Saponins in Insect Pest Control
Abstract
Insect herbivores are dangerous to all stages of plants, e.g., vegetative as well as reproductive growth, leaves, and shoots. Some of the herbivores feed by sucking plant sap, whereas some insects choose to chew various parts of plants. Thus, all types of herbivores damage plants by feeding directly and cause multiple diseases to plants, leading to plant damage indirectly. However, due to insect attack, plants produce some bioactive compounds (which are known as saponins) to improve their defense mechanism against herbivores. These saponins are further divided into two main categories, i.e., steroidal saponins and terpenoidal saponins. Here, we have highlighted the importance of saponins from multiple plant families against various herbivores. Saponins are present in different wild plants as well as cultivated crops (e.g., soybean, tea, spinach, oat, pepper, capsicum, quinoa, and allium). Some of the saponins play a role as antifeedant while some are insecticidal to different life stages of insect pests. Thus, these saponins play an important role in plant defense against different insect pests. Moreover, different saponins are effective against stored grain pests as well as cosmopolitan insect pests. Therefore, these plant bioactive compounds could be helpful for integrated pest management in different ecosystems.
... Indeed, their repellent activity, combined with their ability to impair the digestion process, leads to a drastic reduction in food intake, which in turn leads to starvation and related health issues (Singh & Kaur, 2018). Moreover, saponins bind with a complex of cholesterol, causing the insects' ecdysial failure (De Geyter et al., 2012;Qasim et al., 2020;Taylor et al., 2004). is the most cultivated forage crop in the world and represents an important source for the extraction of these bioactive molecules (Tava et al., 2022). Saponins from this genus display fungicidal, molluscicidal, nematicidal, antibacterial, antiviral and antitumoral properties (Abbruscato et al., 2014;Avato et al., 2017;D'Addabbo et al., 2011D'Addabbo et al., , 2020Paparella et al., 2015;Tava & Avato, 2006). ...
... Recently, a high anthelmintic activity against gastrointestinal nematodes from donkeys and goats (Maestrini et al., 2019(Maestrini et al., , 2020 was demonstrated for alfalfa saponin mixtures. Moreover, saponins extracted from alfalfa showed insecticidal and antifeedant effects on several pest insects (Qasim et al., 2020;Tava & Avato, 2006). In the pea aphid Acyrthosiphon pisum (Harris, 1776), alfalfa saponins caused a reduction in phloem ingestion, growth, survival and reproduction rate (Pedersen et al., 1976). ...
... Similar effects have been reported in the potato aphid Aulacorthum solani (Kaltenbach, 1843), where alfalfa saponins were provided with a liquid artificial diet (Mazahery-Laghab, 1997). Increased mortality has been reported also in leafhoppers (Cicadellidae) fed with alfalfa crude saponin (5%) (Qasim et al., 2020). The Colorado potato beetle Leptinotarsa decemlineata (Say, 1824) larvae fed with leaves treated with 0.5% alfalfa saponins significantly reduce food intake resulting in inhibition of growth rate combined with higher mortality (Qasim et al., 2020;Szczepaniak et al., 2001;Szczepanik et al., 2004). ...
Popillia japonica is a quarantine pest of priority interest for the EU, given its potentially important economic, social and environmental impacts. Alternative strategies to chemical methods are essential to limit its spread in newly infested areas with favourable climatic and environmental conditions. Saponins are biologically active molecules widely distributed in plants, displaying a well‐known repellent activity combined with a mortality effect against insects. In this context, saponins were extracted from alfalfa Medicago sativa , where medicagenic and zanhic acid glycosides and Soyasaponin I were the most abundant compounds and used in the laboratory and semi‐field experiments for treating leaves of susceptible host plants for P. japonica . Under laboratory conditions, a food deterrence effect and a significant mortality rate were observed using Corylus avellana leaves treated at increasing saponin concentrations, ranging from 1% to 5% w/v. Semi‐field condition experiment supported the food deterrence effect, as a significant food preference was observed for untreated plants of Vitis vinifera compared to treated plants. The promising results obtained suggest that alfalfa saponins could represent a potential eco‐friendly approach for Japanese beetle control.
