A new abietane diterpenoid from Isodon inflexus

A new ent-abietane diterpenoid, 3α,6β-dihydroxy-7,17-dioxo-ent-abieta-15(16)-ene (1), and three known ent-kaurane diterpenids, kamebacetal A (2), kamebakaurin (3), and excisanin A (4), and a known triterpenoid, ursolic acid (5), were isolated from the aerial parts of Isodon inflexus. Their chemical structures were determined by extensive analysis of spectroscopic data including 1D-and 2D-NMR experiments. All isolates (1–5) were evaluated for their potential to inhibit LPS-induced nitric oxide production in RAW264.7 cells. Of these, compounds 1–4 inhibited the production of NO with IC₅₀ values ranging from 1.0 to 26.5 μM.     

Iodine (III)-mediated synthesis of some 2-aryl/hetarylbenzoxazoles as antibacterial/antifungal agents

Ten 2-aryl/hetarylbenzoxazoles (5a, 5b, and 6a–h) were synthesized via oxidative cyclization of Schiff bases (3a, 3b, and 4a–h) with 1.1 equivalent of iodobenzene diacetate (IBD) in methanol. All of these 2-aryl/hetarylbenzoxazoles (5a, 5b, and 6a–h) were tested in vitro for their antibacterial and antifungal activities against Bacillus subtilis, Bacillus stearothermophilus, Escherichia coli, and Pseudomonas putida. These compounds also were screened for their antifungal activity against Aspergillus flavus and Aspergillus niger. Biological activity of these compounds was compared with those of commercially available antibiotics, chloramphenicol and antifungal agent cycloheximide. Most of these compounds, 5a, 5b, 6a, 6b, 6d, 6e, 6g, 6h, were equipotent or more potent than these commercial drugs at concentration 100 μg/ml.     

Synthesis,antioxidant and antimicrobial evaluation of simple aromatic esters of ferulic acid

Aromatic ester derivatives of ferulic acid where the phenolic hydroxyl is free (6a–d) or acetylated (5a–d) were evaluated for their antioxidant and antimicrobial properties. The superoxide radical scavenging capacity of compounds 5d and 6d–e (IC₅₀ of 0.19, 0.27 and 0.20 mM, respectively) was found to be twice as active as α-tocopherol (IC₅₀ = 0.51 mM). DPPH radical scavenging capacity was moderate and only found in compounds bearing free phenolic hydroxyl groups (6a–e). With regard to antimicrobial properties, compounds 6b and 6c displayed significant activity against Enterococcus faecalis (MICs = 16 μg/mL) and vancomycin-resistant E. faecalis (MIC for 6b, 32 and for 6c, 16 μg/mL). Compound 6c also demonstrated prominent activity against planktonic Staphylococcus aureus with a MIC value of <8 μg/mL and it inhibited bacterial biofilm formation by S. aureus with a MBEC value of <8 μg/mL, which was 64 and 128 times more potent than ofloxacin and vancomycin, respectively.     

Stilbene and dihydrophenanthrene derivatives from <Emphasis Type="Italic">Pholidota chinensis</Emphasis> and their nitric oxide inhibitory and radical-scavenging activities

Two new stilbene derivatives, (E)-2′,3,3′-trihydroxy-5-methoxystilbene (1, Pholidotol C) and (Z)-3,3′-hydroxy-5-methoxystilbene (2, Pholidotol D), were isolated from the air-dried whole plant of Pholidota chinensis Lindl., together with eight known dihydrophenanthrene derivatives, lusianthridin (3), cannabidihydrophenanthrene (4), coelonin (5), hircinol (6), erianthridin (7), 4,5-dihydroxy-2-methoxy-9,10-dihydrophenanthrene (8), eulophiol (9), and 2,4,7-trihydroxy-9,10-dihydrophenanthrene (10), and a benzoxepin derivative bulbophylol B (11). Their inhibitory effects on nitric oxide (NO) production activity and 1,1-diphenyl-2-picrylhydrazil radical-scavenging activity were examined. Among these compounds, 11 exhibited the most potent activity toward NO production inhibition activity and radical-scavenging activity; moreover, 11 reduced inducible nitric oxide synthase mRNA expression.     

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.     

