A rapid thin-layer chromatography bioautographic method for detecting the monoamine oxidase inhibitors in plants

<div><p>It is well known that the isolation of monoamine oxidase (MAO) inhibitors from natural sources is an important strategy for drug development in the treatment of depression, Parkinson's disease and Alzheimer's disease. The present work describes developing a thin-layer chromatography (TLC) bioautographic method for detecting MAO inhibitors from plant extracts. The basic principle of the method is that the enzyme oxidises tryptamine into an aldehyde which in turn reacts with 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyltetrazolium bromide to form a blue formazan which makes a blue-coloured background on the TLC plates. Inhibitors of MAO produced white spots on the background. The new TLC bioautographic method has several advantages such as lower consumption of the enzyme, shorter experimental time, more easily observed background of TLC plate and better reproducibility. The detection limits were 10 ng for several known MAO inhibitors.</p></div

Colletotrichine B, a new sesquiterpenoid from <i>Colletotrichum gloeosporioides</i> GT-7, a fungal endophyte of <i>Uncaria rhynchophylla</i>

<p>One new compound, colletotrichine B (<b>1</b>), was produced by the fungal <i>Colletotrichum gloeosporioides</i> GT-7. The structure of <b>1</b> was elucidated on the basis of spectroscopic analysis and X-ray crystallographic analysis. Monoamine oxidase (MAO), acetylcholinesterase (AChE) and phosphoinositide 3-kinase (PI3Kα) inhibitory activity of <b>1</b> was also evaluated. Compound <b>1</b> showed only AChE inhibiting activity with IC₅₀ value of 38.0 ± 2.67 μg/mL.</p

A new furanosteroid from <i>Talaromyces</i> sp. lgt-4, a fungal endophyte isolated from <i>Tripterygium wilfordii</i>

<p>Wortmannolol (<b>1</b>), a new furanosteroid, along with five known compounds, wortmannolone (<b>2</b>), ergosterol (<b>3</b>), <i>p</i>-hydroxyphenyl ethanol (<b>4</b>), trans-6-dodecene (<b>5</b>), (2<i>Z</i>, 4<i>E</i>) -5-(8-hydroxy-1,5-dimethyl-3-oxo-6-oxabicyclo [3.2.1] octan-8-yl) -3-methylpenta-2,4-dienoic acid (<b>6</b>) were isolated from a fungal endophyte <i>Talaromyces</i> sp<i>.</i> lgt-4. Their structures were elucidated by IR, MS, 1D and 2D NMR spectra. Compound <b>1</b> show weak monoamine oxidase inhibitory activity.</p

Two new cyclic dipeptides from <i>Rhinocladiella</i> sp. lgt-3, a fungal endophyte isolated from <i>Tripterygiun wilfordii</i> Hook

<div><p>Two new cyclic dipeptides, rhinocladin A (<b>1</b>) and rhinocladin B (<b>2</b>), were isolated from a fungal endophyte (<i>Rhinocladiella</i> sp. lgt-3) of <i>Tripterygiun wilfordii</i> Hook. Their structures were elucidated by 1D and 2D NMR spectra. The monoamine oxidase inhibitory activity of <b>1</b> and <b>2</b> was also evaluated.</p></div

Two new compounds, deacetylisowortmins A and B, isolated from an endophytic Fungus, <i>Talaromyces wortmannii</i> LGT-4

<p>Two new compounds, deacetylisowortmins A (<b>1</b>) and B (<b>2</b>), were isolated from <i>Talaromyces wortmannii</i> LGT-4<i>.</i> Their structures were established by 1D and 2D NMR spectra, as well as comparison of the experimental and calculated electronic circular dichroism spectra. Monoamine oxidase and acetylcholinesterase inhibitory activities of <b>1</b> and <b>2</b> were also evaluated.</p

Colletotrichine A, a new sesquiterpenoid from <i>Colletotrichum gloeosporioides</i> GT-7, a fungal endophyte of <i>Uncaria rhynchophylla</i>

<p>One new compound, Colletotrichine A (<b>1</b>), was produced by the fungal <i>Colletotrichum gloeosporioides</i> GT-7. The structure was established by 1D and 2D NMR spectra. Monoamine oxidase (MAO) and acetylcholinesterase (AChE) inhibitory activity of <b>1</b> was also evaluated. Compound <b>1</b> showed AChE-inhibiting activity with IC₅₀ value of 28 μg/mL.</p