Secondary Metabolite Profiles Research Articles

Brugmansia suaveolens Bercht. & J. Presl: phytochemistry, cytotoxicity and its larvicidal activity against Aedes aegypti L. (Diptera: Culicidae)

The mosquito family (Diptera: Culicidae) contains several species of great public health relevance due to their role as vectors of human diseases. Aedes aegypti, is responsible for transmitting some of the most important vector-borne viruses that affect humanity, including Dengue, Chikungunya and Zika. The widespread and intensive use of chemical insecticides has caused significant adverse environmental effects and contributed to the emergence of populations, reducing their efficiency. Therefore, it becomes urgent to develop new alternative tools for vector control. In this context, our study aimed to trace the profile of the main secondary metabolites, followed by determining the larvicidal action against the A. aegypti mosquito lineage; and in vitro safety, through cytotoxicity in eukaryotic cells. The extracts were obtained by maceration with better yields for leaves, in relation to the phytochemical profile, the presence of different classes of secondary metabolites was identified, such as triterpenes, flavonoids, tannins, saponins and alkaloids. Low larvicidal lethality was observed at the concentrations tested (250-1000 ppm). The analysis of the cytotoxic potential showed a low toxic activity after direct exposure of the extracts to Saccharomyces cerevisiae cells, even though the species was classified as toxic. The study presented results not determined in previous research of this species, providing an innovative, relevant and significant character for future research.

Extraction of itaconic acid by endophytic Aspergillus sp., isolated from Garcinia indica: Spectroscopic, structural and quantum computational studies

Endophytic fungi are generally absorbed into the metabolic networks of their hosts, causing changes in metabolite synthesis and higher levels of active compounds in medicinal plants. The primary objective of this research is to study the secondary metabolite profile of Aspergillus sp., BGSm03, a fungal endophyte isolated from a shrub called Garcinia indica grown in the Bisle Ghat region of Karnataka, India. Organic acids were effectively produced during fermentation with the isolate Aspergillus sp., BGSm03. Itaconic Acid (IA) was extracted and purified from them using chromatography. For the chemical structure and characterization of substances, spectroscopic analyses such as ultraviolet (UV), infrared (IR), and mass spectrometry (MS) are carried out. Following that, the single-crystal X-ray diffraction (SC-XRD) technique is used to determine the 3D molecular structure and to identify the various intra and intermolecular interactions responsible for the stability of the crystal structure of IA. The energy and other quantum chemical characteristics of IA were calculated using density functional theory (DFT). Furthermore, the purified IA is evaluated for antimicrobial and anticancer activity.

The Antibacterial, Antitumor Activities, and Bioactive Constituents' Identification of Alectra sessiliflora Bacterial Endophytes.

Due to increased antimicrobial resistance against current drugs, new alternatives are sought. Endophytic bacteria associated with medicinal plants are recognized as valuable sources of novel secondary metabolites possessing antimicrobial, antitumor, insecticidal, and antiviral activities. In this study, five bacterial endophytes were isolated and identified from the medicinal plant, Alectra sessiliflora, and their antibacterial and antitumor activities were investigated. In addition, the crude extracts of the endophytes were analyzed using gas chromatography (GC) coupled with time-of-flight mass spectrometry (TOF-MS). The identified bacterial endophytes belong to three genera viz Lysinibacillus, Peribacillus, and Bacillus, with the latter as the dominant genus with three species. Ethyl acetate extracts from the endophytes were used for antimicrobial activity against eleven pathogenic strains through minimum inhibitory concentration (MIC). The antitumor activity against the Hela cervical, Hek 293 kidney, and A549 lung carcinoma cells was determined by the MTS [3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxy-phenyl)-2-(4-sulfophenyl)-2H-tetrazolium] assay. Lysinibacillus sp. strain AS_1 exhibited broad antibacterial activity against the pathogenic strains with MIC values ranging from 4 to 8 mg/ml, while Bacillus sp. strain AS_3 displayed MIC of 0.25 mg/ml. Crude extracts of Lysinibacillus sp. strain AS_1, Peribacillus sp. strain AS_2, and Bacillus sp. strain AS_3 showed growth inhibition of more than 90% against all the cancer cell lines at a concentration of 1,000 μg/ml. Untargeted secondary metabolite profiling of the crude extracts revealed the presence of compounds with reported biological activity, such as antimicrobial, antioxidant, anti-inflammatory, antitumor, and antidiabetic properties. This study reported for the first time, bacterial endophytes associated with A. sessiliflora with antibacterial and antitumor activities.

