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.     

Antioxidative iridoid glycosides and phenolic compounds from <Emphasis Type="Italic">Veronica peregrina</Emphasis>

Eight iridoid glycosides and four phenolic compounds were isolated from the EtOAc soluble fraction of Veronica peregrina MeOH extract as the radical scavengers for antioxidant activity. The compounds were identified as protocatechuic acid (1), luteolin (2), veronicoside (3), minecoside (4), specioside (5), amphicoside (6), catalposide (7), 6-O-cis-p-coumaroyl catalpol (8), p-hydroxy benzoic acid methyl ester (9), verproside (10), verminoside (11), and chrysoeriol 7-glucuronide (12) by spectroscopic analysis. All compounds except for 1 and 2 were isolated for the first time from this plant. The antioxidant activity was evaluated by the ORAC(Oxygen Radical Absorbance Capacity) assay, which measures scavenging activity against peroxy radicals induced by 2,2′-azobis (2-methoxypropion-amidine) dihydrochloride, and the ORAC value is expressed as relative trolox equivalent. Compounds 2, 4, 5, 6, 8, and 12 exhibited potent antioxidant activity, and compounds 1, 11 had similar activity with trolox, whereas the other compounds showed weaker activity than trolox.     

Studies on the constituents from the fruits of <Emphasis Type="Italic">Phaleria macrocarpa</Emphasis>

From the fruits of Phaleria macrocarpa, icariside C₃ (1), phalerin (2), and mangiferin (3) were isolated and their structures were identified on the basis of spectroscopic data. Icariside C₃ (1) showed a slow vasorelaxant activity against noradrenaline-induced contraction of isolated rat aorta. The structure of phalerin (2) was revised as 2,4′,6-trihydroxy-4-methoxybenzophenone-2-O-β-d-glucoside.     

New prenylated flavones from <Emphasis Type="Italic">Artocarpus champeden</Emphasis>, and their antimalarial activity in vitro

Two new prenylated flavones, artocarpones A and B (1 and 2), and seven known isoprenylated flavonoids, artonin A (3), cycloheterophyllin (4), artoindonesianin E (5), artoindonesianin R (6), heterophyllin (7), heteroflavanone C (8), and artoindonesianin A-2 (9), have been isolated from the stem bark of Artocarpus champeden. Their structures were determined by spectroscopic analysis. Among the compounds isolated, 8 had the most potent inhibitory activity against the growth of Plasmodium falciparum 3D7 clone, with an IC₅₀ value of 1 nmol L⁻¹.     

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.     

Norlignan derivatives from <Emphasis Type="Italic">Curculigo crassifolia</Emphasis> and their DPPH radical scavenging activity

A novel norlignan derivative, crassifogenin C (1), and a known compound, curcapital (2), were isolated from the ethanolic extract of the rhizomes of Curculigo crassifolia. Their structures were elucidated on the basis of spectroscopic evidence and comparisons with literature data. Curcapital (2) was isolated from this plant for the first time. The free radical scavenging activity of the isolated compounds along with crassifoside E (3) and crassifoside F (4), which were reported previously, was evaluated by the 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay. All compounds showed strong radical scavenging activity. The primary structure-activity relationship is also discussed.     

A new lignan from <Emphasis Type="Italic">Aphanamixis polystachya</Emphasis>

A new lignan, polystachyol (1), two lignan glycosides, lyoniside (2) and nudiposide (3), and a sterol, ergosta-4,6,8(14),22-tetraen-3-one (4), with stigmasterol, and oleic and linoleic acids, have been isolated from an MeOH extract of the dried bark of Aphanamixis polystachya. The structures of the isolated compounds were elucidated by analysis of 1D and 2D NMR and mass spectroscopic data. The compounds did not have growth inhibitory activity against HeLa cells.     

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.     

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.     

Cytotoxic prenylated flavones from Artocarpus champeden

Two new prenylated flavones, artoindonesianins A-2 (1) and A-3 (2), together with three known prenylated flavones, artonin B (3), heterophyllin (4) and cudraflavone C (5), have been isolated and identified from the chloroform extract of the heartwood of Artocarpus champeden. The structures of these compounds were determined on the basis of spectroscopic data, including UV, IR, 1-D and 2-D NMR, and mass spectra. The cytotoxic properties of the new compounds, together with three prenylated flavones isolated previously, artoindonesianins Q (6), R (7) and T (8), were evaluated against murine leukemia P-388 cells. Based on their IC₅₀ values, compounds 1, 2, 4, 5 and 8 showed strong cytotoxic properties.     

