Biologically active <Emphasis Type="Italic">C</Emphasis>-alkylated flavonoids from <Emphasis Type="Italic">Dodonaea viscosa</Emphasis>

A new C-alkylated flavonoid (5,7-dihydroxy-3′-(4″-acetoxy-3″-methylbutyl)-3,6,4′-trimethoxyflavone (1), along with two known C-alkylated flavonoids (5,7-dihydroxy-3′-(3-hydroxymethylbutyl)-3,6,4′-trimethoxyflavone (2), 5,7,4′-trihydroxy-3′-(3-hyroxymethylbutyl)-3,6-dimethoxyflavone (3) and two new source C-alkylated flavonoids (5,7-dihydroxy-3′-(2-hydroxy-3-methyl-3-butenyl)-3,6,4′-trimethoxyflavone (4), 5,7,4′-trihydroxy-3,6-dimethoxy-3′-isoprenyl-flavone (5) were isolated from the aerial parts of Dodonaea viscosa. The structures of all compounds were established on the basis of 1D and 2D NMR spectroscopy and mass spectrometry. The isolated compounds were evaluated for their inhibitory effect on urease and α-chymotrypsin enzyme. All the compounds (1–5) exhibited mild inhibition against urease but remained recessive in case of α-chymotrypsin.     

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.     

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).     

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 <Emphasis Type="Italic">Erythrina</Emphasis> alkaloid from <Emphasis Type="Italic">Erythrina herbacea</Emphasis>

A new Erythrina alkaloid, 10-hydroxy-11-oxoerysotrine (1), has been isolated from the flowers of Erythrina herbacea together with five known compounds: erytharbine (2), 10,11-dioxoerysotrine (3), erythrartine (4), erysotramidine (5) and erysotrine-N-oxide (6). The structure of the new compound was elucidated on the basis of its spectral data, including 2-D NMR and mass (MS) spectra. The new compound is a rare C-10 oxygenated Erythrina alkaloid. The antioxidant activities of the isolated compounds 1–6 were evaluated by scavenging with peroxynitrite.     

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.     

Constituents of cultivated <Emphasis Type="Italic">Agaricus blazei</Emphasis>

Two phenylhexane derivatives (1, 2), benzoylergostane (3), N-benzoyl-l-leucine methyl ester (4), two known ergostanes, and highly degraded incisterol were isolated from fruit bodies of Agaricus blazei. Compound 3 exhibited strong cytotoxicity toward HepG2 cells (IC₅₀ = 6.0 ± 0.33 μM).     

Cytotoxic lasiodiplodin derivatives from the fungus <Emphasis Type="Italic">Syncephalastrum racemosum</Emphasis>

Chemical investigation of fungal biomass of the fungus Syncephalastrum racemosum led to the isolation of new natural products (3R),(5S)-5-hydroxy-de-O-methyllasiodiplodin (1), 6-oxode-O-methyllasiodiplodin (2), in addition to five known compounds, de-O-methyllasiodiplodin (3), lasiodiplodin (4), (3R),(5R)-5-hydroxy-de-O-methyllasiodiplodin (5), ergosterol (6), and ergosterol peroxide (7). Their structures were elucidated by spectroscopic techniques. The absolute configuration of 1 was determined by a modified Mosher’s method. Compound 1 showed cytotoxicity against cholangiocarcinoma, KKU-M139, KKU-M156, and KKU-M213 cell lines with IC₅₀ values in the range of 14–19 μg/mL, while 3 showed cytotoxicity against KB, BC1, and NCI-H187 cell lines with IC₅₀ values of 12.67, 9.65, and 11.07 μg/mL, respectively.     

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.     

Antitubercular triterpenes and phytosterols from <Emphasis Type="Italic">Pandanus tectorius </Emphasis>Soland. var. <Emphasis Type="Italic">laevis</Emphasis>

Bioassay-guided chromatographic purification of the antitubercular chloroform extract of Pandanus tectorius Soland. var. laevis leaves afforded a new tirucallane-type triterpene, 24,24-dimethyl-5β-tirucall-9(11),25-dien-3-one (1), squalene and a mixture of the phytosterols stigmasterol and β-sitosterol. Microplate Alamar Blue Assay (MABA) showed that 1 inhibited the growth of Mycobacterium tuberculosis H₃₇Rv with a MIC of 64 μg/mL, while squalene and the sterol mixture have MICs of 100 and 128 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.     

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.     

