New antibacterial depsidones from an ant-derived fungus Spiromastix sp. MY-1.

Six new (1-6) and seven known depsidones (7-13) were isolated from the culture of an ant (Monomorium chinensis)-derived fungus Spiromastix sp. MY-1. Their structures were elucidated by extensive spectroscopic analysis including high resolution MS, 1D and 2D NMR data. The new bromide depsidones were obtained through supplementing potassium bromide in the fermentation medium of Spiromastix sp. MY-1. All isolated compounds showed various bioactivities against the tested phytopathogenic bacteria. Particularly, new bromide compound 4, named spiromastixone S, exhibited the strongest activity against Xanthomonas oryzae pv. oryzae with a MIC value of 5.2 µmol·-1.

Discovery of an unprecedented benz[α]anthraquinone-type heterodimer from a rare actinomycete Amycolatopsis sp. HCa1.

The angucylines are a family of aromatic polyketides featuring a tetracyclic benz[a]anthraquinone skeleton. This class of polycyclic aromatic polyketides are exclusively associated with actinomycetes and can undergo many modifications such as oxidation, ring cleavage, glycosylation and dimerization. Here we report the discovery of a new ether-linked benz[a]anthraquinone heterodimer, named mycolatone (1), from a grasshopper-derived actinomycete, Amycolatopsis sp. HCa1. The structure of mycolatone (1) was determined by comprehensive two-dimensional NMR analysis, high-resolution electrospray ionization mass spectrometry and biogenetic consideration. This new heterodimeric molecule is structurally derived from the dimerization of two tetracyclic angucylines, 2-hydroxy-5-O-methyltetragomycin and PD116779, through an ether bond between C-8 and C-8'. This new structural feature enrich the structural diversity of angucylines. Additionally, the surface tension activity and cytotoxic activities of 1 against human cervical cancer cell line (Hela), human gastric adenocarcinoma cell line (SGC-7901) and human lung adenocarcinoma cell line (SPC-A-1) were evaluated.

Bioactive phenazines from an earwig-associated Streptomyces sp.

Three new phenazine-type compounds, named phenazines SA-SC (1-3), together with four new natural products (4-7), were isolated from the fermentation broth of an earwig-associated Streptomyces sp. NA04227. The structures of these compounds were determined by extensive analyses of NMR, high resolution mass spectroscopic data, as well as single-crystal X-ray diffraction measurement. Sequencing and analysis of the genome data allowed us to identify the gene cluster (spz) and propose a biosynthetic pathway for these phenazine-type compounds. Additionally, compounds 1-5 exhibited moderate inhibitory activity against acetylcholinesterase (AChE), and compound 3 showed antimicrobial activities against Micrococcus luteus.

Streptoxamine, an unprecedented benzoisoindole-deferoxamine hybrid from the locust-derived Streptomyces sp. HKHCa2.

An unusual benzoisoindole-deferoxamine hybrid, streptoxamine (1), has been isolated from the ethyl acetate crude extract of the fermentation broth of a locust-associated actinomycete, Streptomyces sp. HKHCa2, which was isolated from an insect, Oxya chinensis. The structure of this secondary metabolite was elucidated on the basis of its one-dimension, two-dimension NMR, and mass spectroscopic data. This natural product features a hybrid pattern of a benzoisoindole with an "iron carrier" deferoxamine B through C-N linkage. Compound 1 showed weak antibacterial activity against the gram-positive bacteria, Staphylococcus aureus and Mycobacterium smegmatis.

Tomenphantadenine, an unprecedented germacranolide-adenine hybrid heterodimer from the medicinal plant Elephantopus tomentosus L.

