Lignan glycosides from the Rhizomes of Smilax trinervula and their Biological activities

Phytochemical investigation of the rhizomes of Smilax trinervula led to isolation and structure elucidation of eight lignan glycosides, including five new lignans, namely, (7S, 8R, 8′R)-4, 4′, 9-trihydroxy-3, 3′, 5, 5′-tetramethoxy-7, 9′-epoxylignan-7′-one 4′-O-β-d-glucopyranoside (1), (7S, 8R, 8′R)-4, 4′, 9-trihydroxy-3, 3′, 5, 5′-tetramethoxy-7, 9′-epoxylignan-7′-one 4-O-β-d- glucopyranoside (2) (7S, 8R)-4, 9, 9′-trihydroxy-3, 3′, 5-trimethoxy-4′, 7-epoxy-8, 5′-neolignan 9′-O-β-d-glucopyranoside (3), (7R, 8R)-4, 9, 9′-trihydroxy-3, 5-dimethoxy-7.O.4′, 8.O.3′- neolignan 9′-O-β-d-glucopyranoside (4), and (7S, 8R)-4, 9, 9′-trihydroxy-3, 3′, 5-trimethoxy-8, 4′-oxy-neolignan 4-O-β-d-glucopyranoside (5), along with three known compounds (6-8). Their structures were established mainly on the basis of 1D and 2D NMR spectral data, ESI–MS and comparison with the literature. Compounds 1-8 were tested in vitro for their cytotoxic activity against four human tumor cell lines (SH-SY5Y, SGC-7901, HCT-116, Lovo). Compounds 3 and 5 exhibited cytotoxic activity against Lovo cells, with IC₅₀ value of 10.4 μM and 8.5 μM, respectively.     

Two new guaiane sesquiterpenes from Datura metel L. with anti-inflammatory activity

Chemical investigation of an acidic methanol extract of the whole plants of Datura metel resulted in the isolation of two new guainane sesquiterpenes, 1β,5α,7β-guaiane-4β,10α,11-triol (1) and 1α,5α,7α-11-guaiene-2α,3β,4α,10α,13-pentaol (2), along with eight known compounds: pterodontriol B (3), disciferitriol (4), scopolamine (5), kaempferol 3-O-β-d-glucosyl(1 → 2)-β-d-galactoside 7-O-β-d-glucoside (6), kaempferol 3-O-β-glucopyranosyl(1 → 2)-β-glucopyranoside-7-O-α-rhamnopyranoside (7), pinoresinol 4′′-O-β-d-glucopyranoside (8), (7R,8S,7′S,8′R)-4,9,4′,7′-tetrahydroxy-3,3′-dimethoxy-7,9′-epoxy-lignan-4-O-β-d-glucopyranoside (9), and (7S,8R,7′S,8′S)-4,9,4′,7′-tetrahydroxy-3,3′-dimethoxy-7,9′-epoxylignan-4-O-β-d-glucopyranoside (10). Their structures were elucidated by extensive spectroscopic methods, including 1D and 2D NMR and MS spectra. Compounds 2-4 and 6-10 were shown to have modest anti-inflammatory effects through inhibition of NO production in LPS-stimulated BV cells.     

