Valuable Secondary Metabolites Research Articles

How climate change-related abiotic factors affect the production of industrial valuable compounds in Lamiaceae plant species: a review.

The interest in medicinal and aromatic plants (MAPs) has increased significantly in recent years, driven by the growing demand for natural products. MAPs are a valuable source of secondary metabolites, which renders them useful to a number of industries, including cosmetics, pharmaceuticals, and food. The Lamiaceae family includes economically important MAPs that produce valuable secondary metabolites such as essential oils (EOs) and phenolic compounds (PCs). The quantity and quality of these secondary metabolites are affected by abiotic stress factors. In a climate change scenario, the Lamiaceae is one of the most affected families, especially due to its wide distribution in the Mediterranean region. In the present study, the most common climate-related environmental stress factors, namely, drought, salinity, temperature, light, and heavy metals, were reviewed and discussed in order to assess their impact on the chemical profiles of EOs and PCs, as well as on the biological properties (antioxidant, antibacterial, antimelanogenic, pest-repellent, and UV-protective) of Lamiaceae species. It can be posited that these stresses typically act as a catalyst for the secondary metabolism of these plants, resulting in increased production of EO compounds (e.g., 1,8-cineole, linalool, camphor, borneol, and limonene) and PCs (e.g., rosmarinic, caffeic, and salvianolic acids) and subsequent enhancement of their biological activities. In view of the industrial applications of these bioactive compounds, it is of interest to explore the changes in secondary metabolism induced by environmental factors as it is possible to increase the accumulation of valuable secondary metabolites.

Co-regulatory network analysis of the main secondary metabolite (SM) biosynthesis in Crocus sativus L.

Saffron (Crocus sativus L.) is being embraced as the most important medicinal plant and the commercial source of saffron spice. Despite the beneficial economic and medicinal properties of saffron, the regulatory mechanism of the correlation of TFs and genes related to the biosynthesis of the apocarotenoids pathway is less obvious. Realizing these regulatory hierarchies of gene expression networks related to secondary metabolites production events is the main challenge owing to the complex and extensive interactions between the genetic behaviors. Recently, high throughput expression data have been highly feasible for constructing co-regulation networks to reveal the regulated processes and identifying novel candidate hub genes in response to complex processes of the biosynthesis of secondary metabolites. Herein, we performed Weighted Gene Co-expression Network Analysis (WGCNA), a systems biology method, to identify 11 regulated modules and hub TFs related to secondary metabolites. Three specialized modules were found in the apocarotenoids pathway. Several hub TFs were identified in notable modules, including MADS, C2H2, ERF, bZIP, HD-ZIP, and zinc finger protein MYB and HB, which were potentially associated with apocarotenoid biosynthesis. Furthermore, the expression levels of six hub TFs and six co-regulated genes of apocarotenoids were validated with RT-qPCR. The results confirmed that hub TFs specially MADS, C2H2, and ERF had a high correlation (P < 0.05) and a positive effect on genes under their control in apocarotenoid biosynthesis (CCD2, GLT2, and ADH) among different C. sativus ecotypes in which the metabolite contents were assayed. Promoter analysis of the co-expressed genes of the modules involved in apocarotenoids biosynthesis pathway suggested that not only are the genes co-expressed, but also share common regulatory motifs specially related to hub TFs of each module and that they may describe their common regulation. The result can be used to engineer valuable secondary metabolites of C. sativus by manipulating the hub regulatory TFs.

Corylus avellana as a potential alternative source for the production of taxol and taxanes

This paper demonstrates the increased interest that scientists have recently shown in the non-food components of the hazel plant, such as leaves, as well as hard and green shells, in addition to the nuts. The review discusses studies conducted to determine the qualitative and quantitative profiles of different parts of Corylus avellana. It has been demonstrated that extracts made from various Corylus avellana components possess a variety of biological properties, such as anticancer, antiproliferative, and antioxidant effects. It has been shown that secondary metabolites can be directly synthesized by in vitro cell culture, which allows the production of valuable secondary metabolites such as paclitaxel, one of the most important anticancer compounds synthesized by hazel. A brief review of existing literature data serves to emphasize C.avellana as a source of bioactive compounds. Further research is needed to explore the health benefits of C.avellana extracts and their use as food supplements. Keywords: Hazel, Corylus avellana, secondary metabolites, taxol, anticancer drug

