Function analysis and characterisation of a novel chitinase, MdCht9, in Musca domestica.

Insect chitinases have been proposed as potential targets for pest control. In this work, a novel group IV chitinase gene, MdCht9, from Musca domestica was found to have multiple functions in the physiological activity, including chitin regulation, development and antifungal immunity. The MdCht9 gene was cloned and sequenced, its phylogeny was analysed and its expression was determined in normal and 20E treated larvae. Subsequently, RNA interference (RNAi)-mediated MdCht9 knockdown was performed, followed by biochemical assays, morphological observations and transcriptome analysis. Finally, the recombinant protein MdCht9 (rMdCht9) was purified and tested for anti-microbial activity and enzyme characteristics. The results showed that MdCht9 consists of three domains, highly expressed in a larval salivary gland. RNAi silencing of MdCht9 resulted in significant down-regulation of chitin content and expression of 15 chitin-binding protein (CBP) genes, implying a new insight that MdCht9 might regulate chitin content by influencing the expression of CBPs. In addition, more than half of the lethality and partial wing deformity appeared due to the dsMdCht9 treatment. In addition, the rMdCht9 exhibited anti-microbial activity towards Candida albicans (fungus) but not towards Escherichia coli (G-) or Staphylococcus aureus (G+). Our work expands on previous studies of chitinase while providing a potential target for pest management.

Heterodimers of Aromadendrane Sesquiterpenoid with Benzoquinone from the Chinese Liverwort Mylia nuda.

Mylnudones A-G (1-7), unprecedented 1,10-seco-aromadendrane-benzoquinone-type heterodimers, and a highly rearranged aromadendrane-type sesquiterpenoid (8), along with four known analogs (9-12), were isolated from the liverwort Mylia nuda. Compounds 1-6 and 7, bearing tricyclo[6.2.1.02,7] undecane and tricyclo[5.3.1.02,6] undecane backbones, likely formed via a Diels-Alder reaction and radical cyclization, respectively. Their structures were determined by spectroscopic analysis, computational calculation, and single-crystal X-ray diffraction analysis. Dimeric compounds displayed cytoprotective effects against glutamic acid-induced neurological deficits.

Efficient Production of Flavonoid Glucuronides in Escherichia coli Using Flavonoid O-Glucuronosyltransferases Characterized from Marchantia polymorpha.

As a model liverwort, Marchantia polymorpha contains various flavone glucuronides with cardiovascular-promoting effects and anti-inflammatory properties. However, the related glucuronosyltransferases have not yet been reported. In this study, two bifunctional UDP-glucuronic acid/UDP-glucose:flavonoid glucuronosyltransferases/glucosyltransferases, MpUGT742A1 and MpUGT736B1, were identified from M. polymorpha. Extensive enzymatic assays found that MpUGT742A1 and MpUGT736B1 exhibited efficient glucuronidation activity for flavones, flavonols, and flavanones and showed promiscuous regioselectivity at positions 3, 6, 7, 3', and 4'. These enzymes catalyzed the production of a variety of flavonoid glucuronides with medicinal value, including apigenin-7-O-glucuronide and scutellarein-7-O-glucuronide. With the use of MpUGT736B1, apigenin-4'-O-glucuronide and apigenin-7,4'-di-O-glucuronide were prepared by scaled-up enzymatic catalysis and structurally identified by NMR spectroscopy. MpUGT742A1 also displayed glucosyltransferase activity on the 7-OH position of the flavanones using UDP-glucose as the sugar donor. Furthermore, we constructed four recombinant strains by combining the pathway for increasing the UDP-glucuronic acid supply with the two novel UGTs MpUGT742A1 and MpUGT736B1. When apigenin was used as a substrate, the extracellular apigenin-4'-O-glucuronide and apigenin-7,4'-di-O-glucuronide production obtained from the Escherichia coli strain BB2 reached 598 and 81 mg/L, respectively. Our study provides new candidate genes and strategies for the biosynthesis of flavonoid glucuronides.

GhiPLATZ17 and GhiPLATZ22, zinc-dependent DNA-binding transcription factors, promote salt tolerance in upland cotton.

