Publications by authors named "Wen-Bo Han"

A chemical investigation of the soil-derived fungus sp. XZ8 led to the isolation of five new indole alkaloids, trichindoles A-E (-), with diverse architectures, along with seven known analogues (-). Their structures were elucidated by extensive spectroscopic data analysis, and their absolute configurations were determined by single-crystal X-ray diffraction and modified Mosher's method.

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Four undescribed cytochalasins (1-4), three undescribed orsellinic acid derivatives (5-7) and two known metabolites including methyl lecanorate (8) and methyl orsellinate (9) were isolated from the solid-state cultivation of a soil-derived fungus Trichocladium asperum SQ2-3 collected in Qinghai-Tibet Plateau. Their structures were elucidated by analysis of NMR (1D and 2D) and mass spectrometry data. The absolute configurations of 1-7 were assigned by a combination of the modified Mosher's method, microscale derivatization and Mo(OAc)-induced circular dichroism experiment.

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Co-cultivation of isopod-associated fungi sp. SF09 and SF09A led to the reciprocal induction of thirteen new compounds (- and -) with diverse architectures. Importantly, compounds and are rare fungal sesquiterpene-saccharide hybrids incorporating a xylopyranose moiety, compound (±)- represents the first example of a natural linear sesquiterpene racemate, and compound is a rare α-pyrone derivative with a xylopyranose motif.

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Eighteen nitrogen-containing compounds (-) were isolated from cultures of the lichen-associated collected from the Qinghai-Tibet Plateau, including seven phenazine derivatives with three new ones, named subphenazines A-C (-), two new furan pyrrolidones (-), and nine known alkaloids. The structures were elucidated by spectroscopic data analysis, and absolute configurations were determined by single-crystal X-ray diffraction and ECD calculations. The phenazine-type derivatives, in particular compound , exhibited significantly better antineuroinflammatory activity than other isolated compounds (-).

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Inhibition of oxidative stress and ferroptosis is currently considered to be a promising therapeutic approach for neurodegenerative diseases. Herpotrichones, a class of compounds derived from insect symbionts, have shown potential for neuroprotective activity with low toxicity. However, the specific mechanisms through which herpotrichones exert their neuroprotective effects remain to be fully elucidated.

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Glioblastoma is the prevailing and highly malignant form of primary brain neoplasm with poor prognosis. Exosomes derived from glioblastoma cells act a vital role in malignant progression via regulating tumor microenvironment (TME), exosomal tetraspanin protein family members (TSPANs) are important actors of cell communication in TME. Among all the TSPANs, TSPAN6 exhibited predominantly higher expression levels in comparison to normal tissues.

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, an endophytic fungus associated with the herbal medicine , produced four new polyketides, aspeversins A-D (1-2 and 5-6) and four known compounds, -methylaverufin (2), aversin (3), varilactone A (7) and spirosorbicillinol A (8). Their structures were elucidated by extensive spectroscopic data analysis, and their absolute configurations were determined by calculated electronic circular dichroism (ECD) and Mo(AcO)-induced CD data. Compound 5 was found to exhibit α-glucosidase inhibitory activity with an IC value of 25.

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Nigrograna sp. LY66, an endophytic fungus associated with the herbal medicinal plant Clematis shensiensis, produced four undescribed steroids, nigergostanes A-D (1-4), including an unusual ketal-containing nigergostane (1), and four undescribed sesquiterpenoids decorated with cyclohexanone motifs, nigbisabolanes A-D (7-10), along with three known compounds, 23R-hydroxy-(20Z,24R)-ergosta-4,6,8(14),20(22)-tetraen-3-one (5), ergosta-5,7,22-trien-3β-ol (6), and curculonone A (11). The structures and absolute configurations of these undescribed compounds were confirmed using spectroscopic data (NMR and HRESIMS), modified Mosher's method, and ECD experiments.

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sp., a lichen-associated fungus, produced six skeletally new dimeric spiciferones (-) and four known metabolites (-). The new structures were elucidated by spectroscopic analysis, and their absolute configurations were determined by electronic circular dichroism calculations.

