Extraction and Analyses of Flavonoids and Phenolic Acids from Canadian Goldenrod and Giant Goldenrod

The Invasive Alien Plant Solidago canadensis: Phytochemical Composition, Ecosystem Service Potential, and Application in Bioeconomy

Solidago canadensis L. (Canadian goldenrod) is a widely distributed invasive herb from the Asteraceae family. It contains compounds that can change the soil structure and its nutritional components and thus affect indigenous species' growth, germination, and survival. Consequently, it can pose a major ecological threat to biodiversity. On the other hand, many studies show that this species, due to its chemical properties, can be used for many positive purposes in pharmacy, agriculture, medicine, cosmetic industry, etc. S. canadensis contains a diverse array of bioactive compounds that may be responsible for antioxidant, antimicrobial, and anticancer activities. Many studies have discussed the invasiveness of S. canadensis, and several chemical and genetic differences between this plant in native and introduced environments have been discovered. Previous ecological and environmental evaluations of the potential of S. canadensis as an ecosystem services provider have come out with four promising groups of its products: active extracts, essential oil, fuel, and others. Although identified, there is a need for detailed validation and prioritisation of ecosystem services. This article aims to overview the S. canadensis invasive features, emphasising chemical characterisation and its potential for providing ecosystem services. Moreover, it identifies scenarios and proposes a methodology for estimating S. canadensis use in bioeconomy.

Disparate Effects of Two Clerodane Diterpenes of Giant Goldenrod (Solidago gigantea Ait.) on Bacillus spizizenii

New substances with antimicrobial properties are needed to successfully treat emerging human, animal, or plant pathogens. Seven clerodane diterpenes, previously isolated from giant goldenrod (Solidago gigantea) root, were tested against Gram-positive Bacillus subtilis, Bacillus spizizenii and Rhodococcus fascians by measuring minimal bactericidal concentration (MBC), minimal inhibitory concentration (MIC) and half-maximal inhibitory concentration (IC50). Two of them, Sg3a (a dialdehyde) and Sg6 (solidagoic acid B), were proved to be the most effective and were selected for further study. Bacillus spizizenii was incubated with the two diterpenes for shorter (1 h) or longer (5 h) periods and then subjected to genome-wide transcriptional analyses. Only a limited number of common genes (28 genes) were differentially regulated after each treatment, and these were mainly related to the restoration of cell membrane integrity and to membrane-related transports. Changes in gene activity indicated that, among other things, K+ and Na+ homeostasis, pH and membrane electron transport processes may have been affected. Activated export systems can be involved in the removal of harmful molecules from the bacterial cells. Inhibition of bacterial chemotaxis and flagellar assembly, as well as activation of genes for the biosynthesis of secondary metabolites, were observed as a general response. Depending on the diterpenes and the duration of the treatments, down-regulation of the protein synthesis-related, oxidative phosphorylation, signal transduction and transcription factor genes was found. In other cases, up-regulation of the genes of oxidation-reduction processes, sporulation and cell wall modification could be detected. Comparison of the effect of diterpenes with the changes induced by different environmental and nutritional conditions revealed several overlapping processes with stress responses. For example, the Sg6 treatment seems to have caused a starvation-like condition. In summary, there were both common and diterpene-specific changes in the transcriptome, and these changes were also dependent on the length of treatments. The results also indicated that Sg6 exerted its effect more slowly than Sg3a, but ultimately its effect was greater.

The co-phytotoxicity of two Asteraceae invasive plants Solidago canadensis L. and Bidens pilosa L. with different invasion degrees

The phytotoxicity of invasive plants (IPS) has been identified as one of the main factors influencing their invasion success. The invasion of IPS can occur to varying degrees in the habitats. Two IPS can invade one habitat. This study aimed to evaluate the mono- and co-phytotoxicity of two Asteraceae IPS Solidago canadensis L. and Bidens pilosa L. with different invasion degrees (including light invasion (relative abundance <50%) and heavy invasion (relative abundance ≥50%)) on the horticultural Asteraceae species Lactuca sativa L., through a hydroponic experiment conducted on 9 cm Petri dishes. Leaf extracts of the two IPS can cause significant mono- and co-phytotoxicity. The mono- and co-phytotoxicity of the two IPS were concentration-dependent. The mono-phytotoxicity of S. canadensis was significantly increased with increasing invasion degree, but the opposite was true for the mono-phytotoxicity of B. pilosa. Leaf extracts of B. pilosa with light invasion caused stronger phytotoxicity than those of S. canadensis with light invasion. There may be an antagonistic effect for the co-phytotoxicity caused by mixed leaf extracts of the two IPS compared with those of either S. canadensis or B. pilosa. The phytotoxicity of the two IPS on the growth performance of neighboring plants may play a more important role in their mono-invasion than in their co-invasion. The phytotoxicity appeared to affect the growth performance of S. canadensis individuals more significantly when the invasion was heavy, while the growth performance of B. pilosa individuals seemed to be more influenced by phytotoxicity when the invasion was light. Consequently, the concentration of leaf extracts of IPS, the invasion degree of IPS, the species identity of IPS, and the species number of IPS modulated the mono- and co-phytotoxicity of the two IPS.

