Major Secondary Metabolites Research Articles

The impact of transposable elements on tomato diversity

Tomatoes come in a multitude of shapes and flavors despite a narrow genetic pool. Here, we leverage whole-genome resequencing data available for 602 cultivated and wild accessions to determine the contribution of transposable elements (TEs) to tomato diversity. We identify 6,906 TE insertions polymorphisms (TIPs), which result from the mobilization of 337 distinct TE families. Most TIPs are low frequency variants and TIPs are disproportionately located within or adjacent to genes involved in environmental responses. In addition, genic TE insertions tend to have strong transcriptional effects and they can notably lead to the generation of multiple transcript isoforms. Using genome-wide association studies (GWAS), we identify at least 40 TIPs robustly associated with extreme variation in major agronomic traits or secondary metabolites and in most cases, no SNP tags the TE insertion allele. Collectively, these findings highlight the unique role of TE mobilization in tomato diversification, with important implications for breeding.

Plants Metabolites: Possibility of Natural Therapeutics Against the COVID-19 Pandemic.

COVID-19, a disease induced by SARS-CoV-2 (Severe Acute Respiratory Syndrome Coronavirus-2), has been the cause of a worldwide pandemic. Though extensive research works have been reported in recent days on the development of effective therapeutics against this global health crisis, there is still no approved therapy against SARS-CoV-2. In the present study, plant-synthesized secondary metabolites (PSMs) have been prioritized to make a review focusing on the efficacy of plant-originated therapeutics for the treatment of COVID-19. Plant metabolites are a source of countless medicinal compounds, while the diversity of multidimensional chemical structures has made them superior to treat serious diseases. Some have already been reported as promising alternative medicines and lead compounds for drug repurposing and discovery. The versatility of secondary metabolites may provide novel antibiotics to tackle MDR (Multi-Drug Resistant) microbes too. This review attempted to find out plant metabolites that have the therapeutic potential to treat a wide range of viral pathogens. The study includes the search of remedies belonging to plant families, susceptible viral candidates, antiviral assays, and the mode of therapeutic action; this attempt resulted in the collection of an enormous number of natural therapeutics that might be suggested for the treatment of COVID-19. About 219 plants from 83 families were found to have antiviral activity. Among them, 149 plants from 71 families were screened for the identification of the major plant secondary metabolites (PSMs) that might be effective for this pandemic. Our investigation revealed that the proposed plant metabolites can serve as potential anti- SARS-CoV-2 lead molecules for further optimization and drug development processes to combat COVID-19 and future pandemics caused by viruses. This review will stimulate further analysis by the scientific community and boost antiviral plant-based research followed by novel drug designing.

Isolation of secondary metabolites from the Iranian medicinal plant Eremurus persicus.

Eremurus persicus (Jaub. & Spach) Boiss. belonging to Xanthorrhoeaceae family is an endemic medicinal plant widely distributed in Iran. Its leaves have been traditionally used as a food and also as medicinal plant. Regarding the widespread application of E.persicus in Iranian folk medicine, and the insignificant investigation of its components, this study aimed at the isolation and identification of major secondary metabolites of this plant. By applying various chromatographic techniques, corchoionoside A (1), 4-amino-4-carboxychroman-2-one (2), isoorientin (3), ziganein 5-methyl ether (4), auraptene (5), and imperatorin (6) were isolated from the EtOAc and CHCl3 fractions of the crude extract. Except isoorientin (3), all the identified phytoconstituents were reported for the first time from Eremurus genus.

