Anti-oxidative and inhibitory activities on nitric oxide (NO) and prostaglandin E<Subscript>2</Subscript> (COX-2) production of flavonoids from seeds of <Emphasis Type="Italic">Prunus tomentosa</Emphasis> Thunberg

Chemical investigation of the 80% Me₂CO extract from the seeds of Prunus tomentosa led to the isolation and identification of six flavonoids: kaempferol (1), kaempferol 3-O-α-L-rhamnopyranoside (2; afzelin), kaempferol 3-O-β-D-(6-acetyl)-glucopyranosyl(1→4)-α-L-rhamnopyranoside (3; multiflorin A), kaempferol 3-O-β-D-glucopyranosyl(1→4)-α-L-rhamnopyranoside (4; multiflorin B), quercetin 3-O-α-L-rhamnopyranoside (5; quercitrin), and quercetin 3-O-β-D-glucopyranosyl (1→4)-α-L-rhamnopyranoside (6; multinoside A). Anti-oxidative and inhibitory activities on nitric oxide (NO) and prostaglandin E₂ production in interferon-γ (INF-γ) and lipopolysaccharide (LPS)-activated RAW 264.7 cells in vitro (COX-2) of the isolated compounds were evaluated. Compounds 1, 5, and 6 exhibited potent anti-oxidative activity in the DPPH radical scavenging assay with IC₅₀ values of 57.2, 59.4, and 54.3 μg/mL respectively. The positive control, ascorbic acid, had an IC₅₀ of 55.5 μg/mL. Compounds 1, 5, and 6 also reduced COX-2 levels in a dose dependent manner with IC₅₀ values of 10.2, 8.7, and 9.6 μg/mL respectively, with the positive control, indomethacin, having an IC₅₀ of 5.1 μg/mL. All six compounds inhibited NO production in a dose dependent manner with IC₅₀ values of 35.1, 42.8, 40.0, 44.8, 43.7, and 43.9 μg/mL respectively, while the positive control, L-NMMA, had an IC₅₀ of 42.1 μg/mL.     

Potential anthelmintics: polyphenols from the tea plant <Emphasis Type="Italic">Camellia sinensis</Emphasis> L. are lethally toxic to <Emphasis Type="Italic">Caenorhabditis elegans</Emphasis>

A novel gallate of tannin, (−)-epigallocatechin-(2β→O→7′,4β→8′)-epicatechin-3′-O-gallate (8), together with (−)-epicatechin-3-O-gallate (4), (−)-epigallocatechin (5), (−)-epigallocatechin-3-O-gallate (6), and (+)-gallocatechin-(4α→8′)-epigallocatechin (7), were isolated from the tea plant Camellia sinensis (L.) O. Kuntze var. sinensis (cv., Yabukita). The structure of 8, including stereochemistry, was elucidated by spectroscopic methods and hydrolysis. The compounds, along with commercially available pyrogallol (1), (+)-catechin (2), and (−)-epicatechin (3), were examined for toxicity towards egg-bearing adults of Caenorhabditis elegans. The anthelmintic mebendazole (9) was used as a positive control. Neither 2 nor 3 were toxic but the other compounds were toxic in the descending order 8, 7 ≈ 6, 9, 4, 5, 1. The LC₅₀ (96 h) values of 8 and 9 were evaluated as 49 and 334 μmol L⁻¹, respectively. These data show that many green tea polyphenols may be potential anthelmintics.     

Isolation and quantitative analysis of peroxynitrite scavengers from <Emphasis Type="Italic">Artemisia princeps</Emphasis> var. <Emphasis Type="Italic">orientalis</Emphasis>

Young and mature Artemisia princeps var. orientalis (APO, Compositae) are used as a health food and a medicinal plant, respectively, in Korea. Here, we identified the in vitro potent peroxynitrite (ONOO⁻)-scavenging effect (IC₅₀, 0.26 μg/mL) of the components from the EtOAc fraction. Octadecylsilane column chromatography on the EtOAc fraction yielded two caffeoylquinic acid compounds, 3,5-di-O-caffeoyl-muco-quinic acid (1) and methyl 4,5-di-O-caffeoylquinate (2) by NMR spectroscopic data, which have not been reported before from APO. The IC₅₀ values of compounds 1 and 2 were 0.18 ± 0.01 μg/mL and 0.12 ± 0.00 μg/mL, respectively, lower than that of the positive control (L-penicillamine). HPLC data indicated that young APO (1: 30.3 mg/g dried weight, 2: 27.7 mg/g) contained considerably higher quantities of the two caffeoylquinic acids than mature APO (1: 1.77 mg/g dried weight, 2: 4.10 mg/g).     

