African medicinal plant

The bark of the tree Burkea africana is used medicinally in large areas of sub-Saharan Africa. The constituents responsible for its putative activity are not well known. We have investigated the bark of B. africana for antioxidant and radical scavenging activity. A hydroethanol bark extract showed high activity, and most of this activity was located in semipolar fractions of the extract. From chromatographic purification and spectroscopical structure studies, we conclude that the active constituents are proanthocyanidins. Two major components appear to be fisetinidol-(4alpha- --> 8)-catechin 3-gallate and bis-fisetinidol-(4alpha- --> 6, 4alpha- --> 8)-catechin 3-gallate. The latter compound is a new natural product. Smaller amounts of monomeric flavan-3-ols (catechin, epicatechin and fisetinidol) were also found.     

Characterization of pentasaccharide glycosides from the roots of Ipomoea arborescens

Ten new pentasaccharide glycosides, arboresins 1-6 (1-6) and murucins 6-9 (8-11), along with five known glycolipids, were isolated from the roots of Ipomoea arborescens, and their structures were elucidated by spectroscopic and chemical methods. Compounds 1-6 and 8-11 were evaluated for cytotoxicity against a small panel of cancer cell lines.     

Terpenoids from the medicinal plant Maytenus ilicifolia

Four new terpenoids (1-4) were isolated from the root bark of Maytenus ilicifolia. Their structures were determined by spectroscopic studies, and complete 1H and 13C NMR assignments were achieved by 2D NMR spectroscopy. We also report an efficient method for the separation of quinonemethide triterpenes based on centrifugal partition chromatography.     

Inhibitors of bacterial multidrug efflux pumps from the resin glycosides of Ipomoea murucoides

A reinvestigation of the CHCl 3-soluble extract from flowers of the Mexican medicinal arborescent morning glory, Ipomoea murucoides, through preparative-scale recycling HPLC, yielded six new pentasaccharides, murucoidins VI-XI (1- 6), as well as the known pescaprein III (7), stoloniferin I (8), and murucoidins I-V (9- 13). Their structures were characterized through the interpretation of their NMR spectroscopic and FABMS data. Compounds 1-6 were found to be macrolactones of three known glycosidic acids identified as simonic acids A and B, and operculinic acid A, with different fatty acids esterifying the same positions, C-2 on the second rhamnose unit and C-4 on the third rhamnose moiety. The lactonization site of the aglycone was placed at C-2 or C-3 of the second saccharide unit. The esterifying residues were composed of two short-chain fatty acids, 2-methylpropanoic and (2S)-methylbutyric acids, and two long-chain fatty acids, n-dodecanoic (lauric) acid and the new (8R)-(-)-8-hydroxydodecanoic acid. For the latter residue, its absolute configuration was determined by analysis of its Mosher ester derivatives. All members of the murucoidin series exerted a potentiation effect of norfloxacin against the NorA overexpressing Staphylococcus aureus strain SA-1199B by increasing the activity 4-fold (8 microg/mL from 32 microg/mL) at concentrations of 5-25 microg/mL. Stoloniferin I (8) enhanced norfloxacin activity 8-fold when incorporated at a concentration of 5 microg/mL. Therefore, this type of amphipathic oligosaccharide could be developed further to provide more potent inhibitors of this multidrug efflux pump.     

Cytotoxic ent-kauranoids from the medicinal plant Isodon xerophilus

Bioassay-directed fractionation of the leaves of the medicinal plant Isodon xerophilus led to the isolation of a series of potential antitumor molecules. Thirteen new (1-13) and 23 (14-36) known diterpenoids were isolated and identified, representing ent-kauranoids of several structural types. The structures of 1-13 were determined by means of spectroscopic studies. The absolute configurations of the new compounds were clarified by CD spectroscopic studies or were postulated on biogenetic grounds. All compounds obtained were evaluated for their cytotoxic activity against the K562, MKN45, and HepG2 cell lines. Compounds 1, 2, 11, 16-19, 23, 26-28, 30, and 32 demonstrated significant cytotoxic activity for one or more cell lines.     