... Saponin menjadi molekul amfipatik karena ikatan yang kuat antara rantai oligosakarida yang larut dalam air dan aglikon yang larut dalam lemak, dan molekul amfipatik ini mudah berinteraksi dengan membran sel untuk masuk ke dalam sel. Setelah saponin masuk ke dalam sel target, saponin menghasilkan aktivitas biologis spesifik, misalnya antimikroba, insektisida, hemolisis, serta alelopati (Qasim et al., 2020). Aplikasi saponin dari tumbuhan Quillaja saponaria dapat menekan aktifitas dan mengubah perilaku serangga hama kutu daun pada tanaman kacang (Acyrthosiphon pisum) (De Geyter et al, 2012). ...
... Herbivora yang memakan tanaman inang dengan toksisitas saponin tinggi akan mengalami kehilangan nafsu makan dan selanjutnya serangga tersebut akan menjadi lemah dan akhirnya mati (Adel et al, 2000). Sebagian besar herbivora menghindari memakan tanaman yang diperkaya saponin (Qasim et al, 2020). Senyawa tanin berperan sebagai antifeedant yaitu senyawa yang dapat menghambat serangan serangga dan hewan pemakan rumput (Bakri, 2020). ...
Walang sangit (Leptocorisa acuta thumb) is found in rice plants from flowering to harvest. These insects eat rice grains that are developing which have the potential to cause losses both in terms of quality and quantity. Synthetic pesticides are the main alternative for controlling walang sangit because they offer convenience and provide significant results on production per hectare. There have been many reports of the toxicity of synthetic pesticides which have negative effects including contamination of water and soil resources, loss of natural enemies of pests and insect pollinators which disrupt ecosystem functions. Utilization of plant materials with the potential for botanical pesticides is a safe control alternative for the environment and living things. The aim of the research was to determine the effectiveness of various plant materials with the potential of vegetable pesticides (extracts of maja fruit, sirsak leaves and lemon grass) against the activity of the walang sangit pest (L.acuta thumb) and to obtain plant materials with the best potential of vegetable pesticides. The study was carried out using a randomized block design consisting of 4 treatments (water, maja fruit extract, sirsak leaf extract and lemongrass extract ) with a concentration of 30% for each treatment which was repeated 3 times, so there were 12 experimental plots. Treatment P1 (maja fruit extract) was a treatment capable of suppressing the highest attacks of walang sangit with an average attack intensity of 19.44% and the lowest was treatment P0 (control) with an average attack intensity of 85.33%. The results of the 5% BNT test showed no significant difference between treatments P1, P2 and P3, but significantly different from treatment P0 in terms of controlling the locust pest (L.acuta thumb).
... Pengendalian ulat grayak diduga dapat ditangani dengan mengaplikasikan berbagai insektisida nabati dari berbagai bahan tumbuhan lokal maupun tanaman yang dibudidayakan sebab mengandung senyawa anti insekta dengan aroma dan rasa yang tidak disukai hama. Beberapa referensi melaporkan bahwa ulat grayak dapat dikendalikan dengan bahan yang mengandung berbagai jenis senyawa metabolit sekunder yang kaya dengan senyawa turunan dari hidrokarbon (Qasim et al., 2020;Akeme et al., 2021;Paredes-Sánchez et al., 2021), namun beberapa senyawa hidrokarbon dari sintetik dapat merusak tanah (Amin et al., 2020), oleh karena itu diperlukan senyawa alami sehingga tidak merusak tanah dan lingkungan. ...