A new acyclic diterpene acid and bioactive compounds from <Emphasis Type="Italic">Knema glauca</Emphasis>

Investigation of the chemical constituents of the fruits of Knema glauca (Myristicaceae) yielded a new acyclic diterpene acid, named glaucaic acid 4, together with four acylphenols, including 1-(2,6-dihydroxyphenyl) tetradecan-1-one 1, malabaricone A 6, dodecanoylphloroglucinol 7 and 1-(2,4,6-trihydroxyphenyl)-9-phenylnonan-1-one 8, two lignans sesamin 2 and asarinin 3, and a flavan, myristinin D 5. In addition, myristinin A 9 and (±)-7,4′-dihydroxy-3′-methoxyflavan 10 were isolated from its leaves and stems, respectively. When tested against small-cell lung cancer (NCI-H187), epidermoid carcinoma (KB) and breast cancer (BC) cell lines, compounds 1, 6–8 and 10 displayed weak to moderate cytotoxicity. The acylphenols 6–8 displayed antituberculosis activity against the microbe Mycobacterium tuberculosis with MIC values of 25, 50 and 100 μg/mL, respectively, and antiviral activity against herpes simplex virus type 1, with 7 as the most active compound (IC₅₀ = 3.05 μg/mL). Malabaricone A 6 was also active against the malarial parasite Plasmodium falciparum with an IC₅₀ value of 2.78 μg/mL.     

A new lignan glucoside from the stems of <Emphasis Type="Italic">Callicarpa japonica</Emphasis> Thunb. var. <Emphasis Type="Italic">luxurians</Emphasis> Rehd.

A new lignan glucoside (1) was isolated from the stems of Callicarpa japonica Thunb. var. luxurians Rehd. (Verbenaceae), along with six known lignan glucosides and three known triterpenoids. The chemical structure of 1 was characterized as (+)-lyoniresinol 3α-O-(6″-3,5-dimethoxy-4-hydroxybenzoyl)-β-d-glucopyranoside on the basis of spectroscopic data. In addition, the radical-scavenging effect of four lignans on the stable free radical 1,1-diphenyl-2-picrylhydrazyl was examined. Among the tested compounds, three compounds, including 1, showed almost the same scavenging activity as that of α-tocopherol.     

Five new glycosides from <Emphasis Type="Italic">Hypericum erectum</Emphasis> Thunb.

Five new glycosides, quercetin 3′-O-β-d-galactopyranoside (1), quercetin 3-O-(2″-acetyl)-β-d-glucopyranoside (2), 4,6-dihydroxy-2-methoxyphenyl 1-O-β-d-glucopyranoside (3), 4-hydroxy-2,6-dimethoxyphenyl 1-O-α-l-rhamnopyranosyl (1 → 6)-β-d-glucopyranoside (4) and 3-methyl-but-2-en-1-yl β-d-glucopyranosyl (1 → 6)-β-d-glucopyranoside (5), were isolated from Hypericum erectum Thunb. Their structures were established on the basis of spectral and chemical data.     

A new phenolic glycoside syringate from the bark of <Emphasis Type="Italic">Juglans mandshurica</Emphasis> MAXIM. var. <Emphasis Type="Italic">sieboldiana</Emphasis> MAKINO

A new phenolic glycoside syringate, 4′-hydroxy-2′,6′-dimethoxyphenol 1-O-β-d-(6-O-syringoyl) glucopyranoside (1), together with two known ones, 2′-hydroxy-4′-methoxyphenol 1-O-β-d-(6-O-syringoyl) glucopyranoside (2) and 4′-hydroxy-2′-methoxyphenol 1-O-β-d-(6-O-syringoyl) glucopyranoside (3), were isolated from the bark of Juglans mandshurica MAXIM. var. sieboldiana MAKINO. Their structures were established on the basis of spectral and chemical data.     

