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PubMed2004

Tetrahydrofuran lignans from Nectandra megapotamica with trypanocidal activity.

The phytochemical investigation of the crude ethanol extract of the leaves of Nectandra megapotamica afforded three new (2d, 3b, and 3c) and eight known (1a-d, 2a-c, and 3a) tetrahydrofuran lignans. Regarding the in vitro trypanocidal activity, the lignan-rich fraction, at a concentration of 2.0 mg/mL, was 100% active. Compound 1a was the most active, showing an IC(50) value of 2.2 microM and lysis of 94% of the parasites at 32 microM. Compounds 1b, 1d, 2a, 2c, and 3a displayed moderate activity, while compound 1c was inactive.

Animals↗
PubMed2004

Aglacins I-K, three highly methoxylated lignans from Aglaia cordata.

Further chemical investigation of the stem bark of Aglaia cordata has led to the isolation and identification of three new lignans, namely, aglacins I-K (1-3), all of which contain two contiguous trimethoxylated phenyl systems. Among them, aglacins I and J (1 and 2) are new members of the aryltetralin cyclic lactol class, while aglacin K (3) is a new example of tetrahydrofuran lignan. The structures of these compounds were established on the basis of spectroscopic data interpretation.

Aglaia↗
PubMed2004

New furofuran and butyrolactone lignans with antioxidant activity from the stem bark of Styrax japonica.

A new furofuran lignan, styraxlignolide B (1), and four new dibenzyl-gamma-butyrolactone lignans, styraxlignolides C-F (2-5), were isolated from the EtOAc-soluble fraction of stem bark of Styrax japonica. Known compounds, taraxerol (6), syringin (7), and (-)-pinoresinol glucoside (8), were also obtained. The structures of styraxligonolides B-F were determined as 2alpha-(4'-hydroxy-3'-methoxyphenyl)-6alpha-(3' ',4' '-methylenedioxyphenyl)-8-oxo-3,7-dioxabicyclo[3.3.0]octane 4'-O-(beta-D-glucopyranoside) (1), (2S,3S)-2alpha-(3' '-hydroxy-4' '-methoxybenzyl)-3beta-(4'-hydroxy-3'-methoxybenzyl)-gamma-butyrolactone 4'-O-(beta-D-glucopyranoside) (2), (2S,3S)-2alpha-(4' '-hydroxy-3' '-methoxybenzyl)-3beta-(4'-hydroxy-3'-methoxybenzyl)-gamma-butyrolactone 4'-O-(beta-D-glucopyranoside) (3), (2S,3S)-2alpha-(4' '-hydroxy-3' '-methoxybenzyl)-3beta-(4'-hydroxy-3'-methoxybenzyl)-gamma-butyrolactone 4' '-O-(beta-D-glucopyranoside) (4), and (2S,3S)-2alpha-(3' ',4' '-dimethoxybenzyl)-3beta-(4'-hydroxy-3'-methoxybenzyl)-gamma-butyrolactone 4'-O-(beta-D-glucopyranoside) (5) by spectroscopic means including 2D NMR. Compounds 1-8 were tested in vitro for antioxidant activity against 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals. Styraxlignolide C (2), styraxlignolide D (3), styraxlignolide E (4), and (-)-pinoresinol glucoside (8) exhibited weak radical-scavenging activity in the DPPH assay, with IC50 values of 380, 278, 194, and 260 microM, respectively.

4-Butyrolactone↗
PubMed2005

Lignans from bark of Larix olgensis var. koreana.

Six new lignans (2-7) were isolated from the bark of Larix olgensis var. koreana, and their structures were determined on the basis of their spectroscopic data. Seven known lignans were also obtained and identified as (+)-lariciresinol 9'-p-coumarate (1), (+)-lariciresinol, (-)-secoisolariciresinol, (+)-isolariciresinol, vladinol D, sesquipinsapol B, and ehletianol C. Compound 1 showed weak inhibition against K562, SHG44, HCT-8, A549, and PC-3M tumor cells with IC50 values of 2.9, 21.4, 32.9, 33.8, and 28.0 microg/mL, respectively.

Antineoplastic Agents, Phytogenic↗
PubMedDate not supplied

Isolation and structure of the cytostatic lignan glycoside phyllanthostatin A.

An unusual cytostatic (PS ED50 4 micrograms/ml) lignan ester has been isolated from the Central American tree Phyllanthus acuminatus and designated phyllanthostatin A [1]. Separation of an MeOH extract of the root by size exclusion chromatography, high speed counter-current distribution, and semipreparative hplc afforded glycoside 1 in 0.007% yield. In solution, phyllanthostatin A was slowly transformed into justicidin B [4]. The structure of lignan glycoside 1 was determined by hrfabms and 2D-nmr spectroscopy.