The phytochemical and morphological diversity analysis of Ziziphus nummularia (Burm.f.) Wight & Arn. populations in South of Iran

Ziziphus nummularia is a multipurpose and tropical tree with medicinal, nutritional, industrial, and economic values. This tree, which belongs to the Rhamnaceae family, is originated from the South of Asia and North of Africa. This research was carried out to investigate the phytochemical and morphological diversity of 20 wild populations collected from different Southern regions of Iran. Statistical significant difference ranges between population were found in respect to saponin of the leaf (2.2-5.4 mg/g) and fruit (1.2-3.2 mg/g), phenol of the leaf (0.7-2.9 mg/g) and fruit (0.03-0.4 mg/g), tannin of the leaf (0.8-3.5 mg/g) and fruit (1.5-1.7 mg/g), and flavonoid of the leaf (3.3-4.3 mg/g) and fruit (1.5-2.4 mg/g). A factor analysis based on principal component analysis (PCA) revealed that the first three components (PC1-PC3) explain 79.04% of total variations. The first component (PC1) is explained by the most important traits of the PCA coefficient such as the leaf saponin, width of the end leaf, fruit saponin, length of the end leaf, leaf length and width, and leaf phenol with 42% of the total variation. Hierarchical cluster analysis divided the populations into four main groups with high diversity. In general, the Izeh Tarakab population had the highest content of leaf and fruit saponin. The content of leaf and fruit saponin as the major secondary metabolite could be a good determinant for detecting diversity in the wild population of Z. nummularia.

CONTRIBUCIÓN AL ESTUDIO FITOQUÍMICO DEL ZUMO DE Colignonia parviflora SUBSP. BIUMBELLATA (SAQTA)

En el presente trabajo se investigó las raíces de Colignonia parviflora subsp. biumbellata, fue adquirida en la ciudad de Chinchero, a 3780 msnm. Fueron identificados 24 componentes químicos entre ésteres metílicos, monoterpeno, sesquiterpenos, fenilpropanos y alcoholes alifáticos en el aceite esencial de la raíz. La identificación fue a través de la comparación de los espectros de masas con el banco de datos del sistema de CG-EM (NIST 14) y por el análisis de sus espectros de masas obtenidos por cromatografía gaseosa acoplada a espectrómetro de masas. En la fase apolar del zumo de la raíz fueron identificados sus ácidos grasos mayoritarios y los metabolitos secundarios β-sitosterol, estigmasterol, estigmasta-7- en-3-ol, estigmasta-7,22-dien-3-ol, el éster metílico del ácido ferúlico y el ácido oleánico.

Assessment of Photoprotective, Antioxidant and Anti-Skin Cancer Activities of Leaf Extracts of Certain Medicinal Plants

PLANT extracts acquiring antioxidant potential have recently been used for topical applications for significant protection against ultra violet (UV)-induced sunburn. The current study was conducted for screening Pluchea discoridis (Asteracea), Lawsonia inermis (Lythraceae), Aloe vera (Liliaceae) and Eucalyptus camaldulensis (Myrtaceae) for their photoprotective, antioxidant and anti-skin cancer properties.Multivariate data analysis based on spectrophotometric evaluation of major secondary metabolites was performed. Each plant had its specific pattern of metabolites. P. discoridis and E. camaldulensis were separated from other plants due to their high content of secondary metabolites where P. discoridis was discriminated by high content of flavonoids and saponins. E. camaldulensis, was discriminated by high content of phenolics and tannins.Different concentrations of plant extracts were read for absorbance at UVB spectrum. Sun protection factors (SPFs) were calculated. The highest concentration (10mg/mL) of P. discoridis extract had the highest SPF, i.e., 23.94± 0.98.The antioxidant activity using 2,2-Diphenyl-1-picryl-hydrazyl (DPPH) assay revealed that P. discoridis and L. inermis extracts had the best free radical scavenging activity with DPPH at 100μg/mL of 85.69± 1.8 and 85.35± 2.5%, respectively.Human skin tumor cell line (A431) was incubated with the plant extracts. P. discoridis had the best anti-skin cancer activity of lowest LC50 value. The effect induced by the P. discoridis extract was also identical to that of the standard chemotherapeutic drug (doxorubicin).The present study revealed that P. discoridis is a promising plant for use in sunscreen formulations and anti-skin cancer treatment.

