Co-production of sugars and aroma compounds from tobacco waste using biomass-degrading enzymes produced by Aspergillus brunneoviolaceus Ab-10.

Biomass-degrading enzymes produced by microorganisms have a great potential in the processing of agricultural wastes. In order to produce suitable biomass-degrading enzymes for releasing sugars and aroma compounds from tobacco scraps, the feasibility of directly using the scraps as a carbon source for enzyme production was investigated in this study. By comparative studies of ten fungal strains isolated from tobacco leaves, Aspergillus brunneoviolaceus Ab-10 was found to produce an efficient enzyme mixture for the saccharification of tobacco scraps. Proteomic analysis identified a set of plant biomass-degrading enzymes in the enzyme mixture, including amylases, hemicellulases, cellulases and pectinases. At a substrate concentration of 100 g/L and enzyme dosage of 4 mg/g, glucose of 17.6 g/L was produced from tobacco scraps using the crude enzyme produced by A. brunneoviolaceus Ab-10. In addition, the contents of 23 volatile molecules, including the aroma compounds 4-ketoisophorone and benzyl alcohol, were significantly increased after the enzymatic treatment. The results provide a strategy for valorization of tobacco waste by integrating the production of biomass-degrading enzymes into the tobacco scrap processing system.

NtMYB305a binds to the jasmonate-responsive GAG region of NtPMT1a promoter to regulate nicotine biosynthesis.

MYB transcription factors play essential roles in regulating plant secondary metabolism and jasmonate (JA) signaling. Putrescine N-methyltransferase is a key JA-regulated step in the biosynthesis of nicotine, an alkaloidal compound highly accumulated in Nicotiana spp. Here we report the identification of NtMYB305a in tobacco (Nicotiana tabacum) as a regulatory component of nicotine biosynthesis and demonstrate that it binds to the JA-responsive GAG region, which comprises a G-box, an AT-rich motif, and a GCC-box-like element, in the NtPMT1a promoter. Yeast one-hybrid analysis, electrophoretic mobility shift assay and chromatin immunoprecipitation assays showed that NtMYB305a binds to the GAG region in vitro and in vivo. Binding specifically occurs at the ∼30-bp AT-rich motif in a G/C-base-independent manner, thus defining the AT-rich motif as previously unknown MYB-binding element. NtMYB305a localized in the nucleus of tobacco cells where it is capable of activating the expression of a 4×GAG-driven GUS reporter in an AT-rich motif-dependent manner. NtMYB305a positively regulates nicotine biosynthesis and the expression of NtPMT and other nicotine pathway genes. NtMYB305a acts synergistically with NtMYC2a to regulate nicotine biosynthesis, but no interaction between these two proteins was detected. This identification of NtMYB305a provides insights into the regulation of nicotine biosynthesis and extends the roles played by MYB transcription factors in plant secondary metabolism.

Roles and Preliminary Mechanism of Tobacco cis-Abienol in Inducing Tomato Resistance against Bacterial Wilt.

Bacterial wilt negatively impacts the yield and quality of tomatoes. cis-Abienol, a labdane diterpenoid abundantly produced in the trichome secretion of Nicotiana spp., can induce bacterial wilt resistance in plants; however, study on its practical application and acting mechanism is very limited. This study established the application conditions of cis-abienol for inducing tomato bacterial wilt resistance by pot-inoculation experiments and investigated the underlying mechanism by determining the physio-biochemical indexes and transcriptomic changes. The results showed that applying cis-abienol to the roots was the most effective approach for inducing tomato bacterial wilt resistance. The optimal concentration was 60 µg/mL, and 2-3 consecutive applications with 3-6 days intervals were sufficient to induce the bacterial wilt resistance of tomato plants. cis-Abienol could enhance the antioxidant enzyme activity and stimulate the defensive signal transduction in tomato roots, leading to the upregulation of genes involved in the mitogen-activated protein kinase cascade. It also upregulated the expression of JAZ genes and increased the content of jasmonic acid (JA) and salicylic acid (SA), which control the expression of flavonoid biosynthetic genes and the content of phytoalexins in tomato roots. cis-Abienol-induced resistance mainly depends on the JA signalling pathway, and the SA signalling pathway is also involved in this process. This study established the feasibility of applying the plant-derived terpenoid cis-abienol to induce plant bacterial wilt resistance, which is of great value for developing eco-friendly bactericides.