Chromatography, High Pressure Liquid↗
PubMed1996

Two new lignans, interiotherins A and B, as anti-HIV principles from Kadsura interior.

Two new lignans, interiotherins A (1) and B (2), along with two known lignans, angeloylgomisin R (3) and schisantherin D (4), were isolated from Kadsura interior. Their structures and stereochemistries were determined from spectral data. Compounds 1 and 4 inhibit HIV replication with EC50 values of 3.1 and 0.5 micrograms/mL, respectively.

Anti-HIV Agents↗
PubMed1998

Lignans from Chilean propolis.

Three new (1, 3, 4) and two known lignans (2 and 5) were isolated from Chilean propolis. Compound 1 was identified as a trimeric coniferyl alcohol acetate and 3 as the diastereomer of the dimeric coniferyl alcohol acetate 2. Compound 4 was identified as a dihydrobenzofuran lignan aldehyde, which was isolated together with the related known acetate 5.

Chile↗
PubMed2000

Hepatoprotective diastereomeric lignans from Saururus chinensis herbs.

Two new diastereomeric sauchinones (2, 3), along with the known sauchinone (1), a phenylpropanoid (sarisan), and two known lignans (galbacin and saucernetin), were isolated from the n-hexane fraction of Saururus chinensis using reversed-phase HPLC. The stereostructures of the lignans, sauchinone A (2) and 1'-epi-sauchinone (3), were established by analysis of spectroscopic data. Incubation of cultured rat hepatocytes intentionally injured by CCl(4) with each of the compounds 1, 2, and 3 significantly reduced the levels of glutamic pyruvic transaminase released by the damaged hepatocytes.

Animals↗
PubMed1980

Lignans in man and in animal species.

In our laboratories, for several years, two phenolic compounds have been detected during gas chromatographic-mass spectrometric analysis of urinary steroid extracts from human and animal species. Although features of the mass spectra of their trimethylsilyl (TMS) ether derivatives resembled those of oestrogens, they were atypical of steroids. The possibility that they were artefacts of the isolation procedures was discounted after careful studies with blanks, by varying the extraction method and because they were present almost exclusively as conjugates of glucuronic acid. Several of the general characteristics of the unknown compounds were reported after one (referred to as compound 180/442) was found to have a cyclic pattern of excretion during the menstrual cycle of an adult vervet monkey (Fig. 1). An investigation of the nature and distribution of the compounds has shown them to be urinary constituents in humans, baboons, vervet monkeys and rats, and further related compounds have been detected, so far only in vervet monkey urine. We now report spectroscopic and chemical studies that show the two original compounds to be lignans, which have a 2,3-dibenzylbutane skeleton as their basic structure. Unlike all previously known natural lignans, invariably of plant origin, the two mammalian compounds carry phenolic hydroxy groups only in the meta position of the aromatic rings.

Adult↗
PubMed2002

Novel substituted methylenedioxy lignan suppresses proliferation of cancer cells by inhibiting telomerase and activation of c-myc and caspases leading to apoptosis.

Conventional solvent fractionation and bioactivity based target assays were used to identify a new anti-cancer molecule from Phyllanthus urinaria, a herbal medicinal plant used in South India. At each step of the purification process the different fractions that were isolated were tested for specific anti-proliferative activity by assays measuring the inhibition of [(3)H]thymidine incorporation, and trypan blue drug exclusion. The ethyl acetate fraction that contained the bioactivity was further purified and resolved by HPLC on a preparative column. The purity of each of the fractions and their bioactivity were checked. Fraction 3 demonstrated a single spot on TLC and showed maximum anti-proliferative activity. This fraction was further purified and the structure was defined as 7'-hydroxy-3',4',5,9,9'-pentamethoxy-3,4-methylene dioxy lignan using NMR and mass spectrometry analysis. The pure compound and the crude ethyl acetate fraction which showed anti-proliferative activities were examined for ability to target specific markers of apoptosis like bcl2, c-myc and caspases and for effects on telomerase. Four specific cancer cell lines HEp2, EL-1 monocytes, HeLa and MCP7 were used in this study. The results indicate that 7'-hydroxy-3',4',5,9,9'-pentamethoxy-3,4-methylene dioxy lignan was capable of inhibiting telomerase activity and also could inhibit bcl2 and activate caspase 3 and caspase 8 whose significance in the induction of apoptosis is well known. We believe that this compound could serve as a valuable chemotherapeutic drug after further evaluations.