<p><strong><em>Cryptothecia aleurodes</em></strong><strong> (Arthoniaceae), a misunderstood species</strong></p>

Cryptothecia aleurodes was considered to be a widespread, rare tropical lichen having white ascigerous areas and a crustose whitish-grey thallus containing norstictic acid. A revision of its type specimen from Guadeloupe and the study of recent specimens from Martinique proved that the species has been misunderstood. In this paper, Cryptothecia aleurodes is shown to have a K– and C+ red thallus containing notably gyrophoric acid as major secondary metabolite but lacking norstictic acid. A detailed description and illustrations are provided. The species is known with certainty only from the Caribbean and has probably a Neotropical distribution. Previous reports of C. aleurodes from the Seychelles and Thailand are shown to be misidentifications and reports from India are considered dubious.

Phytochemical Composition and Evaluation of Anti-Inflammatory Activity in Glycosmis pentaphylla (Retz.)DC. - An Ethnobotanically Important Medicinal Plant

The present study was undertaken with an objective to investigate the phytochemical composition and in vitro anti-inflammatory potential in the leaves of Glycosmis pentaphylla (Retz.) DC, an ethno-medicinally important medicinal plant belonging to the Rutaceae family. Determination of secondary metabolites in any plant material is necessary as it helps to know about the major constituents present in them. Extractants like hexane, ethyl acetate, acetone, ethanol and distilled water were selected based on the polarity of the solvents used and was further evaluated for phytochemicals through qualitative and quantitative analysis based on standard procedures. Inflammation is a part of body's immune response and it is necessary to heal the tissue damage through an inflammatory response. As modern non-steroidal anti-inflammatory drugs can cause severe side effects like depression, gastric problems and so on, it is advisable to use plant derived products to treat inflammation. In this context, the potential of Glycosmis pentaphylla as an anti-inflammatory agent has been critically evaluated using in vitro cyclooxygenase and lipoxygenase inhibitory assays. The results revealed that major secondary metabolites evaluated were present in the ethanolic extract, indicating that ethanol can dissolve most of the phytoconstituents. Also, on quantification, it was found that the leaf ethanolic extract possessed alkaloids as a major constituent. As secondary metabolites can possess several pharmacological activities like anti-bacterial, anti-fungal, anti-tumour and so on, the potential of Glycosmis pentaphylla in elucidating anti-inflammatory effects was checked through in vitro anti-inflammatory assays. It was observed that, the leaf extract showed promising cycloxygenase and lipoxygenase inhibition indicating that, the extract can be used as an effective non-steroidal anti-inflammatory drug. From the phytochemical composition, it can be gleaned that, the anti-inflammatory activity might be due to the presence of alkaloids. Hence, this research work can aid the pharmaceuticals to isolate herbal anti-inflammatory drugs rich in alkaloids from Glycosmis pentaphylla.

De novo transcriptome analysis unravels tissue-specific expression of candidate genes involved in major secondary metabolite biosynthetic pathways of Plumbago zeylanica: implication for pharmacological potential.