Improving Photocatalytic Activity for Formaldehyde Degradation by Encapsulating C60 Fullerenes into Graphite-like C3N4 through the Enhancement of Built-in Electric Fields.

The photocatalytic degradation of formaldehyde by graphite-like C3N4 is one of the most attractive and environmentally friendly strategies to address the significant threat to human health posed by indoor air pollutants. Despite its potential, this degradation process still faces issues with suboptimal efficiency, which may be attributed to the rapid recombination of photogenerated excitons and the broad band gap. As a proof of concept, a series of graphite-like C3N4@C60 composites combining graphite-like C3N4 and C60 was developed via an in situ generation strategy. The obtained graphite-like C3N4@C60 composites exhibited a remarkable increase in the photocatalytic degradation efficiency of formaldehyde, of up to 99%, under visible light irradiation, outperforming pure graphite-like C3N4 and C60. This may be due to the composites' enhanced built-in electric field. Additionally, the proposed composites maintained a formaldehyde removal efficiency of 84% even after six cycles, highlighting their potential for indoor air purification and paving the way for the development of efficient photocatalysts.

Insights into Gene Regulation of Jasmonate-Induced Whole-Plant Senescence of Tobacco under Non-Starvation Conditions.

Jasmonate (JA)-induced plant senescence has been mainly studied with a dark/starvation-promoted system using detached leaves; yet, the induction of whole-plant senescence by JA remains largely unclear. This work reports the finding of a JA-induced whole-plant senescence of tobacco under light/non-starvation conditions and the investigation of underlying regulations. Methyl jasmonate (MeJA) treatment induces the whole-plant senescence of tobacco in a light-intensity-dependent manner, which is suppressed by silencing of NtCOI1 that encodes the receptor protein of JA-Ile (the bioactive derivative of JA). MeJA treatment could induce the senescence-specific cysteine protease gene SAG12 and another cysteine protease gene SAG-L1 to high expression levels in the detached leaf patches under dark conditions but failed to induce their expression in tobacco whole plants under light conditions. Furthermore, MeJA attenuates the RuBisCo activase (RCA) level in the detached leaves but has no effect on this protein in the whole plant under light conditions. A genome-wide transcriptional assay also supports the presence of a differential regulatory pattern of senescence-related genes during MeJA-induced whole-plant senescence under non-starvation conditions and results in the finding of a chlorophylase activity increase in this process. We also observed that the MeJA-induced senescence of tobacco whole plants is reversible, which is accompanied by a structural change of chloroplasts. This work provides novel insights into JA-induced plant senescence under non-starvation conditions and is helpful to dissect the JA-synchronized process of whole-plant senescence.

Minimizing Global Buffer Access in a Deep Learning Accelerator Using a Local Register File with a Rearranged Computational Sequence.

We propose a method for minimizing global buffer access within a deep learning accelerator for convolution operations by maximizing the data reuse through a local register file, thereby substituting the local register file access for the power-hungry global buffer access. To fully exploit the merits of data reuse, this study proposes a rearrangement of the computational sequence in a deep learning accelerator. Once input data are read from the global buffer, repeatedly reading the same data is performed only through the local register file, saving significant power consumption. Furthermore, different from prior works that equip local register files in each computation unit, the proposed method enables sharing a local register file along the column of the 2D computation array, saving resources and controlling overhead. The proposed accelerator is implemented on an off-the-shelf field-programmable gate array to verify the functionality and resource utilization. Then, the performance improvement of the proposed method is demonstrated relative to popular deep learning accelerators. Our evaluation indicates that the proposed deep learning accelerator reduces the number of global-buffer accesses to nearly 86.8%, consequently saving up to 72.3% of the power consumption for the input data memory access with a minor increase in resource usage compared to a conventional deep learning accelerator.

