Variety Of Secondary Metabolites Research Articles

Inhibitory Activity of Enzyme Α-Glucosidase Ethanol Extract Combination Of Mareme Plant (Glochidion arborescens (Müll. Arg.) Boerl.) Leaves And Sala Plant (Cynometra ramiflora Linn) Leaves

Diabetes Mellitus (DM) is still one of the world's major health problems, contributing to many complications leading to increased morbidity and mortality. Different approaches have been performed to enhance the patient's quality of life. Over the past decade, due to a trend in herbal medicines, numerous plants have been claimed to be advantageous in alleviating DM features in pre-clinical research, including Mareme and Sala plants. Mareme and Sala leaves contain flavonoid compounds which are potential as antidiabetic agents. This study aimed to determine the in vitro inhibitory activity of the ethanolic extracts of both plants on the α-glucosidase enzyme that plays a pivotal role in diabetic pathophysiology. The inhibition potential of the combination of Mareme and Sala leaf ethanol extracts and the positive control, namely acarbose, were measured using an ELISA reader at 450 nm based on the formation of p-nitrophenol. The ELISA reader measurements showed that the combination of Mareme leaves and Sala leaf ethanol extract could not inhibit α-glucosidase activity in vitro, indicated by the IC50 calculation of 374.47 ppm. Nevertheless, our research revealed the presence of diverse secondary metabolites, including flavonoids, in both extracts, which could potentially be responsible for further pharmacological activities.

Insights into the Potential Role of Gordonia alkanivorans Strains in Biotechnologies

Members of many species of the genus Gordonia are known for their significant metabolic potential, including the ability to utilize compounds of different structures. The aim of the work was to study the ability of nine G. alkanivorans strains to degrade persistent organic pollutants and to analyze the genomic peculiarities of these strains. The genomes of nine Gordonia alkanivorans strains were sequenced and assembled. The utilization of these strains as alkane and benzoate degraders in environmental biotechnologies, coupled with their capacity to potentially produce diverse secondary metabolites, holds promising prospects for both environmental and pharmaceutical applications.

Diverse biological activities and secondary metabolites profile of Penicillium brevicompactum HE19ct isolated from the high-Andean medicinal plant Perezia coerulescens

Endophytic fungi produced attractive primary and secondary metabolites for industries, pharmacology, and biotechnology. The bioactive potential of HE19ct, identified as Penicillium brevicompactum according to ITS-BenA-caM, was addressed. Antimicrobial and antioxidant activities and secondary metabolite contents using four culture media in Agar-plate (ApF) and Submerged (SmF) fermentation were evaluated. Some plant growth-promoting (PGP) traits and their related genes were tested. HE19ct exhibited antimicrobial activity against Staphylococcus aureus, Enterococcus faecalis, Candida albicans, C. tropicalis, Fusarium sp., Geotrichum candidum, and Alternaria sp. All cultures showed DPPH scavenging activity and phenolic compounds, where ethyl acetate extract of SmF with malt extract showed higher activity and SmF/ApF with potato-dextrose exhibited higher yield, respectively. HE19ct solubilized tricalcium-phosphate and produced siderophore, endoglucanase, proteinase, and amylase. It enhanced the alfalfa's germination at 15 °C, root development, and phenols production at 15 and 24 °C. Phenols, tannins, anthraquinones, triterpenoids/steroids, and alkaloids production were detected depending on culture media. Polyketide synthase type I gene (PksI), subtilisin-like protease prb 1 (Pbr), and siderophore D (sidD) were PCR-amplified. Finally, HE19CT could be a promising source of interesting bioactive compounds for pharmacology and agriculture mainly in extreme conditions, then metabolomic and functional genetic research must be performed to support their appropriate application.