Comprehensive study of secondary metabolite profile and pharmacological effects of medicinal plant Toddalia asiatica

Design, preparation and evaluation of germicidal Toddalia asiatica herbal antiseptic detergentWere L. L. Munyendo, Ambrose K. Kiprop

Profiling of secondary metabolites and DNA typing of three different Annona cultivars grown in Egypt

ObjectivesNatural products are often efficacious and safe alternatives to synthetic drugs. This study explored secondary leaves and bark metabolites profiles in extracts of a new Egyptian hybrid, Annona cherimola × Annona squamosa, known as Abdel Razek. This hybrid exhibited 100% similarity with A. cherimola as evidenced by random amplified polymorphic DNA (RAPD) and inter-simple sequence repeat (ISSR) analyses.MethodsPrimary constituents in methanol extracts of different plant organs were identified. Extracts richest in alkaloids and polyphenolics were assessed for in vitro antioxidant activity and the most potent were further studied in vivo for treating gastric ulcer in rats. The latter activity was assessed histopathologically.ResultsStructural analysis with HPLC/ESI-MSn, and UPLC/HESI-MS/MS identified 63 metabolites, including seven amino acids, 20 alkaloids, 16 flavonoids, eight phenolics and other compounds. Severe stomach alteration was observed after ethanol induction in rats. Ulcer score, oxidative stress biomarkers, cell organelles biomarker enzymes, and gastrointestinal histological features improved to variable degrees after treatment with Annona Abdel Razek hybrid leaves and bark methanol extracts.ConclusionExtracts of Annona Abdel Razek had showed in vitro antioxidant effect and may be promising for the treatment of gastric ulcers.Graphical abstract

Umbilicaria phaea var. coccinea: conservation status, variety rank, and secondary chemistry

Originally described from a single collection in northern California, Umbilicaria phaea var. coccinea has since been reported from additional sites in California, Oregon and Washington. Although relatively rare in all three states, there is currently no conservation status for U. phaea var. coccinea in California. Developing conservation strategies and status ranks requires a sound understanding of distribution, frequency, habitat requirements and taxonomic placement. Therefore, we evaluated distributions and constructed climate envelope models for both varieties of U. phaea. Umbilicaria phaea var. coccinea appears to be restricted to relatively small habitats within the range of U. phaea var. phaea and is only locally common in portions of the Klamath River watershed. To assess evolutionary relationships between the varieties, we evaluated four molecular loci: ITS2, LSU, Mcm7, and mtSSU. A combined phylogeny using maximum-likelihood and Bayesian inference indicated that U. phaea is monophyletic. Within the U. phaea clade, var. coccinea and var. phaea do not form mutually exclusive, monophyletic clades; instead, individuals are intermixed. Based on variation in pigment production, morphology, and geographic distribution, we recommend continued designation of U. phaea var. coccinea as a variety. To better understand the chemical diversity within U. phaea, we compared qualitative differences between secondary metabolite profiles of U. phaea var. phaea and U. phaea var. coccinea acetone extracts using ultraperformance-liquid chromatography high resolution tandem mass spectrometry in negative ion mode. UV spectroscopy, thin-layer chromatography and chemical spot testing were used to further characterize the compounds present. Overall, ten compounds were detected in extracts of U. phaea var. phaea and U. phaea var. coccinea. Five previously known chemical substances were identified in both U. phaea varieties including: orsellinic acid, lecanoric acid, hiascic acid, gyrophoric acid, and orsellinylgyrophorate, along with four unknown metabolites. One additional unknown substance whose chemical properties are consistent with a polyhydroxylated anthraquinone pigment was detected only in U. phaea var. coccinea. Given its rarity, chemical uniqueness, and distinct ecological association, U. phaea var. coccinea warrants a protected status throughout its range.