Systematic Analysis of BELL Family Genes in Zizania latifolia and Functional Identification of ZlqSH1a/b in Rice Seed Shattering.

The loss of seed shattering is an important event in crop domestication, and elucidating the genetic mechanisms underlying seed shattering can help reduce yield loss during crop production. This study is the first to systematically identify and analyse the BELL family of transcription factor-encoding genes in Chinese wild rice (Zizania latifolia). ZlqSH1a (Zla04G033720) and ZlqSH1b (Zla02G027130) were identified as key candidate genes involved in seed shattering in Z. latifolia. These genes were involved in regulating the development of the abscission layer (AL) and were located in the nucleus of the cell. Over-expression of ZlqSH1a and ZlqSH1b resulted in a complete AL between the grain and pedicel and significantly enhanced seed shattering after grain maturation in rice. Transcriptome sequencing revealed that 172 genes were differentially expressed between the wild type (WT) and the two transgenic (ZlqSH1a and ZlqSH1b over-expressing) plants. Three of the differentially expressed genes related to seed shattering were validated using qRT-PCR analysis. These results indicate that ZlqSH1a and ZlqSH1b are involved in AL development in rice grains, thereby regulating seed shattering. Our results could facilitate the genetic improvement of seed-shattering behaviour in Z. latifolia and other cereal crops.

Synthesis of cembratriene-ol and cembratriene-diol in yeast via the MVA pathway.

BACKGROUND: Cembranoids are one kind of diterpenoids with multiple biological activities. The tobacco cembratriene-ol (CBT-ol) and cembratriene-diol (CBT-diol) have high anti-insect and anti-fungal activities, which is attracting great attentions for their potential usage in sustainable agriculture. Cembranoids were supposed to be formed through the 2-C-methyl-D-erythritol-4-phosphate (MEP) pathway, yet the involvement of mevalonate (MVA) pathway in their synthesis remains unclear. Exploring the roles of MVA pathway in cembranoid synthesis could contribute not only to the technical approach but also to the molecular mechanism for cembranoid biosynthesis. RESULTS: We constructed vectors to express cembratriene-ol synthase (CBTS1) and its fusion protein (AD-CBTS1) containing an N-terminal GAL4 AD domain as a translation leader in yeast. Eventually, the modified enzyme AD-CBTS1 was successfully expressed, which further resulted in the production of CBT-ol in the yeast strain BY-T20 with enhanced MVA pathway for geranylgeranyl diphosphate (GGPP) production but not in other yeast strains with low GGPP supply. Subsequently, CBT-diol was also synthesized by co-expression of the modified enzyme AD-CBTS1 and BD-CYP450 in the yeast strain BY-T20. CONCLUSIONS: We demonstrated that yeast is insensitive to the tobacco anti-fungal compound CBT-ol or CBT-diol and could be applied to their biosynthesis. This study further established a feasibility for cembranoid production via the MVA pathway and provided an alternative bio-approach for cembranoid biosynthesis in microbes.

Deep-Learning-Based Wi-Fi Indoor Positioning System Using Continuous CSI of Trajectories.

In a Wi-Fi indoor positioning system (IPS), the performance of the IPS depends on the channel state information (CSI), which is often limited due to the multipath fading effect, especially in indoor environments involving multiple non-line-of-sight propagation paths. In this paper, we propose a novel IPS utilizing trajectory CSI observed from predetermined trajectories instead of the CSI collected at each stationary location; thus, the proposed method enables all the CSI along each route to be continuously encountered in the observation. Further, by using a generative adversarial network (GAN), which helps enlarge the training dataset, the cost of trajectory CSI collection can be significantly reduced. To fully exploit the trajectory CSI's spatial and temporal information, the proposed IPS employs a deep learning network of a one-dimensional convolutional neural network-long short-term memory (1DCNN-LSTM). The proposed IPS was hardware-implemented, where digital signal processors and a universal software radio peripheral were used as a modem and radio frequency transceiver, respectively, for both access point and mobile device of Wi-Fi. We verified that the proposed IPS based on the trajectory CSI far outperforms the state-of-the-art IPS based on the CSI collected from stationary locations through extensive experimental tests and computer simulations.