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Tricrilactones A-H (1-8), a new family of oligomeric 10-membered macrolides featuring collectively five unique ring skeletons, were isolated from a hitherto unexplored fungus, Trichocladium crispatum. Compounds 1 and 7 contain two unconventional bridged (aza)tricyclic core skeletons, 2, 3, 5, and 6 share an undescribed tetracyclic 9/5/6/6 ring system, 4 bears an uncommon 9/5/6/10/3-fused pentacyclic architecture, and 8 is a dimer bridged by an unexpected C-C linkage. Their structures, including absolute configurations, were elucidated by spectroscopic analysis, quantum chemical calculations, and X-ray diffraction analysis.

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Article Synopsis
  • The rise of superbugs like MRSA poses significant health risks, particularly in hospital settings, urging the need for new antimicrobial solutions.
  • Polyketides, known for their antimicrobial properties, are explored in this study through a strain isolated from the Qinghai-Tibet Plateau, utilizing genome mining and metabolic analysis to identify potential antibacterial compounds.
  • Results led to the discovery of several antimicrobial pigment compounds and establish a relationship between their structure and activity, highlighting the effectiveness of combining genomic and metabolic techniques in finding new bioactive metabolites.
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In this research, twenty aromatic and branched aliphatic polyketides, including seven previously undescribed butenolide derivatives, piterriones A-G and one known analogue, along with twelve known altenusin derivatives, were isolated from the isopod-associated fungus Pidoplitchkoviella terricola. Their structures were elucidated by analysis of NMR (1D and 2D) and mass spectrometry data, and their absolute configurations were determined by Mosher's method, microscale derivatization, and comparison of their specific rotations and ECD spectra. Dihydroaltenuene B exhibited mushroom tyrosinase inhibitory activity with an IC value of 38.

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Fourteen eremophilane sesquiterpenoids (-), including nine new congeners, septoreremophilanes A-I (-), together with three known sesquiterpenes (-), two known tetralone derivatives (, ), and two known cholesterol analogues (, ), were isolated from the endophytic fungus . Compounds - and belong to the family of the highly oxygenated eremophilane sesquiterpenoids with a 6/6/5 tricyclic system and bearing a hemiacetal moiety. The inhibitions of all metabolites against eight bacteria were estimated , and nine new metabolites (-) were tested for antineuroinflammatory activity.

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Sixteen metabolites, including seven C-alkylated salicylaldehyde derivatives (-) and nine prenylated indole alkaloids (-), three of which are new, namely, asperglaucins A and B ( and ) and neoechinulin F (), were separated from the endolichenic fungus SQ-8. Asperglaucin A () represents an unusual phthalide-like derivative with a benzo[]thiophen-1(3)-one scaffold. All compounds were assessed for antibacterial, antineuroinflammatory, and antioxidant activities.

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Two new sterpurane sesquiterpenoids named sterpurol D (1) and sterpurol E (2), and one skeletally new sesquiterpene, cryptomaraone (3), bearing a 5,6-fused bicyclic ring system, along with five known ones, sterpurol A (4), sterpurol B (5), paneolilludinic Acid (6), murolane-2α, 9β-diol-3-ene (7) and (-)-10,11-dihydroxyfarnesol (8) were isolated from an endolichenic fungus Cryptomarasmius aucubae. The structures of the new compounds were elucidated by analysis of NMR spectroscopic spectra and HRESIMS data. The absolute configurations of 1 and 2 were established by spectroscopic data analysis and comparison of specific optical rotation, as well as the biosynthetic consideration.

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Fifteen eremophilane sesquiterpenoids, including nine undescribed congeners, septeremophilane A-H, and chaetopenoid G, together with four conjugated unsaturated polyketide fatty acids, including an undescribed derivative, were isolated from cultures of the fungus Septoria rudbeckiae, a plant pathogenic fungus isolated from the halophyte Karelinia caspia. Septeremophilane A represents an unprecedented tetranor-eremophilane sesquiterpenoid with an α,β-unsaturated δ-lactone unit bearing a hemiacetal group, while septeremophilane B-H possesses a trinor-eremophilane skeleton. Their structures and absolute configurations were established based on spectroscopic data (NMR and HRESIMS), quantum chemical calculations and electronic circular dichroism (ECD) experiments.

