Glycoside Content Research Articles

Identification of geographic, climatic, and soil factors dominating Stevia rebaudiana yield and quality

Raising crop yields and quality through plant ecological research has become an important approach to sustainably improving crop products. Stevia rebaudiana is widely introduced and cultivated around the world because of the continuous increase in demand for steviol glycosides. When selecting regions or plots suitable for high-yield and high-quality cultivation, it is necessary to understand the main ecological factors that contribute to the formation of S. rebaudiana yield and quality. In this study, sampling plots from different geographic and climatic regions in Xinjiang and Jiangsu were selected for S. rebaudiana cultivation. The geographic, climatic and soil ecological factors were analyzed based on a PLSR (partial least squares regression) model to discover the potentially influential factors in the yield and quality formation of the crop. The results suggest that not all geographic and climatic ecological factors contributed to yield formation; however, these factors, such as latitude, altitude and annual sunshine duration, had high or moderate influences on the concentration of each steviol glycoside and total steviol glycoside. Soil organic matter (OM), total potassium (TK), available potassium (AK), zinc (Zn), and catalase (CAT) had high or moderate effects on the concentrations of each steviol glycoside and total steviol glycoside. However, the other soil factors showed variability in the extent to which they drove the steviol glycosides. The study contributes to a more profound understanding of the ecological driving mechanisms of S. rebaudiana yield and quality formation. The yield or steviol glycoside concentrations of sweetleaf may be improved by modifying certain key ecological factors.

The manufacturing process provides green teas with differentiated nonvolatile profiles and influences the deterioration of flavor during storage at room temperature

Hundreds of green tea products are available on the tea market and exhibit different characteristics. In the present study, seven types of green tea were processed, and their nonvolatile profiles were analyzed by liquid chromatography–mass spectrometry. Non-spreading green tea contained higher concentrations of catechins and flavonoid glycosides, but lower concentrations of amino acids, caffeine, and theaflavins. Non-rolling green teas with a straight appearance contained higher concentrations of flavonoid glycosides and theaflavins. In contrast, leaf-rolling green teas contained much lower concentrations of flavonoid glycosides and catechins. These seven green tea qualities all decreased following prolonged storage, concurrent with increasing concentrations of proanthocyanidins, catechins dimers, theaflavins, and organic acids. The leaf-rolling green teas exhibited reduced levels of deterioration during storage in terms of their nonvolatile profile and sensory quality. Findings show that moderate destruction on tea leaves during green tea processing is beneficial to both tea flavor and quality maintenance during storage.

Impact of Dry Processing on Secondary Metabolites in the Petals of Marigold (Tagetes spp.) Cultivar

The edible flowers of marigold (Tagetes spp.) are cultivated for their aesthetic appeal and high utility as functional health food ingredients. Carotenoid and flavonoid contents in marigold petals highlight the importance of selecting the appropriate cultivar and its processing methods for their industrial applications. The comparative understanding of the effects of dry processing on functional components across different marigold cultivars is still lacking. Therefore, this study investigated functional compound changes in the dry processing effect on four marigold cultivars with distinct flower shapes (Durango, Inca) and colors (yellow, orange). The petals in hot air drying (HAD) with 30, 60, and 90 °C applications were analyzed for the measurement of their individual secondary metabolite contents, total phenolic and flavonoid contents, and antioxidant activities. In freeze drying (FD), the lutein content varied significantly based on flower color, exhibiting higher levels in cultivars with orange petals. Otherwise, the levels of quercetin derivatives displayed distinct differences based on varieties other than color, with Inca cultivars demonstrating higher levels of quercetin 7-O-glucoside (Q7G) than Durango cultivars. In HAD, the lutein levels show a tendency to increase above 60 °C regardless of the cultivar. The content of quercetin glycosides decreased, while the aglycone increased in HAD treatments, regardless of the temperatures. Correlation and PCA results highlighted the impact of phenol compounds on antioxidant activity. Overall, these findings underscore the significance of variety and color in determining the chemical composition and antioxidant properties of marigold flowers.

Identifying Potential Sources of Phthalate Contamination in the Leaves of Stevia Rebaudiana (Bertoni) and the Development of Removal Technology.