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.     

Triterpenoids with antioxidant activities from Myricaria squamosa

A new triterpenoid, namely myricarin C (compound 1), together with three known compounds myricarin A (compound 2) and myricarin B (compound 3), 3α-hydroxy-D-friedoolean-14-en-28-oic acid (compound 4), was isolated from the overground part of Myricaria squamosa. Compound 2 and compound 3 existed in the solution by the form of cis-trans isomers. Their structures were elucidated by means of extensive spectroscopic methods, including 1D-NMR, 2D-NMR, and HR-ESI-MS. The antioxidant properties of all compounds were calculated based on the DPPH radical scavenging activities. Results showed that myricarin A and myricarin C had general antioxidant activities with EC₅₀ values of 40.90 μg/ml, 42.22 μg/ml, respectively, compared to the control, rutin (5.17 μg/ml). The EC₅₀ values of myricarin B was 195.81 μg/ml. Compound 4 had no antioxidant activities.     

Two new monoterpenes from Sibiraea laevigata

Two new monoterpenes, 3-(2-oxo-4-methyl-3-pentenyl)furan-5H-2-one (1) and 3-[(2E)-4-hydroxyl-4-methyl-2-pentenyl)]furan-5H-2-one (2), along with eight known compounds (3–10), were isolated from the stalks and infructescence of Sibiraea laevigata. Their structures were elucidated by spectroscopic methods including extensive 1D and 2D NMR techniques. In addition, all of these isolates were evaluated for their cytotoxic and antioxidant activities. The results showed that compounds 5–7 displayed cytotoxicity with IC₅₀ values ranging from 34.8 to 43.2 μg ml^?1 against tumor cell lines. Furthermore, 5 and 9 showed antioxidant activities.     

海南红树林内生真菌Fusarium sp. HSL-3次级代谢产物研究

目的 研究海南红树林内生真菌Fusarium sp. HSL-3次级代谢产物,并对其进行抗炎和抗肿瘤活性筛选。方法 采用大米培养基对菌株静置培养,同时采用柱层析色谱法和HPLC对该真菌的次级代谢产物进行分离纯化,并且通过核磁共振及质谱等有机波谱手段,对得到的化合物进行结构鉴定。结果 共分离得到8个化合物,分别为lateritin(1)、4-carbomethoxy-6-hydroxy-2-quinolone(2)、3,5-dimethoxydihydrofusarubin D(3)、anhydrofusarbin(4)、3,3''-methylene-bis (4-hydroxybenzaldehyde)(5)、crypticin B(6)、vanillyl alcohol(7)和3,4-dihydroxyphenylaceticacid(8),其中化合物2和5为首次从镰刀菌属Fusarium中分离得到。化合物3和5对RAW264.7细胞表现出良好的抗炎活性(化合物3在50 µmol·L^-1时的NO抑制率为87%,化合物5在50 µmol·L^-1时的NO抑制率为71%),而化合物1对非小细胞肺癌细胞A549有显著的细胞毒活性,IC₅₀值为(7.92±0.27)µmol·L^-1。结论 从海南红树林内生真菌Fusarium sp. HSL-3中分离得到的化合物3和5具有较强的抗炎活性,化合物1有显著的抗肿瘤活性。     

Free-radical-scavenging principles from Phlomis caucasica

Seven free-radical-scavenging phenolic compounds including five flavonoids, rutin (1), chrysoeriol 7-O-rutinoside (2), kaempferol 3-O-glucoside (3), chrysoeriol 7-O-glucoside (4) and naringenin (5), and two phenylethanoid glycosides, forsythoside B (6) and acteoside (7) were isolated from the methanol extract of the aerial parts of the Iranian medicinal plant Phlomis caucasica by reversed-phase preparative high-performance liquid chromatography (HPLC), and the structures of these compounds were elucidated by spectroscopic means. The free-radical-scavenging properties of 1–7 were assessed by 2,2-diphenyl-1-picryl hydrazyl (DPPH) assay. Among these compounds, forsythoside B (6) and acteoside (7) were found to be the most potent antioxidants with the RC₅₀ values of 4.97 and 4.27 μg/ml, respectively.     