Improvement of sulforaphane production in hairy root cultures of broccoli (Brassica oleracea L. var. italica) by eliciting Myrosinase gene expression and its effect on breast cancer cells

Plant-derived hairy root cultures have the potential to be a significant biotechnological tool for producing valuable secondary metabolite compounds. This study deals with the production of broccoli’s hairy root cultures via the mediation of Agrobacterium rhizogenes and investigates the effects of different concentrations of copper sulfate (CuSO4) and zinc sulfate (ZnSO4) as two elicitors on the production of sulforaphane in broccoli's hairy root. The expression of the Myrosinase (MY) gene, associated with sulforaphane production, was quantified using real-time PCR. Moreover, the cytotoxic effect of different treatments of sulforaphane on the breast cancer cell line, MDA-MB-231, was estimated and the transcription levels of apoptosis-associated genes were also determined. The highest amount of sulforaphane was produced at 4 µM CuSO4 after 16 h and 16 µM ZnSO4 after 8 h of elicitation. Overexpression of the MY gene was found to be associated with increased production of sulforaphane. All sulforaphane treatments induced a dose-dependent reduction in the viability of cancer cells. The sulforaphane extracted from broccoli's hairy roots treated with CuSO4 exerted a higher cytotoxic effect on the MDA-MB-231 breast cancer cell line than the sulforaphane extracted from broccoli's hairy root treated with ZnSO4. All treatments of sulforaphane up-regulated the Apoptosis Regulator (Bax) gene, Proapoptotic Bcl2 Associated X, Caspase-3, Caspase-8, and Caspase-9, while down-regulating the B-cell lymphoma 2 (Bcl-2) gene (antiapoptotic) transcription. The overall results showed an antiapoptotic effect of sulforaphane extract derived from broccoli's hairy roots on MDAMB-231 breast cancer cells, thereby establishing the potential anticancer activity of the sulforaphane produced in broccoli's hairy root cultures.

Mycorrhizal Symbiosis Can Change the Composition of Secondary Metabolites in Fruits of Solanum nigrum L.

Solanum nigrum is a common weed in arable land, while being used in traditional medicine around the world due to its remarkable levels of valuable secondary metabolites. Agronomic and biological techniques can alter the production of a specific metabolite by influencing plant growth and metabolism. The effects of colonization with three arbuscular mycorrhizal fungi (AMF), including Funneliformis mosseae, Rhizoglomus intraradices, and Rhizoglomus fasciculatum, on the chemical composition of S. nigrum fruits were evaluated by gas chromatography-mass spectrometry (GC-MS) analysis. More than 100 different chemical constituents were evaluated by GC-MS. Our study revealed that the levels of phenols (quinic acid), benzenes (hydroquinone), sulfur-containing compounds, lactone and carboxylic acids were improved by R. intraradices. In contrast, hydroxymethylfurfural increased by 68 % in R. fasciculatum inoculated with uninoculated S. nigrum plants, and this species was also the most efficient in inducing sugar compounds (D-galactose, lactose, and melezitose). Our results suggest that AMF colonization is an effective biological strategy that can alter the chemical composition and improve the medicinal properties of S. nigrum.

Improvement and prediction of the extraction parameters of lupeol and stigmasterol metabolites of Melia azedarach with response surface methodology

BackgroundMelia azedarach is known as a medicinal plant that has wide biological activities such as analgesic, antibacterial, and antifungal effects and is used to treat a wide range of diseases such as diarrhea, malaria, and various skin diseases. However, optimizing the extraction of valuable secondary metabolites of M. azedarach using alternative extraction methods has not been investigated. This research aims to develop an effective, fast, and environmentally friendly extraction method using Ultrasound-assisted extraction, methanol and temperature to optimize the extraction of two secondary metabolites, lupeol and stigmasterol, from young roots of M. azedarach using the response surface methodology.MethodsBox-behnken design was applied to optimize different factors (solvent, temperature, and ultrasonication time). The amounts of lupeol and stigmasterol in the root of M. azedarach were detected by the HPLC-DAD. The required time for the analysis of each sample by the HPLC-DAD system was considered to be 8 min.ResultsThe results indicated that the highest amount of lupeol (7.82 mg/g DW) and stigmasterol (6.76 mg/g DW) was obtained using 50% methanol at 45 °C and ultrasonication for 30 min, and 50% methanol in 35 °C, and ultrasonication for 30 min, respectively. Using the response surface methodology, the predicted conditions for lupeol and stigmasterol from root of M. azedarach were as follows; lupeol: 100% methanol, temperature 45 °C and ultrasonication time 40 min (14.540 mg/g DW) and stigmasterol 43.75% methanol, temperature 34.4 °C and ultrasonication time 25.3 min (5.832 mg/g DW).ConclusionsThe results showed that the amount of secondary metabolites lupeol and stigmasterol in the root of M. azedarach could be improved by optimizing the extraction process utilizing response surface methodology.