Antioxidative activity of the flower of <Emphasis Type="Italic">Torenia fournieri</Emphasis>

The edible flower of Torenia fournieri Linden ex E. Fourn was found to possess potent antioxidative activity in a rat brain homogenate model. Bioassay-guided isolation of the active compounds from a CH₂Cl₂–MeOH (1:1) extract led to the isolation of acteoside (1), luteolin-7-O-β-glucoside (2), apigenin-7-O-α-rhamnosyl-(1→6)-β-glucoside (3), and apigetrin (4).     

Cytotoxic constituents of<Emphasis Type="Italic">diadema setosum</Emphasis>

5,8-Epidioxycholest-6-en-3-ol (1), cholesterol (2), glycerol 1-palmitate (3) and glycerol 1,3-dioleate-2-stearate (4) were isolated from the methanol extract of the sea urchinDiadema setosum, which was collected from the Halong sea, Vietnam. Chemical structures were established based on extensive 1D, 2D-NMR, FAB-MS, EI-MS spectroscopic data and GC-MS analysis. The NMR spectral data of compound 1 were reassigned by using HMQC and HMBC. Compound1 was found to have strong cytotoxic effect against various cancer cell lines, such as KB (IC₅₀, 2.0 μg/mL), FL (IC₅₀, 3.93 μg/mL), and Hep-2 (IC₅₀, 2.4 μg/mL) byin vitro assay.     

A new furostanol saponin from <Emphasis Type="Italic">Asparagus cochinchinensis</Emphasis>

A new furostanol saponin, (25S)-26-O-β-d-glucopyranosyl-5β-furost-20(22)-en-3β, 15β,26-triol-3-O-[α-l-rhamnopyranosyl-(1–4)]-β-d-glucopyranoside, namely, aspacochioside D (1) were isolated from Asparagus cochinchinensis (Lour.) Merr, along with three known saponins, aspacochioside C (2), (25S)-5β-spirostan-3β-yl-O-[O-α-l-rhamnopyranosyl-(1–4)]-β-d-glucopyranoside (3), and pseudoprotoneodioscin (4). The structure of 1 was elucidated on the basis of chemical reactions and spectral analysis (IR, GC, ESI-MS, ¹H-NMR, ¹³C-NMR, DEPT, HMBC, HMQC and NOESY). The antiproliferative effects of 1–4 were evaluated in a cytotoxicity assay against the human tumor cell line, A549. Compound 2 (Aspacochioside C) exhibited moderate cytotoxicity against A-549, with an IC₅₀ value of 3.87 μg/mL.     

<Emphasis Type="Italic">In vitro</Emphasis> Na<Superscript>+</Superscript>/K<Superscript>+</Superscript>-ATPase inhibitory activity and antimicrobial activity of sesquiterpenes isolated from <Emphasis Type="Italic">Thujopsis dolabrata</Emphasis>

A series of sesquiterpenes and hinokitiol-related compounds (1–15) was isolated from the essential oil of Thujopsis dolabrata Sieb. et Zucc. var. hondai Makino, and their structures were determined by combined spectroscopic analyses. The inhibitory effects of these compounds on microbial cell growth and Na⁺/K⁺-ATPase were evaluated in vitro. It was found that (−)-elema-1,3,11(13)-trien-12-ol (5), α,β,γ-costol (8), and chamigrenol (11) inhibit the activities of Na⁺/K⁺-ATPase, with IC₅₀ values of 11.2 ± 0.11, 12.2 ± 0.09, and 15.9 ± 0.54 μg/mL, respectively. Thujopsene (1), cedrol (9), γ-cuparenol (10), and chamigrenol (11) showed potent antibacterial activity, with MIC values in the range of 25–50 μg/mL, and β-thujaplicin (12) exhibited a broad spectrum of antibacterial and antifungal activity. These results indicate that these isolated compounds are promising candidates for the development of potent Na⁺/K⁺ ATPase inhibitors and antimicrobial agents.     