Sesquiterpenoids and lignans from the fruits of Illicium simonsii Maxim

Twenty-two known compounds were isolated from the 95% alcohol extract of the fruits of Illicium simonsii Maxim, including seven sesquiterpenoids (16–22) and fifteen lignans (1–15). In the present research, compounds 3 ((7S,8R,8′S)-3,3′-dimethoxy-4,4′,9-trihydroxy-7,9′-epoxylignan-7′-one), 4 ((−)-(7′S,8S,8′R)-4,4′-dihydroxy-3,3′,5,5′-tetramethoxy-7′,9-epoxylignan-9′-ol-7-one), 5 ((+)-8-hydroxypinoresinol), 6 ((+)-8-hydroxymedioresinol), 8 ((2R,3R)-2β-(4″-hydroxy-3″-methoxybenzyl)-3α-(4′-hydroxy-3′-methoxybenzyl)-γ-butyrolactone 2-O-(β-D-glucopyranoside), 12 ((+)-8-methoxyisolariciresinol), 13 (α-conidendrin), 14 (boehmenan) and 15 (7R,8R,7′E-7′,8′-didehydro-4,7,9,9′- tetrahydroxy-3-methoxy-8-O-4′-neolignan) were reported from the Illicium genus for the first time, and compounds 1 (simulanol), 7 ((+)-secoisolariciresinol monoglucoside), 10 ((+)-9-O-β-D-glucopyranosyl lyoniresinol), 11 ((+)-isolariciresinol), 18 (neoanisatin), 19 (veranisatin A), 20 (4,5-d₂-8′-oxo-dihydrophaseic acid) and 22 (Oligandrumin A) were firstly isolated from the plant. Their structures were elucidated on the basis of NMR spectroscopic and mass spectrometric data. Moreover, the chemotaxonomic significance of the isolated compounds is discussed.     

Three new neolignan glucosides from the stems of Dendrobium aurantiacum var. denneanum

Three new neolignan glucosides (1–3), together with four known analogs (4–7), have been isolated from the stems of Dendrobium aurantiacum var. denneanum. Structures of the new compounds including the absolute configurations were determined by spectroscopic and chemical methods as (−)-(8R,7′E)-4-hydroxy-3,3′,5,5′-tetramethoxy-8,4′-oxyneolign-7′-ene-9,9′-diol 4,9-bis-O-β-d-glucopyranoside (1), (−)-(8S,7′E)-4-hydroxy-3,3′,5,5′-tetramethoxy-8,4′-oxyneolign-7′-ene-9,9′-diol 4,9-bis-O-β-d-glucopyranoside (2), and (−)-(8R,7′E)-4-hydroxy-3,3′,5,5′,9′-pentamethoxy-8,4′-oxyneolign-7′-ene-9-ol 4,9-bis-O-β-d-glucopyranoside (3), respectively.     

Neolignans from Aniba lancifolia

The branches of the shrub Aniba lancifolia Kubitzki et Rodrigues (Lauraceae) contain besides 2-hydroxy-4,5- dimethoxyallylbenzene and its dimer cyclohexan-2-allyl- 5-en-4,5-dimethoxy-4-O-(2′-allyl-4′,5′-dimethoxyphenyl)-1-one (lancilin, 2) 6 further novel neolignans: (4S,2′R)- and (4R,2′E)-cyclohexan-2-allyl-2,5-dien-4,5-dimethoxy-4-[2′-(1′-guaiacyl)-propyl]-1-one (lancifolins A and B, 3a and 3b), (4S,2′R)- and (4R,2′R)-cyclohexan- 2-allyl-2,5-dien-4,5-dimethoxy-4-[2′-(1′-veratryl)-propyl]-1-one (lancifolins C and D, 3c and 3d), (4S,2′R)-and (4R,2′R)-cyclohexan-2-allyl-2,5-dien-4,5-dimethoxy-4-[2′-(1′-piperonyl)-propyl]-1-one (lancifolins E and F, 3e and 3f).     

Minor phenolics from Angelica keiskei and their proliferative effects on Hep3B cells

A new coumarin, (?)-cis-(3′R,4′R)-4′-O-angeloylkhellactone-3′-O-β-d-glucopyranoside (1) and two new chalcones, 3′-[(2E)-5-carboxy-3-methyl-2-pentenyl]-4,2′,4′-trihydroxychalcone (4) and (±)-4,2′,4′-trihydroxy-3′-{2-hydroxy-2-[tetrahydro-2-methyl-5-(1-methylethenyl)-2-furanyl]ethyl}chalcone (5) were isolated from the aerial parts of Angelica keiskei (Umbelliferae), together with six known compounds: (R)-O-isobutyroyllomatin (2), 3′-O-methylvaginol (3), (?)-jejuchalcone F (6), isoliquiritigenin (7), davidigenin (8), and (±)-liquiritigenin (9). The structures of the new compounds were determined by interpretation of their spectroscopic data including 1D and 2D NMR data. All known compounds (2, 3, and 6–9) were isolated as constituents of A. keiskei for the first time. To identify novel hepatocyte proliferation inducer for liver regeneration, 1–9 were evaluated for their cell proliferative effects using a Hep3B human hepatoma cell line. All isolates exhibited cell proliferative effects compared to untreated control (DMSO). Cytoprotective effects against oxidative stress induced by glucose oxidase were also examined on Hep3B cells and mouse fibroblast NIH3T3 cells and all compounds showed significant dose-dependent protection against oxidative stress.     

