Chemical Constituents of the Stems of Spatholobus parviflorus and Their Cholinesterase Inhibitory Activity

Placovinane: 1″β-Ethoxy-6,4′-dimethoxy-3″,3″-dimethyl-1″,2″-dihydropyranoisoflavone, a New Isoflavone Derivative

Isoflavonoids possess a 3-phenylchroman skeleton and are the biologically active secondary metabolites of various plants that are used for different health promoting and restoring effects through a variety of mechanisms. Chromatographic separation of the n-hexane extract from the stems of Placolobium vietnamense led to the isolation of a new isoflavone derivative, placovinane (1), together with four known compounds (2–5). The structures of isolated compounds were identified from their spectroscopic data and by comparison with the literature. All isolated compounds were evaluated for their α-glucosidase inhibition. They all exhibited potent α-glucosidase inhibition with IC50 values ranging from 11.0 to 87.3 µM, which was significantly less than the positive control acarbose (IC50 179 µM). The cytotoxicity of 1 was evaluated against KB, Hep G2, and MCF7 cell lines, and displayed weak cytotoxicity toward KB and Hep G2 cell lines, with the IC50 values of 89.6 and 93.8 μM, respectively.

Genus Spatholobus: a comprehensive review on ethnopharmacology, phytochemistry, pharmacology, and toxicology

Edible medicinal plants are important sources for the development of health beneficial products and drugs. Several species of the genus Spatholobus are considered as medicinal and food homologous plants in various Asian countries for the treatment of menstrual pain, anemia, paralysis, arthralgia, etc. Regarding this genus, mounting investigations on different aspects have been conducted; however, a comprehensive review about these findings is yet to be compiled. Herein, we reviewed the up-to-date information on the botanical description, distribution, ethnopharmacology, phytochemistry, pharmacology, and toxicology of the Spatholobus species for the first time to support their development potential. Thus far, 175 phytochemicals have been isolated, and flavonoids are the predominant constituents. Furthermore, 141 compounds show the ideal characteristic behavior of a drug-like molecule. Besides, the compounds and crude extracts of this genus have been demonstrated to exert a wide range of in vitro and in vivo bioactivities, such as antitumor activity, antioxidant activity, antiinflammatory activity, antiischemic activity, antimicrobial activity, and neuroprotective activity. Toxicity studies have revealed that Spatholobus species seem to have no apparent toxic effects. Even so, the need for in-depth studies to reveal the scientific connotation of the widely documented traditional actions, the structure-activity relationship of the bioactive compounds, and the systematic toxic reactions are warranted, and also to provide essential evidence for the beneficial use of Spatholobus plants and developing novel health care products and therapeutic drug from this genus.

Xylaria feejeensis, SRNE2BP a Fungal Endophyte with Biocontrol Properties to Control Early Blight and Fusarium Wilt Disease in Tomato and Plant Growth Promotion Activity

Over the past decade endophytic fungi have been known as a source of secondary metabolites with the ability to act as a biocontrol agents. Xylaria feejeensis, SRNE2BP a fungal endophyte isolated from a mangrove tree exhibited antagonistic activity against two fungal pathogens of tomato. Crude extract of X. feejeensis SRNE2BP significantly inhibited Fusarium oxysporum MFLUCC 19-0157 growth as shown approximately 60-75% in in vitro and in situ assays. Both assays showed that the endophyte also inhibited mycelium formation of Alternaria solani MFLUCC 19-0093 by 56% and 87%, respectively. The half maximal inhibitory concentration of X. feejeensis SRNE2BP crude extract against A. solani and F. oxysporum was approximately 7 mg/l. Crude extract and mycelium of X. feejeensis SRNE2BP showed potential in controlling early blight and fusarium wilt disease in tomato, respectively. Seedlings from seeds coated with crude extract of X. feejeensis SRNE2BP had lower disease severity (31.71%) of early blight disease compared to un-treated seeds (57.13%). Soil treated with 10% endophytic mycelium not only reduced fusarium wilt in tomato plant (55.55% severity compared with 91.66% in un-treated soil) but also promoted seed emergence and growth of tomato. Structure analysis revealed that 12 secondary metabolites, especially mellein derivatives, are major components of the crude extract of X. feejeensis SRNE2BP. These compounds could be responsible for antifungal activities; however, further study is required. Our findings strongly suggest that colonization with this fungal endophyte can be beneficial to the host plant especially with regards to plant growth promotion and broad antagonistic activity.

Isolation and characterization of chemical constituents from Chaerophyllum bulbosum roots and their enzyme inhibitory and antioxidant effects

Isolation and bioactive effects of the roots of Chaerophyllum bulbosum L. were firstly investigated herein. Enzyme (acetylcholinesterase, butyrylcholinesterase, urease, α-amylase, α-glucosidase, and tyrosinase) inhibitory effects of C. bulbosum root extracts were tested. Three known compounds, n-heptadecanyl eicosanoate (1), stigmasterol (2), and β-sitosterol-3-O-β-d-glucopyranoside (3) were isolated from C. bulbosum. Antioxidant and enzyme inhibitory effects of isolated compounds were investigated. The hexane extract (IC₅₀: 349.58 ± 0.06 μg/mL) displayed a higher α-glucosidase inhibitory effect than the standard (IC₅₀: 378.66 ± 0.14 μg/mL). The best inhibitory effect was found in compound 2 on AChE (46.40 ± 0.31%), BChE (56.41 ± 0.54%), and urease (92.47 ± 0.11%); compound 1 on α-amylase (22.27 ± 0.61%); and compound 3 on α-glucosidase (12.43 ± 0.25%) and tyrosinase (19.00 ± 0.16%). All isolated compounds showed moderate antioxidant effects in all assays. This study contributes to the therapeutic uses of Chaerophyllum roots and emphasizes the value of C. bulbosum species for the development of novel therapeutic agents.

Antibacterial and cytotoxic activities of phenolic constituents from the stem extracts of Spatholobus parviflorus

A new 2-arylbenzofuran, spathobenzofuran (1), together with ten known compounds including a 2-arylbenzofuran, three pterocarpans and six isoflavones were isolated from the acetone crude extract of the stems of Spatholobus parviflorus. All compounds were characterised by spectroscopic methods. Compound 4 was active (MIC 8 µg/mL) against Gram-negative Pseudomonas aeruginosa TISTR 781 while compound 2 had modest activity against Gram-positive Staphylococcus aureus TISTR 1466 with a MIC value of 16 µg/mL. All isolated compounds showed no cytotoxicity against Vero and KB cells.