... Senyawa yang masuk dalam tubuh larva berakibat pada alat pencernaannya menjadi terganggu (Lushchak et al., 2018). Senyawa saponin bisa bersifat insektisida, karena menghambat serapan (uptake) makanan di saluran pencernaan dan juga menghambat pertumbuhan stadium larva dengan mengganggu tahap moulting larva (Qasim et al., 2020). Perubahan permeabilitas membran menyebabkan disorganisasi molekular pada pencernaan disebabkan oleh saponin (Boaventura et al., 2020). ...
To overcome the emergence of environmental pollution due to the control of pests and plant diseases from the use of chemical pesticides, preventive measures are needed by exploring the potential of endemic and non-endemic plants as the main ingredients for making organic insecticides. The purpose of this study was to determine the effectiveness of extracts from plant materials from Tanjung, Belimbing Wuluh, Jingah, Jelatang, Gambir, Ketapang, Kemang, and Pulai to be used as the main ingredients of insecticides to control the mortality of armyworm (Spodoptera litura F.) in vivo in the laboratory of Balai Penelitian Lahan Rawa. To obtain the purpose of this study, the data were analyzed by means of variance to determine the significance of the value of the treatment, if there were at least two pairs of different treatments, then it was continued with the mean difference test using the BNJ 5% model. The results showed that the 8 types of swamp plant extracts were effective in controlling armyworm pests because their mortality was above 60% in a period of ≤ 48 hours. The highest pest mortality occurred in the application of feed with Pulai plant extract, which was around 84.0% after 60 hours of application.
... Some saponins have shown insecticidal activity, attributed to their impact on the epidermis's waxy layer and integument and their ability to disrupt cell membranes (Cui et al., 2019;Rai et al., 2021). Their disruptive effect on the insect integument potentially facilitates fungal infection (Qasim et al., 2020). ...
Sustainable agriculture practices are indispensable for achieving a hunger-free world, especially as the global population continues to expand. Biotic stresses, such as pathogens, insects, and pests, severely threaten global food security and crop productivity. Traditional chemical pesticides, while effective, can lead to environmental degradation and increase pest resistance over time. Plant-derived natural products such as secondary metabolites like alkaloids, terpenoids, phenolics, and phytoalexins offer promising alternatives due to their ability to enhance plant immunity and inhibit pest activity. Recent advances in molecular biology and biotechnology have improved our understanding of how these natural compounds function at the cellular level, activating specific plant defense through complex biochemical pathways regulated by various transcription factors (TFs) such as MYB, WRKY, bHLH, bZIP, NAC, and AP2/ERF. Advancements in multi-omics approaches, including genomics, transcriptomics, proteomics, and metabolomics, have significantly improved the understanding of the regulatory networks that govern PSM synthesis. These integrative approaches have led to the discovery of novel insights into plant responses to biotic stresses, identifying key regulatory genes and pathways involved in plant defense. Advanced technologies like CRISPR/Cas9-mediated gene editing allow precise manipulation of PSM pathways, further enhancing plant resistance. Understanding the complex interaction between PSMs, TFs, and biotic stress responses not only advances our knowledge of plant biology but also provides feasible strategies for developing crops with improved resistance to pests and diseases, contributing to sustainable agriculture and food security. This review emphasizes the crucial role of PSMs, their biosynthetic pathways, the regulatory influence of TFs, and their potential applications in enhancing plant defense and sustainability. It also highlights the astounding potential of multi-omics approaches to discover gene functions and the metabolic engineering of genes associated with secondary metabolite biosynthesis. Taken together, this review provides new insights into research opportunities for enhancing biotic stress tolerance in crops through utilizing plant secondary metabolites.