Phytochemical and chemotaxonomic study on Piper pleiocarpum Chang ex Tseng

The phytochemical study of Piper pleiocarpum Chang ex Tseng led to the isolation of eighteen compounds (1–18), including ten lignanoids, galbelgin (1), (+) sesamin (2), denudatin A (3), hancinone (4), (7S,8S, 3′R)-Δ^8'-3,3′,4-trimethoxy-3′,6′-dihydro-6′-oxo-7.0.4′,8.3′-lignan[(2S,3S,3aR)-2-(3,4-dimethoxyphenyl)-3,3a-dihydro-3a-methoxy-3-methyl-5-(2-propenyl)-6(2H))-benzofuranone] (5), (−)-(7R,8R)-machilin D (6), (1R,2R)-2-[2-methoxy-4-((E)-prop-1-enyl)phenoxy]-1-(3,4-dimethoxyphenyl)propyl acetate (7), piperbonin A (8), machilin D (9), 4-methoxymachilin D (10), one amide alkaloid, Δ^α,β-dihydropiperine (11), six polyoxygenated cyclohexenes, ent-curcuminol F (12), uvaribonol E (13), ellipeiopsol A (14), 1S,2R,3R,4S-1-ethoxy-2-[(benzoyloxy)methyl]cyclohex-5-ene-2,3,4-triol, 3-acetate (15), (+)-crotepoxide (16), (+)-senediol (17), and one benzoate derivative, 2-acetoxybenzyl benzoate (18). Their structures were established by spectroscopic data and by comparison with the literature. All the compounds were firstly isolated from P. pleiocarpum, while ten compounds 6–7, 9–10, 12–15, 17–18 were isolated from the genus Piper and the family Piperaceae for the first time. The chemotaxonomic significance of these compounds was also discussed. The isolation of compounds 6–7, 9–10 may be used as chemotaxonomic markers for the genus of Piper.     

Two new dihydrobenzofuran-type neolignans from Breynia fruticosa

(7S,8R,7′S)-9,7′,9′-Trihydroxy-3,4-methylenedioxy-3′-methoxy [7-O-4′,8-5′] neolignan (1) and (7S,8R,7′S)-9,9′-dihydroxy-3,4-methylenedioxy-3′,7′-dimethoxy [7-O-4′,8-5′] neolignan (2), two new natural dihydrobenzofuran-type neolignans, along with 9,9′-dihydroxy-3,4-methylenedioxy-3′-methoxy [7-O-4′,8-5′] neolignan (3) and (-)-machicendiol (4), were isolated from the whole plants of Breynia fruticosa. The structures of 1 and 2, including the absolute configurations, were determined by spectroscopic methods and circular dichroism (CD) techniques. The absolute configuration of 4 was confirmed by calculations of the OR spectrum, together with OR and ECD spectra of its p-bromobenzoate ester (4a).     

Synthesis of 6-substituted uridines. synthesis of (R or S)-6-(3-amino-2-carboxypropyl)uridine