Diversity and metabolomic characterization of Penicillium expansum isolated from apples grown in Argentina and Spain

Apples (Malus domestica) are one of the most consumed fruits globally. It is a relevant crop in Argentina and Spain, and one of the main fruits for export and industrialization in these countries. Quality control of apples, fundamentally in the postharvest stage, is critical to prevent fungal diseases. The blue mould, caused by Penicillium expansum, is responsible for great economic losses due to the deterioration of the fruit and mycotoxin production. Many studies have characterized this pathogen; however, little is known about the differences between populations from distant geographical origins. The objective of the present study was to characterize two P. expansum populations, from Argentina and Spain, through morphological, metabolomic and molecular approaches, and to evaluate the existence of differences related to their geographical source. A total of 103 isolates, 53 from Argentina and 50 from Spain were studied. Their morphological features were consistent with the species description. The secondary metabolite profiles revealed low chemical diversity. All 103 isolates shared the production of 13 compounds, namely andrastins, aurantioclavine, chaetoglobosins, communesins, expansolides, roquefortine C and patulin. Penostatins and citrinin were produced by 102 and 101 isolates, respectively. A region of the β-tubulin gene was selected to analyse the diversity of the P. expansum isolates. No substantial differences were observed between isolates of different geographical origins through morphology, patulin accumulation, secondary metabolite profiles and phylogenetic analysis. However, the analysis of polymorphisms revealed 29 haplotypes with a relative separation between isolates of both populations; 13 haplotypes contained Argentinean isolates, while Spanish isolates were separated into 16 haplotypes. The diversity indices of Shannon (H’=2.075; H’=2.402) and Simpson (SiD = 0.850; SiD = 0.895) for isolates from Argentina and Spain, respectively, indicated that the diversity of P. expansum is greater in Spain than in Argentina. This distribution could be explained both by the existence of haplotype exchange between both countries, with the ancestral haplotypes originating in Spain, and the subsequent adaptation to the environmental conditions or apples varieties grown in each region.

Morpho-Metric and Specialized Metabolites Modulation of Parsley Microgreens through Selective LED Wavebands

Plant factories and high-tech greenhouses offer the opportunity to modulate plant growth, morphology and qualitative content through the management of artificial light (intensity, photoperiod and spectrum). In this study, three Light Emitting Diode (LED) lighting systems, with blue (B, 460 nm), red (R, 650 nm) and mixed red + green-yellow + blue (RGB) light were used to grow parsley microgreens to understand how light quality could change the phenotype and the profile of secondary metabolites. Plants showed altered morphological characteristics and higher amounts of secondary metabolites under RGB LEDs treatment. The results demonstrated that microgreens under red light showed the highest fresh yield, petiole length, coumaric acid content but also the highest nitrate content. Plants under RGB light showed the highest dry matter percentage and highest content of total and single polyphenols content, while blue light showed the highest ascorbic acid and ABTS antioxidant activity. Moreover, microgreens under red light showed more compact leaves with less intercellular spaces, while under blue and RGB light, the leaves displayed ticker spongy mesophyll with higher percentage of intercellular spaces. Therefore, the specific spectral band was able to modify not only the metabolic profile, but also it could modulate the differentiation of mesophyll cells. Light quality as a preharvest factor helps to shape the final parsley microgreens product as a whole, not only in terms of yield and quality, but also from a morpho-anatomical point of view.

Flowers and Leaves Extracts of Stachys palustris L. Exhibit Stronger Anti-Proliferative, Antioxidant, Anti-Diabetic, and Anti-Obesity Potencies than Stems and Roots Due to More Phenolic Compounds as Revealed by UPLC-PDA-ESI-TQD-MS/MS.