The present study provides comparative transcriptome analysis, besides identifying functional secondary metabolite genes of Plumbago zeylanica with pharmacological potential for future functional genomics, and metabolomic engineering of secondary metabolites from this plant towards diversified biomedical applications. Plumbago zeylanica is a widely used medicinal plant of the traditional Indian system of medicine with wide pharmacological potential to treat several disorders. The present study aimed to carry out comparative transcriptome analysis in leaf and root tissue of P. zeylanica using Illumina paired end sequencing to identify tissue-specific functional genes involved in the biosynthesis of secondary metabolites, contributing to its therapeutic efficacy. De novo sequencing assembly resulted in the identification of 62,321 "Unigenes" transcripts with an average size of 1325bp. Functional annotation using BLAST2GO resulted in the identification of 50,301 annotated transcripts (80.71%) and GO assigned to 18,814 transcripts. KEGG pathway annotation of the "Unigenes" revealed that 2465 transcripts could be assigned to 242 KEGG pathway maps wherein the number of transcripts involved in secondary metabolism was distinct in root and leaf transcriptome. Among the secondary metabolite biosynthesis pathways, the cluster of "Unigenes" encoding enzymes of 'Phenylpropanoid biosynthesis pathway' represents the largest group (84 transcripts) followed by 'Terpenoid Backbone biosynthesis' (48 transcripts). The transcript levels of the candidate unigenes encoding key enzymes of phenylpropanoid (PAL, TAL) and flavanoid biosynthesis (CHS, ANS, FLS) pathways were up-regulated in root, while the expression levels of candidate "Unigenes" transcript for monoterpenoid (DXS, ISPF), diterpenoid biosynthesis (SPS, SDS) and indole alkaloid pathways (STR) were significantly higher in leaf of P. zeylanica. Interestingly, validation of differential gene expression profile by qRT-PCR also confirmed that candidate "Unigenes" enzymes of phenylpropanoid and flavonoid biosynthesis were highly expressed in the root, while the key regulatory enzymes of terpenoid and indole alkaloid compounds were up-regulated in the leaf, suggesting that (differences in) the levels of these functional genes could be attributed to the (differential) pharmacological activity (between root and leaf) in tissues of P. zeylanica.

Diketopiperazines from Batnamyces globulariicola, gen. & sp. nov. (Chaetomiaceae), a fungus associated with roots of the medicinal plant Globularia alypum in Algeria

Eight diketopiperazines including five previously unreported derivatives were isolated from an endophytic fungus cultured from the medicinal plant Globularia alypum collected in Algeria. The strain was characterised by means of morphological studies and molecular phylogenetic methods and was found to represent a species of a new genus in the Chaetomiaceae, for which we propose the name Batnamyces globulariicola. The taxonomic position of the new genus, which appears phylogenetically related to Stolonocarpus and Madurella, was evaluated by a multi-locus genealogy and by morphological studies in comparison to DNA sequence data reported in the recent monographs of the family. The culture remained sterile on several culture media despite repeated attempts to induce sporulation, and only some chlamydospores were formed. After fermentation in submerged culture and extraction of the cultures with organic solvents, the major secondary metabolites of B. globulariicola were isolated and their chemical structures were elucidated by extensive spectral analysis including nuclear magnetic resonance (NMR) spectroscopy, high-resolution electrospray ionisation mass spectrometry (HRESIMS), and electronic circular dichroism (ECD) measurements. The isolated compounds were tested for their biological activities against various bacteria, fungi, and two mammalian cell lines, but only three of them exhibited weak cytotoxicity against KB3.1 cells, but no antimicrobial effects were observed.

Systematic Analysis of Kelch Repeat F-box (KFB) Protein Gene Family and Identification of Phenolic Acid Regulation Members in Salvia miltiorrhiza Bunge.

S. miltiorrhiza is a well-known Chinese herb for the clinical treatment of cardiovascular and cerebrovascular diseases. Tanshinones and phenolic acids are the major secondary metabolites and significant pharmacological constituents of this plant. Kelch repeat F-box (KFB) proteins play important roles in plant secondary metabolism, but their regulation mechanism in S. miltiorrhiza has not been characterized. In this study, we systematically characterized the S. miltiorrhiza KFB gene family. In total, 31 SmKFB genes were isolated from S. miltiorrhiza. Phylogenetic analysis of those SmKFBs indicated that 31 SmKFBs can be divided into four groups. Thereinto, five SmKFBs (SmKFB1, 2, 3, 5, and 28) shared high homology with other plant KFBs which have been described to be regulators of secondary metabolism. The expression profile of SmKFBs under methyl jasmonate (MeJA) treatment deciphered that six SmKFBs (SmKFB1, 2, 5, 6, 11, and 15) were significantly downregulated, and two SmKFBs (SmKFB22 and 31) were significantly upregulated. Tissue-specific expression analysis found that four SmKFBs (SmKFB4, 11, 16, and 17) were expressed preferentially in aerial tissues, while two SmKFBs (SmKFB5, 25) were predominantly expressed in roots. Through a systematic analysis, we speculated that SmKFB1, 2, and 5 are potentially involved in phenolic acids biosynthesis.