KEY MESSAGE: The utilization of transcriptome analysis, functional validation, VIGS, and DAB techniques have provided evidence that GhiPLATZ17 and GhiPLATZ22 play a pivotal role in improving the salt tolerance of upland cotton. PLATZ (Plant AT-rich sequences and zinc-binding proteins) are known to be key regulators in plant growth, development, and response to salt stress. In this study, we comprehensively analyzed the PLATZ family in ten cotton species in response to salinity stress. Gossypium herbaceum boasts 25 distinct PLATZ genes, paralleled by 24 in G. raimondii, 25 in G. arboreum, 46 in G. hirsutum, 48 in G. barbadense, 43 in G. tomentosum, 67 in G. mustelinum, 60 in G. darwinii, 46 in G. ekmanianum, and a total of 53 PLATZ genes attributed to G. stephensii. The PLATZ gene family shed light on the hybridization and allopolyploidy events that occurred during the evolutionary history of allotetraploid cotton. Ka/Ks analysis suggested that the PLATZ gene family underwent intense purifying selection during cotton evolution. Analysis of synteny and gene collinearity revealed a complex pattern of segmental and dispersed duplication events to expand PLATZ genes in cotton. Cis-acting elements and gene expressions revealed that GhiPLATZ exhibited salt stress resistance. Transcriptome analysis, functional validation, virus-induced gene silencing (VIGS), and diaminobenzidine staining (DAB) demonstrated that GhiPLATZ17 and GhiPLATZ22 enhance salt tolerance in upland cotton. The study can potentially advance our understanding of identifying salt-resistant genes in cotton.

Recent advances in the degradation efficacy and mechanisms of mycotoxins in food by atmospheric cold plasma.

Food contaminated by mycotoxins has become a worldwide public problem with political and economic implications. Although a variety of traditional methods have been used to eliminate mycotoxins from agri-foods, the results have been somewhat less than satisfactory. As an emerging non-thermal processing technology, atmospheric cold plasma (ACP) has great potential for food decontamination. Herein, this review mainly presents the degradation efficiency of ACP on mycotoxins in vitro and agri-foods as well as its possible degradation mechanisms. Meanwhile, ACP effects on food quality, factors affecting the degradation efficiency and the toxicity of degradation products are also discussed. According to the literatures, ACP could efficiently degrade many mycotoxins (e.g., aflatoxin, deoxynivalenol, zearalenone, ochratoxin A, fumonisin, and T-2 toxin) both in vitro and various foods (e.g., hazelnut, peanut, maize, rice, wheat, barley, oat flour, and date palm fruit) with little effects on the nutritional and sensory properties of food. The degradation efficacy was dependent on many factors including ACP treatment parameter, working gas, mycotoxin property, and food substrate. The mycotoxin degradation by ACP was mainly attributed to the reactive oxygen and nitrogen species in ACP, which can damage the chemical bonds of mycotoxins, consequently reducing the toxicity of mycotoxins.

Detoxification of DON-induced hepatotoxicity in mice by cold atmospheric plasma.

Deoxynivalenol (DON) is one of the most common mycotoxins distributed in food and feed, which causes severe liver injury in humans and animals. Cold atmospheric plasma (CAP) has received much attention in mycotoxin degradation due to the advantages of easy operation, high efficiency, and low temperature. So far, the majority of studies have focused on the degradation efficiency and mechanism of CAP on DON, while there is still little information available on the hepatotoxicity of DON after CAP treatment. Herein, this study aimed to investigate the effect of CAP on DON-induced hepatotoxicity both in vitro and in vivo and its underlying mechanisms. The results showed that 120-s CAP treatment achieved 97 % degradation of DON. The vitro hepatotoxicity of DON in L02 cells was significantly reduced with CAP treatment time. Meanwhile, CAP markedly alleviated DON-induced liver injury in mice including the balloon-like degeneration of liver tissues and elevation of AST and ALP level. The underlying mechanism for CAP detoxification of DON-induced hepatotoxicity was further elucidated. The results showed that DON caused severe oxidative stress in cells by suppressing the antioxidant signaling pathway of Nrf2/HO-1/NQO-1, consequently leading to mitochondrial dysfunction and cell apoptosis, accompanied by cellular senescence and inflammation. CAP blocked DON inhibition on the Nrf2/HO-1/NQO-1 signaling pathway through the efficient degradation of DON, accordingly alleviating the oxidative stress and liver injury induced by DON. Therefore, CAP is an effective method to eliminate DON hepatotoxicity, which can be applied in the detoxification of mycotoxin-contaminated food and feed to ensure human and animal health.