Steviosides extracted from the leaves of the plant Stevia rebaudiana are increasingly used in the food industry as natural low-calorie sweeteners. Phthalates in food are often assumed to arise from food containers or packaging materials. Here, experiments were carried out to identify the potential sources of DMP, DBP, DIBP, and DEHP in the leaves of stevioside through investigation of their content in native stevioside tissues, soils, and associated agronomic materials. The results show that phthalate contamination was present in all the samples tested, and the influence of regional factors at the provincial level on the content of plasticizers in stevia leaves was not significant. Phthalates in stevia leaves can be absorbed into the plant body through leaves and roots. Using resin removal, the phthalate content in stevioside glycosides was reduced to less than 0.05 ppm, and some indicators were far lower than the limit standard in EU food.

Evidence for Reductions in Physical and Chemical Plant Defense Traits in Island Flora.

Reduced defense against large herbivores has been suggested to be part of the "island syndrome" in plants. However, empirical evidence for this pattern is mixed. In this paper, we present two studies that compare putative physical and chemical defense traits from plants on the California Channel Islands and nearby mainland based on sampling of both field and common garden plants. In the first study, we focus on five pairs of woody shrubs from three island and three mainland locations and find evidence for increased leaf area, decreased marginal leaf spines, and decreased concentrations of cyanogenic glycosides in island plants. We observed similar increases in leaf area and decreases in defense traits when comparing island and mainland genotypes grown together in botanic gardens, suggesting that trait differences are not solely driven by abiotic differences between island and mainland sites. In the second study, we conducted a common garden experiment with a perennial herb-Stachys bullata (Lamiaceae)-collected from two island and four mainland locations. Compared to their mainland relatives, island genotypes show highly reduced glandular trichomes and a nearly 100-fold reduction in mono- and sesquiterpene compounds from leaf surfaces. Island genotypes also had significantly higher specific leaf area, somewhat lower rates of gas exchange, and greater aboveground biomass than mainland genotypes across two years of study, potentially reflecting a broader shift in growth habit. Together, our results provide evidence for reduced expression of putative defense traits in island plants, though these results may reflect adaptation to both biotic (i.e., the historical absence of large herbivores) and climatic conditions on islands.

Effect of Ultrasound-Assisted Vacuum Far-Infrared on the Drying Characteristics and Qualities Attributes of Cistanche Slices

This study applied direct-contact ultrasound-assisted Vacuum Far-Infrared (VFIR) to dry Cistanche slices, investigating the influence of radiation temperature (45 °C, 55 °C, 65 °C), ultrasonic frequency (20 kHz, 40 kHz, 60 kHz) and ultrasonic power (72 W, 96 W, 120 W) on the physicochemical properties, drying characteristics, and microstructure of Cistanche slices. The results showed that the application of ultrasound had a significant enhancement effect on the drying process, with drying time decreasing as radiation temperature, ultrasonic power, and ultrasonic frequency increased. The drying rate curves under three experimental factors exhibited a brief acceleration stage followed by a deceleration stage. Under different drying conditions, the contents of Iridoid and phenylethanoid glycosides in dried products were higher than those under natural drying (ND). Specifically, the content of catalpol at 55 °C, 96 W, 40 kHz (0.56 mg/g) and the content of Leonuride at 55 °C, 96 W, 60 kHz (0.67 mg/g) increased by 1.81 and 1.9 times, compared to ND. The rest of the nutrient content and antioxidant activity increased with the increase in ultrasonic frequency. Compared to ND, ultrasonic-assisted VFIR drying improved the color and rehydration capacity of dried products. Observation of the microstructure revealed that the application of ultrasound made the interior of Cistanche slices loose and porous. In summary, ultrasonic-assisted VFIR drying not only enhances the drying rate but also improves the quality of dried products.

Ozone Treatment as an Approach to Induce Specialized Compounds in Melissa officinalis Plants.