Plants produce a diverse array of secondary metabolites, including saponins, which play significant roles in defense against herbivores. This review investigates the potential of saponins from dicotyledonous plants, particularly within the Fabaceae (Leguminosae) family—encompassing species such as alfalfa, grass peas, lupins, lentils, chickpeas, and soybeans—as tools for sustainable pest management. We provide a comparative analysis with other natural pest control agents, emphasizing the unique advantages and limitations of saponins. The molecular and biochemical mechanisms by which saponins affect pest physiology are explored, alongside discussions on their synergistic effects with other pest control substances. Recent field trials and case studies are reviewed to assess the practical applications, effectiveness, and challenges encountered. The environmental impact, safety considerations, and economic feasibility of saponin use are critically examined. Innovations in saponin extraction, formulation, and application methods are highlighted. Perspectives on integrating saponins into integrated pest management systems and addressing regulatory hurdles are also discussed. Further research is needed to explore the development of cost-effective extraction methods, the potential for resistance development among pests, and the scalability of saponin-based solutions in large-scale agricultural systems. This review offers a comprehensive overview of how saponins can contribute to sustainable agriculture, highlighting key areas for future research and innovation.
Bean flower thrips ( Megalurothrips usitatus ) is a major French bean ( Phaseolus vulgaris L.) pest. Small‐scale farmers manage the pest using mixed plant extracts although their efficacy has not been scientifically validated. We evaluated the efficacy of mixed plant extracts comprising; Capsicum frutescens , Allium sativum , Lantana camara , Tagetes minuta and Azadirachta indica , against M. usitatus under laboratory and screenhouse. We identified and quantified the secondary metabolites associated with insecticidal activity using spectrophotometry and liquid chromatography–mass spectrometry (LC–MS). The plant combinations included PE1 ( C. frutescens + A. sativum + L. camara + T. minuta extracts infused for 14 days), PE2 (same as PE1 but infused for 24 h) and PE + N (the five plant extracts infused for 24 h) in distilled water. We used an organic commercial botanical (Pyneem) as a positive control and distilled water as a negative control. Pyneem and PE + N induced the highest mortality at 88% and 77%, respectively, in the laboratory, and 68% and 71%, respectively, in the screenhouse. Phenolics, terpenoids and organosulfur compounds were identified in PE + N and individual plant extracts in varied quantities. These compounds were significantly higher ( p < 0.001) in PE + N compared to individual plant extracts. The study showed that PE + N efficiently manages bean flower thrips, and mixing different plant extracts amplifies the secondary metabolites' abundance. The use of mixed plant extracts could be incorporated into integrated pest management strategies for thrips management in legumes. The specific compounds identified in PE + N should be investigated further to understand their modes of action against the pest.
Many plant protein ingredients have unpleasant flavor (e.g., green, beany, bitterness) characteristics. Isolation of the protein fraction will reduce the intensity of the undesirable flavors but in most cases the flavor issue is not eliminated. The objective of this review is to provide information about undesirable flavors associated with plant proteins and approaches to mitigate these flavors. The focus of the review will be on flavor associated with plant proteins from pulses, soybean, and oilseeds (e.g., hempseed, flaxseed). While other plant proteins exist, they will not be covered extensively in this limited review. The undesirable flavors are defined as volatile organic compounds (VOCs) and non‐volatile organic compounds (non‐VOCs). Example VOCs include aldehydes, ketones, and isobutyl pyrazines whereas saponins, bitter peptides, and phenolics are among the most common non‐VOCs. The raw material used as the source for the protein dictates the undesirable flavors remaining in the protein ingredient. The intensity of the binding of the VOCs and non‐VOCs to protein serves as the basis for the detection and difficulty in removing these compounds from the protein. A discussion about flavor binding and processing methods to mitigate unwanted flavors in protein ingredients will be provided. Methods presented will focus on extraction and thermal treatment. Although flavor masking is an approach to minimize undesirable, this topic will not be covered. Understanding the compounds responsible for the flavor issues and methods to minimize their impacts on sensory characteristic of protein ingredients can provide manufacturers with solutions to addressing flavor issues inherent to plant proteins.
