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.     

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.     

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.     

Inhibition of DNA topoisomerases I and II and cytotoxicity of compounds from <Emphasis Type="Italic">Ulmus davidiana</Emphasis> var. <Emphasis Type="Italic">japonica</Emphasis>

Twenty five compounds including ten triterpenes (1–3, 5–11), six flavonoids (12–15, 24, 25), five lignans (17, 18, 21–23), two butenyl clohexnone glycosides (19–20), one fructofuranoside (16) and one fatty acid (4) were isolated from the roots of Ulmus davidiana var. japonica. The structures of those compounds were identified by comparing their physicochemical and spectral data with those of published in literatures. All the compounds were evaluated for DNA topoisomerase inhibitory activities and cytotoxicities. Among the purified compounds, 4 and 19 showed more potent inhibitory acitivities (IC₅₀: 39 and 19 μM, respectively) than camptothecin, as the positive control (IC₅₀: 46 μM) against topoisomerase I. Compounds, 4, 10, 12, 19, 24 and 25 showed strong inhibitory activities toward DNA topoisomerase II (IC₅₀: 0.1, 0.52, 0.47, 0.42, 0.17 μM and 17 nM, respectively), which were more potent than that of etoposide as positive control (IC₅₀: 20 μM). In A549 cell line, 5 and 6 showed cytotoxicities (IC₅₀: 4 μM and 3 μM, respectively, with IC₅₀ of camptothecin as positive control: 10.3 μM). In the HepG2 cell line, 3, 5 and 7 showed cytotoxicity (IC₅₀: 4, 3 and 4 μM, respectively, with IC₅₀ of camptothecin: 0.3 μM). Compounds 6, 12 and 23 showed cytotoxicities in the HT-29 cell line (IC₅₀: 19, 19 and 15 μM, respectively, with IC₅₀ of camptothecin: 2 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.     

Biological activity of chemical constituents from <Emphasis Type="Italic">Clausena harmandiana</Emphasis>

The activity guided fractionation of the Clausena harmandiana root extracts led to the isolation of a coumarin, a ferulate, and eight carbazoles. This is the first report of the isolation of compounds 2–4 and 6–10 from this species, and this is the first time 10 was isolated from this genus. Compound 4 showed strong cytotoxicity against NCI-H187 cells with an IC₅₀ value of 1.63 μg/mL. Compound 5 demonstrated strong cytotoxicity against MCF-7 and KB cell lines with IC50 values of 2.21 and 1.74 μg/mL, respectively. Compounds 3 and 4 exhibited moderate cytotoxicity against the MCF-7 cell line, and 8 showed moderate cytotoxicity against NCIH187 and KB cell lines. Compounds 3 and 5 showed antiplasmodial activity with IC₅₀ values of 3.27 and 2.94 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.     

Scopoletin from the flower buds of <Emphasis Type="Italic">Magnolia fargesii</Emphasis> inhibits protein glycation,aldose reductase,and cataractogenesis <Emphasis Type="Italic">Ex Vivo</Emphasis>

Five compounds previously known structures, scopoletin (1), northalifoline (2), stigmast-4-en-3-one (3), tiliroside (4), and oplopanone (5) were obtained from the flower buds of Magnolia fargesii using chromatographic separation methods. The structures of 1–5 were identified by the interpretation of their spectroscopic data including 1D- and 2D-NMR as well as by comparison with reported values. Three compounds 1–3 were found from M. fargesii for the first time in this study. All the isolates (1–5) were subjected to in vitro bioassays to evaluate the inhibitory activity on advanced glycation end products formation and rat lens aldose reductase (RLAR). Compound 1 showed a remarkable inhibitory activity on advanced glycation end products formation with IC₅₀ value of 2.93 μM (aminoguanidine: 961 μM), and showed a significant RLAR inhibitory activity with IC₅₀ value of 22.5 μM (3.3-tetramethyleneglutaric acid: 28.7 μM). Compound 4 exhibited potent inhibitory activity against RLAR (IC₅₀ = 14.9 μM). In the further experiment ex vivo, cataractogenesis of rat lenses induced with xylose was significantly inhibited by compound 1 treatment.     

<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.     

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.     

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.     

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.     

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.     

