RESUMEN
A series of known diterpenoids from Isodon serra (Maxim.) Hara exhibited antibacterial activities against Staphylococcus aureus and even methicillin-resistant S. aureus (MRSA). Among these diterpenoids, hebeirubescensin K (7), effusanin E (8), and nodosin (9) showed the optimal minimum inhibitory concentration (MIC) values ranging from 3.12 to 6.25 µg/mL against tested MRSA strains, and they also inhibited bacterial proliferation, biofilm formation, and key gene expressions related to adhesion and virulence of MRSA. In vivo experiments also demonstrated the antibacterial abilities of 7-9 as topical drugs and promoted wound healing caused by a MSRA infection. It is the first time that the anti-S. aureus and MRSA activities of diterpenoids from I. serra has been systematically reported. These current findings provide insight into the anti-MRSA mechanism of diterpenoids from I. serra; indicating these compounds may be used as antimicrobial agents and contribute to the development as well as application of I. serra in phytomedicine for MRSA infections.
RESUMEN
Phytic acid, a naturally occurring compound predominantly found in cereals and legumes, is the focus of this review. This review investigates its distribution across various food sources, elucidating its dual roles in foods. It also provides new insights into the change in phytic acid level during food storage and the evolving trends in phytic acid management. Although phytic acid can function as a potent color stabilizer, flavor enhancer, and preservative, its antinutritional effects in foods restrict its applications. In terms of management strategies, numerous treatments for degrading phytic acid have been reported, each with varying degradation efficacies and distinct mechanisms of action. These treatments encompass traditional methods, biological approaches, and emerging technologies. Traditional processing techniques such as soaking, milling, dehulling, heating, and germination appear to effectively reduce phytic acid levels in processed foods. Additionally, fermentation and phytase hydrolysis demonstrated significant potential for managing phytic acid in food processing. In the future, genetic modification, due to its high efficiency and minimal environmental impact, should be prioritized to downregulate the biosynthesis of phytic acid. The review also delves into the biosynthesis and metabolism of phytic acid and elaborates on the mitigation mechanism of phytic acid using biotechnology. The challenges in the application of phytic acid in the food industry were also discussed. This study contributes to a better understanding of the roles phytic acid plays in food and the sustainability and safety of the food industry.
Asunto(s)
Manipulación de Alimentos , Ácido Fítico , Ácido Fítico/análisis , Manipulación de Alimentos/métodos , 6-FitasaRESUMEN
Maize (Zea mays L.) C-type cytoplasmic male sterility (CMS-C) is a highly used CMS system for maize commercial hybrid seed production. Rf4 is the major dominant restorer gene for CMS-C. Inbreds were recently discovered which contain the restoring Rf4 allele yet are unable to restore fertility due to the lack of an additional gene required for Rf4's restoration. To find this additional gene, QTL mapping and positional cloning were performed using an inbred that contained Rf4 but was incapable of restoring CMS-C. The QTL was mapped to a 738-kb interval on chromosome 2, which contains a Pentatricopeptide Repeat (PPR) gene cluster. Allele content comparisons of the inbreds identified three potential candidate genes responsible for fertility restoration in CMS-C. Complementation via transformation of these three candidate genes showed that PPR153 (Zm00001eb114660) is required for Rf4 to restore fertility to tassels. The PPR153 sequence is present in B73 genome, but it is not capable of restoring CMS-C without Rf4. Analysis using NAM lines revealed that Rf4 requires the presence of PPR153 to restore CMS-C in diverse germplasms. This research uncovers a major CMS-C genetic restoration pathway and can be used for identifying inbreds suitable for maize hybrid production with CMS-C cytoplasm.