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Article Synopsis
  • * The structures of these compounds were determined using advanced techniques like spectroscopy, single-crystal X-ray diffraction, and ECD calculations.
  • * Some of the new compounds showed strong inhibitory activity against mushroom tyrosinase, proving to be more effective than the standard control, kojic acid, with a notable interaction revealed through molecular-docking analysis.
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Article Synopsis
  • Two new metabolites, eucalyptacid A and eucalactam B, were discovered alongside six known compounds from the endophytic fungus KY-9, isolated from rice cultures.
  • The structures of these compounds were confirmed using NMR, ESIMS, and chemical methods, revealing interesting features like a rare fatty acid and a unique cyclic depsipeptide.
  • Some isolated compounds showed antifungal activity against certain plant pathogens, suggesting strain KY-9 could be useful for developing biological control agents against fungal infections.
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Indolizidine alkaloids such as anticancer drugs vinblastine and vincristine are exceptionally attractive due to their widespread occurrence, prominent bioactivity, complex structure, and sophisticated involvement in the chemical defense for the producing organisms. However, the versatility of the indolizidine alkaloid biosynthesis remains incompletely addressed since the knowledge about such biosynthetic machineries is only limited to several representatives. Herein, we describe the biosynthetic gene cluster (BGC) for the biosynthesis of curvulamine, a skeletally unprecedented antibacterial indolizidine alkaloid from sp.

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Herpotrichones A and B ( and ), two intermolecular [4 + 2] adducts with an unprecedented pentacyclic 6/6/6/6/3 skeleton, were isolated from sp. SF09, an isopod-associated fungus, along with a new shunt product protrichone (). Their structures were elucidated by the analysis of spectroscopic data, residual dipolar coupling (RDC)-based computer-assisted 3D structure elucidation (CASE-3D), and single-crystal X-ray diffraction in combination with electronic circular dichroism (ECD) calculations.

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Bioactivity-guided isolation of the cultures of the endophytic fugus Xylaria sp. XC-16 residing in a deciduous tree Toona sinensis led to the discovery of four new allelochemicals (1-4), including three cytochalasins, epoxycytochalasin Z (1), epoxycytochalasin Z (2), and epoxyrosellichalasin (3), and an abietane-type diterpenoid, hydroxyldecandrin G (4), along with four known analogues, 10-phenyl-[12]-cytochalasins Z (5) and Z (6), cytochalasin K (7), and cytochalasin E (8). The structures of these compounds were elucidated by comprehensive spectroscopic methods, and their absolute configurations were determined by electronic circular dichroism (CD) and X-ray diffraction.

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Four new secondary metabolites, chaetosemins G-J (1-4), along with 11 known ones (5-15) were isolated from the culture of C. seminudum C208 and Chaetomium sp. C521.

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Patients with diabetes, obesity, and hyperlipidemia are all high-risk groups for fatty liver; however, the mechanism of fatty liver formation is not completely understood. Studies have indicated that abnormal fat metabolism, oxidative stress, and insulin resistance are positively correlated with peroxidation and abnormal cytokine production. Recent studies have revealed that Solanum nigrum extracts (SNE) possess anti-inflammatory, antioxidation, antihyperlipidemia, and liver protection abilities.

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Curvularia sp. IFB-Z10, a white croaker-associated fungus, generates a skeletally unprecedented indolizine alkaloid named curindolizine (1), which displays an anti-inflammatory action in lipopolyssacharide (LPS)-induced RAW 264.7 macrophages with an IC50 value of 5.

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The endophytic fungus Guignardia mangiferae isolated from Ilex cornuta leaves was shown to produce a family of meroterpenes with toll-like receptor 3 regulating activity (1-9), of which 1-3 possessed new structures. The absolute stereochemistry of 1-3 was assigned through a combination of nuclear magnetic resonance experiments, chemical derivation, CD spectra, and single-crystal X-ray diffraction analyses (CuK α ). The precursor labeled cultivation suggests that these meroterpenes are most likely assembled through terpenoid-shikimate pathways.

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