Cholinesterase inhibitors from <Emphasis Type="Italic">Cleistocalyx operculatus</Emphasis> buds

Five flavonoids, myricetin-3′-methylether 3-O-β-d-galactopyranoside (1), myricetin-3′,5′-dimethylether 3-O-β-d-galactopyranoside (2), quercetin (3), kaempferol (4), and tamarixetin (5) were isolated from the buds of Cleistocalyx operculatus (Myrtaceae). The chemical structures of these compounds were determined on the basis of spectroscopic analyses, including 2D NMR. Their anti-Alzheimer effects were evaluated via acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory activity assays. All five compounds 1–5 showed potential inhibitory activities against AChE with IC₅₀ values of 19.9, 37.8, 25.9, 30.4 and 22.3 μM, respectively, while compounds 1, 3, 4 and 5 also possessed BChE inhibitory activity with IC₅₀ values of 152.5, 177.8, 62.5, and 160.6 μM, respectively.     

Stilbenes and oligostilbenes from leaf and stem of <Emphasis Type="Italic">Vitis amurensis</Emphasis> and their cytotoxic activity

Chromatographic separation of the EtOAc fraction from the leaf and stem of Vitis amurensis led to the isolation of six oligostilbenoids (i.e., r-2-viniferin (1), trans-amurensin B (2), trans-ɛ-viniferin (3), gnetin H (4), amurensin G (5), (+)-ampelopsin A (8)) and four stilbenoids (i.e., trans-resveratrol (6), (+)-ampelopsin F (7), piceatannol (9), and trans-piceid (10)). The structures have been identified on the basis of spectroscopic evidence and physicochemical properties. The isolates were investigated for cytotoxic activity against three cancer cell lines in vitro using the MTT assay method. Amurensin G (5) and trans-resveratrol (6) showed significant cytotoxic activity against L1210, K562 and HTC116 cancer cell lines with IC₅₀ values ranging from 15.7 ± 2.1 to 30.9 ± 1.8 μM. (+)-Ampelopsin A (8) and trans-piceid (10) exhibited considerable cytotoxic activity against L1210 (IC₅₀ values of 30.6 ± 4.1 and 28.7 ± 2.81 μM, respectively) and K562 (IC₅₀ values of 38.6 ± 0.82 and 24.6 ± 0.76 μM, respectively). Gnetin H (4) showed only weak cytotoxic activity against L1210 with an IC₅₀ value of 40.1 ± 4.23 μM. On the other hand, r-2-viniverin (1), trans-amurensin B (2), trans-ɛ-viniferin (3), (+)-ampelopsin F (7), and piceatannol (9) exhibited no activity on three cancer cell lines.     

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.     

<Emphasis Type="Italic">In vitro</Emphasis> sortase a inhibitory and antimicrobial activity of flavonoids isolated from the roots of <Emphasis Type="Italic">Sophora flavescens</Emphasis>

A series of flavonoids (1–14) was isolated from the roots of Sophora flavescens. We evaluated their ability to inhibit both microbial growth and sortase A, an enzyme that plays a key role in cell wall protein anchoring and virulence in Staphylococcus aureus. Most prenylated flavonoids (7–13) displayed potent inhibitory activity against gram-positive and gram-negative bacteria except E. coli, with minimum inhibitory concentrations values ranging from 4.40 to 27.7 μM, and weak or no activity against fungal strains tested. Kurarinol (6) was a potent inhibitor of sortase A, with an IC₅₀ value of 107.7 ± 6.6 μM. A preliminary structure-activity relationship, including essential structural requirements, is described.     

Patchouli alcohol: in vitro direct anti-influenza virus sesquiterpene in <Emphasis Type="Italic">Pogostemon cablin</Emphasis> Benth.

During the screening of anti-influenza virus substances from traditional herbal medicines, the methanol extract from the leaves of Pogostemon cablin Benth. showed potent in vitro antiviral activity (99.8% inhibition at a concentration of 10 μg/mL) against influenza virus A/PR/8/34 (H1N1). The anti-influenza virus principle was isolated from the hexane-soluble fraction, through solvent fractionation, repeated silica gel column chromatography, and reversed-phase HPLC. The major active principle was a volatile substance that was identified as a sesquiterpene, patchouli alcohol (1), on the basis of its spectral analyses. When anti-influenza virus activity against A/PR/8/34 was evaluated by the plaque forming assay, patchouli alcohol reduced the number of plaques by 75% at 2 μg/mL and 89% at 10 μg/mL. Patchouli alcohol showed dose-dependent anti-influenza virus activity, and its IC₅₀ value was estimated to be 2.635 μM. Although 11 different sesquiterpenes were tested for antiviral activity against influenza virus A/PR/8/34, no or negligible activity was observed except for patchouli alcohol. Patchouli alcohol did not show anti-influenza virus activity against A/Guizhou/54/89 (H3N2), but showed weak activity against B/Ibaraki/2/85 (IC₅₀ = 40.82 μM). Patchouli alcohol did not show inhibitory activity against influenza virus neuraminidase.     

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.     

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.