Asunto(s)
Infertilidad Vegetal , Sitios de Carácter Cuantitativo , Zea mays , Zea mays/genética , Infertilidad Vegetal/genética , Citoplasma/metabolismo , Citoplasma/genética , Mapeo Cromosómico , Genes de Plantas , Proteínas de Plantas/genética , AlelosRESUMEN
Dietary prenylated stilbenoids, found in various food sources, offer multiple health benefits, including liver protection. However, the underlying mechanisms of hepatoprotection remain unclear. In this study, we synthesized 13 natural prenylated stilbenoids and examined their hepatoprotective activities, with silent mating type information regulation 2 homologue-1 (SIRT1) as the primary target for screening. Among all of the prenylated stilbenoids tested, 4-C-geranyl oxyresveratrol demonstrated superior performance. It activated SIRT1 activity more effectively than resveratrol, a well-known SIRT1 activator. To further investigate the mechanism of liver protection, two in vitro models were used: the palmitic acid-induced lipid accumulation model and the H2O2-induced apoptosis model. Our findings suggested that 4-C-geranyl oxyresveratrol mitigated lipid accumulation through the SIRT1-PGC1α pathway, reduced apoptosis via the SIRT1-p53-p21 pathway, and exerted antioxidant effects through the SIRT1-Nrf2 pathway. These findings provide new insights into the chemical basis of the health benefits of prenylated stilbenoids and their potential use as functional food additives.
Asunto(s)
Sirtuina 1 , Estilbenos , Sirtuina 1/metabolismo , Peróxido de Hidrógeno , Resveratrol , Estilbenos/metabolismo , LípidosRESUMEN
BACKGROUND: A growing body of researches indicate that the disrupted expression of long non-coding RNA (lncRNA) is linked to a range of human disorders. Therefore, the effective prediction of lncRNA-disease association (LDA) can not only suggest solutions to diagnose a condition but also save significant time and labor costs. METHOD: In this work, we proposed a novel LDA predicting algorithm based on graph convolutional network and transformer, named GCNFORMER. Firstly, we integrated the intraclass similarity and interclass connections between miRNAs, lncRNAs and diseases, and built a graph adjacency matrix. Secondly, to completely obtain the features between various nodes, we employed a graph convolutional network for feature extraction. Finally, to obtain the global dependencies between inputs and outputs, we used a transformer encoder with a multiheaded attention mechanism to forecast lncRNA-disease associations. RESULTS: The results of fivefold cross-validation experiment on the public dataset revealed that the AUC and AUPR of GCNFORMER achieved 0.9739 and 0.9812, respectively. We compared GCNFORMER with six advanced LDA prediction models, and the results indicated its superiority over the other six models. Furthermore, GCNFORMER's effectiveness in predicting potential LDAs is underscored by case studies on breast cancer, colon cancer and lung cancer. CONCLUSIONS: The combination of graph convolutional network and transformer can effectively improve the performance of LDA prediction model and promote the in-depth development of this research filed.
Asunto(s)
Neoplasias de la Mama , Neoplasias del Colon , MicroARNs , ARN Largo no Codificante , Humanos , Femenino , ARN Largo no Codificante/genética , ARN Largo no Codificante/metabolismo , MicroARNs/genética , Algoritmos , Neoplasias de la Mama/genética , Biología Computacional/métodosRESUMEN
Cajaninstilbene acid (CSA), longistylin A (LLA), and longistylin C (LLC) are three characteristic stilbenes isolated from pigeon pea. The objective of this study was to evaluate the antibacterial activity of these stilbenes against Staphylococcus aureus and even methicillin-resistant Staphylococcus aureus (MRSA) and test the possibility of inhibiting biofilm formation. The minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) of these stilbenes were evaluated. And the results showed that LLA was most effective against tested strains with MIC and MBC values of 1.56 µg/mL followed by LLC with MIC and MBC values of 3.12 µg/mL and 6.25 µg/mL as well as CSA with MIC and MBC values of 6.25 µg/mL and 6.25-12.5 µg/mL. Through growth curve and cytotoxicity analysis, the concentrations of these stilbenes were determined to be set at their respective 1/4 MIC in the follow-up research. In an anti-biofilm formation assay, these stilbenes were found to be effectively inhibited bacterial proliferation, biofilm formation, and key gene expressions related to the adhesion and virulence of MRSA. It is the first time that the anti-S. aureus and MRSA activities of the three stilbenes have been systematically reported. Conclusively, these findings provide insight into the anti-MRSA mechanism of stilbenes from pigeon pea, indicating these compounds may be used as antimicrobial agents or additives for food with health functions, and contribute to the development as well as application of pigeon pea in food science.