Antineoplastic Agents, Phytogenic↗
PubMed2003

Synthesis and chiral HPLC analysis of the dibenzyltetrahydrofuran lignans, larreatricins, 8'-epi-larreatricins, 3,3'-didemethoxyverrucosins and meso-3,3'-didemethoxynectandrin B in the creosote bush (Larrea tridentata): evidence for regiospecific control of coupling.

The creosote bush (Larrea tridentata) lignans are linked via 8-8' bonds, with the simplest apparently being E-p-anol derived. Of the latter, four of the six theoretically possible diastereoisomers were isolated, namely (-)-larreatricin, (-)-8'-epi-larreatricin, meso-3,3'-didemethoxynectandrin B and the new compounds, (+)- and (-)-3,3'-didemethoxyverrucosins. Following synthesis of each in either racemic or meso form, and chiral HPLC separation of the antipodes of the racemates, it was established that naturally occurring (-)-larreatricin and (-)-8'-epi-larreatricin were present in 92 and 98% enantiomeric excess, respectively, whereas 3,3'-didemethoxyverrucosin was essentially racemic and 3,3'-didemethoxynectandrin B was in the meso-form. The evidence suggests that formation of these lignans occurs under regiospecific, rather than stereoselective, coupling control. This contrasts with laccase-catalyzed "random" coupling of E-p-anol in vitro which generates the corresponding racemic 8-8', 8-3' and 8-O-4' linked dimeric moieties.

Chromatography, High Pressure Liquid↗
PubMed2005

Reactivity of 4-vinylphenol radical cations in solution: implications for the biosynthesis of lignans.

Nanosecond laser flash photolysis studies of the radical cation of 4-hydroxy-3-methoxystyrene show that the radical cation reacts with neutral 4-hydroxy-3-methoxystyrene and non-phenolic styrenes with rate constants that range from 1 x 10(8) to 5 x 10(8) M(-1) s(-1). Similar 4-vinylphenol radical cations such as the radical cations of isoeugenol and coniferyl alcohol display reduced reactivity, presumably due to the presence of beta-alkyl substituents. Overall, the results show that the reactivity of 4-vinylphenol radical cations with neutral styrenes parallels the reactivity of non-phenolic styrene radical cations, which are known to undergo efficient radical cation mediated dimerization reactions to give lignan-like compounds. The possibility that the biosynthesis of some lignans may follow a radical cation mediated mechanism is discussed.

Cations↗
PubMed1991

Purification of a new peroxidase catalysing the formation of lignan-type compounds.

A novel peroxidase that catalyses the dimerization of ferulic acid or caffeic acid via oxidative coupling and formation of beta beta'-linkage to the lignan-type compounds 8,8'-bis(caffeic acid) or 8,8'-bis(ferulic acid) respectively was purified from the leaves of Bupleurum salicifolium. The enzyme, for which the name caffeate peroxidase is proposed, was purified 2700-fold. It is a glycoprotein and has an Mr of 38,000 as determined by gel filtration and SDS/PAGE. The Km values for ferulic acid and caffeic acid were 0.24 mM and for H2O2 0.04 mM with caffeic acid and 0.48 mM with ferulic acid. The purified peroxidase does not exhibit activity on other phenylpropanoids tested and has no detectable phenol oxidase or NADPH oxidase activity. The caffeate peroxidase could be involved in the biosynthesis of lignans.

Catalysis↗
PubMed1999

Evaluation of the trypanocidal activity of lignans isolated from the leaves of Zanthoxylum naranjillo.

Seven lignans isolated from the hexane extract of the leaves of Zanthoxyllum naranjillo (Rutaceae) were tested in both in vitro and in vivo assays against two strains of Trypanosoma cruzi (Bolivia and Y). Of the seven assayed lignans, three were inactive [(+)-sesamin, (+)-piperitol-4'-O-gamma, gamma-dimethylallyl ether and (-)-3,4-dimethoxy-3',4'-demethylenedioxycubebin] and three were partially active in the in vitro assays [(-)-hibalactone, (-)-kaerophylin and (-)-cubebin]. Healthy animals developed the disease after injection of the tested infected blood samples containing these three compounds. One compound [(-)-methylpluviatolide] was highly effective in the in vitro assay and healthy animals injected with the tested samples did not develop the disease. Moreover, only (-)-methylpluviatolide was highly active against the bloodstream forms of both strains of T. cruzi for the in vivo assay. However, it was not active against the tissue forms of the parasite.

Animals↗
PubMed1999

Lignan and phenylpropanoid glycosides from Lancea tibetica and their antitumor activity.