Addition of 5-bromo-2′,3′-O-isopropylidene-5′-O-trityluridine (2) in pyridine to an excess of 2-lithio-1,3-dithiane (3) in oxolane at 78° gave (6R)-5,6-dihydro-(1,3-dithian-2-yl)-2′,3′-O-isopropylidene -5′-O-trityluridine (4), (5S,6S)-5-bromo-5,6-dihydro-(1,3-dithian-2-yl)-2′,3′-O-isopropylidene-5′-O-trityluridine (5), and its (5R) isomer 6 in yields of 37, 35, and 10%, respectively. The structure of 4 was proved by Raney nickel desulphurization to (6S)-5,6-dihydro-2′,3′-O-isopropylidene-6-methyl-5′-O-trityluridine (7) and by acid hydrolysis to give D-ribose and (6R)-5,6-dihydro-6-(1,3-dithian-2-yl)uracil (9). Treatment of 4 with methyl iodide in aqueous acetone gave a 30&%; yield of (R,S)-5,6-dihydro-6-formyl-2′,3′-O-isopropylidene-5′-O-trityl-uridine (10), characterized as its semicarbazone 11. Both 5 and 6 gave 4 upon brief treatment with Raney nickel. Both 5 and 6 also gave 6-formyl-2′,3′-O-isopropylidene-5′- O-trityluridine (12) in ～41%; yield when treated with methyl iodide in aqueous acetone containin- 10%; dimethyl sulfoxide. A by-product, identified as the N-methyl derivative (13) of 12 was also formed in yields which varied with the amount of dimethyl sulfoxide used. Reduction of 12 with sodium borohydride, followed by deprotection, afforded 6-(hydroxymethyl)uridine (17), characterized by hydrolysis to the known 6-(hydroxymethyl)uracil (18). Knoevenagel condensation of a mixture of the aldehydes 12 and 13 with ethyl cyanoacetate yielded 38%; of E- (or Z-)6-[(2-cyano-2-ethoxycarbonyl)ethylidene]-2′,3′-O-isopropylidene-5′-O-trityluridine (19) and 10%; of its N-methyl derivative 20. Hydrogenation of 19 over platinum oxide in acetic anhydride followed by deprotection gave R (or S)-6-(3-amino-2-carboxypropyl)uridine (23).     

Enantiomeric lignans with anti-β-amyloid aggregation activity from the twigs and leaves of Pithecellobium clypearia Benth

To develop potential agents for slowing the progression of Alzheimer′s disease, two pairs of new enantiomeric lignans, including a couple of rarely 8′,9′-dinor-3′,7-epoxy-8,4′-oxyneolignanes named (7S, 8S)- and (7R, 8R)-pithecellobiumin A (1a/1b) and a pair of 2′,9′-epoxy-arylnaphthalenes named (7R, 8R, 8′R)- and (7S, 8S, 8′S)-pithecellobiumin B (2a/2b) were separated by chiral high performance liquid chromatography (HPLC). Their planar structures were elucidated by spectroscopic data analyses. The absolute configurations were determined by comparing of experimental and calculated electronic circular dichroism (ECD). The inhibitory activity on Aβ aggregation of all optical pure compounds was tested by ThT assay. Interestingly, enantiomeric inhibitors 1a (62.1%) and 1b (81.6%) exhibited different degrees of anti-Aβ aggregation activity. However, 2a (65.4%) and 2b (68.4%) showed similar inhibition rate. The different inhibition profiles were explained by molecular dynamics and docking simulation studies.     

Polyphenols from the bark of Rhus verniciflua and their biological evaluation on antitumor and anti-inflammatory activities

Bioassay-guided fractionation and chemical investigation of the extract of Rhus verniciflua bark resulted in the identification of six polyphenols, rhusopolyphenols A–F (1–6), together with four known compounds including (2R,3S,10S)-7,8,9,13-tetrahydroxy-2-(3,4-dihydroxyphenyl)-2,3-trans-3,4-cis-2,3,10-trihydrobenzopyrano[3,4-c]-2-benzopyran-1-one (7), peapolyphenol C (8), cilicione-b (9) and (αR)-α,3,4,2′,4′-pentahydroxydihydrochalcone (10). The structures of these polyphenols were elucidated by spectroscopic analysis, including 1D and 2D NMR, and HR-ESIMS, and their absolute configurations were further confirmed by a combination of chemical methods and CD data analysis. All isolates were evaluated for their antiproliferative activities against four human tumor cell lines (A549, SK-OV-3, SK-MEL-2, and HCT-15), and compounds 4–6, 9 and 10 showed antiproliferative activity against the tested cells, with IC₅₀ values of 3.31–18.51 μM. On the basis of the expanded understanding that inflammation is a crucial cause of tumor progression, the anti-inflammatory activities of these compounds were determined by measuring nitric oxide (NO) levels in the medium of murine microglia BV-2 cells. Compounds 5 and 10 significantly inhibited NO production in lipopolysaccharide (LPS)-stimulated murine microglia BV-2 cells with IC₅₀ values of 28.90 and 12.70 μM, respectively.     