Asunto(s)
Cajanus , Staphylococcus aureus Resistente a Meticilina , Estilbenos , Antibacterianos/farmacología , Estilbenos/farmacología , Pruebas de Sensibilidad Microbiana , Anticuerpos/farmacología , BiopelículasRESUMEN
Two new phenolic glycosides (1 and 2), one known analogue (3), along with a new diterpene glucoside (4) were obtained from ethanolic extract of the stems of Eurya chinensis R. Br. The structures of these isolated compounds were identified by extensive analysis of HRESIMS and NMR spectroscopic data. The cytotoxicities of these compounds were evaluated on MCF-7, A549, HepG2, CaCo2 and 5-8 F cell lines by MTT method, but no obvious activities were observed.
Asunto(s)
Diterpenos , Ericales , Humanos , Glicósidos/farmacología , Glicósidos/química , Estructura Molecular , Células CACO-2 , Glucósidos , Diterpenos/químicaRESUMEN
Tetrahymenosis, caused by about 10 Tetrahymena species, is an emerging problem inflicting a significant economic loss on the aquaculture industry worldwide. However, in the order Tetrahymenida, there are many unresolved evolutionary relationships among taxa. Here we report 21 new sequences, including SSU-rRNA, ITS1-5.8S-ITS2 rRNA and LSU-rRNA, genes of 10 facultative parasitic Tetrahymena associated with tetrahymenosis, and conduct phylogenetic analyses based on each individual gene and a three-gene concatenated dataset. The main findings are: (1) All the parasitic and facultative parasitic species cluster in borealis group. (2) With the addition of new sequences, Tetrahymena is still divided into three groups, namely the "borealis group", the "australis group," and the "paravorax group." (3) the cluster pattern of all the newly sequenced facultative parasitic Tetrahymena species shows that members of the "borealis" group may be more susceptible to parasitism. (4) phylogeny based on concatenated genes show that T. pyriformis, T. setosa, and T. leucophrys have close relationship.
RESUMEN
Goss's wilt, caused by the Gram-positive actinobacterium Clavibacter nebraskensis, is an important bacterial disease of maize. The molecular and genetic mechanisms of resistance to the bacterium, or, in general, Gram-positive bacteria causing plant diseases, remain poorly understood. Here, we examined the genetic basis of Goss's wilt through differential gene expression, standard genome-wide association mapping (GWAS), extreme phenotype (XP) GWAS using highly resistant (R) and highly susceptible (S) lines, and quantitative trait locus (QTL) mapping using 3 bi-parental populations, identifying 11 disease association loci. Three loci were validated using near-isogenic lines or recombinant inbred lines. Our analysis indicates that Goss's wilt resistance is highly complex and major resistance genes are not commonly present. RNA sequencing of samples separately pooled from R and S lines with or without bacterial inoculation was performed, enabling identification of common and differential gene responses in R and S lines. Based on expression, in both R and S lines, the photosynthesis pathway was silenced upon infection, while stress-responsive pathways and phytohormone pathways, namely, abscisic acid, auxin, ethylene, jasmonate, and gibberellin, were markedly activated. In addition, 65 genes showed differential responses (up- or down-regulated) to infection in R and S lines. Combining genetic mapping and transcriptional data, individual candidate genes conferring Goss's wilt resistance were identified. Collectively, aspects of the genetic architecture of Goss's wilt resistance were revealed, providing foundational data for mechanistic studies.