Plant diseases and insect pests are major limiting factors that reduce crop production worldwide. Silicon is one of the most abundant elements in the lithosphere and has a positive impact on plant health by effectively mitigating biotic and abiotic stresses. It also enhances plant resistance against insect pests and fungal, bacterial, and viral diseases. This chapter critically examines how silicon-modulated physical, biochemical, and molecular mechanisms play a critical role in plant defense against pathogens and insect pests. Also, it discusses how silicon-modulated phytohormone signaling and enzyme production contribute to plant resistance against biotic stresses. Another focus in this chapter is on recent achievements in in-vivo and in-vitro research that have indicated that silicon has an important role to play in the protection of plants against insect herbivores and several viral, bacterial, and fungal diseases. This chapter concludes by pointing out that the future silicon-related research could focus on engineering economically important crops to minimize plant biotic stresses in order to ensure food security.KeywordsLithosphere ElementsBiotic StressesPlant DefenseSoil FertilizationSoil Management
Saponins are glucosides that are well known for their foaming aptitude .its biochemical properties depends on their polarity, hydrophobicity and nature of the reactive groups. Saponins exhibits diuretic, cardiac stimulant, anti-catarrhal, anti-inflammatory, antioxidant, aphrodisiac, emmenagogue, antispasmodic, expectorant, hepatoprotective, hormone modulating and adrenal adaptogenic effects
Cockroach (Periplaneta americana) is a household pest, which transmit disease in the environment. The development of resistance due to resistance has prompted efforts to seek alternative biological control methods. Community based-plant species, C. odorata was studied for its insecticidal activity of cockroach, P. americana at room temperature. Mortality of P. americana was sparingly recorded in treatment with the lowest concentration of the leaf extract after a short period of exposure (6 hrs). However, the maximum Mortality rate was recorded after exposure of the test species to the highest concentration of leaf extract. The survivals and mortality rate were very highly significant at 0.001% level of confidence. Phytochemical analysis showed alkaloids, flavonoids, saponin and tannin present in the plant species used. Based on this study, leaf extract of C. odorata have exhibited some measures of efficacy in the control of P. americana. Further investigation could be carried out to know the bioactive chemical with this insecticidal property, responsible for the control of this nuisance pest.
In natural ecosystems, plants interact with biotic components such as microbes, insects, animals and other plants as well. Generally, researchers have focused on each interaction separately, which condenses the significance of the interaction. This limited presentation of the facts masks the collective role of constantly interacting organisms in complex communities disturbing not only plant responses but also the response of organisms for each other in natural ecological settings. Beneficial microorganisms interact with insect herbivores, their predators and pollinators in a bidirectional way through the plant. Fascinatingly, insects employ diverse tactics to protect themselves from parasites or predators. Influences of microbial and insects attack on plants can bring changes in info-chemical frameworks and play a role in the food chain also. After insect herbivory and microbial pathogenesis, plants exhibit intense morpho-physiological and chemical reprogramming that leads to repellence/attraction of attacking organism or its natural enemy. The characterization of such interactions in different ecosystems is receiving due consideration, and underlying molecular and physiological mechanisms must be the point of concentration to unveil the evolution of multifaceted multitrophic interactions. Therefore, we have focused this phenomenon in a more realistic setting by integrating ecology and physiology to portray these multidimensional interfaces. We have shown, in this article, physiological trajectories in plant-microbe and insect relationship and their ecological relevance in nature. We focus and discuss microbial pathogenesis in plants, induced defense and the corresponding behavior of herbivore insects and vice-versa. It is hoped that this review will stimulate interest and zeal in microbes mediated plant-insect interactions along with their ecological consequences and encourage scientists to accept the challenges in this field.