Antiviral triterpenoids from the medicinal plant Schefflera heptaphylla

Schefflera heptaphylla (L.) Frodin is a principal ingredient of an herbal tea formulation widely used for the treatment of common cold in southern China. An extract of the long leafstalk of the compound leaf of S. heptaphylla exhibited the most potent antiviral activity against respiratory syncytial virus (RSV). Further antiviral-guided fractionation and isolation of the leafstalk extract of S. heptaphylla led to obtain two highly active pure triterpenoids, namely 3alpha-hydroxylup-20(29)-ene-23,28-dioic acid and 3-epi-betulinic acid 3-O-sulfate, together with an inactive saponin, 3alpha-hydroxylup-20(29)-ene-23,28-dioic acid 28-O-alpha-l-rhamnopyranosyl-(1-->4)-O-beta-d-glucopyranosyl-(1-->6)-beta-d-glucopyranoside. An antiviral assay using a cytopathic effect (CPE) reduction method showed that the two triterpenoids possessed broader antiviral activity against respiratory syncytial virus (RSV) with a similar 50% inhibition concentration (IC(50)) value of 6.25 microg/mL, influenza A (H1N1) virus with IC(50) values of 25 and 31.3 microg/mL, Coxsackie B3 (Cox B3) virus with IC(50) values of 12.5 and 20 microg/mL and herpes simplex virus type 1 (HSV-1) with IC(50) values of 18.8 and 25 microg/mL, respectively, whereas the saponin did not have antiviral activity against these four viruses at a concentration of 100 microg/mL.     

Components of the ether-insoluble resin glycoside fraction from the seed of Cuscuta australis.

An ether-insoluble resin glycoside fraction was obtained from the seeds of Cuscuta australis. Identification and characterization of alkaline hydrolysis products by means of GC, FABMS, and 1H, 13C, and 2D NMR revealed the material to be composed of three new glycosidic acids, cuscutic acids A1-A3 (1-3); triglycosides with (11S)-jalapinolic or (11S)-convolvulinolic acid as the aglycon; and acetic, isobutyric, (2S)-2-methylbutyric, tiglic, and (2R,3R)-nilic acids. The resin glycoside is considered to be a complex mixture of glycosidic ester-type oligomers (up to heptamers) with a core consisting of a number of the above cuscutic acids each acylated with one or two carboxylic acid moieties.     

药用沙棘果汁中1个新的黄酮苷类化合物

目的 对药用沙棘Hippophae rhamnoides果汁的化学成分进行研究.方法 选用大孔树脂、硅胶柱色谱、Sephadex LH-20、ODS、HPLC等色谱分离技术及HR-ESI-MS、1H-NMR、13C-NMR、HSQC、HMBC、NOESY等波谱分析技术进行分离、纯化与鉴定.结果 从药用沙棘果汁经D-10...     

Lignans from cell suspension cultures of Phyllanthus niruri, an Indonesian medicinal plant

Cell suspension cultures of Phyllanthus niruri were used to study the lignan profiles and biosynthesis. Suspension cultures yielded two lignans: the new cubebin dimethyl ether (1) and urinatetralin (2), a new lignan from P. niruri, but reported earlier from P. urinaria. This is the first report of cell suspension cultures of P. niruri that successfully produce lignans. Feeding 0.5 mM ferulic acid or 0.5 mM caffeic acid, being early precursors of lignan biosynthesis, resulted in an increase up to 0.7 mg g(-1) DW of 1 (control value 0.1 mg g(-1) DW) and up to 0.3 mg g(-1) DW of 2 (control value 0.2 mg g(-1) DW). Comparison of the lignan profiles of cell suspensions, callus cultures, aerial plant parts, roots, and seeds showed significant differences.     

青叶胆酮类化合物的成分研究

目的　分离鉴定青叶胆 Swertia mileensis全草的酮类成分。方法　 95 %乙醇浸提 ,经硅胶柱色谱分离纯化 ,UV,IR,MS,1 H和 1 3CNMR波谱方法确定化学结构。结果　分得 12个酮成分 ,分别为 1-羟基 - 2 ,3,4 ,5 -四甲氧基酮 (1- hydroxy- 2 ,3,4 ,5 - tetramethoxyxanthone, ) ;1-羟基 - 2 ,3,7-三甲氧基酮 (1- hydroxy- 2 ,3,7-trim ethoxyxanthone, ) ;1-羟基 - 2 ,3,5 ,7-四甲氧基酮 (1- hydroxy- 2 ,3,5 ,7- tetram ethoxyxanthone, ) ;1,5 -二羟基 - 2 ,3-二甲氧基酮 (1,5 - dihydroxy- 2 ,3- dimethoxyxanthone, ) ;1,5 -二羟基 - 2 ,3,7-三甲氧基酮 (1,5 - dihy-droxy- 2 ,3,7- trimethoxyxanthone, ) ;1-羟基 - 2 ,3,5 -三甲氧基酮 (1- hydroxy- 2 ,3,5 - trimethoxyxanthone, ) ;1,5 -二羟基 - 2 ,3,4 ,7-四甲氧基酮 (1,5 - dihydroxy- 2 ,3,4 ,7- tetramethoxyxanthone, ) ;1,8-二羟基 - 2 ,3,6 -三甲氧基酮 (1,8- dihydroxy- 2 ,3,6 - trimethoxyxanthone, ) ;1-羟基 - 2 ,3,4 ,7-四甲氧基酮 (1- hydroxy- 2 ,3,4 ,7- te-tramethoxyxanthone, ) ;1,2 ,3,5 -四甲氧基酮 (1,2 ,3,5 - tetromethoxyxanthone, ) ;1-羟基 - 2 ,3,4 ,6 -四甲氧基酮 (1- hydroxyl- 2 ,3,4 ,6     