Genome-Wide Identification, Characterization, and Expression Analysis of Four Subgroup Members of the GH13 Family in Wheat (Triticum aestivum L.).

The glycoside hydrolase 13 (GH13) family is crucial for catalyzing α-glucoside linkages, and plays a key role in plant growth, development, and stress responses. Despite its significance, its role in plants remains understudied. This study targeted four GH13 subgroups in wheat, identifying 66 GH13 members from the latest wheat database (IWGSC RefSeq v2.1), including 36 α-amylase (AMY) members, 18 1,4-α-glucan-branching enzyme (SBE) members, 9 isoamylase (ISA) members, and 3 pullulanase (PU) members. Chromosomal distribution reveals a concentration of wheat group 7 chromosomes. Phylogenetic analysis underscores significant evolutionary distance variations among the subgroups, with distinct molecular structures. Replication events shaped subgroup evolution, particularly in regard to AMY members. Subcellular localization indicates AMY member predominance in extracellular and chloroplast regions, while others localize solely in chloroplasts, confirmed by the heterologous expression of TaSEB16 and TaAMY1 in tobacco. Moreover, 3D structural analysis shows the consistency of GH13 across species. Promoter cis-acting elements are suggested to be involved in growth, stress tolerance, and starch metabolism signaling. The RNA-seq data revealed TaGH13 expression changes under drought and submergence stress, and significant expression variation was observed between strong and weak gluten varieties during seed germination using quantitative real-time PCR (qRT-PCR), correlating with seed starch content. These findings demonstrate the pivotal role of GH13 family gene expression in wheat germination, concerning variety preference and environmental stress. Overall, this study advances the understanding of wheat GH13 subgroups, laying the groundwork for further functional studies.

CD58 acts as a tumor promotor in hepatocellular carcinoma via activating the AKT/GSK-3ß/ß-catenin pathway.

BACKGROUND: Hepatocellular carcinoma (HCC) is one of the most prevalent malignancies worldwide because of rapid progression and high incidence of metastasis or recurrence. Accumulating evidence shows that CD58-expressing tumor cell is implicated in development of various cancers. The present study aimed to reveal the functional significance of CD58 in HCC progression and the underlying mechanisms. METHODS: Immunohistochemical staining (IHC), and western blotting were used to detect the expression of CD58 in HCC tissues and cells. The levels of sCD58 (a soluble form of CD58) in the cell supernatants and serum were assessed by ELISA. CCK-8, colony formation, and xenograft assays were used to detect the function of CD58 on proliferation in vitro and in vivo. Transwell assay and sphere formation assay were performed to evaluate the effect of CD58 and sCD58 on metastasis and self-renewal ability of HCC cells. Western blotting, immunofluorescence (IF), TOP/FOP Flash reporter assay, and subcellular fractionation assay were conducted to investigate the molecular regulation between CD58/sCD58 and AKT/GSK-3ß/ß-catenin axis in HCC cells. RESULTS: CD58 was significantly upregulated in HCC tissues. Elevation of CD58 expression correlated with more satellite foci and vascular invasion, and poorer tumor-free and overall survival in HCC patients. Higher sCD58 levels were in HCC patients' serum compared to healthy individuals. Functionally, CD58 promotes the proliferation of HCC cells in vitro and in vivo. Meanwhile, CD58 and sCD58 induce metastasis, self-renewal and pluripotency in HCC cells in vitro. Mechanistically, CD58 activates the AKT/GSK-3ß/ß-catenin signaling pathway by increasing phosphorylation of AKT or GSK3ß signaling, promoting expression of Wnt/ß-catenin target proteins and TCF/LEF-mediated transcriptional activity. Furthermore, AKT activator SC-79 or inhibitor LY294002 abolished the inhibitory effect of CD58 silencing on the proliferation, metastasis, and stemness of HCC cells. CONCLUSIONS: Taken together, CD58 promotes HCC progression and metastasis via activating the AKT/GSK-3ß/ß-catenin pathway, suggesting that CD58 is a novel prognostic biomarker and therapeutic target for HCC.

Interaction of PKR with STCS1: an indispensable step in the biosynthesis of lunularic acid in Marchantia polymorpha.