Cadinane- and drimane-type sesquiterpenoids produced by Paecilomyces sp. TE-540, an endophyte from Nicotiana tabacum L., are acetylcholinesterase inhibitors.

Sesquiterpenoids with diverse skeleton types are regarded as potential lead compounds in pharmacological and other applications. Herein, we report the discovery of two new cadinane-type sesquiterpenoids, paecilacadinol A (1) and B (2); two new drimane-type sesquiterpenoids, ustusol D (3) and ustusol E (4); and six known analogs (5-10) from the endophytic fungus Paecilomyces sp. TE-540, enriching the structural diversity of naturally occurring sesquiterpenoids. Their planar structures were determined on the basis of detailed interpretation of 1D and 2D NMR spectroscopy and HRESIMS data, while their stereochemical structures were established by X-ray crystallographic analyses for 1 and 3-8 and theoretical calculations for 2. Notably, compounds 1 and 2 represent novel examples of cadinane-type sesquiterpenoids with ether bonds formed by intramolecular dehydration. Compounds 5 and 6 showed moderate activities against acetylcholinesterase (AChE), with IC50 values of 43.02 ± 6.01 and 35.97 ± 2.12 µM, respectively. Docking analysis predicted that 5 bound well in the catalytic pocket of AChE via hydrophobic interactions with Trp84, Gly117, Ser122, and Tyr121 residues, while 6 was located with Asp72 and Ser122 residues.

Antimicrobial Meroterpenoids and Erythritol Derivatives Isolated from the Marine-Algal-Derived Endophytic Fungus Penicillium chrysogenum XNM-12.

One new meroterpenoid-type alkaloid, oxalicine C (1), and two new erythritol derivatives, penicierythritols A (6) and B (7), together with four known meroterpenoids (2-5), were isolated from the marine algal-derived endophytic fungus Penicillium chrysogenum XNM-12. Their planar structures were determined by means of spectroscopic analyses, including UV, 1D and 2D NMR, and HRESIMS spectra. Their stereochemical configurations were established by comparing the experimental and calculated electronic circular dichroism (ECD) spectra for compound 1, as well as by comparison of the optical rotations with literature data for compounds 6 and 7. Notably, oxalicine C (1) represents the first example of an oxalicine alkaloid with a cleaved α-pyrone ring, whereas penicierythritols A (6) and B (7) are the first reported from the Penicillium species. The antimicrobial activities of compounds 1-7 were evaluated. Compounds 1 and 6 exhibited moderate antibacterial effects against the plant pathogen Ralstonia solanacearum with minimum inhibitory concentration (MIC) values of 8 and 4 µg/mL, respectively. Compound 6 also possesses moderate antifungal properties against the plant pathogen Alternaria alternata with a MIC value of 8 µg/mL.

Consumption of Wild Rice (Zizania latifolia) Prevents Metabolic Associated Fatty Liver Disease through the Modulation of the Gut Microbiota in Mice Model.

Metabolic associated fatty liver disease (MAFLD) due to excess weight and obesity threatens public health worldwide. Gut microbiota dysbiosis contributes to obesity and related diseases. The cholesterol-lowering, anti-inflammatory, and antioxidant effects of wild rice have been reported in several studies; however, whether it has beneficial effects on the gut microbiota is unknown. Here, we show that wild rice reduces body weight, liver steatosis, and low-grade inflammation, and improves insulin resistance in high-fat diet (HFD)-fed mice. High-throughput 16S rRNA pyrosequencing demonstrated that wild rice treatment significantly changed the gut microbiota composition in mice fed an HFD. The richness and diversity of the gut microbiota were notably decreased upon wild rice consumption. Compared with a normal chow diet (NCD), HFD feeding altered 117 operational taxonomic units (OTUs), and wild rice supplementation reversed 90 OTUs to the configuration in the NCD group. Overall, our results suggest that wild rice may be used as a probiotic agent to reverse HFD-induced MAFLD through the modulation of the gut microbiota.