Chalcones isolated from <Emphasis Type="Italic">Angelica keiskei</Emphasis> and their inhibition of IL-6 production in TNF-α-stimulated MG-63 cell

Six chalcone compounds, 2′,4′,4-trihydroxy-3′-[2-hydroxy-7-methyl-3-methylene-6-octaenyl]chalcone (1), 2′,4′,4-trihydroxy-3′-geranylchalcone (2), 2′,4′,4-trihydroxy-3′-[6-hydroxy-3,7-dimethyl-2,7-octadienyl]chalcone (3), 2′,4-dihydroxy-4′-methoxy-3′-[2-hydroperoxy-3-methyl-3-butenyl]chalcone (4), 2′,4-dihydroxy-4′-methoxy-3′-geranylchalcone (5), and 2′,4-dihydroxy-4′-methoxy-3′-[3-methyl-3-butenyl]chalcone (6) were isolated from the leaves of Angelica keiskei K (Umbelliferae). The structure of each isolated compound was determined using spectroscopic methods. Among the isolates, compounds 1–3 appeared to have potent inhibitory activity of IL-6 production in TNF-α-stimulated MG-63 cell, while compounds 4–6 did not. The distinct structural difference between compounds 1–3 and 4–6 was the presence of C-4′ hydroxyl group in the chalcone moiety. Our results imply that the inhibitory activity of IL-6 production in TNF-α-stimulated MG-63 cell may be affected by the presence of C-4′ hydroxyl group in the chalcone moiety.     

Baimantuoluosides D-G,four new withanolide glucosides from the flower of <Emphasis Type="Italic">Datura metel</Emphasis> L.

In our search for bioactive anti-psoriasis compounds from the flower of Datura metel L, we isolated four new withanolide glucosides, baimantuoluosides D, E, F and G (1–4). The structures of the new compounds are (5α,6α,7β,22R)-5,6,7,27-tetrahydroxy-1-oxowitha-2,24-dien-27-O-β-D-glucopyranoside (1), (5α,6β,7α,22R)-5,6,7,27-tetrahydroxy-1-oxowitha-2,24-dien-27-O-β-D-glucopyranoside (2), (5α,6β,7α,12β,22R)-5,6,7,12,27-pentahydroxy-1-oxowitha-2,24-dien-27-O-β-D-glucopyranoside (3), and (5α,6β,22R)-5,6,27-trihydroxy-1-oxowitha-2,24-dien-27-O-β-D-glucopyranoside (4) on the basis of chemical and physicochemical evidence.     

Inhibition of nitric oxide production in RAW 264.7 macrophages by diterpenoids from <Emphasis Type="Italic">Phellinus pini</Emphasis>

8,14-labdadien-13-ol (1) and dehydroabietic acid (2) were isolated from the fruit body of Phellinus pini. Elucidation of their structures was based on spectroscopic methods including IR, MS, and NMR (1D and 2D). Two compounds were screened for their ability to inhibit NO production in LPS-activated RAW 264.7 cells. Compounds 1 and 2 at 30 μM and 50 μM, respectively, inhibited NO production in activated macrophages.     

Secoiridoid and iridoid glucosides from the leaves of <Emphasis Type="Italic">Fraxinus griffithii</Emphasis>

Phytochemical investigation of the dried leaves of Fraxinus griffithii collected in Okinawa has led to the isolation of three new secoiridoid glucosides, griffithosides A–C (1–3), and one new iridoid glucoside, 7-epi-7-O-(E)-caffeoylloganic acid (4), along with eight known secoiridoid glucosides (5–12). The structures of these compounds were elucidated by means of NMR, MS, and other spectroscopic techniques, as well as comparison with literature data. The isolated compounds were tested for radical-scavenging activity. Among them, compounds 3, 4, and 7 exhibited substantial radical-scavenging activity.     

Antioxidative and anti-inflammatory effects of phenolic compounds from the roots of <Emphasis Type="Italic">Ulmus macrocarpa</Emphasis>

The roots of Ulmus macrocarpa Hance (Ulmaceae) have been used as an oriental traditional medicine for the treatment of inflammation, ulcers, cancers, and parasites. Activity guided isolation from the roots of U. macrocarpa yielded three flavonoids [catechin 7-O-β-D-apiofuranoside (1), (+)-catechin (2), taxifolin 6-C-glucopyranoside (3)], and one coumarin [fraxin (4)]. To investigate the antioxidative and anti-inflammatory effects of these compounds, DPPH radical scavenging activity and inhibitory activity against nitric oxide (NO) production in LPS-stimulated RAW 264.7 cells were examined and the expression of inducible NO synthase (iNOS) and cyclooxidase-2 (COX-2) were measured by RT-PCR and Western Blotting in HaCaT cells. Compounds 1, 2, and 3 showed moderate antioxidative activities compared with L-ascorbic acid as a positive control. NO production was reduced and the expressions of iNOS and COX-2 and their mRNA were inhibited by the addition of samples (1–4). These results suggest that the phenolic compounds from the roots of U. macrocarpa might be developed as antioxidant and anti-inflammatory agents.     

Promotion of IL-8 production in PMA-stimulated HL-60 cells by sesquiterpene quinones from a marine sponge, <Emphasis Type="Italic">Hippospongia</Emphasis> sp.

