lignans and obovatol

(+)/(-)-Diobolignans A-F, six pairs of enantiomeric obovatol dimeric neolignans, were isolated from the bark of Magnolia officinalis var. biloba. (+)/(-)-Diobolignans A to C possessed a dioxane ring between the benzene ring and the propyl side chain, while (+)/(-)-diobolignans D to F possessed a furan ring. Meanwhile, (+)/(-)-diobolignans B and C, as well as (+)/(-)-diobolignans E and F, were two epimeric pairs of enantiomers, respectively. Their structures were determined by extensive analyses of HRESIMS, UV, IR, NMR and electronic circular dichroism (ECD) calculations. The bioassay showed (+)-diobolignan A displayed cytotoxic activities against human cancer cell lines HGC27 and HT29 with the IC

Topics: Biphenyl Compounds; Lignans; Magnolia; Phenyl Ethers; Plant Bark

Topics: Antifungal Agents; Biphenyl Compounds; Botrytis; Dose-Response Relationship, Drug; Lignans; Mannich Bases; Microbial Sensitivity Tests; Molecular Structure; Phenyl Ethers; Structure-Activity Relationship

Six new obovatol trimeric neolignans, houpulignans A-F (1-6) were isolated from the leaves of Magnolia officinalis var. biloba. Their structures were determined on the basis of the interpretation of HRESIMS, NMR data, and electronic circular dichroism (ECD) calculations. Compounds 1 and 2 are the first examples of neolignans derived from three units of obovatol bearing a rare 1,4-benzodioxepane moiety. Compound 3 possesses a benzodihydropyran ring, meanwhile three units of obovatol in 4-6 are connected by an alkyl chain. Compounds 1-3 inhibited NO production in LPS-stimulated RAW264.7 cells with IC

Topics: Animals; Biphenyl Compounds; Lignans; Macrophages; Magnolia; Mice; Nitric Oxide; Phenyl Ethers; Plant Extracts; Plant Leaves; RAW 264.7 Cells

In the course of screening for neuroprotective natural products, Magnoliae Cortex showed potent inhibition of hippocampal neuronal HT22 cell death. Obovatol, honokiol, and magnolol were isolated from the ethanolic extract of Magnoliae Cortex. Isolated compounds obovatol, honokiol, and magnolol were protective against 5mM glutamate-induced cell death. When cells were stressed using glutamate, cell viability decreased to 16.98±4.58% over the control (100.00±10.15%). In contrast, 10 μM obovatol, 10 μM honokiol, and 50 μM magnolol increased cell viability to 91.80±1.70%, 93.59±1.93%, and 85.36±7.40%, respectively. The neuroprotective effects of obovatol and honokiol were attributable to the inhibition of intracellular reactive oxygen species production, followed by protection of the mitochondrial membrane potential (ΔΨm), recovery of Bcl-2 and Bid levels, inhibition of apoptosis-inducing factor expression, and phosphorylation of mitogen-activated protein kinases such as p38 kinases, extracellular signal-regulated kinases, and c-Jun N-terminal kinases. On the contrary, magnolol did not show any significant effect on the ΔΨm and apoptotic factors. Among three compounds, obovatol most strongly scavenged 2,2-diphenyl-1-picrylhydrazyl radicals and inhibited the elevation of intracellular reactive oxygen species levels in glutamate-stressed HT22 cells. These data suggest that obovatol and honokiol may have clinical applications for preventing neurodegenerative disorders.

Topics: Animals; Apoptosis; Apoptosis Inducing Factor; BH3 Interacting Domain Death Agonist Protein; Biphenyl Compounds; Cell Death; Cell Line; Cell Survival; Extracellular Signal-Regulated MAP Kinases; Glutamic Acid; JNK Mitogen-Activated Protein Kinases; Lignans; Magnoliaceae; Membrane Potential, Mitochondrial; Mice; Neurons; Neuroprotective Agents; Oxidative Stress; p38 Mitogen-Activated Protein Kinases; Phenyl Ethers; Phosphorylation; Picrates; Plant Extracts; Reactive Oxygen Species; Signal Transduction

In the course of a study on lignan profiles of tropical and subtropical members of the Magnoliaceae, Magnolia garrettii, an evergreen tree known from northern Thailand, Vietnam, and southern Yunnan (China), was investigated. The work resulted in the isolation of two dimeric lignans from the dichloromethane extract of the leaves of M. garrettii, garrettilignan A (1) and garrettilignan B (2), each substituted with two additional p-allylphenolic moieties. Garrettilignans A (1) and B (2) represent new skeletal types within the neolignan class. Additionally, four known neolignans, magnolol, honokiol, 4'-methylhonokiol, and obovatol, were identified.

Topics: Austria; Biphenyl Compounds; Lignans; Magnolia; Molecular Structure; Nuclear Magnetic Resonance, Biomolecular; Phenyl Ethers; Plant Leaves

To characterize antifungal principles from the methanol extract of Magnolia obovata and to evaluate their antifungal activities against various plant pathogenic fungi.. Four neolignans were isolated from stem bark of M. obovata as antifungal principles and identified as magnolol, honokiol, 4-methoxyhonokiol and obovatol. In mycelial growth inhibition assay, both magnolol and honokiol displayed more potent antifungal activity than 4-methoxyhonokiol and obovatol. Both magnolol and honokiol showed similar in vivo antifungal spectrum against seven plant diseases tested; both compounds effectively suppressed the development of rice blast, tomato late blight, wheat leaf rust and red pepper anthracnose. 4-Methoxyhonokiol and obovatol were highly active to only rice blast and wheat leaf rust respectively.. The extract of M. obovata and four neolignans had potent in vivo antifungal activities against plant pathogenic fungi.. Neolignans from Magnolia spp. can be used and suggested as a novel antifungal lead compound for the development of new fungicide and directly as a natural fungicide for the control of plant diseases such as rice blast and wheat leaf rust.

Topics: Allyl Compounds; Antifungal Agents; Biphenyl Compounds; Chromatography, Thin Layer; Fungi; Lignans; Magnolia; Microbial Sensitivity Tests; Mycelium; Phenyl Ethers; Plant Bark; Plant Diseases; Plant Extracts