Benzofuranoid neolignans from Aniba simulans

Forteen neolignans, isolated from the benzene extract of Aniba simulans (Lauraceae) trunk wood, included the hitherto undescribed (2S, 3S, 5R)-5-allyl-5,7-dimethoxy-2-(3′,4′,5′-trimethoxyphenyl)-3-methyl-2,3,5,6-tetra-hydro-6-oxobenzofuran, (2R,3S,5R) -5-allyl-5-methoxy-2-(3′-methoxy-4′,5′-methylenedioxyphenyl)-3-methy1-2,3,5, 6-tetrahydro-6-oxobenzofuran, (2S,3S)-6-O-allyl -5-methoxy-2-(3′-methoxy-4′-5′-methylenedioxyphenyl)-3-methyl-2,3-dihydrobenzofuran, (2R,3S)-6-O-allyl-5-methoxy-2- (3′-methoxy-4′,5′-methylenedioxyphenyl)-3-methyl-2,3-dihydrobenzofuran and 7-allyl-6-hydroxy-5-methoxy-2-(3′-methoxy-4,5′ -methylenedioxyphenyl)-3-methylbenzofuran.     

Enantiomeric trans β-aryl-δ-iodo-γ-lactones derived from 2,5-dimethylbenzaldehyde induce apoptosis in canine lymphoma cell lines by downregulation of anti-apoptotic Bcl-2 family members Bcl-xL and Bcl-2

For many years, studies focused on developing new natural or synthetic compounds with antineoplastic activity have attracted the attention of researchers. An interesting group of such compounds seem to be those with both lactone moiety and an aromatic ring which, in addition to antimicrobial or antiviral activity, also exhibit antitumor properties. The study shows antitumor activity of two enantiomeric trans isomers of 5-(1-iodoethyl)-4-(2′,5′-dimethylphenyl)dihydrofuran-2-one. Our aim was to determine their antitumor activity manifested as an ability to induce apoptosis in selected canine cancer cell lines as well as to evaluate differences in their strength depending on the configuration of their stereogenic centers. The enantiomers (+)-(4R,5S,6R)-1 and (?)-(4S,5R,6S)-2 were found to induce classical caspase-dependent apoptosis through downregulation of the expression of anti-apoptotic proteins Bcl-xL and Bcl-2. Although the mechanism of apoptosis induction was the same for both enantiomers, they differed in their strength, as stronger antineoplastic activity in vitro was exhibited by isomer (+)-(4R,5S,6R)-1.     

New flavonoids from the fruits of Cornus mas,Cornaceae

One new β-hydroxychalcone, 4-acetoxy-5,2′,4′,6′,β-pentahydroxy-3-methoxychalcone (1), one new flavanone, 7,3′-dihydroxy-5,4′-dimethoxyflavanone (2) and seven known compounds, 2R, 3R-trans-aromadendrin (3), naringenin-7-O-methylether (4), myricetin (5), quercetin-3-O-rutinoside (6), ursolic acid (7), gallic acid (8) and d-glucose (9) were isolated from the methanolic fruit extract of Cornus mas L. (=Cornus mascula L.), Cornaceae. The structures of the new compounds were elucidated on the basis of extensive spectroscopic methods, including 2D NMR experiments and of known compounds by comparison of physical and spectral data with literature.     