Bioactive metabolites from the sponge-derived fungus <Emphasis Type="Italic">Aspergillus versicolor</Emphasis>

As part of an ongoing search for bioactive metabolites from the fungus Aspergillus versicolor derived from a marine sponge Petrosia sp., an aromatic polyketide derivative (1), two xanthones (2 and 3), and five anthraquinones (4–8) were isolated by bioactivity-guided fractionation. The gross structures were determined based on the NMR and MS spectroscopic data, and the absolute configurations were defined by comparison of optical rotation data with those of reported. Compounds 2, 4, 5, and 7 exhibited significant cytotoxicity against five human solid tumor cell lines (A-549, SK-OV-3, SK-MEL-2, XF-498, and HCT-15) with IC50 values in the range of 0.41–4.61 μg/mL. Compounds 4 and 7 exhibited antibacterial activity against several clinically isolated Gram-positive strains with MIC values of 0.78–6.25 μg/mL.     

Two new triterpenoid acids from <Emphasis Type="Italic">Kadsura coccinea</Emphasis>

An investigation of EtOAc extracts of Kadsura coccinea (Lem.) A. C. Smith, has led to the isolation of two new compounds characterized as 3-hydroxy-12-hydroxyl coccinic acid (1) and 3-hydroxy-neokadsuranic acid A (2). Their structures were established by 1D and 2D NMR techniques and mass spectroscopy. Antiproliferative effects of the isolated compounds were evaluated against four human tumor cell lines (A549, HCT116, HL-60 and HepG2), and it was found that compound 1 exhibited antiproliferative effects with IC₅₀ values ranging from 3.01 to 18.08 μg/mL.     

A new flavonol glycoside from <Emphasis Type="Italic">Hylomecon vernalis</Emphasis>

Purification of a MeOH extract from the aerial parts of Hylomecon vernalis Maxim. (Papaveraceae) using column chromatography furnished a new acetylated flavonol glycoside (1), together with twenty known phenolic compounds (2–21). Structural elucidation of 1 was based on 1D- and 2D-NMR spectroscopy data analysis to be quercetin 3-O-[4‴-O-acetyl-α-L-arabinopyranosyl]-(1‴→6″)-β-D-galactopyranoside (1). The structures of compounds 2–21 were elucidated by spectroscopy and confirmed by comparison with reported data; quercetin 3-O-[2‴-O-acetyl-α-L-arabinopyranosyl]-(1‴→6″)-β -D-galactopyranoside (2), quercetin 3-O-α-L-arabinopyranosyl-(1‴→6″)-β-D-galactopyranoside (3), quercetin 3-O-β -D-galactopyranoside (4), kaempferol 3,7-O-α-L-dirhamnopyranoside (5), diosmetin 7-O-β -D-glucopyranoside (6), diosmetin 7-O-β -D-xylopyranosyl-(1‴→6″)-β-D-glucopyranoside (7), p-hydroxybenzoic acid (8), protocatechuic acid (9), caffeic acid (10), 6-hydroxy-3,4-dihydro-1-oxo-β -carboline (11), (Z)-3-hexenyl-β -D-glucopyranoside (12), (E)-2-hexenyl-β -D-glucopyranoside (13), (Z)-3-hexenyl-α-Larabinopyranosyl-(1″→6′)-β-D-glucopyranoside (14), oct-1-en-3-yl-α-L-arabinopyranosyl-(1″→6′)-β-D-glucopyranoside (15), benzyl-β-D-apiofuranosyl-(1″→6′)-β-D-glucopyranoside (16), benzyl-α-L-arabinopyranosyl-(1″→6′)-β-D-glucopyranoside (17), benzyl-β-D-xylopyranosyl-(1″→6′)-β-Dglucopyranoside (18), 2-phenylethyl-α-L-arabinopyranosyl-(1″→6′)-β-D-glucopyranoside (19), 2-phenylethyl-β-D-apiofuranosyl-(1″→6′)-β-D-glucopyranoside (20), and aryl-β-D-glucopyranoside (21). Compounds 2-21 were isolated for the first time from this plant. The isolated compounds were tested for cytotoxicity against four human tumor cell lines in vitro using a Sulforhodamin B bioassay.     

Solalyratins A and B,new anti-inflammatory metabolites from <Emphasis Type="Italic">Solanum lyratum</Emphasis>

A new coumestan (solalyratin A, 1) and a novel cyclic eight-membered α,β-unsaturated ketone (solalyratin B, 3), together with three known compounds, puerariafuran (2), coumestrol (4) and 9-hydroxy-2′,2′-dimethylpyrano[5′,6′:2,3]-coumestan (5), were isolated from the whole plant of Solanum lyratum. Their structures were elucidated on the basis of spectroscopic analyses. In vitro, compounds 1–5 showed anti-inflammatory activities, with IC₅₀ values in the range 6.3–9.1 μM.     