Asunto(s)
Transcriptoma , Zea mays , Zea mays/genética , Zea mays/microbiología , Estudio de Asociación del Genoma Completo , Mapeo Cromosómico , Secuencia de Bases , Enfermedades de las Plantas/genética , Enfermedades de las Plantas/microbiología , Resistencia a la Enfermedad/genéticaRESUMEN
The blood-brain barrier (BBB) is a dynamic barrier separating neurocytes and brain tissues from blood that is extremely sealed and strictly regulated by transporters such as aquaporin-4 (AQP-4), glucose transporter (GLUT), and specialized tight junctional complexes (TJCs) including tight junctions (TJs), adherens junctions (AJs), and Zonulae occludens (ZOs). With specifically selective transcellular and paracellular permeability, the BBB maintains a homeostatic microenvironment to protect the central nervous system (CNS). In recent years, increasing attention has been paied to the importance of BBB disruption and dysfunction in the pathology of neurological disorders and diseases, such as Alzheimer's diseases (AD), Parkinson diseases (PD), stroke and cerebral edema. However, the further research on how the integral structure and function of BBB are altered under the physiological or pathological conditions is still needed. Focusing on the ultrastructural features of the BBB and combining the latest research on associated proteins and transporters, physiological regulation and pathological change of the BBB were elucidated. By summarizing the protective effects of known bioactive compounds derived from marine life on the BBB, this review aims to highlight the BBB as a key to the treatment of several major neurological diseases instead of a normally described obstacle to drug absorption and transport. Overall, the BBB's morphological characteristics and physiological function and their regulation provide the theoretical basis for the study on the BBB and inspire the diagnosis of and therapy for neurological diseases.
Asunto(s)
Enfermedad de Alzheimer , Barrera Hematoencefálica , Humanos , Barrera Hematoencefálica/metabolismo , Transporte Biológico/fisiología , Uniones Estrechas , Proteínas de Transporte de Membrana/metabolismo , Enfermedad de Alzheimer/patologíaRESUMEN
Plant pathogens cause significant crop loss worldwide, and new resistance genes deployed to combat diseases can be overcome quickly. Understanding the existing resistance gene diversity within the germplasm of major crops, such as maize, is crucial for the development of new disease-resistant varieties. We analysed the nucleotide-binding leucine-rich repeat receptors (NLRs) of 26 recently sequenced diverse founder lines from the maize nested association mapping (NAM) population and compared them to the R gene complement present in a wild relative of maize, Zea luxurians. We found that NLRs in both species contain a large diversity of atypical integrated domains, including many domains that have not previously been found in the NLRs of other species. Additionally, the single Z. luxurians genome was found to have greater integrated atypical domain diversity than all 26 NAM founder lines combined, indicating that this species may represent a rich source of novel resistance genes. NLRs were also found to have very high sequence diversity and presence-absence variation among the NAM founder lines, with a large NLR cluster on Chr10 representing a diversity hotspot. Additionally, NLRs were shown to be mobile within maize genomes, with several putative interchromosomal translocations identified.
Asunto(s)
Plantas , Zea mays , Zea mays/genéticaRESUMEN
Two new withaphysalin-type withanolides (18-O-ethylwithaphysalin R and 5-O-ethylphysaminimin C, 1 and 2), along with twelve known withanolides (3-14), were purified and identified from Physalis peruviana L. The chemical structures of these new isolates were elucidated through analyzing spectroscopic and HRESIMS data. All the obtained metabolites were appraised for their potential antiproliferative activity against the human breast cancer cell line MCF-7. Compound 7 was discovered to exhibit potent activity with an IC50 value of 3.51 µM and compounds 2, 6 and 14 showed weak cytotoxic effect.