Increase of secondary metabolites in sweet basil (Ocimum basilicum L.) leaves by exposure to N2O5 with plasma technology

Exposure to N2O5 generated by plasma technology activates immunity in Arabidopsis through tryptophan metabolites. However, little is known about the effects of N2O5 exposure on other plant species. Sweet basil synthesizes many valuable secondary metabolites in its leaves. Therefore, metabolomic analyses were performed at three different exposure levels [9.7 (Ex1), 19.4 (Ex2) and 29.1 (Ex3) μmol] to assess the effects of N2O5 on basil leaves. As a result, cinnamaldehyde and phenolic acids increased with increasing doses. Certain flavonoids, columbianetin, and caryophyllene oxide increased with lower Ex1 exposure, cineole and methyl eugenol increased with moderate Ex2 exposure and l-glutathione GSH also increased with higher Ex3 exposure. Furthermore, gene expression analysis by quantitative RT-PCR showed that certain genes involved in the syntheses of secondary metabolites and jasmonic acid were significantly up-regulated early after N2O5 exposure. These results suggest that N2O5 exposure increases several valuable secondary metabolites in sweet basil leaves via plant defense responses in a controllable system.

The genomes of seven economic Caesalpinioideae trees provide insights into polyploidization history and secondary metabolite biosynthesis

The Caesalpinioideae subfamily contains many well-known trees that are important for economic sustainability and human health, but a lack of genomic resources has hindered their breeding and utilization. Here, we present chromosome-level reference genomes for the two food and industrial trees Gleditsia sinensis (921 Mb) and Biancaea sappan (872 Mb), the three shade and ornamental trees Albizia julibrissin (705 Mb), Delonix regia (580 Mb), and Acacia confusa (566 Mb), and the two pioneer and hedgerow trees Leucaena leucocephala (1338 Mb) and Mimosa bimucronata (641 Mb). Phylogenetic inference shows that the mimosoid clade has a much higher evolutionary rate than the other clades of Caesalpinioideae. Macrosynteny comparison suggests that the fusion and breakage of an unstable chromosome are responsible for the difference in basic chromosome number (13 or 14) for Caesalpinioideae. After an ancient whole-genome duplication (WGD) shared by all Caesalpinioideae species (CWGD, ∼72.0 million years ago [MYA]), there were two recent successive WGD events, LWGD-1 (16.2–19.5 MYA) and LWGD-2 (7.1–9.5 MYA), in L. leucocephala. Thereafter, ∼40% gene loss and genome-size contraction have occurred during the diploidization process in L. leucocephala. To investigate secondary metabolites, we identified all gene copies involved in mimosine metabolism in these species and found that the abundance of mimosine biosynthesis genes in L. leucocephala largely explains its high mimosine production. We also identified the set of all potential genes involved in triterpenoid saponin biosynthesis in G. sinensis, which is more complete than that based on previous transcriptome-derived unigenes. Our results and genomic resources will facilitate biological studies of Caesalpinioideae and promote the utilization of valuable secondary metabolites.

Comparison of Extraction Techniques for Determining Bioactive Compounds and Antioxidant Activity of Spirulina platensis