An unusual adenine-substituted germacrane sesquiterpene lactone, tomenphantadenine (1), has been isolated from the whole plant of Elephantopus tomentosus L. The structure of this compound was established by comprehensive spectroscopic analysis including high resolution (HR) ESI-MS, 1D and 2D nuclear magnetic resonance (NMR) spectroscopic data. This compound features novel hybrid pattern of germacrane sesquiterpene with adenine through C-N linkage, and a possible biosynthetic pathway for it was proposed. Compound 1 showed potent antibacterial activity against the gram-positive Staphylococcus aureus and weak acetylcholinesterase (AChE) inhibitory activity.

Daphnauranins A and B, two new antifeedants Isolated from Daphne aurantiaca roots.

Daphnauranins A (1) and B (2), two sesquiterpenoids were isolated from the roots of Daphne aurantiaca Diels. One is an unprecedented 5/7 oxacycloheptane ring system, the other is a sesquiterpene-lignan complex. Their structures were elucidated by comprehensive spectroscopic methods including MS and NMR. Their absolute configurations were further confirmed by the quantum ECD calculations. Daphnauranins A and B showed anti-insect activities against male fruit fly with anti-feeding rate up to 46.2±7.1 and 44.7±5.4% at 1mM, respectively.

Nematicidal Stemona Alkaloids from Stemona parviflora.

Eight new alkaloids, 3ß-n-butylstemonamine (1), 8-oxo-3ß-n-butylstemonamine (2), 3-n-butylneostemonine (3), 10-epi-3-n-butylneostemonine (4), 8-oxo-oxymaistemonine (5) protostemonine N4-oxide (6), (19S)-hydroxy-21-methoxystemofoline (7), and parvistemonine A (8), were isolated from the roots of Stemona parviflora, together with 17 known alkaloids. The structures of the new alkaloids were elucidated based on a comprehensive spectroscopic data analysis. The absolute configurations of 1-4 were determined by the ECD exciton chirality method and quantum ECD calculations. Protostemonine (10) and stemofoline (12) showed strong nematicidal activity against Panagrellus redivevus, with IC50 values of 0.10 and 0.46 µM, respectively.

Mexicanolide-Type Limonoids from the Roots of Trichilia sinensis.

Four new mexicanolide-type limonoids 1-4, along with two known limonoids 5-6, were isolated from the ethanolic extracts of roots of the Traditional Chinese Medicine Trichilia sinensis. Their structures were unambiguously determined by analysis of spectroscopic data, including 1D and 2D NMR as well as MS, and by comparison with literature data. In addition, the acetylcholinesterase (AChE) inhibitory activity of compounds 1-6 was evaluated by the Ellman method. All these compounds showed weak AChE inhibitory activity, with the inhibition percentages ranging from 18.5% to 27.8%.

A New Degraded Sesquiterpene from the Twigs of Trigonostemon lutescens.

A new degraded sesquiterpene, tectoionol C (1), together with five known compounds wilsonol F (2), heterodendrin (3), epi-heterodendrin (4), 7-deoxogeayine (5), and 1H-indole-3-carboxylicacid, methyl ester (6), was isolated from the twigs of Trigonostemon lutescens. Their structures were determined by spectroscopic methods including 1D and 2D NMR techniques, as well as by comparison with published data.

A new apotirucallane-type triterpenoid from Atalantia buxifolia.

A new triterpenoid (1) with apotirucallane skeleton was isolated from the ethanol extract of the roots of Atalantia buxifolia (Poir.) Oliv. The complete structural assignment of the new compound was elucidated by a combination of 1D, 2D NMR (HMQC, HMBC, COSY, and NOESY), and HR-ESI-MS analysis. Moreover, this new compound was evaluated in vitro for its cytotoxic, antimicrobial and enzymes inhibitory activities.

Five new eudesmane-type sesquiterpenoids from Chinese agarwood induced by artificial holing.

Five new eudesmane-type sesquiterpenoids (1-5), along with six known ones (6-11), were isolated from Chinese agarwood induced by artificial holing originating from Aquilaria sinensis (Lour.) Gilg (Thymelaeaceae). The structures of the new sesquiterpenoids were established by spectroscopic methods including UV, IR, MS, 1D, and 2D NMR. Compounds 1, 3, 6 and 7 exhibited antibacterial activities against both Staphylococcus aureus and Ralstonia solanacearum, and compound 5 only showed an inhibitory activity towards S. aureus. Compounds 1, 6, 7 and 10 showed weak acetylcholinesterase inhibitory activity.