Long-Term Investigation of Marine-Derived Aspergillus Diversity in the Republic of Korea

Aspergillus species play a crucial role in terrestrial environments as degraders and are well known for producing various secondary metabolites. Recently, Aspergillus species have been discovered in marine environments, exhibiting adaptability to high salinity and producing diverse secondary metabolites with valuable properties. However, limited research has focused on their marine diversity, leading to inaccurate species identification. The current study addresses this gap by investigating diverse marine habitats in the Republic of Korea, including sediment, seawater, seaweed, and marine animals. From three coasts of the Korean Peninsula, 472 Aspergillus strains were isolated from the various marine habitats. A total of 41 species were accurately identified using multigenetic markers: internal transcribed spacer, calmodulin, and β-tubulin. The findings underscore the importance of accurate identification and provide a basis for elucidating the functional role of marine-derived Aspergillus species in marine ecosystems.

Chemical profiling of botanical extracts obtained in NADES systems using centrifugal partition chromatography combined with 13 C NMR dereplication-Hypericum perforatum as a case study.

Natural deep eutectic solvents (NADES) have emerged as interesting extractants to develop botanical ingredients. They are nontoxic and biodegradable, nonflammable, easy to prepare, and able to solubilize a wide range of molecules. However, NADES extracts remain difficult to analyze because the metabolites of interest stay highly diluted in the nonvolatile viscous NADES matrix. This study presents a robust analytical workflow for the chemical profiling of NADES extracts. It is applied to Hypericum perforatum aerial parts extracted with the neutral mixture fructose/glycerol/water (3/1/1, w/w/w), and compared to the chemical profiling of a classical dry methanol extract. Exploiting polarity differences between metabolites, the H. perforatum NADES extract was partitioned in a liquid-liquid solvent system to trap the hydrophilic NADES constituents in the lower phase. The upper phase, containing a diversity of secondary metabolites from H. perforatum, was fractionated by centrifugal partition chromatography. All fractions were chemically investigated using a 13 C NMR dereplication method which involves hierarchical clustering analysis of the whole NMR dataset, a natural metabolite database for metabolite identification, and 2D NMR analyses for validation. Liquid chromatography-mass spectrometry (LC-MS) analyses were also performed to complete the identification process. A range of 21 metabolites were unambiguously identified, including glycosylated flavonols, lactones, catechins, phenolic acids, lipids, and simple sugars, and 15 additional minor extract constituents were annotated by LC-MS based on exact mass measurements. The proposed identification process is rapid and nondestructive and provides good prospects to deeply characterize botanical extracts obtained in nonvolatile and viscous NADES systems.

Multi-integrated approach for unraveling small open reading frames potentially associated with secondary metabolism in Streptomyces.

Small open reading frames (smORFs) are widely distributed in various living organisms. However, their functions remain largely unexplored. In addition, annotation and detection of smORFs are limited using existing methods and hindered by their specific properties. In this study, we systematically investigated smORFs and smORF-encoded peptides (SEPs) in Streptomyces, which are well-known bacterial producers of diverse bioactive secondary metabolites. We established a peptidogenomic workflow based on multi-integrated comprehensive database search and database-independent de novo sequencing to identify smORFs in Streptomyces xinghaiensis NRRL B-24674T (S187). In addition, we described SEPome related to the secondary metabolism, which include 68 novel SEPs and 79 common smORFs with Streptomyces coelicolor A3 (2). Functional analysis of universal smORFs revealed enrichment in biosynthetic processes, stress response, ribosomes, and nucleic acid binding. Meanwhile, 5 Cryptic smORF-encoded Peptides (CSEPs) distributed in non-annotated regions of the genome, and non-coding RNAs could encode for CSEPs. A total of 66 new RNAs, including 32 non-coding RNAs (ncRNAs) were revealed, and 4 ncRNA-encoded peptides were identified. Furthermore, an investigation of carbon metabolism showed that NagE functions in spore formation and secondary metabolism in Streptomyces. Particularly, NagE was observed to function in the biosynthesis of anti-complement agents in S. xinghaiensis, suggesting a novel role of the phosphoenolpyruvate phosphotransferase system in microbial secondary metabolism. We thus provide an effective strategy for analyzing public data sets of model strains to identify smORFs for non-model species. The ncRNAs and SEPs present rich sources for engineering streptomycetes to produce bioactive compounds. IMPORTANCE Due to their small size and special chemical features, small open reading frame (smORF)-encoding peptides (SEPs) are often neglected. However, they may play critical roles in regulating gene expression, enzyme activity, and metabolite production. Studies on bacterial microproteins have mainly focused on pathogenic bacteria, which are importance to systematically investigate SEPs in streptomycetes and are rich sources of bioactive secondary metabolites. Our study is the first to perform a global identification of smORFs in streptomycetes. We established a peptidogenomic workflow for non-model microbial strains and identified multiple novel smORFs that are potentially linked to secondary metabolism in streptomycetes. Our multi-integrated approach in this study is meaningful to improve the quality and quantity of the detected smORFs. Ultimately, the workflow we established could be extended to other organisms and would benefit the genome mining of microproteins with critical functions for regulation and engineering useful microorganisms.