Spirulina platensis (S. platensis) is a high-nutrient blue-green algae that has been used as a food supplement for a long time. It contains carbohydrates, lipids, proteins, vitamins, minerals, and bioactive compounds essential for basic human nutrition. It is known to have anti-cancer, antioxidant, anti-inflammatory, neuroprotective, hepatoprotective, and hypocholesterolemic properties due to the bioactive compounds it contains. In this study, the effects of freeze-thawing, a rapid freezing (-20°C) and thawing (4°C) process, and ultrasonically assisted extraction techniques on the color, antioxidant capacity, total phenolic content, and phenolic composition of Spirulina platensis extracts were investigated. The antioxidant capacity of the extracts obtained was determined by two different methods, DPPH (2,2-diphenyl-1-picryl hydrazyl) and ABTS (2,2-azinobis (3-ethylbenzothiazollin-6-sulfonic acid)). The sugar profile was determined by HPLC-RID and phenolic composition was determined by HPLC-ESI-DAD-MS/MS. The antioxidant activity and total phenolic content of samples prepared by the freeze-thawing were higher than those prepared by ultrasonic-assisted conventional extraction technique. In addition to ferulic acid 4-O-glucuronide and brevifolin carboxylate, an isocoumarin derivative, as the dominant phenolic compound in S. platensis extracts, a total of 10 phenolic compounds including catechin isomer, resveratrol C-hexoside, myricetin, ferulic acid, gallic acid, phloroglucinol, and lutein were detected. Glucose was the predominant sugar in both samples. The total sugar content was higher in the freeze-thawed samples (217.92 mg/100 g DW) than in the ultrasonic-assisted conventional extraction technique (182.91 mg/100 g DW). S. platensis has a significant amount of antioxidants, valuable secondary metabolites, and potential commercial applications and medicinal properties, but releasing these compounds is difficult due to the cell wall. This study was carried out to determine how different extraction techniques alter the release of bioactive compounds.

Analysis of light recipe, seeding density, and fertilization effects on secondary metabolite accumulation and growth-defense responses in Brassicaceae microgreens

Although there have been large improvements to crop yield over time, this has not been accompanied by an increase in human nutritional wellbeing. In fact, there are worsening health crises associated with over- and under-consumption of particular food groups, resulting in negative human health outcomes. One solution to this is to utilize controlled environment agriculture to produce microgreens that have a high density of valuable Secondary Metabolites (SMs) such as antioxidants, phenolics, or pigment molecules that are associated with positive human health outcomes. However, optimal growth recipes to produce microgreens and their valuable nutritional compounds are not well known due to much species-specific variation, as well as biological tradeoffs between biomass and SM production. This is known as the growth defense hypothesis which describes how plants have a finite carbon budget from which to allocate to growth, or defensive, processes. To further research in this regard, this project used climate chambers to grow three species of Brassicaceae microgreens (kohlrabi, mustard, and radish) in highly controlled environmental conditions, where we used five Light Recipes, two fertilization levels, and two seeding density treatments. Our results showed that there were significant differences in SM production of these microgreens due to changes in incident light, as well as significant interactions between Fertilizer and Light Recipe for all SMs except Anthocyanins. For example, for all three species, the High Far-Red Light Recipe had the significantly highest Phenolic concentration, but with lower values of the other four SMs. The low-intensity 24-V high efficiency LEDs had the significantly highest Trolox Equivalent Antioxidant Capacity (TEAC) concentrations, while the High Red recipe had the highest Ferric Reducing Antioxidant Power (FRAP) and Flavonoid concentrations. For Anthocyanins, there were less clear patterns, with the No Green or High Red recipes having generally higher concentrations, but not always significantly. We did find some evidence supporting the growth-defense hypothesis, where our higher biomass values were negatively correlated with SM concentrations. We also found significant differences between the concentrations of SMs in leaves and stems for kohlrabi and mustard microgreens. Finally, we found some significant relationships between increasing Fertilizer dosage and SMs, for instance that Flavonoids and FRAP concentrations increased with Fertilizer application, while Anthocyanin decreased, and Phenolic and TEAC had little effect. In conclusion, we found that there were significant relationships for Light Recipe and Fertilizer, and oftentimes their interaction, for the accumulation of SMs in Brassicaceae microgreens, which can inform microgreen production environments.

Composition and antimicrobial activity of Rosmarinus officinalis L. and Artemisia monosperma L. leaf essential oils and methanolic extracts from plants grown in normal and saline habitats in Egypt