Unlike bibenzyls derived from the vascular plants, lunularic acid (LA), a key precursor for macrocyclic bisbibenzyl synthesis in nonvascular liverworts, exhibits the absence of one hydroxy group within the A ring. It was hypothesized that both polyketide reductase (PKR) and stilbenecarboxylate synthase 1 (STCS1) were involved in the LA biosynthesis, but the underlined mechanisms have not been clarified. This study used bioinformatics analysis with molecular, biochemical and physiological approaches to characterize STCS1s and PKRs involved in the biosynthesis of LA. The results indicated that MpSTCS1s from Marchantia polymorpha catalyzed both C2→C7 aldol-type and C6→C1 Claisen-type cyclization using dihydro-p-coumaroyl-coenzyme A (CoA) and malonyl-CoA as substrates to yield a C6-C2-C6 skeleton of dihydro-resveratrol following decarboxylation and the C6-C3-C6 type of phloretin in vitro. The protein-protein interaction of PKRs with STCS1 (PPI-PS) was revealed and proved essential for LA accumulation when transiently co-expressed in Nicotiana benthamiana. Moreover, replacement of the active domain of STCS1 with an 18-amino-acid fragment from the chalcone synthase led to the PPI-PS greatly decreasing and diminishing the formation of LA. The replacement also increased the chalcone formation in STCS1s. Our results highlight a previously unrecognized PPI in planta that is indispensable for the formation of LA.

Simulation of the expanding universe in hyperbolic metamaterials.

The particle horizon represents the boundary between observable and unobservable regions of the universe, which changes as the universe expands. Based on transformation optics, hyperbolic electromagnetic metamaterials can be utilized to simulate metrics with different signs due to their unique anisotropic properties. In this paper, we use hyperbolic metamaterials to visually depict the variation of the particle horizon under three models of an expanding universe (open, flat, and closed) by substituting one-dimensional time with one-dimensional space. The good agreement between theory and simulation confirms that hyperbolic metamaterials are excellent for simulating space-times, suggesting their potential as a new platform for cosmological analogies.

A simulation study on the phase transition behavior of solid nitrogen under extreme conditions.

There are numerous examples of materials that exhibit interesting phenomena at extremely low temperatures, but the difficulty of obtaining absolute zero at high pressure in experiments is sometimes a hurdle to reveal the exact explanation of these low temperature phenomena. Based on the calculations of the phonon spectrum and Gibbs free energy of α-N2 and γ-N2 under different pressures, we found that solid nitrogen at 0 K showed a re-entrant phase transition under continuously increasing pressure. The extremely low temperature in this pressure range turned out to be the main external condition for inducing phase transition as well as phase reversal.

Composition and structural characteristics of compressed alkaline earth metal hydrides.

The metallization of alkaline earth metal hydrides offers a way to achieve near-room temperature superconductivity. In order to explore the metallization mechanism of these hydrides under pressure, a detailed understanding of the property changes of alkaline earth metal hydrides is required. Based on first-principles calculations, we have systematically investigated the dihydrides (XH2, X = Be, Mg, Ca, Sr, Ba) and tetrahydrides (XH4, X = Mg, Ca, Sr, Ba) of alkaline earth metals, respectively. By applying external pressure, we show that the structures of these alkaline earth metal hydrides undergo a series of phase transitions. Moreover, we investigate how the size of the bandgap decreases and eventually closes and reveal the role of electronegativity of metal elements in the critical pressure of hydride metallization. Remarkably, the hydrogen units (H6 or H8) formed in XH4 can accelerate the metallization process. The increase of the energy level difference in hydrogen units promotes the electroacoustic coupling effect, which is conducive to realization of high superconducting transition temperature (Tc). Our theoretical findings identify MgH4-I4/mmm as having potential to be a high-temperature superconductor and provide unusual ideas for the search of unknown high-temperature superconducting materials.

The Role of Reactive Oxygen Species in Plant Response to Radiation.

Radiation is widespread in nature, including ultraviolet radiation from the sun, cosmic radiation and radiation emitted by natural radionuclides. Over the years, the increasing industrialization of human beings has brought about more radiation, such as enhanced UV-B radiation due to ground ozone decay, and the emission and contamination of nuclear waste due to the increasing nuclear power plants and radioactive material industry. With additional radiation reaching plants, both negative effects including damage to cell membranes, reduction of photosynthetic rate and premature aging and benefits such as growth promotion and stress resistance enhancement have been observed. ROS (Reactive oxygen species) are reactive oxidants in plant cells, including hydrogen peroxide (H2O2), superoxide anions (O2•-) and hydroxide anion radicals (·OH), which may stimulate the antioxidant system of plants and act as signaling molecules to regulate downstream reactions. A number of studies have observed the change of ROS in plant cells under radiation, and new technology such as RNA-seq has molecularly revealed the regulation of radiative biological effects by ROS. This review summarized recent progress on the role of ROS in plant response to radiations including UV, ion beam and plasma, and may help to reveal the mechanisms of plant responses to radiation.