A new lignan glucoside, the first 7,9'-monoepoxyte-trahydrofuran type lignan with the cis-relationship of H-7 and H-8, named tibeticoside (1), as well as ten known compounds have been isolated from the medicinal plant (roots, stems and leaves) Lancea tibetica. The structure of tibeticoside (1) has been elucidated on the basis of chemical and spectral evidence, especially by 2D-NMR (1H-1H COSY, HMQC, HMBC, NOESY). In addition, sylvatesmin (6) exhibited effective antitumor activity on B16 cells.

Animals↗
PubMed2001

Lignans from the rhizomes of Coptis japonica differentially act as anti-inflammatory principles.

Coptis japonica Makino (Ranunculaceae) is known to possess several biological activities such as anti-inflammatory effects. In this study, five lignans, isolariciresinol (1), lariciresinol glycoside (2), pinoresinol (3), pinoresinol glycoside (4) and syringaresinol glycoside (5), isolated from the rhizomes of C. japonica were tested to evaluate their in vitro anti-inflammatory effects. Pinoresinol and isolariciresinol showed higher inhibitory effects on TNF-alpha production, whereas syringaresinol glycoside strongly suppressed lymphocyte proliferation. The results indicate that the lignans may differentially modulate inflammatory cell responses, suggesting that these compounds may participate in anti-inflammatory processes by C. japonica.

Animals↗
PubMed2002

In vivo antioxidant action of a lignan-enriched extract of Schisandra fruit and an anthraquinone-containing extract of Polygonum root in comparison with schisandrin B and emodin.

The in vivo antioxidant action of a lignan-enriched extract of the fruit of Schisandra chinensis (FS) and an anthraquinone-containing extract of the root of Polygonum multiflorum (PME) was compared with their respective active constituents schisandrin B (Sch B) and emodin by examining their effect on hepatic mitochondrial glutathione antioxidant status in control and carbon tetrachloride (CCl 4 )-intoxicated mice. FS and PME pretreatments produced a dose-dependent protection against CCl 4 hepatotoxicity, with the effect of FS being more potent. Pretreatment with Sch B, emodin or alpha-tocopherol (alpha-Toc) also protected against CCl 4 hepatotoxicity, with the effect of Sch B being more potent. The extent of hepatoprotection afforded by FS/Sch B and PME/emodin pretreatment against CCl 4 toxicity was found to correlate well with the degree of enhancement in hepatic mitochondrial glutathione antioxidant status, as evidenced by increases in reduced glutathione level and activities of glutathione reductase, glutathione peroxidase as well as glutathione S-transferases, in both control and CCl 4 -intoxicated mice. alpha-Toc, which did not enhance mitochondrial glutathione antioxidant status, seemed to be less potent in protecting against CCl 4 hepatotoxicity. The ensemble of results indicates that FS/PME produced a more potent in vivo antioxidant action than alpha-Toc by virtue of their ability to enhance hepatic mitochondrial glutathione antioxidant status and that the differential potency of FS and PME can be attributed to the difference in in vivo antioxidant potential between Sch B and emodin. Abbreviations. ALT:alanine aminotransferases CCl 4 :carbon tetrachloride FS:lignan-enriched extract of Schisandra fruit GRD:glutathione reductase GSH:reduced glutathione GSH-Px: Se-glutathione peroxidase GST:glutathione S-transferases mt:mitochondrial MDA:malondialdehyde PME:anthraquinone-containing fraction of Polygonum root Sch B:schisandrin B SDH:sorbitol dehydrogenase alpha-Toc:alpha-tocopherol

Alanine Transaminase↗
PubMed2006

New lignans and cytotoxic constituents from Schisandra propinqua.

The CHCl (3) extract from the stems of Schisandra propinqua (Wall.) Baill exhibited significant cytotoxic activity against cancer cell lines. Subsequent fractionation procedures led to the isolation of four new dibenzocyclooctadiene lignans, propinquanins A - D, along with two known lignans, schisantherin I and heteroclitin A, and three known triterpenoids, isoschisandrolic acid, schisandrolic acid and schisandronic acid. Their structures, including absolute stereochemistry, were elucidated through analyses of NMR data and CD spectra. The isolated compounds were tested for their cytotoxic activity in several tumor cell lines with the MTT assay. Propinquanin B ( 2) was significantly cytotoxic (IC (50) values < 10 microM) in HL-60 and Hep-G2 tumor cell lines. Cell cycle analysis and Hoechst 33 258 staining assay suggested that one possible mechanism of cytotoxic activity by 2 might be related to the induction of apoptosis.

Antineoplastic Agents, Phytogenic↗