Anti-inflammatory phenylpropanoid glycosides from <Emphasis Type="Italic">Clerodendron trichotomum</Emphasis> leaves

The chromatographic separation of MeOH extract from Clerodendron trichotomum Thunberg leaves led to the isolation of three phenylpropanoid compounds. Using spectroscopic methods, the structures of these compounds were determined as β-(3′, 4′-dihydroxyphenyl)ethyl-O-α-L-rhamnopyranosyl (1→3)-β-D-(4-O-caffeoyl)-glucopyranoside, acteoside (verbascoside) (1), β-(3′, 4′-dihydroxyphenyl)ethyl-O-α-L-rhamnopyranosyl (1→3)-β-D-(6-O-caffeoyl)-glucopyranoside, isoacteoside (2), β-(3′, 4′-dihydroxyphenyl) ethyl-O-α-L-rhamnopyranosyl (1→3)-β-D-glucopyranoside, and decaffeoylacteoside (3). We measured the anti-inflammatory activity of these three phenylpropanoid compounds both in vitro (DPPH Reduction Assay, TBARS Assay on Cu ²⁺-induced oxidized LDL, PGE₂ assay) and in vivo (acetic acidinduced vascular permeability in mice and carrageenan-induced hind paw edema in rats). 80% methanol fraction and acteoside had the activity.     

Antibacterial activity of <Emphasis Type="Italic">Capsicum annuum</Emphasis> extract and synthetic capsaicinoid derivatives against <Emphasis Type="Italic">Streptococcus mutans</Emphasis>

The inhibitory effects of the ethyl acetate extract and capsaicin (1) and dihydrocapsaicin (2) isolated from fruits of Capsicum annuum chili pepper type, and synthetic capsaicinoid derivatives (N-(4-hydroxyphenylethyl)decamide (3), (E)-N-(4-hydroxy-3-methoxybenzyl)-3,7-dimethylocta-2,6-dienamide (4), 4-hydroxy-3-methoxy-N-((E)-3,7-dimethylocta-2,6-dienyl)benzamide (5) and N-(4-hydroxy-3-methoxybenzyl)decamide (6) at different concentrations were evaluated against Streptococcus mutans. The minimum inhibitory concentration at which the ethyl acetate extract prevented the growth of S. mutans was 2.5 mg/mL; those of the isolated compounds 1 and 2 were 1.25 μg/mL, while 3 was 5.0 μg/mL, and 4, 5 and 6 were 2.5 μg/mL, respectively.     

A new <Emphasis Type="Italic">ent</Emphasis>-kaurane type diterpenoid glycoside from <Emphasis Type="Italic">Inula japonica</Emphasis> Thunb.

A new ent-kaurane type diterpenoid glycoside, 17-O-β-D-glucopyranosyl-16α-ent-kauran-19-oic acid (1), together with 17-hydroxy-16α-ent-kauran-19-oic acid (2), 16α,17-dihydroxyl-ent-kauran-19-oic acid (3), and 16α-hydroxy-17-acetoxy-ent-kauran-19-oic acid (4) were isolated from the aerial parts of Inula japonica Thunb. The structure of 1 was determined mainly by use of 1D and 2D NMR spectroscopic techniques including HSQC, ¹H-¹H COSY, HMBC, and NOESY. In addition, 4 exhibited significant inhibitory activity on NO production in LPS-stimulated RAW264.7 cells with IC₅₀ value of 14.3 μg/mL.     

Two new acorane sesquiterpenes from <Emphasis Type="Italic">Illicium henryi</Emphasis>

Two new acorane sesquiterpenes, 10-hydroxyacoronene (1) and 1β-isopropyl-4β-methyl-9β-hydroxy spiro[4.5]dec-6-en-8-one (2), one new natural product, 4-hydroxy-4, 6-dimethyl-1-tetralone (3), and one known acorane sesquiterpene, acoradiepoxide (4) were isolated from the twigs and leaves of Illicium henryi. The structures of the new compounds were elucidated primarily on the basis of analysis of spectroscopic data. In addition, the inhibitory effect on NO production of these compounds were tested. Compounds 1 and 4 exhibited slight inhibitory effects on NO production with IC₅₀ values of 82.4 μg/mL and 76.5 μg/mL, respectively.     