Predation-resistant Pseudomonas bacteria engage in symbiont-like behavior with the social amoeba Dictyostelium discoideum

The soil amoeba Dictyostelium discoideum acts as both a predator and potential host for diverse bacteria. We tested fifteen Pseudomonas strains that were isolated from transiently infected wild D. discoideum for ability to escape predation and infect D. discoideum fruiting bodies. Three predation-resistant strains frequently caused extracellular infections of fruiting bodies but were not found within spores. Furthermore, infection by one of these species induces secondary infections and suppresses predation of otherwise edible bacteria. Another strain can persist inside of amoebae after being phagocytosed but is rarely taken up. We sequenced isolate genomes and discovered that predation-resistant isolates are not monophyletic. Many Pseudomonas isolates encode secretion systems and toxins known to improve resistance to phagocytosis in other species, as well as diverse secondary metabolite biosynthetic gene clusters that may contribute to predation resistance. However, the distribution of these genes alone cannot explain why some strains are edible and others are not. Each lineage may employ a unique mechanism for resistance.

Ethnopharmacological Survey, Phytochemical Screening and Antimicrobial Activities of Medicinal Plants Used in the Treatment of Diarrhea in Southeastern Gabon.

Diarrhea is a condition that particularly affects children under five the age of years old in developing countries. The aim of this study was to evaluate the efficacy of medicinal extracts plants used in treatment and to characterize their inhibitory capacity in the growth of bacteria isolates in childhood diarrhea in the southeast region of Gabon. An ethnobotanical survey on the plants used in the treatment of diarrhea in southeastern Gabon was carried out and a phytochemical screening of the collected plants was performed. The antimicrobial activity of aqueous extracts was evaluated; 33 plant species were identified, representing 28 genera and 19 families. Bark (39.5%) was the most commonly used plant part, followed by powder formulations (28.9%). The preferred method of preparation and chewing (44.7%), together with drinking (36.8%), were the most prevalent modes of administration. Phytochemical screening showed a plethora of secondary metabolites (terpenoids, alkaloids and phenolic compounds), and a marked level of anti-diarrheal activity was found with Sida acuta and Santiria. ebo against Shigella spp. (16.22 ± 0.7 mm and 14.05 ± 1.4 mm) and Yersinia pestis (16.35 ± 0.5 mm and 15.51 ± 0.5 mm). The high diversity of secondary plant metabolites and their inhibitory ability against enteric pathogens would justify their use at the local level to treat diarrheal infections.

Sapindus saponaria (Sapindaceae): Chemical Composition and Toxic Effect on Artemia salina (Artemiidae) and Aedes aegypti (Culicidae)

Purpose: Phytochemical analysis of Sapindus saponaria leaves extracts, evaluating their effect on Artemia salina and Aedes aegypti larvae. Theoretical framework: Dengue is a disease transmitted by Aedes aegypti mosquitoes and considered a serious public health problem. Its control is done through the management of adult forms of A. aegypti, which occurs through the application of synthetic insecticides. However, its constant use has selected populations of insects resistant to chemical products and for this reason alternative solutions are sought, such as the use of phytoinsecticides. Method/design/approach: Leaves were collected in areas of native vegetation, from which the ethanolic, aqueous and acetonitrile extracts were obtained, in addition to the ethanolic extract fractions, submitted to phytochemical analysis, with A. aegypti and A. salina larvae used to evaluate the toxic effect of extracts and fractions. Results and conclusion: The ethanol extract showed the greatest diversity of secondary metabolites, the best CL90 and 100% larval mortality, negatively affecting larval time and larval and pupal mortality, in addition to decreasing the number of formed alates. The inhibitory effect is probably linked to the presence of cardiotonic saponins and heterosides, known for their deleterious action in organisms. Research implications: The research indicates the potential use of Sapindus saponaria leaves in the control of the dengue vector. Originality/value: Viability of plant strata for vector control, reducing the application of synthetic insecticides and improving environmental quality.