The present work aims to assess the biological potential of polyphenolic compounds in different parts (flowers, leaves, stems, and roots) of Stachys palustris L. Towards secondary metabolites profile, 89 polyphenolic compounds (PCs) were identified by UPLC-PDA-ESI-TQD-MS/MS, with a total average content of 6089 mg/100 g of dry matter (d.m.). In terms of biological activity, antioxidant activity (radical activity, reducing power), digestive enzyme inhibitory (α-glucosidase, α-amylase, pancreatic lipase) effect, and antiproliferative activity (inhibition of cell viability and induction of apoptosis in different human cancer cell lines) were explored. Leaves, flowers, stems, and roots of S. palustris L. have not been studied in this regard until now. Vescalagin and cocciferin d2, isoverbascoside (verbascoside), luteolin 6-C-glucoside, luteolin 6-C-galactoside, apigenin 6-C-glucoside, (−)-epicatechin, ellagic acid, and malvidin 3-O-diglucoside were detected as main ingredients in the studied parts. Methanolic extract of S. palustris L. leaves and flowers revealed the highest amount of PCs with the strongest antiradical (18.5 and 15.6 mmol Trolox equivalent (TE)/g d.m., respectively) and reducing power effects (7.3 and 5.6 mmol TE/g d.m.). Leaf extracts exhibited better α-amylase and pancreatic lipase inhibition effects, while flower extracts exhibited better α-glucosidase inhibition effect. Regarding antiproliferative activity, extracts of the leaves and flowers significantly reduced cell viability and induced a high level of apoptosis in human lung, pancreatic, bladder, and colon cancer cell lines, as well as in human acute myeloid leukemia; whereas the extracts from stems and roots revealed the weaker effects. The results of this work showed anti-proliferative and potentially anti-diabetic, anti-obesity properties of S. palustris L., especially for flowers and leaves, which may have wide potential applications in the functional food, special food, pharmaceutical, cosmetics industries, and/or in medicine.

Advances in understanding Norway spruce natural resistance to needle bladder rust infection: transcriptional and secondary metabolites profiling

BackgroundNeedle rust caused by the fungus Chrysomyxa rhododendri causes significant growth decline and increased mortality of young Norway spruce trees in subalpine forests. Extremely rare trees with enhanced resistance represent promising candidates for practice-oriented reproduction approaches. They also enable the investigation of tree molecular defence and resistance mechanisms against this fungal disease. Here, we combined RNA-Seq, RT-qPCR and secondary metabolite analyses during a period of 38 days following natural infection to investigate differences in constitutive and infection-induced defence between the resistant genotype PRA-R and three susceptible genotypes.ResultsGene expression and secondary metabolites significantly differed among genotypes from day 7 on and revealed already known, but also novel candidate genes involved in spruce molecular defence against this pathogen. Several key genes related to (here and previously identified) spruce defence pathways to needle rust were differentially expressed in PRA-R compared to susceptible genotypes, both constitutively (in non-symptomatic needles) and infection-induced (in symptomatic needles). These genes encoded both new and well-known antifungal proteins such as endochitinases and chitinases. Specific genetic characteristics concurred with varying phenolic, terpene, and hormone needle contents in the resistant genotype, among them higher accumulation of several flavonoids (mainly kaempferol and taxifolin), stilbenes, geranyl acetone, α-ionone, abscisic acid and salicylic acid.ConclusionsCombined transcriptional and metabolic profiling of the Norway spruce defence response to infection by C. rhododendri in adult trees under subalpine conditions confirmed the results previously gained on artificially infected young clones in the greenhouse, both regarding timing and development of infection, and providing new insights into genes and metabolic pathways involved. The comparison of genotypes with different degrees of susceptibility proved that several of the identified key genes are differently regulated in PRA-R, and that the resistant genotype combines a strong constitutive defence with an induced response in infected symptomatic needles following fungal invasion. Genetic and metabolic differences between the resistant and susceptible genotypes indicated a more effective hypersensitive response (HR) in needles of PRA-R that prevents penetration and spread of the rust fungus and leads to a lower proportion of symptomatic needles as well as reduced symptom development on the few affected needles.