Cytotoxic pterosins from Pteris multifida roots against HCT116 human colon cancer cells

Two new pterosin glycosides, (2S,3S)-pterosin C 3-O-β-d-(4′-(E)-caffeoyl)-glucopyranoside (1) and (2S,3S)-pterosin C 3-O-β-d-(6′-(E)-p-coumaroyl)-glucopyranoside (2), were isolated from Pteris multifida (Pteridaceae) roots along with ten known pterosin compounds (3–12). The chemical structures of the isolated compounds were elucidated by extensive analysis of the 1D, 2D NMR, HRESIMS, and CD spectroscopic data. The cytotoxicities of 1–12 against HCT116 human colorectal cancer cell line were evaluated. Among the isolates, compound 1 showed moderate antiproliferative activity in HCT116 cells with an IC₅₀ value of 8.0 ± 1.7 μM. Additionally, 1 induced the upregulation of the caspase-9 and procaspase-9 levels in Western blots and increased the annexin V/propidium iodide (PI)-positive cell population in flow cytometry.     

(2S)-Prenylflavanones and taraxerane triterpenoids from Mallotus mollissimus

Three prenylflavanones, (2S)-5,7-dihydroxy-4′-methoxy-8-(3″,3″-dimethylallyl)flavanone (3), (2S)-5,4′-dihydroxy-7-methoxy-6-(3″,3″-dimethylallyl)flavanone (6), 8-prenylnaringenin (11), and a new epimeric pair (2″S/2″R)-(2S)-5,7-dihydroxy-4′-methoxy-6-(2″-hydroxy-3″-methylbut-3″-enyl)flavanones (4a/4b) were isolated together with taraxerone, taraxerol, epitaraxerol, β-sitosterol, oleanolic acid, 1-O-docosanoyl glycerol, apigenin, and apigenin 7-O-β-D-glucopyranoside from the MeOH extract of the leaves of Mallotus mollissimus. The structures of the isolated compounds were determined on the basis of 1D/2D NMR and HR-MS spectroscopic data; the 2S configuration of the prenylflavanones 3, 4, and 6 was deduced from CD spectroscopic data. The presence of three taraxerane triterpenoids reinforces the inclusion of M. mollissimus (syn. Croton mollissimus) in Mallotus genus. Among species of Mallotus the occurrence of the (2S)-prenylflavanones 3, 4, and 6 is confined to M. mollissimus.     

Two new glycosides from the whole plant of Anemone rivularis var. flore-minore

Phytochemical investigation on the whole plant of Anemone rivularis var. flore-minore led to the isolation of a new labdane-type diterpene glycoside (1) and a new trihydroxyfuranoid lignanoid glycoside (2), together with three known triterpene and triterpenoid glycosides (3–5). The structures of the two new compounds were elucidated as β-d-glucopyranosyl (13S)-13-hydroxy-7-oxo-labda-8,14-diene-18-oate (1) and (7S,7′R,8R,8′S)-7′-butoxy-7,9′-epoxy-4,4′,9-trihydroxy-3,3′-dimethoxylignane 9-O-β-d-glucopyranoside (2), on the basis of extensive spectral analysis and chemical evidence. Compound 1 is characterized by a glucose (Glc) esterified C-18 carboxyl group, which is a rarely encountered labdane-type diterpene glycoside in nature. The two new compounds (1 and 2) reported here are the first examples of diterpene glycoside and lignanoid glycoside found in the genus Anemone, and the known triterpene and triterpenoid glycosides (3–5) are identified for the first time from the title plant.     