The Effect of Kepel Fruit Extract on The Number of Spermatogenic Cells in Mice (Mus musculus)

The Kepel plant (Stelechocarpus burahol) has garnered research interest due to its diverse secondary metabolites like alkaloids, flavonoids, polyphenols, saponins, triterpenoids, and quinones, thought to impact fertility. This research aims to determine the effect of kepel fruit extract on the number of spermatogenic cells in mice (Mus musculus), consisting of spermatogonia cells, spermatocyte cells, and spermatid cells. Employing a Posttest-Only Control Design, Kepel extraction used 95% ethanol via maceration. 25 mice were divided into groups: positive control, negative control, groups I, II, and III exposed to 50, 100, and 150 mg/kgBW Kepel extract for 36 days. Randomized group design determined sample selection, assessing seminiferous tubules via four fields of vision. Statistical analysis involved one-way ANOVA (5% significance) and LSD test for disparities. Data were analyzed using SPSS 25. ANOVA revealed no significant difference (p > 0.05) in mean spermatogonia and spermatocyte cell counts between control and treatment groups (I, II, III). However, groups I, II, and III exhibited significant spermatid cell reduction. In conclusion, Kepel fruit extract at 50 mg/kgBW, 100 mg/kgBW, and 150 mg/kgBW could lower spermatid cell count, indicating potential as an antifertility agent.

Endophytic Bacillus aerophilus from the Leaves of Azadirachta indica as a Potential Biocontrol against Staphylococcus aureus

Aims: The study entailed isolation and identification of Bacillus aerophilus in the leaves of young Azadirachta indica plants, establishing the antimicrobial activity of the endophyte against Staphylococcus aureus, and screening for phytochemicals. The study investigated the potential of the endophytic Bacillus aerophilus in pathogen inhibition and phytochemical screening for bioactive compounds produced by the endophyte that can be used in drug development. The research contributes to the wider scientific goal of curbing rising cases of antibiotic resistance.
 Place and Duration of Study: Sample: collected from Kanyonyoo in Kitui County, between August 2022 and June 2023.
 Methodology: The bacteria were aseptically isolated and sub-cultured on nutrient agar. For identification, the bacteria underwent biochemical tests and molecular characterization. The 16S rRNA region was amplified and sequenced using universal primers 27F and 1492R. Bacterial isolate K1L003 was identified as Bacillus aerophilus. For antimicrobial testing, the agar disk diffusion method was used against pathogenic Staphylococcus aureus on Mueller Hinton Agar plates (MHA). The controls were doxycycline and vancomycin.
 Results: The endophytic isolate only inhibited Staphylococcus aureus (P < .001), with an inhibition mean similar to doxycycline (26 mm), against the pathogen. The endophytic isolate produced terpenoids, saponins, alkaloids, and flavonoids.
 Conclusion: Endophytic Bacillus aerophilus has better antimicrobial inhibition potential than vancomycin, against Staphylococcus aureus and produces diverse bioactive secondary metabolites. The endophyte has the potential to produce compounds that are useful in treating drug-resistant Staphylococcal infections.

Phytochemical diversity impacts herbivory in a tropical rainforest tree community.

Metabolomics provides an unprecedented window into diverse plant secondary metabolites that represent a potentially critical niche dimension in tropical forests underlying species coexistence. Here, we used untargeted metabolomics to evaluate chemical composition of 358 tree species and its relationship with phylogeny and variation in light environment, soil nutrients, and insect herbivore leaf damage in a tropical rainforest plot. We report no phylogenetic signal in most compound classes, indicating rapid diversification in tree metabolomes. We found that locally co-occurring species were more chemically dissimilar than random and that local chemical dispersion and metabolite diversity were associated with lower herbivory, especially that of specialist insect herbivores. Our results highlight the role of secondary metabolites in mediating plant-herbivore interactions and their potential to facilitate niche differentiation in a manner that contributes to species coexistence. Furthermore, our findings suggest that specialist herbivore pressure is an important mechanism promoting phytochemical diversity in tropical forests.