A new lignan glycoside from <Emphasis Type="Italic">Juniperus rigida</Emphasis>

A new lignan glycoside, named juniperigiside (1) was isolated from the CHCl₃ soluble fraction of the MeOH extract of stems and leaves of Juniperus rigida S.et Z. Compound 1 was identified by 1D- and 2D-NMR spectroscopy as well as CD analysis as (2R,3S)-2,3-dihydro-7-methoxy-2-(4′-hydroxy-3′-methoxyphenyl)-3-hydroxymethyl-5-benzofuranpropanol 4′-O-(3-O-methyl)-α-L-rhamnopyranoside. Five known lignans, icariside E4 (2), desoxypodophyllotoxin (3), savinin (4), thujastandin (5), and (−)-nortrachelogenin (6) in addition to five known labdane diterpenes including trans-communic acid (7), 13-epi-torulosal (8), 13-epi-cupressic acid (9), imbricatoric acid (10), and isocupressic acid (11) were also isolated and their structures were characterized by comparing their spectroscopic data with those in the literature. All compounds were isolated for the first time from this plant, and 5 and 6 were first reported from the genus Juniperus. The isolated compounds were tested for cytotoxicity against four human tumor cell lines in vitro using a Sulforhodamin B bioassay. Compounds 3, 4, 7, and 8 showed considerable cytotoxicity against four human cancer cell lines in vitro.     

Constituents of the roots of <Emphasis Type="Italic">Ligularia dentata</Emphasis> Hara

Nine known compounds, butyrospermol (1), lupeol (2), stigmast-4-en-3-one (3), stigmast-4-ene-3,6-dione (4), (+)-methyl abscisate (5), methyl indole-3-carboxylate (6), vanillin (7), methyl (E)-caffeate (8), and methyl (E)-ferulate (9), and two new compounds, methyl (E)-feruloylglycolate (10), and methyl-7,8-dihydro-(S)-7-methoxyferulate (11), have been isolated from the roots of Ligularia dentata Hara (Compositae). The structures were elucidated on the basis of spectral data.     

CYP3A4 inhibitors isolated from a marine derived fungus <Emphasis Type="Italic">Penicillium</Emphasis> species

More than 50% of clinically used drugs are thought to be metabolized by cytochrome P450 (CYP) 3A4. Discovery of new, inexpensive, CYP3A4 inhibitors will reduce drug dosages needed to cure patients. In our search for new inhibitors of the enzyme CYP3A4, extracts from 102 marine fungi were screened. Seven of the extracts had potent CYP3A4 inhibitory activity. Four aromatic compounds were isolated from an extract of a culture of one of these, a Penicillium sp., and were identified as 3-methoxyphenol (1), 4-methoxyphenylacetic acid (2), 4-(2-hydroxyethyl)phenol (3), and 4-hydroxy-2-methoxyacetanilide (4) by use of spectroscopic data. Interestingly, compound 3 at 250 μg mL⁻¹did not inhibit CYP3A4 whereas compounds 1, 2 and 4 had CYP inhibitory activity with IC₅₀ values of 2.0, 1.6 and 0.41 μg mL⁻¹, respectively.     

Antioxidant compounds from the stem bark of Garcinia atroviridis

A new xanthone, namely garcinexanthone G (1), along with eight known compounds, stigmasta-5,22-dien-3β-ol (2), stigmasta-5,22-dien-3-O-β-glucopyranoside (3), 3β-acetoxy-11α,12α-epoxyoleanan-28,13β-olide (4), 2,6-dimethoxy-p-benzoquinone (5), 1,3,5-trihydroxy-2-methoxyxanthone (6), 1,3,7-trihydroxyxanthone (7), kaempferol (8) and quercetin (9), were isolated from the stem bark of Garcinia atroviridis. Their structures were elucidated based on spectroscopic methods including nuclear magnetic resonance (NMR-1D and 2D), UV, IR, and mass spectrometry. All the isolated compounds were evaluated for their antioxidant properties based on the DPPH radical scavenging activities. Results showed that 1,3,7-trihydroxyxanthone and quercetin showed significant antioxidant activities with EC₅₀ values of 16.20 and 12.68 μg/ml, respectively, as compared to the control, ascorbic acid (7.4 μg/ml).     

Polyphenolic compounds isolated from the leaves of Myrtus communis

Four hydrolyzable tannins [oenothein B (1), eugeniflorin D₂ (2), and tellimagrandins I (3) and II (4)], two related polyphenolic compounds [gallic acid (5) and quinic acid 3,5-di-O-gallate (6)], and four myricetin glycosides [myricetins 3-O-β-d-xyloside (7), 3-O-β-d-galactoside (8), 3-O-β-d-galactoside 6″-O-gallate (9), and 3-O-α-l-rhamnoside (10)] were isolated from the leaves of Myrtus communis. Antioxidant activities of the isolated compounds were evaluated by 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging assay.