Asunto(s)
Antineoplásicos , Physalis , Witanólidos , Humanos , Physalis/química , Witanólidos/química , Extractos Vegetales/químicaRESUMEN
Southern corn leaf blight (SLB), caused by the necrotrophic pathogen Cochliobolus heterostrophus, is one of the maize foliar diseases and poses a great threat to corn production around the world. Identification of genetic variations underlying resistance to SLB is of paramount importance to maize yield and quality. Here, we used a random-open-parent association mapping population containing eight recombinant inbred line populations and one association mapping panel consisting of 513 diversity maize inbred lines with high-density genetic markers to dissect the genetic basis of SLB resistance. Overall, 109 quantitative trait loci (QTLs) with predominantly small or moderate additive effects, and little epistatic effects were identified. We found 35 (32.1%) novel loci in comparison with the reported QTLs. We revealed that resistant alleles were significantly enriched in tropical accessions and the frequency of about half of resistant alleles decreased during the adaptation process owing to the selection of agronomic traits. A large number of annotated genes located in the SLB-resistant QTLs were shown to be involved in plant defence pathways. Integrating genome-wide association study, transcriptomic profiling, resequencing and gene editing, we identified ZmFUT1 and MYBR92 as the putative genes responsible for the major QTLs for resistance to C. heterostrophus. Our results present a comprehensive insight into the genetic basis of SLB resistance and provide resistant loci or genes as direct targets for crop genetic improvement.
Asunto(s)
Estudio de Asociación del Genoma Completo , Zea mays , Mapeo Cromosómico/métodos , Zea mays/genética , Enfermedades de las Plantas/genética , Sitios de Carácter CuantitativoRESUMEN
Eurya chinensis has been recorded as a folk medicine traditionally used for treatment of a variety of symptoms. However, the phytochemical and pharmacological investigations of this plant are still scarce. A novel phenolic glycoside named Euryachincoside (ECS) was isolated by chromatographic separation from E. chinensis, and its chemical structure was identified by analysis of HRMS and NMR data. Its anti-hepatic fibrosis effects were evaluated in both HSC-T6 (rat hepatic stellate cells) and carbon tetrachloride (CCl4)-induced mice with Silybin (SLB) as the positive control. In an in vitro study, ECS showed little cytotoxicity and inhibited transforming growth factor-beta (TGF-ß)-induced Collagen I (Col1) along with alpha-smooth muscle actin (α-SMA) expressions in HSC-T6. An in vivo study suggested ECS significantly ameliorated hepatic injury, secretions of inflammatory cytokines, and collagen depositions. Moreover, ECS markedly mediated Smad2/3, nuclear factor kappa B (NF-κB) and nuclear factor erythroid 2-related factor 2 (Nrf2) signaling pathways both in vitro and vivo. These present findings confirmed that ECS is a novel phenolic glycoside from E. chinensis with promising curative effects on hepatic fibrosis, and its mechanisms may include decreasing extracellular matrix accumulation, reducing inflammation and attenuating free radicals via Smad2/3, NF-κB and Nrf2 signaling pathways, which may shed light on the exploration of more effective phenolic glycoside-based anti-fibrotic agents.