Structure–cytotoxic activity relationship of sesquilignan,morinol A

The cytotoxic activities of sesquilignans, (7S,8S,7′R,8′R)- and (7R,8R,7′S,8′S)-morinol A and (7S,8S,7′S,8′S)- and (7R,8R,7′R,8′R)-morinol B were compared, showing no significant difference between stereoisomers (IC₅₀ = 24–35 μM). As a next stage, the effect of substituents at 7, 7′, and 7″-aromatic ring on the activity was evaluated to find out the higher activity of (7S,8S,7′R,8′R)-7,7′,7″-phenyl derivative 18 (IC₅₀ = 6–7 μM). In the research on the structure–activity relationship of 7″-position of (7S,8S,7′R,8′R)-7,7′,7″-phenyl derivative 18, the most potent compounds were 7,7′,7″-phenyl derivative 18 (IC₅₀ = 6 μM) against HeLa cells. Against HL-60 cells, 7″-(4-nitrophenyl)-7,7′-phenyl derivative 33 and 7″-hexyl-7,7′-phenyl derivative 37 (IC₅₀ = 5 μM) showed highest activity. We discovered the compounds showed four to sevenfold potent activity than that of natural (7S,8S,7′R,8′R)-morinol A. It was also confirmed that the 7′-benzylic hydroxy group have an important role for exhibiting activity, on the other hand, the resonance system of cinnamyl structure is not crucial for the potent activity.     

Flavans and other chemical constituents of Crinum biflorum (Amaryllidaceae)

The ethyl acetate extract from the whole plant of Crinum biflorum Rottb. Showed a moderate activity against Enterococcus faecalis. Its phytochemical investigation led to the isolation of a new flavan-3-ol derivative namely (2R,3R)-3-hydroxy-7-methoxy-3′,4′-methylenedioxyflavan, together with (2S)-7-hydroxy-3′,4′-methylenedioxyflavan, (2R,3R)-7-methoxy-flavan-3-ol, (2S)-7-hydroxy-3′,4′-dimethoxyflavan, 3′,7-dihydroxy-4′-methoxyflavan, 4′,7-dimethoxy-3′-hydroxyflavan, farrerol, β-sitosterol, β-sitosterol-3-O-β-D-glucopyranoside, oleanolic acid, kaempferol, pancratistatin, lupeol, aurantiamide acetate, Narciprimine and 2,3-dihydroxypropyl palmitate. Their structures were elucidated mainly by extensive spectroscopic analysis and comparison with published data. The absolute configuration of the new metabolite was determined by electronic circular dichroism (ECD) analysis and comparison of optical rotation. Some of the isolated compounds were tested for their antimicrobial activity but no inhibition was observed.     

Thiophenes,polyacetylenes and terpenes from the aerial parts of Eclipata prostrata

One new bithiophenes, 5-(but-3-yne-1,2-diol)-5′-hydroxy-methyl-2,2′-bithiophene (2), two new polyacetylenic glucosides, 3-O-β-d-glucopyranosyloxy-1-hydroxy-4E,6E-tetradecene-8,10,12-triyne (8), (5E)-trideca-1,5-dien-7,9,11-triyne-3,4-diol-4-O-β-d-glucopyranoside (9), six new terpenoid glycosides, rel-(1S,2S,3S,4R,6R)-1,6-epoxy-menthane-2,3-diol-3-O-β-d-glucopyranoside (10), rel-(1S,2S,3S,4R,6R)-3-O-(6-O-caffeoyl-β-d-glucopyranosyl)-1,6-epoxy menthane-2,3-diol (11), (2E,6E)-2,6,10-trimethyl-2,6,11-dodecatriene-1,10-diol-1-O-β-d-glucopyranoside (12), 3β,16β,29-trihydroxy oleanane-12-ene-3-O-β-d-glucopyranoside (13), 3,28-di-O-β-d-glucopyranosyl-3β,16β-dihydroxy oleanane-12-ene-28-oleanlic acid (14), 3-O-β-d-glucopyranosyl-(1→2)-β-d-glucopyranosyl oleanlic-18-ene acid-28-O-β-d-glucopyranoside (15), along with fifteen known compounds (1, 3–7, and 16–24), were isolated from the aerial parts of Eclipta prostrata. Their structures were established by analysis of the spectroscopic data. The isolated compounds 1–9 were tested for activities against dipeptidyl peptidase IV (DPP-IV), compound 7 showed significant antihyperglycemic activities by inhibitory effects on DPP-IV in human plasma in vitro, with IC₅₀ value of 0.51 μM. Compounds 10–24 were tested in vitro against NF-κB-luc 293 cell line induced by LPS. Compounds 12, 15, 16, 19, 21, and 23 exhibited moderate anti-inflammatory activities.