Characterization of Nuclear and Mitochondrial Genomes of Two Tobacco Endophytic Fungi Leptosphaerulina chartarum and Curvularia trifolii and Their Contributions to Phylogenetic Implications in the Pleosporales.

The symbiont endophytic fungi in tobacco are highly diverse and difficult to classify. Here, we sequenced the genomes of Curvularia trifolii and Leptosphaerulina chartarum isolated from tobacco plants. Finally, 41.68 Mb and 37.95 Mb nuclear genomes were sequenced for C. trifolii and L. chartarum with the scaffold N50, accounting for 638.94 Kb and 284.12 Kb, respectively. Meanwhile, we obtained 68,926 bp and 59,100 bp for their mitochondrial genomes. To more accurately classify C. trifolii and L. chartarum, we extracted seven nuclear genes and 12 mitochondrial genes from these two genomes and their closely related species. The genes were then used for calculation of evolutionary rates and for phylogenetic analysis. Results showed that it was difficult to achieve consistent results using a single gene due to their different evolutionary rates, while the phylogenetic trees obtained by combining datasets showed stable topologies. It is, therefore, more accurate to construct phylogenetic relationships for endophytic fungi based on multi-gene datasets. This study provides new insights into the distribution and characteristics of endophytic fungi in tobacco.

Extraction of Proanthocyanidins from Chinese Wild Rice (Zizania latifolia) and Analyses of Structural Composition and Potential Bioactivities of Different Fractions.

Due to the importance of proanthocyanidin bioactivity and its relationship with chemical structure, ultrasound-assisted extraction and purification schemes were proposed to evaluate the proanthocyanidin content and analyze the structural composition and potential bioactivities of different proanthocyanidin fractions from Chinese wild rice (Zizania latifolia). Following an optimized extraction procedure, the crude wild rice proanthocyanidins (WRPs) were purified using n-butanol extraction, chromatography on macroporous resins, and further fractionation on Sephadex LH-20 to yield six specific fractions (WRPs-1-WRPs-6) containing proanthocyanidin levels exceeding 524.19 ± 3.56 mg/g extract. Structurally, (+)-catechin, (-)-epicatechin, and (-)-epigallocatechin were present as both terminal and extension units, and (-)-epicatechin was the major extension unit, in each fraction. This is the first preparation of WRP fractions with a different mean degree of polymerization (mDP), ranging from 2.66 ± 0.04 to 10.30 ± 0.46. A comparison of the bioactivities of these fractions revealed that fractions WRPs-1-WRPs-5 had significant DPPH radical scavenging activities, whereas fraction WRPs-6 with a high mDP showed better α-glucosidase and pancreatic lipase inhibitory effects. These findings should help define possible applications of WRPs to functional foods or nutraceuticals.

Composition and Genetic Diversity of the Nicotiana tabacum Microbiome in Different Topographic Areas and Growth Periods.