Asunto(s)
Glicósidos , FN-kappa B , Ratas , Ratones , Animales , FN-kappa B/metabolismo , Glicósidos/farmacología , Glicósidos/metabolismo , Factor 2 Relacionado con NF-E2/metabolismo , Factor de Crecimiento Transformador beta , Cirrosis Hepática/inducido químicamente , Cirrosis Hepática/tratamiento farmacológico , Hígado , Factor de Crecimiento Transformador beta1/metabolismo , Tetracloruro de Carbono/efectos adversos , Tetracloruro de Carbono/metabolismo , Colágeno/metabolismo , Células Estrelladas HepáticasRESUMEN
Northern corn leaf blight, caused by the fungal pathogen Exserohilum turcicum, is a major disease of maize. The first major locus conferring resistance to E. turcicum race 0, Ht1, was identified over 50 years ago, but the underlying gene has remained unknown. We employed a map-based cloning strategy to identify the Ht1 causal gene, which was found to be a coiled-coil nucleotide-binding, leucine-rich repeat (NLR) gene, which we named PH4GP-Ht1. Transgenic testing confirmed that introducing the native PH4GP-Ht1 sequence to a susceptible maize variety resulted in resistance to E. turcicum race 0. A survey of the maize nested association mapping genomes revealed that susceptible Ht1 alleles had very low to no expression of the gene. Overexpression of the susceptible B73 allele, however, did not result in resistant plants, indicating that sequence variations may underlie the difference between resistant and susceptible phenotypes. Modelling of the PH4GP-Ht1 protein indicated that it has structural homology to the Arabidopsis NLR resistance gene ZAR1, and probably forms a similar homopentamer structure following activation. RNA sequencing data from an infection time course revealed that 1 week after inoculation there was a threefold reduction in fungal biomass in the PH4GP-Ht1 transgenic plants compared to wild-type plants. Furthermore, PH4GP-Ht1 transgenics had significantly more inoculation-responsive differentially expressed genes than wild-type plants, with enrichment seen in genes associated with both defence and photosynthesis. These results demonstrate that the NLR PH4GP-Ht1 is the causal gene underlying Ht1, which represents a different mode of action compared to the previously reported wall-associated kinase northern corn leaf blight resistance gene Htn1/Ht2/Ht3.
Asunto(s)
Ascomicetos , Leucina/genética , Ascomicetos/fisiología , Fenotipo , Zea mays/microbiología , Nucleótidos , Enfermedades de las Plantas/microbiología , Resistencia a la Enfermedad/genéticaRESUMEN
In the class Colpodea, there are many unresolved evolutionary relationships among taxa. Here, we report 30 new sequences including SSU-rRNA, ITS1-5.8S- ITS2 rRNA, and the mitochondrial small subunit ribosomal RNA (mtSSU-rRNA) genes of five colpodeans, and conduct phylogenetic analyses based on each individual gene and a two-gene concatenated dataset. For the first time, multi-genes were used to analyze phylogenetic relationships in the class Colpodea. The main findings are: (1) SSU-rRNA, ITS1-5.8S- ITS2 rRNA, and mtSSU-rRNA gene sequences of C. reniformis and C. grandis are provided for the first time, and these two species group into the clade including C. inflata, C. lucida, C. cucullus, and C. henneguyi; (2) clustering pattern and morphological similarity indicate that Bresslauides discoideus has a close relation with Colpodidae spp.; (3) Emarginatophrya genus diagnosis is improved to be 'Hausmanniellidae with sharply shortened and isometric leftmost 1-4 ciliary rows' and Colpoda elliotti is transferred to Emarginatophrya; (4) the genus Colpoda is still non-monophyletic with the addition of 10 populations from five Colpoda species sequences, but there are only two Colpoda groups left based on the present work: Group I comprises C. inflata, C. lucida, C. cucullus, C. henneguyi, C. reniformis, and C. grandis, Group II comprises C. maupasi and C. ecaudata, and the presence of diagonal grooves and the way the vestibular opens might be the two key features that differentiates Colpoda species groups; (5) a close molecular relationship, and highly similar merotelokinetal mode, somatic ciliary pattern, and basic organization of the oral apparatus with P. steinii suggests Bromeliothrix metopoides should be temporarily assigned to Colpodidae.
RESUMEN
The morphology and molecular phylogeny of three freshwater scuticociliates, Variuronema elegans gen. nov., spec. nov. (type species), V. similis spec. nov. and Uronema rigidum spec. nov., collected from Qixing River Wetland, northeastern China, were investigated using live observation and silver carbonate staining methods; the phylogenetic placements were inferred from the small subunit rRNA gene. Variuronema gen. nov., assigned to the family Uronematidae, is distinguished from the other genera mainly by its membranelles 1 and 2, each consisting of four longitudinal rows of kinetids, and the paroral membrane extending anteriorly to the front part of membranelle 3. The phylogenetic analyses indicate that: (1) Variuronema spp. form an independent, fully supported clade. However, its position among other uronematids is unresolved. (2) The family Uronematidae is not monophyletic based on the SSU rRNA gene, which is in accordance with previous studies.