Two new guaiane sesquiterpenoids from Daphne holosericea (Diels) Hamaya.

Two new sesquiterpenoids with guaiane skeletons-holosericin A (1) and holosericin B (2)-were isolated from the medicinal plant Daphne holosericea (Diels) Hamawa (Thymelaeceae). Their structures were elucidated by 1D and 2D-NMR spectroscopy, as well as HR-ESI-MS data. Compounds 1 and 2 were evaluated for inhibitory activities against acetylcholinesterase and compound 2 showed a moderate activity with 31% inhibition.

[Chemical constituents of Dalbergia odorifera].

Fourteen compounds were isolated from Dalbergia odoriferae and purified by repeated column chromatography on silica and sephadex LH-20 gel and structurally identified by spectral analysis. These compounds were identified as 4, 9-dimethoxy-3-hydroxypterocarpan (1), medicarpin (2), 2', 4', 5-trihydroxy-7-methoxyisoflavone (3), 2', 3', 7-trihydroxy-4'-methoxyisoflavan (4), formononetin (5), 3, 8-dihydroxy-9-methoxypterocarpan (6), koparin (7), 3-hydroxy-9-methoxypterocarp-6a-ene (8), 2'-hydroxyformononetin (9), stevenin (10), 2', 7-dihydroxy-4', 5'-dimethoxyisoflavone (11), lyoniresinol (12), 2, 4-dihydroxy-5-methoxy-benzophenone (13) and neokhriol A (14). Compounds 1, 3, 4, 6, 8, 12 and 14 were isolated from this plant for the first time. Antibacterial activity assay showed that compound 4 had inhibitory effect on Ralstonia solanacearum.

Terpenoids and their anti-feedant activity from Cipadessa cinerascens.

Eight tetranortriterpenoids (1-8) and two sesquiterpenoids (9 and 10) including two new compounds, cineracipadesin G (1) and 1ß-hydroperoxy-6α-hydroxy-eudesm-4(15)-ene (9), were isolated from the EtOAc extract of branches of Cipadessa cinerascens. The structures of two new compounds were elucidated by 1D and 2D NMR and MS spectroscopic analyses. The anti-feedant activity of two tetranortriterpenoids (1 and 7) was tested and obvious anti-feedant effects were detected.

2-(2-phenylethyl)chromone derivatives from Chinese agarwood induced by artificial holing.

Three new 2-(2-phenylethyl)chromone derivatives (1-3), together with thirteen known ones (4-16), were isolated from the EtOAc extract of Chinese agarwood induced by artificial holing, originating from Aquilaria sinensis (Lour.) Gilg (Thymelaeaceae). The chemical structures of the new compounds were identified by spectroscopic techniques (UV, IR, MS, 1D and 2D NMR). Compounds 1, 6, 15 and 16 exhibited inhibitory effects on Staphylococcus aureus, and compounds 15 and 16 showed inhibitory effects on Ralstonia solanacearum. Compounds 1-3, 7, 9, 11, 12, 15 and 16 exhibited acetylcholinesterase inhibitory activity. A possible biogenetic pathway of compounds 1-16 was proposed to show the relationships between diepoxy-tetrahydro-2-(2-phenylethyl)chromones, epoxy-tetrahydro-2-(2-phenylethyl) chromones, tetrahydro-2-(2-phenylethyl)chromones, and 2-(2-phenylethyl)chromones of the flidersia type, the four main types of 2-(2-phenylethyl)chromones found in agarwood, on the basis of their appearances in different stage of agarwood formation.

Monoterpenoid coumarins from the peels of Clausena lansium.