A new pyrrole alkaloid isolated from<Emphasis Type="Italic">Arum palaestinum</Emphasis> Boiss. and its biological activities

The phytochemical analysis of the ethyl acetate fraction ofArum palaestinum Boiss. (Araceae) led to the isolation and identification of a new polyhydroxy alkaloid compound; (S)-3,4,5-trihydroxy-1H-pyrrol-2(5H)-one (1), and other five known compounds; caffeic acid (2), isoorientin (3), luteolin (4) and vicenin II (5), as well as the rare compound 3,6,8-trimethoxy, 5,7,3′,4′-tetrahydroxy flavone (6). The structural elucidations of all the compounds were based on spectroscopic data (¹H- and¹³C-NMR, DEPT, HSQC, HMBC and NOE difference techniques) and comparison with literature data. Investigation of the antioxidant activity of the ethyl acetate fraction indicated its strong scavenging capacity for 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radicals (SC₅₀ 3.1 ±0.82 μg/mL). Moreover, the treatment of different human cancer cell lines with the ethyl acetate fraction led to dose-dependant suppression in the proliferation of both breast carcinoma cells (MCF-7; IC₅₀ 59.09±4.1 μg/mL) and lymphoblastic leukemia cells (1301; IC₅₀ 53.1±2.9 μg/mL); however, it was found to have no effect on the growth of hepatocellular carcinoma cells (Hep G2).     

An oxepinoflavone from <Emphasis Type="Italic">Artocarpus elasticus</Emphasis> with cytotoxic activity against P-388 cells

A new oxepinoflavone, artoindonesianin E1 (1), was isolated from the wood of Artocarpus elasticus, along with four known prenylated flavones: artocarpin (2), cycloartocarpin (3), cudraflavones A (4) and C (5). The structure of the new compound was identified by spectroscopic methods. Upon cytotoxic evaluation against murine leukemia P-388 cells, the new compound showed IC₅₀ 5.0 μg/mL.     

Chemical and biologically active constituents of <Emphasis Type="Italic">Pteris multifida</Emphasis>

A new compound, 4-caffeoyl quinic acid 5-O-methyl ether (2), together with 12 known compounds—identified as (2R,3R)-pterosin L 3-O-β-d-glucopyrannoside (3), β-sitosterol β-d-glucopyranoside (4), apigenin 7-Ο-β-d-glucopyranoside (5), luteolin 7-Ο-β-d-glucopyranoside (6), sucrose (7), caffeic acid (8), pterosin C 3-Ο-β-d-glucopyranoside (9), pteroside C (10), 4,5-dicaffeoyl quinic acid (11), pteroside A (12), wallichoside (13) and (2S)-5,7,3′,5′-tetrahydroxyflavanone (14)—were isolated from Pteris multifida. The structure of the new compound was determined by means of physical, chemical and spectroscopic evidence. Compounds 5 and 6 were the main constituents of the plant, with yields of 0.19% and 0.16%, respectively. The cytotoxic activities of 2, 3, and 9–13 were evaluated against a human cell line (KB cells). Among the isolated compounds, pterosin C 3-Ο-β-d-glucopyrannoside (9) and 4,5-dicaffeoylquinic acid (11) showed a significant selective cytotoxicity (IC₅₀ 2.35 and 5.38, respectively), while moderate activity was observed for compound 2 (IC₅₀ 12.3). The chemosystematics of Pteris species is also discussed.     

Chemical composition and antibacterial activity of essential oils of <Emphasis Type="Italic">Eugenia</Emphasis> species

The essential oils of the leaves of Eugenia brasiliensis, Eugenia beaurepaireana, and Eugenia umbelliflora were analyzed by GC–MS. The major compounds found in the oil of E. brasiliensis were spathulenol (12.6%) and τ-cadinol (8.7%), of E. beaurepaireana were β-caryophyllene (8.0%) and bicyclogermacrene (7.2%), and of E. umbelliflora were viridiflorol (17.7%) and β-pinene (13.2%). These oils were assayed to determine their antibacterial activity against Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli. All of the oils analyzed showed antibacterial activity, ranging from moderate to strong, which was most accentuated for the E. umbelliflora and E. brasiliensis oils, which strongly inhibited the growth of S. aureus giving values of MIC = 119.2 and 156.2 μg/mL, respectively.     

Two new phenolic glycosides from <Emphasis Type="Italic">Syringa reticulata</Emphasis>

Two new phenolic glycosides—3′-O-β-d-glucopyranosysalidroside (1) and cis-echinacoside (2)—together with four known ones—forsythoside B (3), decaffeoylacteoside (4), osmanthuside F (5) and (−)-olivil-4′-O-β-d-glucopyranoside (6)—were isolated from the leaves of Syringa reticulata. Their structures were established on the basis of spectral and chemical data.