The present work aimed to investigate the effect of salinity in natural habitats in Egypt on the main secondary metabolites of Rosmarinus officinalis L. and Artemisia monosperma L. plants compared to plants grown at normal conditions. Plants grown under salinity were collected from Egyptian Western Coastal region habitats irrigated with underground water. Results showed that salinity increased the essential oil percentage of R. officinalis L. by 52.7% and A. monosperma L by 0.29% in addition to the total phenolics and flavonoids content in dry leaves compared to control plants. GC/MS analysis of rosemary essential oils revealed that salinity decreased the amount of some major oil monoterpenes component as verbenone, with a slight effect on 1,8 cineole and increased Camphor, endo- Boreneol, and linalool in addition to the appearance of new specific components such as Chrysanthenone monoterpene ketone and Caryophyllene sesquiterpene, while, in the case of Artemisia, the GC/MS showed that Artemisia ketone, Camphor, β -phellandrene monoterpenes andα-Bisabolol sesquiterpenewere the major oil components; salinity decreased Camphor and β -phellandrene content and increased artemisia ketone and α-Bisabolol oil content. About 11 new oil constituents were detected such as ( +)-2-Bornanone and Sesquisabinene hydrate. Mineral ions (N, K+, Ca+2, P, and Mg+2) uptake by R. officinalis and A. monosperma decreased in plants grown under salinity, while Na content increased compared to corresponding controls. Results demonstrated that both plants could tolerate the high salinity level in natural Western Coastal region soil which promoted more production of valuable secondary metabolites. The antimicrobial effect of R. officinalis L. and A. monosperma L. leaf methanolic extracts, results showed that R. officinalis extracts had an inhibitory response against all tested gram-positive and negative bacteria, in addition to the yeast (Candida albicans), whereas there was no any inhibitory effect concerning A. monosperma L extract on the tested species.

Genus-specific secondary metabolome in Allokutzneria and Kibdelosporangium

Rare actinomycete genera are highly recognized as a promising source of structurally diverse and bioactive natural products. Among these genera, Allokutzneria and Kibdelosporangium are two phylogenetically closely related and have been reported to encode some valuable biosynthetic enzymes and secondary metabolites. However, there is currently no relevant systematic research available to outline the linkage of genomic and metabolomics for specific secondary metabolites in these two promising genera. In this study, we first investigated the genus-specific secondary metabolic potential in Allokutzneria and Kibdelosporangium by comparing the diversity and novelty of their secondary metabolite biosynthetic gene clusters (BGCs). The specific secondary metabolites produced by two representative strains of these genera were comprehensively investigated using untargeted metabolomics techniques. The findings unveiled that the majority (95.4%) of the gene cluster families (GCFs) encoded by Allokutzneria and Kibdelosporangium were genus-specific, including NRPS GCFs encoding siderophores. The untargeted metabolomics analysis revealed that the metabolic profiles of two representative strains exhibit extensive specificity, with the culture medium having a big impact on the metabolic profiles. Besides, an MS-cluster featuring a series of hydroxamate-type siderophores was identified from Allokutzneria albata JCM 9917, with two of them, including a novel one (N-deoxy arthrobactin A), being experimentally validated. The present study offers valuable insights for the targeted discovery of genus-specific natural products from microorganisms.

Draft genome sequence of Staphylococcus auricularis PAPLE_T1 isolate of Carica papaya revealing biosynthetic clusters for beneficial metabolites.

Genomic features of Staphylococcus auricularis PAPLE_T1 isolated from waste sample of Carica papaya obtained from Lagos State, Nigeria, revealed its putative capability to synthesize valuable secondary metabolites. S. auricularis PAPLE_T1 has a 2.4 Mb genome and could be useful as biological agro-antibiotics, for soil bioremediation and in biotechnological industry.

Unveiling the anti-cancer potential of Euphorbia greenwayi: cytotoxicity, cell migration, and identification of its chemical constituents

Abstract Background Different herbal phytochemicals have potential in cancer treatment, Euphorbia genus has valuable secondary metabolites and is used in traditional medicine to treat various ailments. However, the specific constituents and biological activity of Euphorbia greenwayi remain largely unexplored. Results Euphorbia greenwayi aerial parts were extracted using methanol. Consequently, the methanol extract was then fractionated with solvents of different polarities viz., n-hexane, chloroform, and ethyl acetate. All were screened for their cytotoxic activity against different cell lines; MCF-7, HepG-2, and SW620. The n-hexane (HF) and chloroform (CF) fractions showed considerable activity against all tested cell lines especially MCF-7 with IC50 values at 18.6 ± 0.2 and 17.5 ± 0.6 μg/ml respectively. Therefore, a cell migration assay on the MCF-7 cell line was applied to both fractions as well as investigation and isolation of the main active constituents. Lupeol, β-sitosterol, and cycloartenol were isolated from the nonpolar fractions of E. greenwayi for the first time. Conclusions Euphorbia greenwayi aerial parts exhibit considerable anti-cancer effects via cytotoxicity. Three chemical constituents with promising cytotoxic activity are identified.