Metabolic profiling and biological activities of Artabotrys hexapetalus leaves

Artabotrys hexapetalus, an endemic shrub in India producing fragrant flowers belongs to Annonaceae family and is mainly used traditionally for the treatment of cholera and scrofula. Present study reveals antimicrobial, antioxidant and anticancer activities of Artabotrys hexapetalus.To screening and evaluate the major secondary metabolites presents, antioxidant, anticancer potential by in vitro assay in A.hexapetalus leaves.All successive extracts of Artabotrys hexapetalus with ethyl ethanoate, chloroform, methanol, ethanol were obtained by Soxhlet method and subjected to phytochemical screening and in vitro antioxidant activity. Antibacterial activity and anticancer activity were determined by Disc diffusion and MTT methods respectively. Compared to other solvents extracts, the methanol extract of A.hexapetalus contains the higher phenolic content (48.45 µg/mg), flavonoid content (49.15 µg/mg) and potential antioxidant capacity (IC50:10.15 ± 0.85 µg/mg). Due to high potential of methanol extract of A hexapetalus was subjected to separation of active molecules. Further, trisaccharide, n-Hexadecanoic acid and Z-8-Methyl-9-tetradecenoic acid was isolated and charecterised by UV-vis, FT-IR, NMR spectral studies. Trisaccharide and partially separated fractions from A.hexapetalus contains higher antioxidant, anticancer (MCF-7) and antimicrobial activity. Here we conclude that, the methanol extract of A.hexapetalus leaves and their fractions possess highly activities against various free radicals, human pathogens and cancer cell line (MCF-7). This is the primary lead to make a new biological agent from A.hexapetalus leaves.

Antioxidant efficacy and in silico toxicity prediction of free and spray-dried extracts of green Arabica and Robusta coffee fruits and their application in edible oil

Extracts of green coffee fruits (GCFEs), either of the Arabica or Robusta variety, obtained by percolation with a 68% (w/w) aqueous ethanol solution using a 0.9:10 (w/w) solid-to-solvent ratio, were tested in this study as antioxidant additives to delay sunflower oil oxidation. In addition, safety of the major secondary metabolites of the extracts was investigated by in silico modeling. For this purpose, GCFEs were spray dried either as such or microencapsulated with a 1:1 (w/w) maltodextrin and gum Arabic mixture as wall material. The encapsulation efficiencies of Arabica and Robusta GCFEs were as high as 96.9 ± 0.04 and 97.36 ± 0.03% and the chlorogenic acid retentions 59.61 ± 1.3 and 73.72 ± 2.49%, respectively. The HPLC-DAD analysis revealed higher contents of total chlorogenic acids and caffeine but a lower content of trigonelline in the Robusta GCFE compared with the Arabica one. The ACD/I-Lab, AdmetSAR, and pKCSM computational tools allowed excluding, for GCFEs major compounds, any toxicological potential in terms of Ames toxicity, carcinogenicity, hERG inhibition, hepatotoxicity, reproductive toxicity and skin sensitization. Foodstuff application of GCFE powders demonstrated that microencapsulated GCFEs were more effective in delaying sunflower oil oxidation than free GCFEs and butylated hydroxytoluene as a synthetic antioxidant. These results suggest the use of microencapsulated GCFE as a source of natural antioxidants to stabilize food products, especially unsaturated vegetable oils.

A Tale of Two Grass Species: Temperature Affects the Symbiosis of a Mutualistic Epichloë Endophyte in Both Tall Fescue and Perennial Ryegrass.