METABOLOME COMPOSITION OF STINGING NETTLE GROWING IN THE CENTRAL CHERNOZEM REGION (REVIEW)

The plant metabolome is the totality of all primary and secondary metabolites and can be considered as a result of the implementation of genetic information, a «link» between the genotype and phenotype. The chemical composition of most medicinal plants and herbal medicinal preparations derived from them, which are multicomponent extracts, is not always fully known. Stinging nettle is one of the valuable plants with a wide distribution area. The metabolome of nettle medicinal plant materials includes a large number of classes of various biologically active substances (BAS). The study of profiles of secondary metabolites is an important direction for studying the variability of the phytochemical composition depending on the climatic conditions of growth, harvesting and drying. In the work, the collection and analysis of scientific information on the study of the profiles of various groups of biologically active substances and their identification in extracts from the raw material of stinging nettle (leaves and grass) growing on the territory of the Central Black Earth region of Russia was carried out by TLC using the so-called «fingerprint» method or «bar coding». The literature data on the results of a comprehensive study of the composition of the metabolome of this raw material (flavonoids, chlorophyll compounds, carotenoids, tannins, oxycinnamic acids, amino acids, organic acids, triterpene glycosides, polysaccharide complex, vitamins and some macroelements) by various groups of scientists over the past 20 years are summarized and systematized. Stinging nettle, growing in the conditions of the Central Chernozem region, as analysis showed, accumulate free amino acids, tannins, organic acids and polysaccharides in significant quantities. The composition of free water-soluble simple sugars, organic acids, vitamins of group B, as well as the complete amino acid composition was studied in the leaves of stinging nettle by capillary electrophoresis. A significant content of riboflavin and choline, as well as butyric and succinic acids has been established. Flavonoids in the leaves of stinging nettle growing in the conditions of the Central Chernozem region are represented by glycosides, the aglycones of which are mainly quercetin, isorhamnetin and kaempferol. The main representatives of the group of hydroxycinnamic acids in the leaves of stinging nettle in this region are chlorogenic acids, 2-coffee-malic and rosemary acids. As chemomarkers, neochlorogenic and cryptochlorogenic acids – isomers of caffeoylquinic acids, as well as caffeic, cafftaric and n-coumaric acids can be used.

Plant metabolism and defence strategies in the flowering stage: Time-dependent responses of leaves and flowers under attack.

Plants developing into the flowering stage undergo major physiological changes. Because flowers are reproductive tissues and resource sinks, strategies to defend them may differ from those for leaves. Thus, this study investigates the defences of flowering plants by assessing processes that sustain resistance (constitutive and induced) and tolerance to attack. We exposed the annual plant Brassica nigra to three distinct floral attackers (caterpillar, aphidand bacterial pathogen)and measured whole-plant responses at 4, 8and 12 days after the attack. We simultaneously analysed profiles of primary and secondary metabolites in leaves and inflorescencesand measured dry biomass of roots, leavesand inflorescences as proxies of resource allocation and regrowth. Regardless of treatments, inflorescences contained 1.2 to 4 times higher concentrations of primary metabolites than leaves, and up to 7 times higher concentrations of glucosinolates, which highlights the plant's high investment of resources into inflorescences. No induction of glucosinolates was detected in inflorescences, but the attack transiently affected the total concentration of soluble sugars in both leaves and inflorescences. We conclude that B.nigra evolved high constitutive rather than inducible resistance to protect their flowers; plants additionally compensated for damage by attackers viathe regrowth of reproductive parts. This strategy may be typical of annual plants.