An extract of a marine sponge, Hippospongia sp., collected in Palau has inhibitory activity against colony formation by Chinese hamster V79 cells. Bioassay-guided isolation gave eleven sesquiterpene quinones. Compounds 1–8 inhibited colony formation by V79 cells with EC₅₀ values between 0.6 and 2.8 μmol L⁻¹. Their effects on the production of an inflammatory cytokine, IL-8, in tetradecanoyl phorbol acetate (PMA)-stimulated HL-60 cells were also investigated, because IL-8 production is sometimes correlated with inhibition of cell growth. Ilimaquinone (1) and its 5 epimer (2) had similar activity against V79 cells (EC₅₀ = 2.8 and 2.3 μmol L⁻¹, respectively) but did not modulate IL-8 production even at 10 μmol L⁻¹. Smenospongidine (3) and its 5 epimer (4), smenospongiarine (5) and its 5 epimer (6), and smenospongine (7) and its 5-epimer (8), at 10 μmol L⁻¹, promoted IL-8 production. Compounds 3, 5, and 7 had slightly stronger activity against V79 cells (EC₅₀ = 0.6, 1.7, and 0.8 μmol L⁻¹, respectively) than the corresponding 5 epimers 4, 6, and 8 (EC₅₀ = 0.8, 2.3, and 2.0 μmol L⁻¹, respectively). A similar structure–activity relationship was observed for promotion of IL-8 production. This is the first report of modulation of IL-8 production by these sesquiterpene quinones.     

A new flavonol galloylrhamnoside and a new lignan glucoside from the leaves of <Emphasis Type="Italic">Koelreuteria henryi</Emphasis> Dummer

A new flavonol galloylrhamnoside, kaempferol 3-O-(2″,3″-di-O-galloyl)-α-l-rhamnopyranoside, and a new lignan glycoside, hinokinin 7-O-β-d-glucopyranoside were isolated from the leaves of Koelreuteria henryi, along with 18 known compounds, including six flavonol glycosides (3–8), three lignans (9–11), four chlorophyll derivatives (12–15), two steroids (16, 17), and three aromatic compounds (18–20). The structures were determined on the basis of spectral analysis and chemical evidence. The scavenging effect of 1–8 and 20 on the stable free radical 1,1-diphenyl-2-picrylhydrazyl was examined. Compounds 1, 5, 6, and 20 showed more potent activity than that of trolox.     

Iridoid glucoside, (3<Emphasis Type="Italic">R</Emphasis>)-oct-1-en-3-ol glycosides,and phenylethanoid from the aerial parts of <Emphasis Type="Italic">Caryopteris incana</Emphasis>

Eleven compounds of interest were isolated from the aerial parts of Caryopteris incana, specifically a new acyl derivative (3) of 8-O-acetylharpagide, two new (3R)-oct-1-en-3-ol glycosides (5, 6), and 6-O-caffeoylphlinoside A (11) along with seven known compounds, 8-O-acetylharpagide (1), 6′-O-p-coumaroyl-8-O-acetylharpagide (2), (3R)-oct-1-en-3-ol (matsutake alcohol) O-α-l-arabinopyranosyl-(1″ → 6′)-O-β-d-glucopyranoside (4), apigenin 7-O-neohesperidinoside (7), 6′-O-caffeoylarbutin (8), and two phenylethanoids, leucosceptoside A (9) and phlinoside A (10). This paper deals with structural elucidation of the new compounds.     

Elaeocarpionoside,a megastigmane glucoside from the leaves of <Emphasis Type="Italic">Elaeocarpus japonicus</Emphasis> Sieb. et Zucc.

From a 1-BuOH-soluble fraction of an extract of the leaves of Elaeocarpus japonicus, six megastigmane glucosides (1–6) were isolated. Five were known compounds (2–6), i.e. amelopsisionoside, citroside A, roseoside, alangionoside A and turpinionoside A, respectively. The structure of the new compound, named elaeocarpionoside, was elucidated to be (3R,4R,5S,6S,7E,9R)-megastigman-7-ene-3,4,9-triol 9-O-β-d-glucopyranoside by spectroscopic analyses and the modified Mosher’s method.     

Eudesmanolides from <Emphasis Type="Italic">Taraxacum mongolicum</Emphasis> and their inhibitory effects on the production of nitric oxide

A new eudesmanolide, 1β,3β-dihydroxy-eudesman-11(13)-en-6α,12-olide (1) was isolated and identified from Taraxacum mongolicum, together with two known compounds, 1β,3β-dihydroxyeudesman-6α,12-olide (2) and loliolide (3). The structure of 1 was established by analysis of its physical and spectroscopic data. 1 was found to have an inhibitory activity on nitric oxide production with an IC₅₀ of 38.9 μM in activated RAW 264.7 cells.     