Efficient pyridine biodegradation by Stenotrophomonas maltophilia J2: Degradation performance, mechanism, and immobilized application for wastewater

Stenotrophomonas maltophilia J2, a highly efficient pyridine-degrading bacterium, was isolated from the aerobic tank of a pesticide-contaminated wastewater treatment plant. The strain J2 demonstrated an impressive pyridine degradation rate of 98.34% ± 0.49% within 72 h, at a pyridine concentration of 1100 mg·L-1, a temperature of 30 °C, a pH of 8.0, and a NaCl concentration of 0.5%. Notably, two new pyridine metabolic intermediates, 1,3-dihydroxyacetone and butyric acid, were discovered, indicating that J2 may degrade pyridine through two distinct metabolic pathways. Furthermore, the immobilized strain J2 was obtained by immobilizing J2 with biochar derived from the stem of Solidago canadensis L. In the pyridine-contaminated wastewater bioremediation experiment, the immobilized strain J2 was able to remove 2000 mg·L-1 pyridine with a 98.66% ± 0.47% degradation rate in 24 h, which was significantly higher than that of the control group (3.17% ± 1.24%), and remained above 90% in subsequent cycles until the 27th cycle. High-throughput sequencing analysis indicated that the J2 +B group had an elevated relative abundance of bacteria and functional genes that could be associated with the degradation of pyridine. The results offer a foundation for the effective use of immobilized strain in the treatment of recalcitrant pyridine-contaminated wastewater.

Phytochemical and Bioactivity Studies on Hedera helix L. (Ivy) Flower Pollen and Ivy Bee Pollen

Bee pollen, known as a 'life-giving dust', is a product of honeybees using flower pollen grains and combining them with their saliva secretions. Thus, flower pollen could be an indicator of the bee pollen botanical source. Identification of bee pollen sources is a highly crucial process for the evaluation of its health benefits, as chemical composition is directly related to its pharmacological activity. In this study, the chemical profiles, contents of phenolic marker compounds and pharmacological activities of Hedera helix L. (ivy) bee pollen samples from Türkiye and Slovenia, as well as ivy flower pollen grains, were compared. High-performance thin-layer chromatography (HPTLC) analyses revealed that pollen samples, regardless of where they were collected, have similar chemical profiles due to the fact that they have the same botanical origins. Marker compounds afzelin, platanoside and quercetin-3-O-β-glucopyranosyl-(1→2)-β-galactopyranoside, common to both bee pollen and flower pollen, were isolated from bee pollen, and their structures were elucidated by nuclear magnetic resonance (NMR) and mass spectrometry (MS). These three compounds, as well as chlorogenic acid and 3,5-dicaffeoylquinic acid (found in flower pollen), were quantified using high-performance liquid chromatography (HPLC) analyses. In vitro tests and effect-directed analyses were used to evaluate the xanthine oxidase inhibition and antioxidant activity of the marker compounds and extracts from flower pollen and bee pollen. This is the first report comparing chemical profiles and related bioactivities of the flower pollen and bee pollen of the same botanical origin, as well as the first report of the chemical profile and related bioactivities of ivy flower pollen.

Allelopathic Activity of Canadian Goldenrod (Solidago canadensis L.) Extracts on Seed Germination and Growth of Lettuce (Lactuca sativa L.) and Garden Pepper Cress (Lepidium sativum L.)