青叶胆-酮类化合物的成分研究

目的：分离鉴定青叶胆Uwertia mileensis全草的山酮类成分。方法：95％乙醇浸提，经硅胶柱色谱分离纯化，UV，IR，MS，^1H和^13CNMR波谱方法确定化学结构。结果：分得12个酮成分，分别为1-羟基-2，3，4，5-四甲氧基山酮（1-hydrox-2，3，4，5-tetramethoxyxanthone，Ⅰ）；1-羟基-2，3，7-三甲氧基山酮（1-hydroxy-2，3，7-trimethoxyxanthone，Ⅱ）；1-羟基-2，3，5，7-四甲氧基山酮（1-hydroxy-2，3，5，7-tetramethoxyxanthone，Ⅲ）；1，5-二羟基-2，3-二甲氧基山酮（1，5-dihydroxy-2，3-dimethoxyxanthone，Ⅳ）；1，5-二羟基-2，3，7-三甲氧基山酮（1，5-dihy-droxy-2，3，7-trimethoxyxanthone，Ⅴ）；1-羟基-2，3，5-三甲氧基山酮（1-hydroxy-2，3，5-trimethoxyxanthone，Ⅵ）；1，5-二羟基-2，3，4，7-四甲氧基山酮（1，5-dihydroxy-2，3，4，7-tetramethoxyxanthone,Ⅶ）；1，8-二羟基-2，3，6-三甲氧基山酮（1，8-dihydroxy-2,3,6-trimethoxyxanthone，Ⅷ）；1-羟基-2，3，4，7-四甲氧基山酮（1-hydroxy-2，3，4，7-tetramethoxyxanthone，Ⅸ）；1，2，3，5-四甲氧基山酮（1，2，3，5-tetromethoxyxanthone，Ⅹ）；1-羟基-2，3，4，6-四甲氧基山酮（1-hydroxyl-2，3，4，6-tetramethoxyxanthone，Ⅺ）；1-羟基-2，3，6，8-四甲氧基山酮（1-hydroxyl-2，3，6，8-tetramethoxyxanthone，Ⅻ）。结论：化合物Ⅰ，Ⅲ，Ⅳ，Ⅴ，Ⅶ-Ⅶ为首次从青叶胆中分得。     

A new medicinal plant from Amazonian Ecuador

Dalbergaria tessmanii, a shrub of the Gesneriaceae locally abundant in the tropical forests of Ecuador, is variously ethnomedicinally employed. For example, none of several Shuar (Jívaro) herbal healers know or use it, but the one Shuar Shaman consulted extols its importance in reducing vaginal bleeding. Although Mestizo native consultants from the provincial capital of Morona-Santiago report its use in alleviating heart problems, those from Pastaza Province employ it to reduce menstrual flow. The Lowland Quechua apparently use it for this purpose as well. This plant has apparently not yet been chemically examined. Its reported use in several different cultural context suggest that it should be phytochemically investigated.     

Chemical constituents from the Colombian medicinal plant Maytenus laevis

The methanol extract of the bark of the Colombian medicinal plant Maytenus laevis gave six new compounds and 28 known compounds. The structures of the new and known compounds were elucidated on the basis of spectroscopic evidence. Several of these compounds were screened for cytokine-inducing activity on human PBMCs to investigate antitumor effects, and canophyllol (12) demonstrated the most effective induction of the cytokines.     

Dammarane-type triterpenes from the Brazilian medicinal plant Cordia multispicata

From the Brazilian medicinal plant Carucaá (Cordia multispicata), oleanane- and ursane-type triterpenoids were previously reported as anti-androgenic constituents of the plant. In this study, purification of the polar elements of the EtOAc-soluble fraction of the plant revealed nine novel dammarane-type triterpenes, named cordianols A-I (1-9) along with the known compound cordialin A (10). The structures of these new compounds were elucidated by means of spectral methods including HRFABMS, (1)H NMR, (13)C NMR, and 2D NMR (HMQC, HMBC, NOESY). Absolute configuration at C-23 of compound 7 was determined by an excitone chirality method. Some of these new compounds revealed a hemiketal structure on the A ring and a hydroxylated or epoxidated 20(22)-(E)-ene side chain and showed weak anti-androgenic activity.     