Identification of a flavonoid C-glycosyltransferase from fern species Stenoloma chusanum and the application in synthesizing flavonoid C-glycosides in Escherichia coli.

BACKGROUND: Flavonoid C-glycosides have many beneficial effects and are widely used in food and medicine. However, plants contain a limited number of flavonoid C-glycosides, and it is challenging to create these substances chemically. RESULTS: To screen more robust C-glycosyltransferases (CGTs) for the biosynthesis of flavonoid C-glycosides, one CGT enzyme from Stenoloma chusanum (ScCGT1) was characterized. Biochemical analyses revealed that ScCGT1 showed the C-glycosylation activity for phloretin, 2-hydroxynaringenin, and 2-hydroxyeriodictyol. Structure modeling and mutagenesis experiments indicated that the glycosylation of ScCGT1 may be initiated by the synergistic action of conserved residue His26 and Asp14. The P164T mutation increased C-glycosylation activity by forming a hydrogen bond with the sugar donor. Furthermore, when using phloretin as a substrate, the extracellular nothofagin production obtained from the Escherichia coli strain ScCGT1-P164T reached 38 mg/L, which was 2.3-fold higher than that of the wild-type strain. Finally, it is proved that the coupling catalysis of CjFNS I/F2H and ScCGT1-P164T could convert naringenin into vitexin and isovitexin. CONCLUSION: This is the first time that C-glycosyltransferase has been characterized from fern species and provides a candidate gene and strategy for the efficient production of bioactive C-glycosides using enzyme catalysis and metabolic engineering.

Regulation of cellular redox homeostasis in Arabidopsis thaliana seedling by atmospheric pressure cold plasma-generated reactive oxygen/nitrogen species.

Atmospheric pressure cold plasma (APCP) holds great potential as an efficient, economical and eco-friendly approach for improving crop production. Although APCP-induced plant growth promotion is undisputedly attributed to the reactive oxygen and nitrogen species (RONS), how these RONS regulate the intracellular redox state and plant growth is still largely unknown. This study systematically investigates the regulation mechanism of APCP-generated RONS on intracellular redox homeostasis in Arabidopsis thaliana seedling by measuring the RONS compositions in APCP-treated solutions and intracellular RONS and antioxidants in Arabidopsis seedlings. The results show that APCP exhibited a dual effect (stimulation or inhibition) on Arabidopsis seedling growth dependent on the treatment time. APCP-generated RONS in liquids increased in a time-dependent manner, leading to an increase of conductivity and oxidation reduction potential (ORP) and decrease of pH. APCP caused an enrichment of intracellular RONS and most of them increased with APCP treatment time. Meanwhile, APCP treatment accelerated malondialdehyde (MDA) generation, and the level of intracellular antioxidants were enhanced by low-dose APCP treatment while decreased at high doses. The results of correlation analysis showed that the extracellular RONS produced by APCP were positively correlated with the intracellular RONS and negatively correlated with the antioxidants. These results demonstrate that the improved antioxidant capacity induced by moderate APCP-generated RONS plays an important role in the growth promotion of Arabidopsis seedlings, which may be a promising alternative for fertilizers in agricultural production.

Unprecedented 4,9-Seco-Oplopanane and Seven Drimane Sesquiterpenoids from the Chinese Liverwort Lejeunea flava (Sw.) Nees.

An unprecedented 4,9-seco-oplopanane (1), two undescribed drimane epimers (2 and 3), and five known drimane sesquiterpenoids (4-8) were isolated from the Chinese liverwort Lejeunea flava (Sw.) Nees. The structures of the new sesquiterpenoids were determined using nuclear magnetic resonance spectroscopy, electronic circular dichroism calculations, and single-crystal X-ray diffraction measurements. The inhibitory capacity of the new compounds against nitric oxide production in lipopolysaccharide-induced RAW 264.7 murine macrophages, along with the cytotoxicity of the new compounds against A549 and HepG-2 human cancer cell lines, were discussed.