Native to N. America, Canadian goldenrod (Solidago canadensis L.) was introduced to Europe as an ornamental plant and quickly spread here and in other parts of the world. The rapid spread of the plant is due to several reasons: phenotypic plasticity, broad climatic tolerance, propagation via underground rhizomes and seeds that mature in large numbers, etc. Additionally, the success of Canadian goldenrod's invasion is determined by its allelochemicals that affect seed germination, root formation and whole growth of nearby plants. Allelopathy of various extracts and essential oils (EOs) of S. canadensis on seed germination and growth of lettuce (Lactuca sativa L.) and garden pepper cress (Lepidium sativum L.) was evaluated and compared with other Solidago species (S. virgaurea, S. × niederederi) collected from the same growing locality in Lithuania. Soil characteristics (conductivity, pH and major elements) of the collecting site were determined. Aqueous flower extracts of all studied Solidago species showed the highest inhibitory effect on model plants. Canadian goldenrod leaf water/diethyl ether extract showed highest inhibitory effect in all relative concentrations (1.0; 0.1; 0.01) suppressing growth of L. sativa (from 0 to 2.3 mm compared with 22.7 mm for control samples) and L. sativum (from 0.5 to 16.8 mm compared with 35.3 mm in control). It was noticed that garden pepper cress was more susceptible to Solidago spp. inhibitory effects than lettuce. S. canadensis root EOs comprised mainly of limonene (35.0%) and β-pinene (26.2%) and inflorescence oils containing α-pinene (21.6%), germacrene D (15.1%), limonene (10.2%) and lupenyl acetate (9.8%) exhibited the highest inhibitory effect on lettuce and garden pepper cress growth. Relative germination and vigor index of model plants was conducted. Chemical composition of extracts and EOs was determined by HPLC/DAD/TOF and GC/MS techniques.

Foliar Application of Iron Oxide Nanoparticles Promotes Growth, Mineral Contents, and Medicinal Qualities of Solidago virgaurea L

Goldenrod (Solidago virgaurea L.) is considered for their medicinal properties for humans. These properties are attributed to some volatile compounds that can be extracted from above- and underground organs of plants. More ingredients of medicinal plants are undoubtedly considered by herbal medicine activists. The study aimed to promote Solidago yield and quality under foliar application of Fe₂O₃ nanoparticles that can be considered as a safe and healthy fertilizer on the basis of US Food and Drug Administration (FDA) regulatory process about color additives. The experiment was performed with concentrations of Fe₂O₃ nanoparticles (0, 0.5, or 1 mg L^-1) and foliar application times (1, 2, 3, 4, or 5 times) on 4- to 5-leaf plants of Solidago virgaurea. Results showed that 4 times foliar application of 1 mg L^-1 caused the best plant growth and mineral element contents (nitrogen, phosphorous, potassium, copper, and zinc) except for Fe content that the more the times of foliar application, the more the Fe content increased. However, the flavonoid (rutin and quercetin) and essential oils (caryophyllene, alpha-pinene, camphene, limonene, linalool, myrcene, and terpinene) as biochemical and medicinal qualities of the treated plants were remarkably promoted when 1 mg L^-1 of nanoparticles was sprayed 5 times. Furthermore, the more the element contents, the more the ingredients. Finally, based on the goals of herbal medicine activists for the production of the essence, extract, or herb, both 5 and 4 times of foliar applications of ferric oxide nanoparticles are safe and may be economic and recommendable.

Phytochemical Constituents and Biological Activities of Jasonia glutinosa L.: The First Report for the Plant Growing in North Africa

Jasonia glutinosa (rock tea), also known as Chiliadenus glutinosa Cass., is a medicinal plant growing in the Mediterranean Basin. It is used for the treatment of depression, gastrointestinal complaints, inflammations, appendicitis, colds, and respiratory disorders. The current study is the first report for the plant species growing in Libya and aims to investigate the phytochemical constituents, antioxidant, cytotoxic, and antimicrobial activities of the plant’s aqueous ethanolic extract. The phytochemical investigation was conducted by the spectrophotometric quantitative assay and the LC-MS analysis. The analysis revealed the presence of 14.67 and 46.72 mg/g of the total phenolics and flavonoids equivalent to gallic acid and rutin, respectively. A total of thirty compounds of phenolic acids and flavonoids were identified by the LC-MS analysis, with a total relative percentage of 18.69%. The analysis revealed the dominance of methoxylated flavonoids and cinnamic acid derivatives, including caffeoylquinic acids. The in vitro antioxidant assays showed 265.55, 513.32, and 27.10 μM Trolox eq/mg of extract in the ABTS, ORAC, and FRAP assays, respectively. Cancer cell growth inhibitions of 9.23, 11.42, and 34.01% at a concentration of 100 μg/mL against MCF-7, HepG2, and PANC-1 cell lines were obtained, which is considered a weak cytotoxic effect when compared to the standard anticancer agent, doxorubicin (DOX). No antimicrobial activity was noticed for the plant extract against all tested microorganisms, i.e., Escherichia coli, Bacillus subtilis, Staphylococcus aureus, Salmonella typhimurium, Candida albicans, and Saccharomyces cerevisiae. The weak antimicrobial effect of the plant did not support the claim of traditional use of the plant as an antimicrobial agent.