Bioactive compounds and DPPH antioxidant activity of underutilized macroalgae (Sargassum spp.) from coastal water of Makassar, Indonesia

Abstract. Widyaswari SG, Metusalach, Kasmiati, Amir N. 2024. Bioactive compounds and DPPH antioxidant activity of underutilized macroalgae (Sargassum spp.) from coastal water of Makassar, Indonesia. Biodiversitas 25: 176-182. This study focuses on determining the chemical component and potential of two species of macroalgae (seaweed) Sargassum spp., i.e., Sargassum polycystum and Sargassum ilicifolium from the coastal waters of Makassar City, South Sulawesi, Indonesia. Several macroalgae are highly cultivated and exported; however, these species of Sargassum remain underutilized due to limited studies on their potential. Brown algae (Phaeophyceae), especially Sargassum spp., contain secondary metabolites known for their health-promoting properties, including antioxidant effects, inhibiting oxidative stress, lowering blood pressure, and improving the immune system. The investigation analyzes the nutritional components and bioactive substances in Sargassum spp. harvested from the Makassar City coastal waters, South Sulawesi, Indonesia. Nutritional content was analyzed using proximate analysis. Phytochemical screening was conducted based on the method by Harborne method. Antioxidant activity was performed using the DPPH method. Total phenolic/flavonoid content based on spectrophotometric method. The investigation reveals the primary chemical composition of Sargassum polycystum showing the presence of valuable secondary metabolites such as alkaloids, flavonoids, phenol hydroquinone, and reactive saponins. Sargassum ilicifolium contains flavonoids, phenol hydroquinone, tannins, and steroids. The IC50 values for the antioxidant activity of S. polycystum and S. ilicifolium were 51.34 ppm and 51.25 ppm, respectively. The compounds in these seaweeds might be beneficial in promoting health. These findings suggest the possibility of underutilized seaweeds as a natural source of antioxidants in food and non-food industries.

The Effect and Potential Mechanism of Fulvic Acid on Flavonoids in Lemon Leaves

Citrus limon (L.) Burm. f. is a horticultural crop known for its abundance of valuable secondary metabolites, including flavonoids, which are found in its fruits and leaves. Our previous research has shown that treating C. limon with fulvic acid (FA) can enhance the levels of vitamin C, total acid, total sugar, total flavonoids, and phenols in its fruits as well as the volatiles and total flavonoids in its leaves. In this current study, we established a method to analyze eight specific flavonoids in lemon leaves and evaluated the impact of irrigation with FA on the content of these flavonoids over a six-month period using HPLC-DAD/MS analysis. Moreover, we investigated the potential mechanisms of FA through ELISA and q-PCR methods. The results indicated that FA increased the contents of four flavonoids, namely, isoorientin, eriocitrin, vitexin, and rutin, and promoted the activity and gene expression of phenylalanineammonialyase (PAL), 4-coumaric acid coenzyme A ligase (4CL), chalcone synthase (CHS), flavonoid 3′-hydroxylase (F3′H), and flavonol synthase (FLS). Furthermore, the relationship between flavonoid content and the activities of biosynthetic enzymes was analyzed using orthogonal partial least squares discriminant analysis (OPLS-DA), which revealed a positive correlation between seven flavonoid levels and the activity of five biosynthetic enzymes under FA treatment.

An inducible CRISPRi circuit for tunable dynamic regulation of gene expression in Saccharopolyspora erythraea.

Actinomyces are gram-positive bacteria known for their valuable secondary metabolites. Redirecting metabolic flux towards desired products in actinomycetes requires precise and dynamic regulation of gene expression. In this study, we integrated the CRISPR interference (CRISPRi) system with a cumate-inducible promoter to develop an inducible gene downregulation method in Saccharopolyspora erythraea, a prominent erythromycin-producing actinobacterium. The functionality of the cumate-inducible promoter was validated using the gusA gene as a reporter, and the successful inducible expression of the dCas9 gene was confirmed. The developed inducible CRISPRi strategy was then employed to downregulate the expression of target genes rppA in the wild-type strain NRRL2338 and sucC in the high erythromycin-producing strain E3. Through dynamic control of sucC expression, a significant enhancement in erythromycin production was achieved in strain E3. This study demonstrated the effectiveness of an inducible gene downregulation approach using CRISPRi and a cumate-inducible promoter, providing valuable insights for optimizing natural product production in actinomyces.