Antimicrobial Mechanism and Secondary Metabolite Profiles of Biocontrol Agent Streptomyces lydicus M01 Based on Ultra-High-Performance Liquid Chromatography Connected to a Quadrupole Time-of-Flight Mass Spectrometer Analysis and Genome Sequencing.

Streptomyces lydicus was used as biopesticide for crop protection in agriculture, however, the antimicrobial mechanism remains unclear and no systematic research on the secondary metabolites of S. lydicus has been reported. In this study, the extract of S. lydicus M01 culture was used to treat plant pathogen Alternaria alternata and morphological changes in the plasma membrane and cell wall of hyphae and conidia were observed. Fluorescence microscopy combined with different dyes showed that the accumulation of reactive oxygen species and cell death were also induced. To investigate the secondary metabolites in the culture filtrate, an online detection strategy of ultra-high-performance liquid chromatography connected to a quadrupole time-of-flight mass spectrometer (UPLC-Q-TOF-MS) was used for identification. The results revealed an excess of 120 metabolites, mainly consisted of fungicides, antibacterial agents, herbicides, insecticides, and plant growth regulators, such as IAA. Among which the five dominant components were oxadixyl, chloreturon, S-metolachlor, fentrazamide, and bucarpolate. On the other hand, the complete genome of S. lydicus M01 was sequenced and a number of key function gene clusters that contribute to the biosynthesis of active secondary metabolites were revealed. This is the first systematic characterization of S. lydicus secondary metabolites, and these results offer novel and valuable evidence for a comprehensive understanding of the biocontrol agent S. lydicus and its application in agriculture.

Identification of Antimycobacterial from Actinobacteria (INACC A758) Secondary Metabolites using Metabolomics Data

Actinobacteria produce active secondary metabolite with medicinal properties, such as antibacterial or anticancer. However, there are some reports about the difficulties in discovering novel secondary metabolites. Therefore, the need for a new approach is obvious. Several factors such as types of nutrients in the culture media or different solvents used for extraction have been proven to influence the Actinobacteria secondary metabolite production. In this study, a combination of culture media optimization and metabolites fingerprint analysis were applied to identify antimycobacterial active compounds from Actinobacteria (InaCC A758). Five culture media were used in the secondary metabolite production of the Actinobacteria. The metabolite fingerprinting was carried out by analyzing the secondary metabolite profile extracted from culture media optimization using UPLC-MS. Multivariate analysis, i.e. cluster analysis and principal component analysis (PCA) was applied. The result showed that a unique antimycobacterial compound candidate against Mycobacterium smegmatis was produced by SYP media cultured InaCC A758 (MIC 6.25 µg/mL).

The Impacts of Microgravity on Bacterial Metabolism.

The inside of a space-faring vehicle provides a set of conditions unlike anything experienced by bacteria on Earth. The low-shear, diffusion-limited microenvironment with accompanying high levels of ionizing radiation create high stress in bacterial cells, and results in many physiological adaptations. This review gives an overview of the effect spaceflight in general, and real or simulated microgravity in particular, has on primary and secondary metabolism. Some broad trends in primary metabolic responses can be identified. These include increases in carbohydrate metabolism, changes in carbon substrate utilization range, and changes in amino acid metabolism that reflect increased oxidative stress. However, another important trend is that there is no universal bacterial response to microgravity, as different bacteria often have contradictory responses to the same stress. This is exemplified in many of the observed secondary metabolite responses where secondary metabolites may have increased, decreased, or unchanged production in microgravity. Different secondary metabolites in the same organism can even show drastically different production responses. Microgravity can also impact the production profile and localization of secondary metabolites. The inconsistency of bacterial responses to real or simulated microgravity underscores the importance of further research in this area to better understand how microbes can impact the people and systems aboard spacecraft.

Selenium Nanoparticles (Se-NPs) Alleviates Salinity Damages and Improves Phytochemical Characteristics of Pineapple Mint (Mentha suaveolens Ehrh.).