Genome sequences of key bacterial symbionts of entomopathogenic nematodes: Xenorhabdus cabanillasii DSM17905, Xenorhabdus ehlersii DSM16337, Xenorhabdus japonica DSM16522, Xenorhabdus koppenhoeferii DSM18168, and Xenorhabdus mauleonii DSM17908.

Xenorhabdus species are bacterial symbionts of entomopathogenic Steinernema nematodes, in which they produce diverse secondary metabolites implicated in pathogenesis. To expand resources for natural product prospecting and exploration of host-symbiont-pathogen relationships, the genomes of Xenorhabdus cabanillasi, Xenorhabdus ehlersii, Xenorhabdus japonica, Xenorhabdus koppenhoeferii, and Xenorhabdus mauleonii were analyzed.

Jasmonates Coordinate Secondary with Primary Metabolism.

Jasmonates (JAs), including jasmonic acid (JA), its precursor 12-oxo-phytodienoic acid (OPDA) and its derivatives jasmonoyl-isoleucine (JA-Ile), methyl jasmonate (MeJA), cis-jasmone (CJ) and other oxylipins, are important in the regulation of a range of ecological interactions of plants with their abiotic and particularly their biotic environments. Plant secondary/specialized metabolites play critical roles in implementing these ecological functions of JAs. Pathway and transcriptional regulation analyses have established a central role of JA-Ile-mediated core signaling in promoting the biosynthesis of a great diversity of secondary metabolites. Here, we summarized the advances in JAs-induced secondary metabolites, particularly in secondary metabolites induced by OPDA and volatile organic compounds (VOCs) induced by CJ through signaling independent of JA-Ile. The roles of JAs in integrating and coordinating the primary and secondary metabolism, thereby orchestrating plant growth-defense tradeoffs, were highlighted and discussed. Finally, we provided perspectives on the improvement of the adaptability and resilience of plants to changing environments and the production of valuable phytochemicals by exploiting JAs-regulated secondary metabolites.

α-Glucosidase, Angiotensin-converting Enzyme, and Acetylcholinesterase Inhibitory Activities of a Marine Red Alga Galaxaura oblongata

Seaweeds have gained interest from the pharmaceutical industry due to their diverse secondary metabolites with potential applications in the prevention and treatment of lifestyle diseases. In spite of the abundance of seaweeds in the coastal area of Iligan Bay in the Philippines, there has been limited investigation into their pharmacological properties. Therefore, this study aimed to evaluate the in vitro α-glucosidase inhibition, angiotensin-converting enzyme (ACE) inhibition, and acetylcholinesterase (AChE) inhibition properties of various fractions obtained from the marine red alga Galaxaura oblongata. The methanol extract of G. oblongata was sequentially partitioned into hexane, dichloromethane, ethyl acetate, butanol, and methanol fractions. All assays were performed in vitro and microplate based. The results of α-glucosidase inhibition activity assay showed that the n-hexane fraction and dichloromethane fraction exhibited greater than 50% inhibitory activity at 200 ppm. Furthermore, ACE inhibition activity assay revealed that dichloromethane fraction, ethyl acetate fraction, and butanol fraction displayed ACE inhibition activity above 50% at 250 ppm. In addition, the hexane fraction, dichloromethane fraction, and ethyl acetate fraction demonstrated potent AChE inhibitory activity at 250 ppm. Overall, the findings show that G. oblongata has antidiabetic, anti-hypertensive, and neuroprotective potentials. This is the first report of the in vitro α-Glucosidase, ACE, and AChE inhibition activities of G. oblongata. Further investigation and purification of the highly potent fractions in each assay is highly suggested to identify and characterize the compounds responsible for the observed bioactivities, which could serve as possible leads for drug discovery efforts in the management of various lifestyle diseases.