Fungal endophytes are the most ubiquitous plant symbionts on earth and are phylogenetically diverse. Studies on the fungal endophytes in tobacco have shown that they are widely distributed in the leaves, stems, and roots, and play important roles in the composition of the microbial ecosystem of tobacco. Herein, we analyzed and quantified the endophytic fungi of healthy tobacco leaves at the seedling stage (SS), resettling growth stage (RGS), fast-growing stage (FGS), and maturing stage (MS) at three altitudes (600, 1000, and 1300 m). We sequenced the internal transcribed spacer (ITS) region of fungal samples to delimit operational taxonomic units (OTUs) and phylogenetically characterize the communities. The results showed that the numbers of clustering OTUs at SS, RGS, FGS, and MS were 516, 709, 469, and 428, respectively. At the phylum level, species in Ascomycota and Basidiomycota had absolute predominance, representing 97.8% and 2.0% of the total number of species, respectively. We also found the number of fungi at the RGS and FGS stages was higher than those at the other two stages. Additionally, OTU richness was determined by calculating the Observed Species, Shannon, Simpson, Chao1, abundance-based coverage estimator (ACE), Good's coverage and phylogenetic distance (PD)_whole_tree indices based on the total number of species. Our results showed RGS samples had the highest diversity indices. Furthermore, we found that the diversity of fungal communities tended to decrease with increasing altitude. The results from this study indicated that tobacco harbors an abundant and diverse endophytic fungal community, which provides new opportunities for exploring their potential utilization.

Environmentally-Friendly Extraction of Flavonoids from Cyclocarya paliurus (Batal.) Iljinskaja Leaves with Deep Eutectic Solvents and Evaluation of Their Antioxidant Activities.

Deep eutectic solvents (DESs) are commonly employed as environmentally-friendly solvents in numerous chemical applications owing to their unique physicochemical properties. In this study, a novel and environmentally-friendly extraction method based on ultrasound assisted-deep eutectic solvent extraction (UAE-DES) was investigated for the extraction of flavonoids from Cyclocarya paliurus (Batal.) Iljinskaja (C. paliurus) leaves, and the antioxidant activities of these flavonoids were evaluated. Nine different DES systems based on either two or three components were tested, and the choline chloride/1,4⁻butanediol system (1:5 molar ratio) was selected as the optimal system for maximizing the flavonoid extraction yields. Other extraction conditions required to achieve the maximum flavonoid extraction yields from the leaves of C. paliurus were as follows: DES water content (v/v), 30%; extraction time, 30 min; temperature, 60 °C; and solid-liquid ratio, 20 mg/mL. Liquid chromatography-mass spectrometry allowed the detection of five flavonoids in the extract, namely kaempferol-7-O-α-l-rhamnoside, kaempferol, quercetin, quercetin-3-O-ß-d-glucuronide, and kaempferol-3-O-ß-d-glucuronide. In vitro antioxidant tests revealed that the flavonoid-containing extract exhibited strong DPPH and ABTS radical-scavenging abilities. Results indicate that UAE-DES is a suitable approach for the selective extraction of flavonoids from C. paliurus leaves, and DESs can be employed as sustainable extraction media for other bioactive compounds.

Benzophenone Derivatives from an Algal-Endophytic Isolate of Penicillium chrysogenum and Their Cytotoxicity.

Chromatographic separation of a marine algal-derived endophytic fungus Penicillium chrysogenum AD-1540, which was isolated from the inner tissue of the marine red alga Grateloupia turuturu, yielded two new benzophenone derivatives, chryxanthones A and B (compounds 1 and 2, respectively). Their structures were undoubtedly determined by comprehensive analysis of spectroscopic data (1D/2D NMR and HRESIMS). The relative and absolute configurations were assigned by analysis of the coupling constants and time-dependent density functional theory (TDDFT) calculations of their electronic circular dichroism (ECD) spectra, respectively. Both compounds possessed an unusual dihydropyran ring (ring D) fused to an aromatic ring, rather than the commonly occurring prenyl moiety, and a plausible biosynthetic pathway was postulated. The cytotoxicities of compounds 1 and 2 were evaluated against six human cell lines, and both of the compounds demonstrated weak to moderate cytotoxicities with IC50 values ranging from 20.4 to 46.4 µM. These new compounds further demonstrate the potential of marine-derived fungi as an untapped source of pharmaceutical components with unique properties that could be developed as drug candidates.

Partial Purification, Identification, and Quantitation of Antioxidants from Wild Rice (Zizania latifolia).