Two new neolignan glycosides from leaves of <Emphasis Type="Italic">Osmanthus heterophyllus</Emphasis>

Two new neolignan glycosides, (7R, 8R)-threo-guaiacylglycerol-8-O-4′-sinapyl ether 7-O-β-d-glucopyranoside (1) and (7S, 8R)-5-methoxydehydrodiconiferyl alcohol 4-O-β-d-glucopyranoside (2), and four known ones (3–6), were isolated from the leaves of Osmanthus heterophyllus. The structures of compounds 1–6 were established on the basis of spectral and chemical data.     

Constituents of the root of <Emphasis Type="Italic">Anemone tomentosa</Emphasis>

A new diterpene glycoside, tomentoside I (1), along with eleven known compounds, including the four coumarins, 4,5-dimethoxyl-7-methylcoumarin (2), 4,7-dimethoxyl-5-methylcoumarin (3), isofraxidin (4) and fraxidin (5) as well as the seven triterpenoids, oleanolic acid (6), oleanolic acid 3-O-α-L-arabinopyranoside (7), oleanolic acid 3-O-β-D-galactopyranosyl-(1→3)-β-D-glucopyranoside (8), hederagenin 3-O-α-L-arabinopyranoside (9), betulinic acid (10), 18-hydroxyursolic acid (11) and 2α,3β,23-trihydroxyurs-12-en-28-oic acid (12) were isolated from the ethanolic extract of the root of Anemone tomentosa and their chemical structures were elucidated by spectroscopic methods. The antimicrobial activities of compounds 1–12 were measured using the agar disc-diffusion method. Also, their antioxidant activities against 1,1-diphenyl-2-picrylhydrazyl (DPPH) were evaluated.     

Lignan and neolignan glucosides,and tachioside 2′-<Emphasis Type="Italic">O</Emphasis>-4″-<Emphasis Type="Italic">O</Emphasis>-methylgallate from the leaves of <Emphasis Type="Italic">Glochidion rubrum</Emphasis>

Thirteen compounds (1–13) were isolated from a MeOH extract of leaves of Glochidion rubrum. The structures of four new compounds were elucidated to be (−)-isolariciresinol 2a-O-β-d-glucopyranoside (1), (7R,8S)- and (7R,8R)-4,7,9,9′-tetrahydroxy-3,3′-dimethoxy-8-O-4′-neolignan 7-O-β-d-glucopyranosides (2 and 3, respectively), and tachioside 2′-O-4″-O-methylgallate (4) on detailed inspection of one- and two-dimensional NMR spectral data.     

Evaluation of Cancer-Preventive Activity and Structure–Activity Relationships of 3-Demethylubiquinone Q2, Isolated from the Ascidian Aplidium glabrum, and its Synthetic Analogs

Purpose 3-Demethylubiquinone Q₂ (1) was isolated from the ascidian Aplidium glabrum. The cancer-preventive properties and the structure–activity relationship for 3-demethylubiquinone Q₂ (1) and 12 of its synthetic analogs (3–14) are reported. Methods Compounds 3–14, having one or several di- or triprenyl substitutions and quinone moieties with methoxyls in different positions, were synthesized. The cancer-preventive properties of compounds 1 and 3–14 were tested in JB6 Cl41 mouse skin cells, using a variety of assessments, including the methanethiosulfonate (MTS) assay, flow cytometry, and soft agar assay. Statistical nonparametric methods were used to confirm statistical significance. Results All quinones tested were shown to inhibit JB6 Cl41 cell transformation, to induce apoptosis, AP-1, and NF-κB activity, and to inhibit p53 activity. The most promising effects were indicated for compounds containing two isoprene units in a side chain and a methoxyl group at the para-position to a polyprenyl substitution. Conclusions Quinones 1 and 3–14 demonstrated cancer-preventive activity in JB6 Cl41 cells, which may be attributed to the induction of p53-independent apoptosis. These activities depended on the length of side chains and on the positions of the methoxyl groups in the quinone part of the molecule.     

Phenylpropanoid glycosides from <Emphasis Type="Italic">Heterosmilax erythrantha</Emphasis> and their antioxidant activity

By various chromatographic methods, one new phenylpropanoid glycoside, heterosmilaside (1), two known phenylpropanoid glycosides, helonioside B (2), and 2′,6′-diacetyl-3,6-diferuloyl sucrose (3), and three known flavonoids, isoquercetin (4), quercetin-3-O-β-D-glucuronopyranoside (5), and quercetin-3-O-(2″-α-L-rhamnopyranosyl)-β-D-glucuronopyranoside (6) were isolated from the methanolic extract of the aerial part of Heterosmilax erythrantha Baill. Their structures were elucidated on the basis of spectroscopic analyses. All the isolated compounds were tested for antioxidant activity in the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging assay. Among them, compounds 5 and 6 showed significant antioxidant activity with SC₅₀ values of 3.7 and 6.5 μg/mL, respectively.