A phytochemical investigation on the peels of Clausena lansium (Lour.) Skeels led to the isolation of two new monoterpenoid coumarins, named clauslactone V (1) and clauslactone W (2), together with three known analogues (3-5). Their structures were elucidated by spectroscopic techniques (UV, IR, MS, 1D and 2D NMR). All the compounds were evaluated for hypoglycemic activity, and compounds 1-5 showed α-glucosidase inhibitory activity in vitro.

Carbazole alkaloids from the peels of Clausena lansium.

A new carbazole alkaloid, claulansine K (1), together with six known carbazole alkaloids (2-7), was isolated from the peels of Clausena lansium (Lour.) Skeels. The new compound was elucidated using a combination of 1D and 2D NMR (HMQC, HMBC, COSY, and ROESY) techniques, and HR-EI-MS analyses. Compound 1 showed in vitro α-glucosidase inhibitory activity with the IC50 value of 0.11 mM. Compound 2 exhibited moderate antibacterial activity against Staphylococcus aureus with the diameter of inhibition zone of 14.2 mm.

[Chemical constituents from Ganoderma philippii].

The chemical investigation on Ganoderma philippii led to the isolation of sixteen compounds by silica gel and Sephadex LH-20 column chromatography. On the basis of spectroscopic data analyses, their structures were elucidated as 2, 5-dihydroxyacetophenone (1), methyl gentisate (2), (S) -dimethyl malate (3), muurola-4, 10 (14) -dien-11beta-ol (4), dihydroepicubenol (5), 5-hydroxymethylfuran carboxaldehyde (6), ergosta-7, 22E-dien-3beta-ol (7), ergosta-7, 22E-dien-3-one (8), ergosta-7, 22E-diene-2beta, 3alpha, 9alpha-triol (9), 6/beta-methoxyergo-sta-7, 22E-dien-3beta, 5alpha-diol (10), ergosta-4, 6, 8(14), 22E-tetraen-3-one (11), ergosta4, 6, 8-(14), 22E-etetraen-3beta-ol (12), 5alpha, 8alpha-epidioxy-ergosta-6, 22E-dien-3beta-ol (13), 7alpha-methoxy-5alpha, 6alpha-epoxyergosta-8-(14), 22E-dien-3beta-ol (14), ergosta-8, 22E-diene-3beta, 5alpha, 6beta, 7alpha-tetraol (15), and ergosta-5, 23-dien-3beta-ol, acetate (16). All the compounds were obtained from this fungus for the first time, and compounds 4 and 5 were isolated from the Ganoderma genus for the first time.

A new 2-(2-phenylethyl)chromone derivative in Chinese agarwood 'Qi-Nan' from Aquilaria sinensis.

Phytochemical analysis of the high quality Chinese agarwood 'Qi-Nan' originating from Aquilaria sinensis (Lour.) Glig led to the isolation of a new 2-(2-phenylethyl)chromone derivative, qinanones G (1), and four known 2-(2-phenylethyl)chromones (2-5). Their structures were elucidated by spectroscopic techniques (UV, IR, 1D and 2D NMR) and MS analyses. The NMR data of chromones 1-3 were first reported, and chromones 2 and 3 showed weak inhibitory activity against acetylcholinesterase.

A new dolabellane diterpenoid and a sesquilignan from Aglaia odorata var. microphyllina.

One new diterpenoid, 11alpha,12betaH-dolabella-4,8(17)-dien-3alpha,7beta,18-triol (1) and one new sesquilignan, 9-methoxy-7',8'-cis-7",8"-cis-buddlenol B (2), together with three known compounds, (+)-diasyringaresinol (3), N-methyl-5- hydroxy-delta3-pyrrolin-2-one (4) and marmin (5), have been isolated from Aglaia odorata var. microphyllina. Their structures were determined using 1D and 2D NMR spectroscopy. Compound 1 exhibited cytotoxic activity against the K562 cell line with an IC50 value of 12.5 microg/mL.