High throughput pre-breeding evaluation of Greek oregano (Origanum vulgare L. subsp. hirtum) reveals multi-purpose genotypes for different industrial uses

Origanum vulgare L. subsp. hirtum (commonly known as Greek oregano) is a perennial species of the Lamiaceae family that counts numerous applications in the food and pharmaceutical industry. The exploitation of Greek oregano germplasm lies in its unique diversity in secondary metabolites, which are accumulated in the aerial parts of the plant. For the industrial exploitation of this crop the starting germplasm is of high importance in terms of valorizing well characterized chemotypes with desired and stable agronomic and phytochemical traits. For this reason, a pre-breeding evaluation of twenty-one accessions collected and preserved under the same environmental conditions was performed in order to develop a descriptive database containing: a) morphometric traits, b) the genetic structure, c) the extensive metabolic fingerprint in terms of volatile composition, polyphenolic and triterpenoid content, and d) the ‘bio-activity’ on the embryonic development of Ascaridia galli eggs for highly divergent accessions. This study revealed the existence of essential oil rich chemotypes superior in morphometric characteristics, containing high carvacrol content (> 75%) and traces of thymol (< 5%), according to the requested international standards. Apart from genotypes considered as ‘high yield essential oil-producers’ (> 6%), accessions of highly productivity of ‘green’ raw materials rich in polyphenols and triterpenoids were also identified. According to their rosmarinic acid content, Greek oregano accessions were classified in three groups; 1) those with significantly high concentration (1640–2726 mg 100 g−1 dry weight), 2) those expressing intermediate content (1103–1200 mg 100 g−1 dry weight), and 3) the ones with significantly low content (< 873 mg 100 g−1 dry weight). A total of 118 polymorphic alleles were identified using sequence-related amplified polymorphism (SRAPs) and simple sequence repeat (SSRs) markers, while 2 genetic clusters based on a single data matrix with SRAPs and SSRs alleles, were identified. The presence of private bands in some accessions was also observed, which can be used in future breeding programs for germplasm authentication purposes. As a result this study provides a comprehensive knowledge on metabolic and genetic diversity of Greek oregano accessions native to Greece, as well as powerful tools for the selection of starting genetic materials for subsequent breeding studies to create superior cultivars. The multifaceted approach was developed to exploit the genetic resources of Greek oregano in further breeding programs for subsequent selection of genotypes with desired traits.

A New Species and Five New Records of Talaromyces (Eurotiales, Aspergillaceae) Belonging to Section Talaromyces in Korea

Talaromyces is a genus within the phylum Ascomycota (class Eurotiomycetes, order Eurotiales, family Trichocomaceae). Many species in this genus are known to produce diverse secondary metabolites with great potential for agricultural, medical, and pharmaceutical applications. During a survey on fungal diversity in the genus Talaromyces in Korea, six strains were isolated from soil, indoor air, and freshwater environments. Based on morphological, physiological, and multi-locus (ITS, BenA, CaM, and RPB2) phylogenetic analyses, we identified five previously unrecorded species in Korea (T. brevis, T. fusiformis, T. muroii, T. ruber, and T. soli) and a new species (T. echinulatus sp. nov.) belonging to section Talaromyces. Herein, detailed descriptions, illustrations, and phylogenetic tree are provided.

Inter- and intraspecific diversity of Salix bark phenolic profiles – A resource for the pharmaceutical industry

Due to their content of phenolic compounds, willow bark preparations are used as an herbal remedy. The large diversity of phenolic secondary metabolites in Salix still provides a resource for the identification of bioactive compounds in particular species, including species not yet in focus from a phytopharmaceutical perspective. The present study describes the bark phenolic profile of 13 Salix species analyzed by HPLC-MS: Salix alba, Salix babylonica, Salix daphnoides, Salix fragilis, Salix hastata, Salix myrsinifolia, Salix pentandra, Salix purpurea, Salix repens (including subspecies S. repens ssp. arenaria and S. repens ssp. repens), Salix rosmarinifolia, Salix sachalinensis, Salix triandra and Salix viminalis. The analyzed profiles comprised the chemical groups of salicylates, flavonoids, procyanidins, phenolic acid derivatives, and some unclassified phenolics. Particular compounds were detected in species where they have not been previously reported. Apart from interspecific diversity, qualitative variability within species was observed as certain components were detected only in some of the analyzed genotypes. The knowledge on specific phenolic profiles of species and genotypes is the basis for the selection of suitable willow bark material with certain desired bioactive properties. Furthermore, the high inter- and intraspecific variability points out the necessity for product standardization of willow bark raw material.