&lt;i&gt;Ficus benghalensis&lt;/i&gt; : A plant with potential pharmacological properties f rom tradition to pharmacy

Purpose: To undertake an overview of the potential pharmacological properties of Ficus benghalensisis. Methods: Data were acquired from several online sources, including Scopus, Elsevier Science Direct, PubMed, and Sci-Hub, using the keywords “Ficus benghalensis”, “medicinal plants”, “anti-oxidant”, “anti-inflammatory”, and “anti-cancer”. Results: Ficus benghalensis has valuable secondary metabolites including terpenoids, ketones, coumarins, oentacyclic, furocoumarin, flavonols, flavonoids, sterols, esters, carbohydrates, carboxylic acid, and polycyclic aromatic hydrocarbons. Due to its phytochemical profile, it is regarded as a plant with potential pharmacological properties such as anti-diarrheal, anti-inflammatory, anti-cancer, anti-oxidant, anti-bacterial, anti-diabetic, anti-tumor, immunomodulatory, anthelmintic, and anti-angiogenic. This review highlights the phytochemistry, traditional uses and pharmacological potential of Ficus benghalensis. Conclusion: Ficus benghalensis has potentials for treating several ailments. However, further research, including in vivo studies and preclinical trials, is necessary to ascertain its biological and pharmacological uses accurately.

Nitric oxide mediates red light-induced perylenequinone production in Shiraia mycelium culture.

Perylenequinones (PQs) from bambusicolous Shiraia fungi serve as excellent photosensitizers for photodynamic therapy. However, the lower yield of PQ production in mycelium cultures is an important bottleneck for their clinical application. Light has long been recognized as a pivotal regulatory signal for fungal secondary metabolite biosynthesis. In this study, we explored the role of nitric oxide (NO) in the growth and PQ biosynthesis in mycelium cultures of Shiraia sp. S9 exposed to red light. The continuous irradiation with red light (627nm, 200lx) suppressed fungal conidiation, promoted hyphal branching, and elicited a notable increase in PQ accumulation. Red light exposure induced NO generation, peaking to 81.7μmol/g FW on day 8 of the culture, with the involvement of nitric oxide synthase (NOS)- or nitrate reductase (NR)-dependent pathways. The application of a NO donor sodium nitroprusside (SNP) restored conidiation of Shiraia sp. S9 under red light and stimulated PQ production, which was mitigated upon the introduction of NO scavenger carboxy-PTIO or soluble guanylate cyclase inhibitor NS-2028. These results showed that red light-induced NO, as a signaling molecule, was involved in the regulation of growth and PQ production in Shiraia sp. S9 through the NO-cGMP-PKG signaling pathway. While mycelial H2O2 content exhibited no significant alternations, a transient increase of intracellular Ca2+ and extracellular ATP (eATP) content was detected upon exposure to red light. The generation of NO was found to be interdependent on cytosolic Ca2+ and eATP concentration. These signal molecules cooperated synergistically to enhance membrane permeability and elevate the transcript levels of PQ biosynthetic genes in Shiraia sp. S9. Notably, the combined treatment of red light with 5μM SNP yielded a synergistic effect, resulting in a substantially higher level of hypocrellin A (HA, 254mg/L), about 3.0-fold over the dark control. Our findings provide valuable insights into the regulation of NO on fungal secondary metabolite biosynthesis and present a promising strategy involving the combined elicitation with SNP for enhanced production of photoactive PQs and other valuable secondary metabolites in fungi.

The Liquid Fermentation Process for Mycelia of Poria cocos (Agaricomycetes) by Single-Factor Experimentation and Response Surface Methodology.

Liquid fermentation could yield substantial mycelia mass and valuable secondary metabolites in large-scale production within a short, fermented duration. The liquid fermented process of mycelia of Poria cocos was optimized using a combination of single-factor experimentation and response surface methodology (RSM) to obtain more extract of P. cocos. The optimal conditions were determined as follows: The carbon source concentration at 1%, the nitrogen source concentration at 1%, the inoculum volume at 7% and a culture time of 9 d. Under these conditions, the ethyl acetate extract mass of P. cocos mycelia reached 0.0577 ± 0.0041 mg. There were significant interactions between nitrogen source concentration and cultivation time. The predicted values by the mathematical model based on the response surface analysis showed a close agreement with experimental data.