Many cool-season grasses form permanent, mutualistic symbioses with asexual Epichloë endophytes. These fungal symbionts often perform a protective role within the association as many strains produce secondary metabolites that deter certain mammalian and invertebrate herbivores. Although initially a serious issue for agriculture, due to mammalian toxins that manifested in major animal health issues, selected strains that provide abiotic stress protection to plants with minimal ill effects to livestock are now commercialized and routinely used to enhance pasture performance in many farming systems. These fungal endophytes and their grass hosts have coevolved over millions of years, and it is now generally accepted that most taxonomic groupings of Epichloë are confined to forming compatible associations (i.e., symptomless associations) with related grass genera within a tribe. The most desired compounds associated with Epichloë festucae var. lolii, an endophyte species associated with perennial ryegrass, are peramine and epoxy-janthitrems. No other major secondary metabolites with invertebrate bioactivity have been identified within this association. However, other agriculturally beneficial compounds, such as lolines, have been discovered in related endophyte species that form associations with fescue grasses. A rationale therefore existed to develop novel grass-endophyte associations between loline-producing endophytes originally isolated from tall fescue with elite cultivars of perennial ryegrass to achieve a wider spectrum of insect bioactivity. A suitable loline-producing endophyte strain of Epichloë sp. FaTG-3 was selected and inoculated into perennial ryegrass. We hypothesed that endophyte transmission frequency, endophyte mycelial biomass and endophyte-derived alkaloid production would differ between the original tall fescue host and the artificial association. Consistent with our hypothesis, our data strongly suggest that plant species significantly affected the plant-endophyte association. This effect became more apparent for transmission frequency and endophyte biomass as the plants matured. Overall, the viable endophyte infection frequency was greater in the tall fescue host than in perennial ryegrass, at all sampling dates. Additionally, temperature was found to be a significant factor affecting endophyte transmission frequency, endophyte mycelial biomass and alkaloid production. Implications for the development of novel grass-endophyte associations are discussed.

De novo transcriptome sequence of Senna tora provides insights into anthraquinone biosynthesis.

Senna tora is an annual herb with rich source of anthraquinones that have tremendous pharmacological properties. However, there is little mention of genetic information for this species, especially regarding the biosynthetic pathways of anthraquinones. To understand the key genes and regulatory mechanism of anthraquinone biosynthesis pathways, we performed spatial and temporal transcriptome sequencing of S. tora using short RNA sequencing (RNA-Seq) and long-read isoform sequencing (Iso-Seq) technologies, and generated two unigene sets composed of 118,635 and 39,364, respectively. A comprehensive functional annotation and classification with multiple public databases identified array of genes involved in major secondary metabolite biosynthesis pathways and important transcription factor (TF) families (MYB, MYB-related, AP2/ERF, C2C2-YABBY, and bHLH). Differential expression analysis indicated that the expression level of genes involved in anthraquinone biosynthetic pathway regulates differently depending on the degree of tissues and seeds development. Furthermore, we identified that the amount of anthraquinone compounds were greater in late seeds than early ones. In conclusion, these results provide a rich resource for understanding the anthraquinone metabolism in S. tora.

Effect of seed treatment with cold plasma and electromagnetic field on red clover germination, growth and content of major isoflavones