The Optimization of Medium Conditions and Auxins in the Induction of Adventitious Roots of Pokeweed (Phytolacca americana L.) and Their Phytochemical Constituents.

Pokeweed, Phytolacca americana L., is considered a widely spreading invasive plant, while saponin contents accumulated in the roots have pharmaceutical uses, such as rheumatism treatments and anti-inflammation. Adventitious root cultures are an important source of diverse secondary metabolites, which have significant applications in various fields. This study focused on the optimization of parameters for root induction using different medium states and treatments with auxins on a pokeweed leaf. Semisolid and liquid MS (Murashige and Skoog, 1962) media were supplemented with indole-3-butyric acid (IBA) and 1-naphthylacetic acid (NAA) at 0.5, 1, 2, and 4 mg/L. Root growth parameters, e.g., induction percentage, root numbers, length, and weight, were measured to determine the adventitious root induction efficiency. Total phenolic content, total flavonoid content, total saponin content, and antioxidant activity were recorded. Results showed that adventitious roots induced in semisolid MS medium supplemented with 0.5 mg/L NAA exhibited a high density of lateral roots. Appropriate medium state and auxin for adventitious root induction in pokeweed were determined as semisolid medium supplemented with 2 mg/L NAA. Considering phytochemicals, adventitious roots induced in liquid medium containing 0.5-1 mg/L NAA had the highest yield extract percentage. Additionally, adventitious roots cultivated in a liquid medium enriched with 1 mg/L NAA exhibited the highest phenolic and saponin contents. A principal component analysis (PCA) biplot and hierarchical cluster analysis (HCA) heatmap demonstrated different response patterns between semisolid and liquid media applied with NAA. The results of the semisolid media were grouped together due to high expression levels of the root induction parameters, while elevated phytochemical values were observed in the liquid media treatments. The results suggested two different media that provide the highest adventitious root induction efficiency and the greatest phytochemical contents: semisolid medium with 2 mg/L NAA and liquid medium with 1 mg/L NAA, respectively. These culture media can be applied to optimize adventitious root culture of pokeweed and in vitro phytochemical production.

Stevia rebaudiana leaves fermented by Lactobacillus plantarum exhibit resistance to microorganisms and cancer cell lines in vitro: A potential sausage preservative

Natural preservatives are causing a rethinking of current preservation means. As a sweetener resource, exploitation of Stevia rebaudiana leaves (SRLs) is still restricted due to human conventional cognition. Herein, Lactobacillus plantarum fermented SRLs containing diverse free secondary metabolites derived from microbial deglycosylation and bioenzymatic decomposition were investigated. The apparent resistance to typical foodborne bacteria (Escherichia coli, Staphylococcus aureus, Bacillus subtilis, Pseudomoas aeruginosa, Bacillus amyloliquefaciens) by fermented SRLs and their extracts were validated. The metabolite diversity and in-depth organic solvent extraction gave the possibilities for better antimicrobial actions, anti-HepG2/SGC-7901 cells in vitro in contrast with aqueous extract of unfermented SRLs. Crucially, compound identification and attribution revealed that fermentation products may be maximally contributing to antimicrobial and antitumor mechanisms rather than intrinsic plant and/or microbial components. Additionally, pork sausage models with 15 g/kg ethyl acetate extract as a preservative candidate presented preferred storage characteristics (21 days and 37 °C) compared to those without ethyl acetate extract, e.g. the minimal total plate count (3.86 ± 0.27 log CFU/g), peroxsignide value (8.02 ± 0.92 meq/kg), and acid value (2.01 ± 0.04 (KOH)/(mg/g)).