A total of 1,622 samples representing 201 Medicago truncatula ecotypes were analyzed using ultrahigh pressure liquid chromatography coupled to mass spectrometry (UHPLC-MS) to ascertain saponin profiles in different M. truncatula ecotypes and to provide data for a genome-wide association study and subsequent line selection for saponin biosynthesis. These ecotypes originated from 14 different Mediterranean countries, i.e., Algeria, Cyprus, France, Greece, Israel, Italy, Jordan, Libya, Morocco, Portugal, Spain, Syria, Tunisia, and Turkey. The results revealed significant differences in the saponin content among the ecotypes. European ecotypes generally contained higher saponin content than African ecotypes (p < 0.0001). This suggests that M. truncatula ecotypes modulate their secondary metabolism to adapt to their environments. Significant differences in saponin accumulation were also observed between the aerial and the root tissues of the same ecotypes (p < 0.0001). While some saponins were found to be present in both the aerial and root tissues, zanhic acid glycosides were found predominantly in the aerial tissues. Bayogenin and hederagenin glycosides were found mostly in roots. The differential spatially resolved accumulation of saponins suggests that saponins in the aerial and root tissues play different roles in plant fitness. Aerial saponins such as zanhic glycosides may act as animal feeding deterrent and root saponins may protect against soil microbes.
Two undescribed triterpenoid saponins together with 5 known ones were isolated from the root bark of Haplocoelum congolanum Hauman. Their structures were elucidated by spectroscopic methods including one-dimensional and two-dimensional nuclear magnetic resonance experiments in combination with mass spectrometry as 3-O-(4-O-[3-hydroxy-3-methylglutaryl])-α-l-arabinopyranosyl-(1→3)-α-l-rhamnopyranosyl-(1→2)-[β-d-glucopyranosyl-(1→4)]-α-l-arabinopyranosyloleanolic acid and 3-O-α-l-arabinofuranosyl-(1→3)-α-l-rhamnopyranosyl-(1→2)-[β-d-glucopyranosyl-(1→4)]-α-l-arabinopyranosyloleanolic acid.
Interactions between plants and herbivores are central to all ecosystems. Although numerous types of interaction have evolved, there is considerable overlap in recognition, signal transduction and gene expression events that orchestrate the plant defence. Responses to herbivore damage can be triggered by simple wounding or insect-derived elicitors such as certain enzymes, fatty acid-derived conjugates, other low-molecular-weight aliphatic compounds and peptides generated from degradation of ingested plant material. Early induced responses in host plants are characterised by membrane depolarisation, intracellular [Ca2+] transients and reactive oxygen species production, followed by the activation of protein kinases and a downstream phytohormone networks that coordinate particular responses. Induced and constitutive toxic or harmful secondary metabolites are crucial components of host defence. Also, proteinase inhibitors or threonine deaminase can reduce the nutritional value of the plant tissue by interfering with the herbivore digestion. Synergistic effects between plant constituents ensure efficient mobilisation of defences that cannot be bypassed easily. Emissions of induced volatile compounds influence local and long-range interactions by repelling herbivores and attracting parasites and parasitoids from a distance, thus employing a third trophic level. Moreover, uninfested parts of the same and neighbouring plants can respond to volatiles by upregulating defence-related genes (priming), allowing an accelerated response to actual damage and thereby reducing the metabolic costs that are associated with a fully operational defence system.
Modern mass spectrometry methods provide a huge benefit to saponin structural characterization, especially when combined with collision-induced dissociation experiments to obtain a partial description of the saponin (ion) structure. However, the complete description of the structures of these ubiquitous secondary metabolites remain challenging, especially since isomeric saponins presenting small differences are often present in a single extract. As a typical example, the horse chestnut triterpene glycosides, the so-called escins, comprise isomeric saponins containing subtle differences such as cis-trans ethylenic configuration (stereoisomers) of a side chain or distinct positions of an acetyl group (regioisomers) on the aglycone. In the present paper, the coupling of liquid chromatography and ion mobility mass spectrometry has been used to distinguish regioisomeric and stereoisomeric saponins. Ion mobility arrival time distributions (ATDs) were recorded for the stereoisomeric and regioisomeric saponin ions demonstrating that isomeric saponins can be partially separated using ion mobility on a commercially available traveling wave ion mobility (TWIMS) mass spectrometer. Small differences in the ATD can only be monitored when the isomeric saponins are separated with liquid chromatography prior to the IM-MS analysis. However, gas phase separation between stereoisomeric and regioisomeric saponin ions can be successfully realized, without any LC separation, on a cyclic ion mobility-enabled quadrupole time-of-flight (Q-cIM-oaToF) mass spectrometer. The main outcome of the present paper is that the structural analysis of regioisomeric and stereoisomeric natural compounds that represents a real challenge can take huge advantages of ion mobility experiments but only if increased ion mobility resolution is attainable.