Pre-sowing treatment of red clover seeds with cold plasma (CP) and electromagnetic field (EMF) was applied aiming to evaluate changes induced in germination and early seedling growth under controlled laboratory conditions, and to estimate treatment effects on plant growth, biomass production, nutritional value and the amounts of major leaf secondary metabolites under long-term field experimental conditions. The effects of seed treatment using radio-frequency EMF (5, 10, 15 min) and CP (2, 5, and 7 min) on seed germination kinetics, morphometric parameters of seedlings were assessed for two cultivars of red clover—‘Vyčiai’ and ‘Sadūnai’. Long-term observations revealed that the effects of seed treatments persist for the entire vegetation season, while the observed effects on germination (CP increased germination rate by 4%–20%) do not provide sufficient information to predict the impact on plants on a longer time scale. The effects on morphometric parameters were dependent on plant cultivar, and were much stronger (up to 24% for ‘Sadūnai’ and 49% for ‘Vyčiai’) after growing the plants in the field for 5 months in comparison to the effects (absent or below 10%) observed in the early growth stages. A minor improvement of nutritional value per biomass unit was observed for ‘Vyčiai’. Protein yield per plant increased substantially (up to 70%). Pre-sowing seed treatment with CP and EMF had an obvious impact on the amounts of major isoflavones in leaves, and the nature of these changes strongly depended on the vegetation stage of plants (before flowering or at flowering stage). CP treatment for 5 min was found to be the most effective in this respect in not flowering plants, inducing a strong increase in biochanin A/formononetin ratio in leaves of both cultivars. However, an opposite effect was observed in the flowering plants, where the CP and EMF treatments decreased biochanin A/formononetin ratio.

Phytochemical analysis of olive flowers' hydroalcoholic extract and in vitro evaluation of tyrosinase, elastase and collagenase inhibition activity

Olea europaea L. is historically one of the most important trees of the Mediterranean countries. Increasing scientific interest regarding its fruits, leaves and olive oil has led to the elucidation of several phytochemical and biological characteristics. However, the phytochemical and biological studies regarding olive flowers remain limited. The aim of the present study was the phytochemical characterization of olive flowers' hydroalcoholic extract from Greek variety Lianolia, the effective isolation of the major secondary metabolites and evaluation of their inhibition activity against tyrosinase, elastase and collagenase. UPLC-HRMS/MS analysis was used to investigate the chemical composition of hydroalcoholic extract resulting in the identification of sixty-three secondary metabolites witch mainly belong to phenilethanoids, triterpenoids, flavonoids and secoiridoids. The orthogonial combination of Centrifugal Partition Chromatography and preparative HPLC in the same purification process led to the isolation of nine major compounds of the extract including two triterpenic acids, two flavonoid glycosides and five secoiridoid derivatives. From them, oleofloside A and oleofloside B are new natural products. Although, the hydroalcoholic extract and isolated secoiridoids exhibited weak or no inhibition activity towards tyrosinase and elastase, they exhibit remarkable anti-collagenase activity with 2΄-ethoxyoleuropein being the most active compound.

Comparative Studies of Fraxinus Species from Korea Using Microscopic Characterization, Phytochemical Analysis, and Anti-Lipase Enzyme Activity.

Fraxinus species belongs to the Oleaceae family, commonly known as Ash tree, and has been utilized as a folk medicine with various medicinal properties, including anti-obesity activity. The goal of the present study was to establish quality control parameters using microscopic characterization, phytochemical differentiation, and anti-lipase activity evaluation of five Fraxinus plants in Korea. Microscopic evaluation of the lower surface, petiole, and midrib of leaves, and stem bark showed discriminative anatomical characteristics, such as the stomatal index of the lower leaf surface; the number of sclerenchyma cells, and the diameter of parenchyma cells in the petiole and midrib; and the cork cell size and fiber frequency in the stem bark. Phytochemical analysis using high-performance liquid chromatography revealed the significant variation in the chemical profiles of the 12 major secondary metabolites among the samples. The orthogonal projections to latent structure-discrimination analysis efficiently differentiated each group belonging to each Fraxinus plant with the anatomical and quantification data. F. rhynchophylla and ligstroside showed the most potent anti-lipase activity among the plants and the 12 major metabolites, respectively. These findings could serve as the scientific criteria for the appropriate identification and establishment of standards for the use of Fraxinus species as medicinal plants.