Bioautography-guided HPTLC-MS as a rapid hyphenated technique for the identification of antimicrobial compounds from selected South African Combretaceae species

INTRODUCTION

Many species within Combretaceae are traditionally used for the treatment of bacterial infections. The similarity in chemistry and antimicrobial activities within the family pose a challenge in selecting suitable species for herbal drug development.

OBJECTIVE

This study aimed at rapidly identifying antimicrobial compounds using bioautography-guided high-performance thin-layer chromatography coupled with mass spectrometry (HPTLC-MS).

METHODS

Hierarchical cluster analysis of ultra-performance liquid chromatography-mass spectrometry data from the methanol extracts of 77 samples, representing four genera within Combretaceae, was carried out. Based on groupings on the dendrogram, 15 samples were selected for bioautography analysis against four pathogens (Staphylococcus aureus, Bacillus cereus, Escherichia coli and Salmonella typhimurium). Active compounds were identified using HPTLC-MS analysis of bands corresponding to the inhibition zones.

RESULTS

Bioautography revealed 15 inhibition zones against the four pathogens, with the most prominent present for Combretum imberbe. Analysis of the active bands, using HPTLC-MS indicated that flavonoids, triterpenoids and combretastatin B5 contributed to the antibacterial activity. The compounds corresponding to molecular ions m/z 471 (Combretum imberbe) and 499 (Combretum elaeagnoides) inhibited all four pathogens, and were identified as imberbic acid and jessic acid, respectively. Chemotaxonomic analysis indicated that arjunic acid, ursolic acid and an unidentified triterpenoid (m/z 471) were ubiquitous in the Combretaceae species and could be responsible for their antibacterial activities.

CONCLUSION

Application of HPTLC-MS enabled the rapid screening of extracts to identify active compounds within taxonomically related species. This approach allows for greater efficiency in the natural product research workflow to identify bioactive compounds in crude extracts.

High-performance thin-layer chromatography - antibacterial assay first reveals bioactive clerodane diterpenes in giant goldenrod (Solidago gigantea Ait.)

The present work introduces a high-performance thin-layer chromatography (HPTLC)-direct bioautography method using the Gram-positive plant pathogenic bacterium, Rhodococcus fascians. The screening and isolation procedure comprised of a non-targeted high-performance thin-layer chromatography-effect-directed analysis (HPTLC-EDA) against Bacillus subtilis, B. subtilis subsp. spizizenii, R. fascians, and Aliivibrio fischeri, a targeted HPTLC-mass spectrometry (MS), and bioassay-guided column chromatographic (preparative flash and semi-preparative HPLC) fractionation and purification. The developed new separation methods enabled the discovery of four bioactive cis-clerodane diterpenes, solidagoic acid H (1), solidagoic acid E (2), solidagoic acid I (3), and solidagoic acid F (4), in the n-hexane extract of giant goldenrod (Solidago gigantea Ait.) leaf for the first time. These compounds were identified by 1D and 2D nuclear magnetic resonance (NMR) spectroscopy. The initially used HPTLC method (chloroform - ethyl acetate - methanol 15:3:2, V/V/V) was changed (to n-hexane - isopropyl acetate - methanol - acetic acid 29:20:1:1, V/V/V/V) to achieve the separation of the closely related isomer pairs (1-2 and 3-4). Compounds 1 and 3 exhibited moderate antibacterial activity against the Gram-positive B. subtilis subsp. spizizenii and R. fascians bacterial strains in microdilution assays with half-maximal inhibitory concentration (IC₅₀) values in the range of 32.3-64.4 µg/mL. The mass spectrometric fragmentation of the isolated compounds was interpreted and their previously published NMR assignments lacking certain resonances were completed.