A new isoflavone glycoside, named 3’-hydroxytectorigenin-7-O-β-D-xylosyl-(1→6)-β-D-glucopyranoside (1) was isolated from the flowers of Pueraria montana var. lobata (Willd.) Sanjappa & Pradeep. The structure of compound 1 was characterised by HR-ESI-MS and NMR spectroscopic methods. In radical scavenging activity test using 2, 2-diphenyl-1-picrylhydrazyl (DPPH), compound 1 showed moderate activity with IC50 value of 42 ± 4.2 μg/mL.
Triterpene saponins (saponosides) are found in higher plants and display a wide range of biological and pharmacological activities. The antitumor effects of saponins have been proved by their cytotoxic, cytostatic, proapoptotic, and anti‐invasive effects in many cellular models. Saponins hold great potential for being developed into chemopreventive and chemotherapeutic drugs. A promising way of reducing the adverse effects of chemotherapy without attenuating its efficiency is provided by the combined application of chemotherapeutic agents and saponosides in subtoxic concentrations. Until recently, saponosides were primarily used as adjuvants that enhance the effect of vaccines. In cancer therapy, saponins are applied in combination with immunotoxins because they increase the selectivity of given immunotoxins against cancer cells and therefore inure normal cells to the cytotoxic effects of immunotoxins. Significantly, certain saponins have been identified that drastically enhance the efficacy of many chemotherapeutic agents, including cisplatin, paclitaxel, doxorubicin, docetaxel, mitoxantrone, and cyclophosphamide. Moreover, saponins used in combination therapy enhance the sensitivity of chemoresistant tumor cells to clinically used chemotherapeutic agents. This review sheds light on the molecular mechanisms underlying cancer co–treatment with saponins and chemotherapy, with a particular focus on modulation of the cell signaling pathways associated with the promotion and progression of cancer cell proliferation, apoptosis, and metastasis.
Ideally, metabolomics should deal with all the metabolites that are found within cells and biological systems. The most common technologies for metabolomics include mass spectrometry, and in most cases, hyphenated to chromatographic separations (liquid chromatography- or gas chromatography-mass spectrometry) and nuclear magnetic resonance spectroscopy. However, limitations such as low sensitivity and highly congested spectra in nuclear magnetic resonance spectroscopy and relatively low signal reproducibility in mass spectrometry impede the progression of these techniques from being universal metabolomics tools. These disadvantages are more notorious in studies of certain plant secondary metabolites, such as saponins, which are difficult to analyse, but have a great biological importance in organisms. In this study, high-performance thin-layer chromatography was used as a supplementary tool for metabolomics. A method consisting of coupling 1H nuclear magnetic resonance spectroscopy and high-performance thin-layer chromatography was applied to distinguish between Ophiopogon japonicus roots that were collected from two growth locations and were of different ages. The results allowed the root samples from the two growth locations to be clearly distinguished. The difficulties encountered in the identification of the marker compounds by 1H nuclear magnetic resonance spectroscopy was overcome using high-performance thin-layer chromatography to separate and isolate the compounds. The saponins, ophiojaponin C or ophiopogonin D, were found to be marker metabolites in the root samples and proved to be greatly influenced by plant growth location, but barely by age variation. The procedure used in this study is fully described with the purpose of making a valuable contribution to the quality control of saponin-rich herbal drugs using high-performance thin-layer chromatography as a supplementary analytical tool for metabolomics research.