Asunto(s)
Cilióforos , Oligohimenóforos , Oligohimenóforos/genética , Filogenia , Agua Dulce , Humedales , ChinaRESUMEN
Broad-spectrum resistance has great values for crop breeding. However, its mechanisms are largely unknown. Here, we report the cloning of a maize NLR gene, RppK, for resistance against southern corn rust (SCR) and its cognate Avr gene, AvrRppK, from Puccinia polysora (the causal pathogen of SCR). The AvrRppK gene has no sequence variation in all examined isolates. It has high expression level during infection and can suppress pattern-triggered immunity (PTI). Further, the introgression of RppK into maize inbred lines and hybrids enhances resistance against multiple isolates of P. polysora, thereby increasing yield in the presence of SCR. Together, we show that RppK is involved in resistance against multiple P. polysora isolates and it can recognize AvrRppK, which is broadly distributed and conserved in P. polysora isolates.
Asunto(s)
Basidiomycota , Zea mays , Basidiomycota/genética , Mapeo Cromosómico , Clonación Molecular , Resistencia a la Enfermedad/genética , Fitomejoramiento , Enfermedades de las Plantas/genética , Puccinia , Zea mays/genéticaRESUMEN
The morphology and ciliary pattern of two new heterotrich ciliates, Blepharisma orientale n. sp. and B. sinicum n. sp., collected from Sanjiang Plain Wetland, northeastern China, were investigated using living observation and protargol staining. Blepharisma orientale n. sp. is characterized by the following combination of characteristics: limnetic; body in vivo 280-380 × 120-190 µm, slender to elongate, cortical granules dark pink, ventral margin somewhat sigmoid; buccal field about 55-60% of body length; 30-39 somatic kineties; 70-76 adoral membranelles, each comprising two long rows of basal bodies; paroral membrane consists of dikinetids with the posterior third obliquely arranged, both basal bodies in each dikinetid are ciliated. Blepharisma sinicum n. sp. is recognized by the combination of the following characters: limnetic; body 190-260 × 100-170 µm in size in vivo, irregularly sigmoid and slightly bilaterally flattened, dorsal margin curved; cortical granules pale pink in color; buccal field about 60-75% of body length; 25-29 somatic kineties; 53-82 adoral membranelles; paroral membrane consisting entirely of dikinetids. Phylogenetic analyses based on small subunit rRNA (SSU rRNA) gene sequence data recovered the two new species as sister taxa, both the sister group of B. penardi.
Asunto(s)
Cilióforos , China , Cilióforos/genética , Filogenia , HumedalesRESUMEN
Dietary prenylated stilbenoids present in many food resources, and have good bioactivities. However, their structure-activity relationships are rarely reported. In this work, eighteen C- and O-prenylated stilbenoids were chemically semisynthesized using one-step approach. They all could inhibit sugar digestive enzymes, including α-glucosidase and α-amylase. 4-Geranyl piceatannol from jackfruit showed the strongest activity by suppressing dipeptidyl peptidase-IV (DPP-IV) activity. The enzyme inhibition kinetics were measured and the inhibition mechanism was revealed. Evaluation of antioxidant activity highlighted that the introduction of prenyl with increasing prenyl chain length can significantly increase the antioxidant activity of stilbenoids. Our results suggested that prenylated stilbenoids could be used as functional food additives to decrease postprandial blood sugar levels by inhibiting sugar digestive enzymes and DPP-IV. Prenylated stilbenoids present remarkable DPP-IV inhibitory activity, providing more useful information for the prevention of type 2 diabetes.