Anti-mycobacterial diynes from the Canadian medicinal plant Aralia nudicaulis

Ethnopharmacological relevance

Aralia nudicaulis, or wild sarsaparilla, is used as a traditional medicinal plant for the treatment of various illnesses by many of the Canadian First Nations. Iroquois and Algonquin First Nations of Eastern Canada use a tea prepared from dried Aralia nudicaulis rhizome as a cough medicine and for the treatment of tuberculosis. Previous investigations of aqueous extracts of Aralia nudicaulis rhizomes have shown it to possess antimycobacterial activity.

Aim of the study

To isolate and identify antimycobacterial constituents from Aralia nudicaulis rhizomes.

Materials and methods

Methanolic extracts of Aralia nudicaulis rhizomes were subjected to bioassay guided fractionation using the microplate resazurin assay (MRA) to assess inhibitory activity against Mycobacterium tuberculosis strain H37Ra. The antimycobacterial constituents were identified by NMR, MS and polarimetry.

Results

Two C17 polyacetylenes with significant antimycobacterial activity were isolated from the Aralia nudicaulis rhizome extract. The polyacetylenes were identified as (3R)-falcarinol and (3R, 9R, 10S)-panaxydol. Falcarinol and panaxydol displayed MICs of 25.6 μM and 36.0 μM and IC₅₀s of 15.3 μM and 23.5 μM against Mycobacterium tuberculosis H37Ra.

Conclusions

Falcarinol and panaxydol were identified as the principal constituents responsible for the antimycobacterial activity of Aralia nudicaulis rhizomes validating an ethnopharmacological use of this plant by the Canadian First Nations.     

Antiplasmodial agents from the Bhutanese medicinal plant Corydalis calliantha

The alkaloidal components of the Bhutanese medicinal plant Corydalis calliantha Long, which is used for the treatment of malaria, have been assessed. Four known alkaloids, protopine (1), scoulerine (2), cheilanthifoline (3) and stylopine (4) are reported from this plant for the first time. The protopine alkaloid, protopine, and the tetrahydroprotoberine alkaloid, cheilanthifoline, showed promising in vitro antiplasmodial activities against Plasmodium falciparum, both wild type (TM4) and multidrug resistant (K1) strains with IC₅₀ values in the range of 2.78–4.29 µm . Such activity had not been demonstrated previously for cheilanthifoline. The results thus support, at a molecular level, the clinical use of this plant in the Bhutanese traditional medicine and identified cheilanthifoline as a potential new antimalarial drug lead. Copyright © 2009 John Wiley & Sons, Ltd.     

Antiprotozoal polyacetylenes from the Tanzanian medicinal plant Cussonia zimmermannii

From the petroleum ether extract of the root bark of Cussonia zimmermannii four polyacetylenes, 1- 4, were isolated, three of which ( 1- 3) were active against Trypanosoma brucei rhodesiense, Trypanosoma cruzi, Plasmodium falciparum, and Leishmania donovani.     

Cyclobutane dimers from the Colombian medicinal plant Achyrocline bogotensis

Five cyclobutane dimers, achyrodimers A-E (1-5), along with 11 known compounds were isolated from the methanol extract of the Colombian medicinal plant Achyrocline bogotensis. Their structures were elucidated by spectroscopy. Several of these compounds were screened for cytokine-inducing activity in human peripheral blood mononuclear cells.     

An arabinogalactan isolated from the medicinal plant Maytenus ilicifolia

An arabinogalactan was obtained from the leaves of Maytenus ilicifolia by hot aqueous 2% KOH extraction, followed by a freezing-thawing process and anion-exchange chromatography. It consisted of arabinose, galactose, galacturonic acid, and rhamnose in a 69:20:6:5 molar ratio. Methylation analysis, partial acid hydrolysis, and (13)C NMR spectroscopy indicated that it was an arabinogalactan containing a (1-->4)-linked beta-Galp main chain, substituted at O-6 with Ara units, which were in turn substituted at O-5 (Araf) and/or O-4 (Arap), O-3, O-3,5, and O-2,5. This arabinogalactan is probably linked to O-4 of some Rhap units of a type I rhamnogalacturonan, formed by repeating (1-->4)-alpha-D-GalpA-(1-->2)-alpha-L-Rhap groups.