SDS-PAGE Protein and HPTLC Polyphenols Profiling as a Promising Tool for Authentication of Goldenrod Honey

The aim of the study was to use protein and polyphenolic profiles as fingerprints of goldenrod honey and to apply them for verification of the labeled variety. The markers for 10 honey samples were correlated with the standard physicochemical parameters and biological activity measured in vitro as antioxidant, antifungal and antibacterial activities. Honey proteins were examined regarding soluble protein, diastase and SDS-PAGE protein profile. The polyphenolic profile was obtained with the use of the HPTLC and the antioxidant activity was detected with standard colorimetric methods. The antimicrobial effect of representative honey samples of different chemical profiles was verified against E. coli and budding yeast. It was found that the SDS-PAGE technique allows for creating the protein fingerprint of the goldenrod honey variety which was consistent for 70% of tested samples. At the same time, the similarity of their polyphenolic profile was observed. Moreover, specific chemical composition resulted in higher bioactivity of honey against tested bacteria and yeast. The study confirmed the usefulness of both SDS-PAGE and HPTLC techniques in honey authentication, as an initial step for selection of samples which required pollen analysis.

Significance of Chromatographic Techniques in Pharmaceutical Analysis

This work presents an overview of the modern approaches embracing advanced equipment and validation parameters of both liquid and gas chromatography techniques, including thin-layer chromatography (TLC), column liquid chromatography (CLC), and gas chromatography (GC), suitable for the identification and quantitative determination of various bioactive compounds occurring in pharmaceutical products and medicinal plants in the time from 2020 to 2021 (November). This review confirmed that HPLC is an incredibly universal tool, especially when combined with different detectors, such as UV-Visible spectroscopy, mass spectrometry (MS), and fluorescence detection for numerous active ingredients in different pharmaceutical formulations without interferences from other excipients. TLC, in combination with densitometry, is a very efficient tool for the determination of biologically active substances present in pharmaceutical preparations. In addition, TLC coupled to densitometry and mass spectrometry could be suitable for preliminary screening and determination of the biological activity (e.g., antioxidant properties, thin layer chromatography (TLC) by 2,2-diphenyl-1-picrylhydrazyl (DPPH) method) of plant materials. Gas chromatography, coupled with a mass spectrometer (GC-MS, GC-MS/MS), is of particular importance in the testing of any volatile substances, such as essential oils. LC, coupled to NMR and MS, is the best solution for identifying and studying the structure of unknown components from plant extracts, as well as degradation products (DPs). Thanks to size-exclusion chromatography, coupled to multi-angle light scattering, the quality control of biological pharmaceuticals is possible.

Acetylcholinesterase inhibitors in the giant goldenrod root

Eight bioactive clerodane diterpenes from the root extract of Solidago gigantea Ait. (giant goldenrod) were quantified by high-performance thin-layer chromatography (HPTLC) and two newly developed hyphenated methods. One uses vanillin sulphuric acid derivatization and densitometry, and the other an inhibition assay of acetylcholinesterase (AChE) and video densitometry. Both methods gave figures of merit for quantification including 5.8-33.9 ng and 175.5-448.7 ng LOQs and 2.7-6.9 RSD% and 8.8-13.9 RSD% inter-day precisions, respectively. Based on the diterpenes' content of 14 root samples collected over a year from the same plant population, the fully flowering plant is suggested to collect the root as a source of these compounds. Excepting one diterpene (with the lowest retardation factor), the quantitative results for the richest sample obtained by the two methods were in harmony. The difference could be due to a matrix effect.

The Role of Flavonoids in Invasion Strategy of Solidago canadensis L

This study provides data on the problem of potential complexation of phenolic compounds synthesized by the plants Solidago canadensis L. and Solidago gigantea Ait. with ammonium forms of nitrogen, partly immobilized in the soil. A comparative analysis of secondary metabolites of the studied plants was performed by HPLC. The leaves of invasively active Solidago canadensis contain nine times more rutin than the plants of Solidago gigantea. Adding to the leaf extracts (v/v1/20) aqueous ammonia solution to pH 8.0 on the chromatograms decreases the intensity or completely causes peaks of flavonoids to disappear; instead, there are peaks of new polar substances (tR 1.5 and 2.0 min). The selective effect of the phenol-ammonium complex on various plant species was revealed. At a concentration of 20 μg/mL, these substances stimulated the formation of lateral roots in soybean seedlings and chrysanthemum cuttings. The suppression of root growth in radish seedlings occurred at a concentration of flavonoids in the extract of 25 μg/mL. In addition, a positive chemotaxis of the Pseudomonas putida (PGPR) was detected in the nitrogen-containing complex based on rutin (5 μg/mL). The identified feature allows PGPR colonization of the root system of Solidago canadensis with corresponding changes in the structure of the microbial community. The ability of the obtained nitrogen-containing polar complexes to regulate the growth processes of plants at extremely low concentration points to promising research in this direction.