New Hydroxydecanoic Acid Derivatives Produced by an Dndophytic Yeast Aureobasidium pullulans AJF1 from Flowers of Aconitum carmichaeli.

Endophytes have been recognized as a source for structurally novel and biologically active secondary metabolites. Among the host plants for endophytes, some medicinal plants that produce pharmaceuticals have been reported to carry endophytes, which could also produce bioactive secondary metabolites. In this study, the medicinal plant Aconitum carmichaeli was selected as a potential source for endophytes. An endophytic microorganism, Aureobasidium pullulans AJF1, harbored in the flower of Aconitum carmichaeli, was cultured on a large scale and extracted with an organic solvent. Extensive chemical investigation of the extracts resulted in isolation of three lipid type compounds (1-3), which were identified to be (3R,5R)-3,5-dihydroxydecanoic acid (1), (3R,5R)-3-(((3R,5R)-3,5-dihydroxydecanoyl)oxy)-5-hydroxydecanoic acid (2), and (3R,5R)-3-(((3R,5R)-5-(((3R,5R)-3,5-dihydroxydecanoyl)oxy)-3-hydroxydecanoyl)oxy)-5-hydroxydecanoic acid (3) by chemical methods in combination with spectral analysis. Compounds 2 and 3 had new structures. Absolute configurations of the isolated compounds (1-3) were established using modified Mosher's method together with analysis of NMR data for their acetonide derivatives. All the isolates (1-3) were evaluated for antibiotic activities against Escherichia coli, Staphylococcus aureus, Bacillus subtilis, Pseudomonas aeruginosa, and their cytotoxicities against MCF-7 cancer cells. Unfortunately, they showed low antibiotic activities and cytotoxic activities.

Bioactive secondary metabolites from an endophytic fungus Phoma sp. PF2 derived from Artemisia princeps Pamp.

Two new isochromanone derivatives, (3S,4S)-3,8-dihydroxy-6-methoxy-3,4,5-trimethylisochroman-1-one (1) and methyl (S)-8-hydroxy-6-methoxy-5-methyl-4a-(3-oxobutan-2-yl)benzoate (2), together with six known compounds (3‒8) were isolated from the cultures of an endophytic fungus Phoma sp. PF2 obtained from Artemisia princeps. The chemical structures of the isolated compounds were elucidated by interpretation of spectroscopic data (1D, 2D NMR, HRESIMS, and CD) and calculation of ECD. All the isolated compounds (1‒8) showed moderate inhibitory activities on nitric oxide levels in lipopolysaccharide-induced RAW264.7 machrophage cells.

Cytotoxic pterosins from Pteris multifida roots against HCT116 human colon cancer cells.

Two new pterosin glycosides, (2S,3S)-pterosin C 3-O-ß-d-(4'-(E)-caffeoyl)-glucopyranoside (1) and (2S,3S)-pterosin C 3-O-ß-d-(6'-(E)-p-coumaroyl)-glucopyranoside (2), were isolated from Pteris multifida (Pteridaceae) roots along with ten known pterosin compounds (3-12). The chemical structures of the isolated compounds were elucidated by extensive analysis of the 1D, 2D NMR, HRESIMS, and CD spectroscopic data. The cytotoxicities of 1-12 against HCT116 human colorectal cancer cell line were evaluated. Among the isolates, compound 1 showed moderate antiproliferative activity in HCT116 cells with an IC50 value of 8.0±1.7µM. Additionally, 1 induced the upregulation of the caspase-9 and procaspase-9 levels in Western blots and increased the annexin V/propidium iodide (PI)-positive cell population in flow cytometry.

Anti-Neuroinflammatory ent-Kaurane Diterpenoids from Pteris multifida Roots.