To provide further insights into the potential health-promoting antioxidants from wild rice (Zizania latifolia), which is an abundant but underutilized whole grain resource in East Asia, a partial purification based on D101 macroporous resin was carried out for the purification and enrichment of the antioxidants from the bioactive ethanol extracts of wild rice. On that basis, 34 phenolic compounds in the antioxidant fractions were identified by a high-performance liquid chromatography-linear ion trap quadrupole-Orbitrap-mass spectrometry (HPLC-LTQ-Orbitrap-MSn). The results suggested that phenolic acids could be enriched in the 10% ethanol-eluted fraction whereas flavonoids (including procyanidins and flavonoid glycosides) could be enriched in 20⁻30% ethanol-eluted fractions. A quantitative analysis determined by the multiple reaction monitoring mode of the ultra-performance liquid chromatography-triple quadrupole-tandem mass spectrometry (UPLC-QqQ-MS/MS) revealed a high content of procyanidins in wild rice. Compared with phenolic acids, flavonoids may contribute more to the potent antioxidant activity of wild rice. This is the first study on the antioxidants from wild rice Z. latifolia. These findings provide novel information on the functional components of wild rice, and will be of value to further research and development on Z. latifolia.

Morphological Characteristics, Nutrients, and Bioactive Compounds of Zizania latifolia, and Health Benefits of Its Seeds.

Zizania latifolia (tribe Oryzeae Dum., subfamily Oryzoideae Care, family Gramineae) is native to East Asian countries. The seeds of Z. latifolia (Chinese wild rice) have been consumed as a cereal in China for >3000 years. Z. latifolia forms swollen culms when infected with Ustilago esculenta, which is the second most-cultivated aquatic vegetable in China. The current review summarizes the nutrients and bioactive compounds of Z. latifolia, and health benefits of its seeds. The seeds of Z. latifolia contain proteins, minerals, vitamins, and bioactive compounds, the activities of which­for example, antioxidant activity­have been characterized. Various health benefits are associated with their consumption, such as alleviation of insulin resistance and lipotoxicity, and protection against cardiovascular disease. Chinese wild rice may be used to prevent and treat metabolic disease, such as diabetes, obesity, and cardiovascular diseases. Various compounds were isolated from the swollen culm, and aerial parts of Z. latifolia. The former suppresses osteoclast formation, inhibits growth of rat glioma cells, and may act as antioxidants and immunomodulators in drugs or foods. The latter exerts anti-fatigue, anti-inflammatory, and anti-allergic effects. Thus, Z. latifolia may be used to produce nutraceuticals and functional foods.

Antifungal Prenylated Diphenyl Ethers from Arthrinium arundinis, an Endophytic Fungus Isolated from the Leaves of Tobacco (Nicotiana tabacum L.).

An endophytic fungus Arthrinium arundinis TE-3 was isolated and purified from the fresh leaves of cultivated tobacco (Nicotiana tabacum L.). Chemical investigation on this fungal strain afforded three new prenylated diphenyl ethers (1-3) as well as three known analogues (4-6). Structure elucidation of the isolated compounds was carried out by analysis of 1D and 2D nuclear magnetic resonance (NMR) and high-resolution electrospray ionization mass spectroscopy (HRESIMS) spectra, as well as by comparison of those data with literature data. The absolute configuration of the stereogenic center at C-8 in 1 was assigned by comparison of the experimental and calculated ECD spectra. Compounds 1 and 2 showed selective antifungal activity against Mucor hiemalis with minimum inhibitory concentration (MIC) values of 8 and 4 µg/mL, respectively. Compounds 5 and 6 exhibited inhibitory activity against Alteraria alternata with an MIC value of 8 µg/mL. In the cytotoxic assay, 2, 5, and 6 displayed moderate in vitro cytotoxicity against the human monocytic cell line (THP-1 cell line), with IC50 values of 40.2, 28.3, and 25.9 µM, respectively. This study indicated that endophytic fungi possess great potential for exploring new bioactive secondary metabolites.