The present study examined the effects of foliar spray of selenium nanoparticles (0, 10 and 20 mg/L) on the yield, phytochemicals and essential oil content and composition of pineapple mint (Mentha suaveolens Ehrh.) under salinity stress (0, 30, 60 and 90 mM NaCl). Obtained results demonstrated that severe salinity stress reduced the fresh weight (FW) and plant height (PH) by 16.40% and 19.10%, respectively compared with normal growth condition. On the other hands, under sever salinity stress relative water content (RWC) and chlorophyll index were reduced by 18.05% and 3.50%, respectively. Interestingly, selenium nanoparticles (Se-NPs; 10 mg/L) application improved the pineapple mint growth. Based on GC-FID and GC-MS analysis, 19 compounds were identified in pineapple mint essential oil. Foliar application of Se-NPs and salinity did not change the essential oil content of pineapple mint, however, the essential oil compounds were significantly affected by salinity and Se-NPs- applications. Foliar application of Se-NPs- had a significant effect on piperitenone oxide, limonene, jasmone, viridiflorol and β-myrsene under different salinity levels. The highest percentage of piperitenone oxide (79.4%) as the major essential oil component was recorded in the no salinity treatment by applying 10 mg/L of nanoparticle. Interestingly, application of 10 mg L−1 Se-NPs- under 60 mM NaCl increased the piperitenone oxide content by 9.1% compared with non-sprayed plants. Finally, the obtained results demonstrated that foliar application of Se-NPs (10 mg L−1) can improve the pineapple mint growth and secondary metabolites profile under saline conditions.

Distinguishing citrus varieties based on genetic and compositional analyses.

Simple sequence repeats (SSR) markers and secondary metabolite composition were used in combination to study seven varieties of citrus for the first time. With reference to established accessions of citrus, two of the varieties (Chanh Giay and Ma Nao Pan) were predicted to be Mexican key limes, while three were mandarin hybrids (Nagpur, Pontianak and Dalandan) and the remaining two (Qicheng and Mosambi) were related to the sweet orange. Notably, Dalandan was genetically more like a mandarin despite often referred to as an orange locally, whereas Mosambi was more likely to be a sweet orange hybrid although it has also been called a sweet lime due to its green peel and small size. Several key secondary metabolites such as polymethoxyflavones (sinensetin, tangeretin etc.), furanocoumarins (bergapten, citropten etc.) and volatiles (citronellol, α-sinensal etc.) were identified to be potential biomarkers for separation of citrus species. However, despite having similar genetic profiles, variations in the volatile profile of the two limes were observed; similarly, there were differences in the secondary metabolite profiles of the three mandarin hybrids despite having a common ancestral parent, highlighting the usefulness of genetic and compositional analyses in combination for revealing both origins and flavour profiles especially in citrus hybrids. This knowledge would be crucial for variety screening and selection for use in flavour or fragrance creation and application.

Soil dynamics modulation of stress enzymes and secondary metabolites in allium cepa (L.) under salinity stress

In Allium cepa (L.) cultivation, salinity stress is the most important environmental factor worldwide that affects plant growth, protection as well as yield stability. The present study was carried out to examine the alterations in soil dynamics, antioxidants, biochemical and secondary metabolic profile of A. cepa under alkaline stress. Various parameters of A. cepa were studied under salinity stress by exposing them to different concentrations of sodium carbonate (SC) and sodium bicarbonate (SBC) salts (0, 10 and 100 mM). Treatment of both SC and SBC in A. cepa increases superoxide dismutase, glutathione peroxidase and catalase concentrations. These were attributed to increase in peroxide, lipid peroxides as well as carbonyl groups. The salinity stress was driven by the alterations in the soil dynamics. Of note, the salt stress induces secondary metabolites changes in A. cepa. The compounds like phenol 2 4-bis (1 1-dimethylethyl), hexadecane, 7,9-di‑tert‑butyl‑1-oxaspiro(4,5) deca-6,9-diene-2,8‑dione, 1,2-benzenedicarboxylic acid, butyl octyl ester, 1,2-benzenedicarboxylic acid, diisooctyl ester are elevated. In addition, the level of total proteins is reduced in all the groups except 10 mM and Proline amino acid in the shoot is elevated. Reversing all the parameters tested to achieve control levels in A. cepa indicates that significant cellular mechanism appeared in stress condition that brings back the altered parameters to normal levels. The biochemical and secondary metabolite profile analysis of the petroleum ether extracts of A. cepa under various alkaline stress conditions reveals that the composition of secondary metabolites and their concentration in A. cepa varies depending on the extent of alkaline stress.