Activated microglia are known to be a major source of cellular neuroinflammation which causes various neurodegenerative diseases, including Alzheimer's disease. In our continuing efforts to search for new bioactive phytochemicals against neuroinflammatory diseases, the 80% methanolic extract of Pteris multifida (Pteridaceae) roots was found to exhibit significant NO inhibitory activity in lipopolysaccharide (LPS)-activated BV-2 microglia cells. Three new ent-kaurane diterpenoids, pterokaurane M1 2-O-ß-d-glucopyranoside (4), 2ß,16α-dihydroxy-ent-kaurane 2,16-di-O-ß-d-glucopyranoside (10), and 2ß,16α,17-trihydroxy-ent-kaurane 2-O-ß-d-glucopyranoside (12), were isolated along with nine other known compounds from P. multifida roots. The chemical structures of the new compounds were determined by 1D- and 2D-NMR, HR-ESI-MS, and CD spectroscopic data analysis. Among the isolates, compounds 1 and 7 significantly inhibited NO production in LPS-stimulated BV-2 cells reducing the expression of the cyclooxygenase-2 (COX-2) protein and the level of pro-inflammatory mediators such as prostaglandin E2 (PGE2), tumor necrosis factor (TNF)-α, interleukin (IL)-1ß, and IL-6. These results suggest that ent-kaurane diterpenes from P. multifida could be potential lead compounds that act as anti-neuroinflammatory agents.

Cytotoxic Ceanothane- and Lupane-Type Triterpenoids from the Roots of Ziziphus jujuba.

Ziziphus jujuba, a plant in the family Rhamnaceae, is used in several Asian countries as a food and traditional medicine. Fifteen new ceanothane-type (1-15) and three new lupane-type triterpenoids (16-18) were isolated from the roots of Z. jujuba, as well as 12 previously known triterpenoids (19-30). Their structures were elucidated by 1D and 2D NMR spectroscopic and HR mass spectrometric data analysis. Compounds 12 and 13 were found to possess a rare E-ring γ-lactone structure, and 14 was assigned as the first 2,28-dinorlupane derivative isolated as a natural product. Twenty-five of the isolates were examined for cytotoxicity against human hepatocellular carcinoma HepG2 cells, and compounds 6-8, 14, 17, 23, 25, 29, and 30 showed cytotoxicity with IC50 values ranging from 1.9 to 5.9 µM.

Chemical constituents isolated from Disporum viridescens leaves and their inhibitory effect on nitric oxide production in BV2 microglial cells.

Excessive NO (nitric oxide) has been associated with the pathogenesis of various neurodegenerative diseases including Alzheimer's disease (AD). In our screening system using LPS-activated BV2 microglial cells, the methanolic extract of Disporum viridescens leaves was found to have significant NO inhibitory activity. Bioactivity-guided isolation yielded a new phenylpropanoid characterized as 4-ally-2,6-dimethoxyphenyl 1-O-ß-D-apiofuranosyl (1→6)-ß-D-glucopyranoside (12) with 21 known compounds from the leaves of D. viridescens. Among them, compounds 2 and 4 significantly inhibited NO production. Thus, we further elucidated the anti-inflammatory mechanism of these lignans. Especially, compound 4 inhibited the expression of both inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) through the suppression of the MAPK signaling pathway. Taken together, the anti-inflammatory activities of the active constituents isolated from D. viridescens leaves could have therapeutic potential against neurodegenerative diseases.

Prickly pear cactus (Opuntia ficus indica var. saboten) protects against stress-induced acute gastric lesions in rats.

The protective activity of prickly pear cactus (Opuntia ficus indica var. saboten) fruit juice and its main constituent, betanin, were evaluated against stress-induced acute gastric lesions in rats. After 6 h of water immersion restraint stress (WIRS), gastric mucosal lesions with bleeding were induced in Sprague-Dawley rats. Pretreatment of a lyophilized powder containing O. ficus indica var. saboten fruit juice and maltodextrin (OFSM) and betanin significantly reduced stress lesions (800-1600 mg/kg). Both OFSM and betanin effectively prevented the decrease in gastric mucus content as detected by alcian blue staining. In addition, OFSM significantly suppressed WIRS-induced increases in the level of gastric mucosal tumor necrosis factor-α and myeloperoxidase (MPO). Betanin alone was only effective in decreasing MPO. These results revealed the protective activity of OFSM against stress-induced acute gastric lesions and that betanin may contribute to OFSM's gastric protective activity, at least in part. When OFSM and betanin were taken together, OFSM exerted gastroprotective activity against stress-induced gastric lesions by maintaining gastric mucus, which might be related to the attenuation of MPO-mediated damage and proinflammatory cytokine production.