Cytotoxic Activities of 9,10-seco-Cycloartane-Type Triterpenoids from the Chinese Liverwort Lepidozia reptans.

Ten new triterpenoids, including nine 9,10-seco-cycloartanes (1-9) and one 9,19-cyclolanostane (10), as well as one sesquiterpenoid (11) and four known compounds (12-15), were extracted and purified from the whole plant of the Chinese liverwort Lepidozia reptans. Multiple techniques (NMR, HRESIMS, IR, and X-ray crystallographic analysis) were applied to determine the structures of the isolated compounds. Bioassay determinations showed that compound 7, which contains an α,ß-unsaturated carbonyl moiety in its structure, inhibited the growth of a panel of cancer cell lines with IC50 values ranging from 4.2 ± 0.2 to 5.7 ± 0.5 µM. Further investigation revealed that compound 7 induces PC-3 cell death via mitochondrial-related apoptosis.

Diverse Prenylated Bibenzyl Enantiomers from the Chinese Liverwort Radula apiculata and Their Cytotoxic Activities.

An EtOH extract of the Chinese liverwort Radula apiculata showed cytotoxic activity against the A549 lung cancer cell line. Bioassay-guided fractionation led to the isolation of 19 prenylated bibenzyls, including eight previously unknown dimeric prenylated bibenzyls [radulapins A-H (1-8)], four new prenylated bibenzyls (9-12), and seven known compounds (13-19). Compounds 1-11 were analyzed as racemates by chiral-phase separation. Their structures were determined by detailed analysis of their spectroscopic data and by single-crystal X-ray diffraction, chiral resolutions, and electronic circular dichroism measurements. Using an MTT assay, these dimers (1-8) showed significant cytotoxic activity against a panel of human cancer cell lines. Further investigation revealed that compound 4 induces PC-3 cell death via mitochondrial-derived apoptosis.

Cloning and expression of circular transcript of mouse growth hormone receptor gene.

Based on reports in the literature and search results on the circBase database, 8 circular transcripts of the mouse growth hormone receptor (GHR) gene were identified. In order to confirm the existence of the circular transcripts of the GHR gene (circGHRs) and to explore their expression patterns, the Kunming mouse (Mus musculus) was used as a research animal. This study detected the existence of circGHRs by RT-PCR amplification and sequencing, one of which was selected as circGHR for detailed analysis. The circular structure of circGHR was confirmed by RNase R treatment and reverse transcription. The spatiotemporal expression of circGHR and GHR mRNA was analyzed by qRT-PCR. The results showed that the full length of mouse circGHR was 820 nt, which was formed by circularization of exons 2-8 of the transcript of the GHR gene. RNase R tolerance analysis shows that mouse circGHR has the general characteristics of circular molecules and is not easily degraded by RNase R. Compared with oligo-d(T)18 primers, random primers have higher reverse transcription efficiency for circGHR, which further shows that circGHR is a poly(A)-free cyclic structure molecule. Tissue expression profile results show that circGHR is highly expressed in the liver and kidney of 1 week-old and 7-week old Kunming mice, but is low in pectoral muscles and leg muscles. The time-series expression profile of circGHR does not show any significant difference between the liver and pectoral muscle tissue. The circGHR expression in the leg muscle was low before 5 weeks of age but increased after 7 weeks of age. This study confirmed the existence of a circular transcript circGHR of the mouse GHR gene, and initially revealed the expression pattern of circGHR. The results of the study laid a foundation for in-depth developmental studies on the biological functions of the mouse circGHR and its mechanism of action regarding the growth and development of mice.

Enantioselective Total Syntheses of Manginoids†A and†C and Guignardones†A and†C.

An enantioselective synthetic approach for preparing manginoids and guignardones, two types of biogenetically related meroterpenoids, is reported. This bioinspired and divergent synthesis employs an oxidative 1,3-dicarbonyl radical-initiated cyclization and cyclodehydration of the common precursor to forge the central ring of the manginoids and guignardones, respectively, at a late stage. Key synthetic steps include silica-gel-promoted semipinacol rearrangement to form the 6-oxabicyclo[3.2.1]octane skeleton and the Suzuki-Miyaura reaction of vinyl bromide to achieve fragment coupling. This synthesis protocol enables the asymmetric syntheses of four fungal meroterpenoids from commercially available materials.