Isolation and characterization of betulinic acid from the stem bark of Feretia canthioides Hiern and its antimalarial potential

BackgroundMalaria is a parasitic disease that constitutes a major global health concern and the increasing resistance of Plasmodium falciparum strains to the commonly used antimalarial drugs has resulted in an increase in treatment failures (Zofou et al.,Malar Res Treat: 561342, 2011). Natural products isolated from plants used in traditional medicine have shown promising antimalarial actions in vitro, and these plants can serve as potential sources for new antimalarial drugs (Wright et al.,Phytother Res 8:149–152, 1994); hence, research into the use of medicinal plants for the treatment of malaria would provide viable options in the effective control of the disease by screening plant extracts for antimalarial activities and also isolating bioactive components from these extracts using TLC and column chromatographic techniques.This research was focused on investigating the antimalarial potentials of the stem bark of Feretia canthioides Hiern used in the traditional treatment of malaria in Nigeria.ResultsIn vitro antimalarial tests carried out on the plant extracts and isolated compound in this research revealed that the methanol extract displayed promising antimalarial activities with an inhibitory concentration (IC50) value of 7.76 μg/ml, the n-hexane extract showed low activity with an IC50 value of 63.10 μg/ml, while the ethyl acetate and dichloromethane extracts were found to be inactive with IC50 values above 100 μg/ml. The isolated compound (betulinic acid) showed good antimalarial activity with an IC50 value of 12.60 μg/ml when compared with chloroquine phosphate which served as the positive control.Detailed phytochemical screening of the plant extracts obtained after extraction of the plant material indicated that the methanolic extract of the stem bark of Feretia canthioides Hiern contained major plant secondary metabolites which include tannins, alkaloids, terpenoids, flavonoids, steroids, alkaloids, saponins and glycosides. Chromatographic techniques carried out on the methanolic extract of this plant led to the isolation of a pentacyclic triterpenoid compound identified to be betulinic acid which is been reported for the first time from the methanolic extract of the stem bark of this plant.ConclusionThe inhibitory concentration values (IC50) of the methanolic extract and isolated compound in this research prove that this plant can serve as an effective agent for the treatment of malaria. This research concluded that the stem bark of Feretia canthioides Hiern can be further investigated as a prospective antimalarial agent.

Glyceollin Transcription Factor GmMYB29A2 Regulates Soybean Resistance to Phytophthora sojae.

Glyceollin isomers I, II, and III are the major pathogen-elicited secondary metabolites (i.e. phytoalexins) of soybean (Glycine max) that, collectively with other 5-deoxyisoflavonoids, provide race-specific resistance to Phytophthora sojae. The NAC-family transcription factor (TF) GmNAC42-1 is an essential regulator of some but not all glyceollin biosynthesis genes, indicating other essential TF(s) of the glyceollin gene regulatory network remain to be identified. Here, we conducted comparative transcriptomics on soybean hairy roots of the variety Williams 82 and imbibing seeds of Harosoy 63 upon treatment with wall glucan elicitor from P. sojae and identified two homologous R2R3-type MYB TF genes, GmMYB29A1 and GmMYB29A2, up-regulated during the times of peak glyceollin biosynthesis. Overexpression and RNA interference silencing of GmMYB29A2 increased and decreased expression of GmNAC42-1, GmMYB29A1, and glyceollin biosynthesis genes and metabolites, respectively, in response to wall glucan elicitor. By contrast, overexpressing or silencing GmMYB29A1 decreased glyceollin I accumulation with marginal or no effects on the expressions of glyceollin synthesis genes, suggesting a preferential role in promoting glyceollin turnover and/or competing biosynthetic pathways. GmMYB29A2 interacted with the promoters of two glyceollin I biosynthesis genes in vitro and in vivo. Silencing GmMYB29A2 in Williams 82, a soybean variety that encodes the resistance gene Rps1k, rendered it compatible with race 1 P. sojae, whereas overexpressing GmMYB29A2 rendered the susceptible Williams variety incompatible. Compatibility and incompatibility coincided with reduced and enhanced accumulations of glyceollin I but not other 5-deoxyisoflavonoids. Thus, GmMYB29A2 is essential for accumulation of glyceollin I and expression of Phytophthora resistance.