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.     

Phenolic constituents of <Emphasis Type="Italic">Acorus gramineus</Emphasis>

The purification of a MeOH extract from the rhizome of Acorus gramineus (Araceae) using column chromatography furnished two new stereoisomers of phenylpropanoid, acoraminol A (1) and acoraimol B (2). It also furnished 17 known phenolic compounds, β-asarone (3), asaraldehyde (4), isoacoramone (5), propioveratrone (6), (1′R,2′S)-1′,2′-dihydroxyasarone (7), (1′S,2′S)-1′,2′-dihydroxyasarone (8), 3′,4′-dimethoxycinnamyl alcohol (9), 3′,4′,5′-trimethoxycinnamyl alcohol (10), kaempferol 3-methyl ether (11), 2-[4-(3-hydroxypropyl)-2-methoxyphenoxy]-1,3-propanediol (12), hydroxytyrosol (13), tyrosol (14), (2S,5S)-diveratryl-(3R,4S)-dimethyltetrahydrofuran (15), (7S,8R)-dihydrodehydrodiconiferyl alcohol (16), 7S,8S-threo-4,7,9,9′-tetrahydroxy-3,3′-dimethoxy-8-O-4′-neolignan (17), 7S,8R-erythro-4,7,9,9′-tetrahydroxy-3,3′-dimethoxy-8-O-4′-neolignan (18), and dihydroyashsbushiketol (19). The structures of the new compounds were elucidated by analysis of spectroscopic data including 1D and 2D NMR data. The absolute configurations of 1 and 2 were determined using the convenient Mosher ester procedure. Compounds 5–19 were isolated for the first time from this plant source. The isolated compounds were tested for cytotoxicity against four human tumor cell lines in vitro using a Sulforhodamine B (SRB) bioassay.     

Lignans from the flowers of <Emphasis Type="Italic">Osmanthus fragrans</Emphasis> var. <Emphasis Type="Italic">aurantiacus</Emphasis> and their inhibition effect on NO production

A new lignan, (7R,7′R,8R,8′R)-8-hydroxypinoresinol 8-O-β-D-glucopyranoside 4′-methyl ether (7), was isolated from the flowers of Osmanthus fragrans var. aurantiacus along with six known lignans: (+)-phillygenin (1), phillyrin (2), (−)-phillygenin (3), (−)-epipinoresinol-β-D-glucoside (4), taxiresinol (5), and (−)-olivil (6). The structure of the new compound was elucidated on the basis of 1D- and 2D-NMR spectroscopic analysis and specific rotation data. The compounds isolated from the flowers of O. fragrans var. aurantiacus were evaluated for inhibitory activities on nitric oxide production in lipopolysaccharide-stimulated macrophage RAW 264.7 cells. (+)-Phillygenin (1), phillyrin (2), and (−)-phillygenin (3) exerted the strongest inhibitory activities on NO production with IC₅₀ values of 25.5, 18.9, and 25.5 μM, respectively. These compounds may prove beneficial in the development of natural agents for prevention and treatment of inflammatory diseases.     

Cytotoxic phenolic compounds from <Emphasis Type="Italic">Chionanthus retusus</Emphasis>

Cytotoxicity-guided fractionation and purification of MeOH extract from Chionanthus retusus Lindl. et Paxton resulted in the isolation of compounds. Fourteen phenolic compounds were isolated from the EtOAc soluble fraction, and their structures were determined by spectroscopic analysis. Isolated compounds were identified as phillygenin (1), scopoletin (2), pinoresinol (3), kaempferol (4), aromadendrin (5), 2-(4-hydroxyphenyl)ethanol (6), 3,3′,5,5′,7-pentahydroxyflavanone (7), luteolin (8), quercetin (9), apigenin (10), chrysoeriol (11), phillyrin (12), oleuropein (13), (7R,8R)-guaiacylglycerol (14). All compounds except for 12 and 13 were isolated for the first time from this plant and genus Chionanthus. Anti-proliferative effect of isolated compounds were evaluated by the sulforhodamin B assay against four human tumor cell lines (A549, SK-OV-3, SK-MEL-2, and HCT15). Compounds 4 and 8–10 were significantly active with ED50 values of 1.84–6.35 μg/mL. Also, compounds 1, 3, 5 and 7 revealed cytotoxic effects at concentrations below 30 μg/mL.