Secondary-metabolites fingerprinting of Argania spinosa kernels using liquid chromatography–mass spectrometry and chemometrics, for metabolite identification and quantification as well as for geographic classification

Argan (Argania spinosa L.) fruit kernels’ composition has been poorly studied and received less research intensity than the resulting Argan oil. The Moroccan Argan kernels contain a wealth of metabolites and can be investigated for nutritional and health aspects as well as for economic benefits. Ultra-Performance Liquid Chromatography Mass Spectrometry (UPLC-MS) was employed to trace the geographical origin of Argan kernels based on secondary-metabolite profiles. One-hundred and twenty Argan fruit kernels from five regions (‘Agadir’, ‘Ait-Baha’ ‘Essaouira’, ‘Tiznit’ and ‘Taroudant’) were studied. Characterization and quantification of 36 secondary metabolites (33 polyphenolic and 3 non-phenolic) were achieved. Those metabolites are highly influenced by the geographic origin. Then, the untargeted UPLC-MS fingerprint was decomposed by metabolomic data handling tools, such as multivariate curve resolution alternating least squares (MCR–ALS) and XCMS. The two resulting data matrices were pretreated and prepared separately by chemometric tools and then two data fusion strategies (low- and mid-levels) were applied on them. The four data sets were comparatively investigated. Principal component analysis (PCA), Partial Least Squares Discriminant Analysis (PLS-DA), and Soft Independent Modeling of Class Analogies (SIMCA) were used to classify samples. The exploration or classification models demonstrated a good ability to discriminate and classify the samples in the geographical-origin based classes.Summarized, the developed fingerprints and their metabolomics-based data handling successfully allowed geographical traceability evaluation of Moroccan Argan kernels.

Penentuan Profil Metabolit Sekunder, Aktivitas Antioksidan dan Antibakteri dari Ekstrak Biji Kurma (Phoenix dactylifera L.) Bebas Lipid

Dates are one of the plants that grow in the Middle East, one of them is the Golden Valley variety. Dates are usually consumed directly and can also be processed into date juice drinks. Dates refined process would produce waste in the form of date seeds are discarded and not processed into other products. This study used lipid-free Golden valley date seed extract to determine the secondary metabolite profile by using LC-MS/MS method, determining phenolic content using the Folin-Ciocalteau method, determining total flavonoids using the aluminium chloride method, determining antioxidant activity by DPPH method, and determination of antibacterial activity by the disc diffusion method. The results showed that the compounds identified from the lipid-free date seed extract were catechin-(4α→8)-catechin, bis((1S,2R,5S)-5-isopropyl-2,3-dimethylcyclo-hexyl)-2,6-dimethylpyridine-3,5-dicarboxylate, 3,5,6-trihydroxy-4',7-dimethoxyflavone, ethyl-2-amino-3-oxobutanoate, and bis(2-isopropyl-5-methylcyclohexyl)-2,6-dimethyl-1,4-dihydro-3,5-pyridine dicarboxylate. Lipid-free date seed extract contains total phenolic and flavonoid totals of 4364.704 mgGAE/100 grams of dried extract and 17200 mgQE/100 grams of dried extract. Its antioxidant activity is very strong in counteracting DPPH free radicals indicated by IC50 value of 10.1951 mg/L. Antibacterial activity shows strong inhibition of Staphylococcus aureus bacteria compared to inhibition of Escherichia coli bacteria that are categorized as weak.