Plants are constantly subjected to environmental changes that deeply affect their metabolism, leading to the inhibition or synthesis of "specialized" compounds, small organic molecules that play a fundamental role in adaptative responses. In this work, Melissa officinalis L. (an aromatic plant broadly cultivated due to the large amounts of secondary metabolites) plants were exposed to realistic ozone (O3) dosages (80 ppb, 5 h day-1) for 35 consecutive days with the aim to evaluate its potential use as elicitor of specialized metabolite production. Ozone induced stomatal dysfunction throughout the whole experiment, associated with a low photosynthetic performance, a decrease in the potential energy conversion activity of PSII, and an alteration in the total chlorophyll content (-35, -36, -10, and -17% as average compared to the controls, respectively). The production of hydrogen peroxide at 7 days from the beginning of exposure (+47%) resulted in lipid peroxidation and visible injuries. This result suggests metabolic disturbance within the cell and a concomitant alteration in cell homeostasis, probably due to a limited activation of antioxidative mechanisms. Moderate accumulated doses of O3 triggered the accumulation of hydroxycinnamic acids and the up-regulation of the genes encoding enzymes involved in rosmarinic acid, phenylpropanoid, and flavonoid biosynthesis. While high accumulated doses of O3 significantly enhanced the content of hydroxybenzoic acid and flavanone glycosides. Our study shows that the application of O3 at the investigated concentration for a limited period (such as two/three weeks) may become a useful tool to stimulate bioactive compounds production in M. officinalis.

Chemical Profile of Ocotea delicata (Lauraceae) Using Ultra High-Performance Liquid Chromatography-High-Resolution Mass Spectrometry-Global Natural Products Social Molecular Networking Workflow.

Ocotea, the largest genus in the Lauraceae family, encompasses numerous species of scientific interest. However, most Ocotea species have only been described morphologically. This study used an untargeted metabolomics workflow with UHPLC-HRMS and GNPS-FBMN to provide the first chemical evaluation of the polar specialized metabolites of O. delicata leaves. Leaves from three O. delicata specimens were extracted using ultrasound-assisted extraction with 70% ethanol. Among the examined samples, 44 metabolites, including alkaloids and flavonoids, were identified. In contrast to other Ocotea species, O. delicata has a wider diversity of kaempferol derivatives than quercetin. The biomass of the specimens showed a significant correlation with the chemical profile. The similarity among specimens was mostly determined by the concentrations of quinic acid, kaempferol glycosides, and boldine. The evaluated specimens exhibited chemical features similar to those of species classified as New World Ocotea, with the coexistence of aporphine and benzylisoquinoline alkaloids.

Spatial and Temporal Disparity Analyses of Glycosylated Benzaldehyde and Identification and Expression Pattern Analyses of Uridine Diphosphate Glycosyltransferase Genes in Prunus mume.

The species Prunus mume consists of uniquely aromatic woody perennials with large amounts of free aromatic substances in the flower cells. Uridine diphosphate glycosyltransferase (UGT) modifies these free aromatic substances into water-soluble glycoside-bound volatiles (GBVs) which play an important role in regulating the use of volatiles by plants for information exchange, defense, and stress tolerance. To investigate the changes in the glycosidic state of aromatic substances during the flowering period of P. mume and discern the location and expression of glycoside synthesis genes, we extracted and enzymatically hydrolyzed GBVs of P. mume and then utilized gas chromatography-mass spectrometry (GC-MS) to characterize and analyze the types and contents of GBV glycosides. Further, we identified and classified the members of the UGT gene family of P. mume using the bioinformatic method and analyzed the correlation between the expression of the UGT family genes in P. mume and the changes in glycosidic content. The results showed that the benzenoids were the main aromatic substance that was glycosylated during flowering in P. mume and that glycosidic benzaldehyde was the most prevalent compound in different flower parts and at different flowering stages. The titer of glycoside benzaldehyde gradually increased during the bud stage and reached the highest level at the big bud stage (999.6 μg·g-1). Significantly, titers of glycoside benzaldehyde significantly decreased and stabilized after flowering while the level of free benzaldehyde, in contrast, significantly increased and then reached a plateau after the flowering process was completed. A total of 155 UGT family genes were identified in the P. mume genome, which were divided into 13 subfamilies (A-E, G-N); according to the classification of Arabidopsis thaliana UGT gene subfamilies, the L subfamily contains 17 genes. The transcriptome analysis showed that PmUGTL9 and PmUGTL13 were highly expressed in the bud stage and were strongly correlated with the content of the glycosidic form of benzaldehyde at all stages of flowering. This study provides a theoretical basis to elucidate the function of UGT family genes in P. mume during flower development, to explore the mechanism of the storage and transportation of aromatic compounds in flower tissues, and to exploit industrial applications of aromatic products from P. mume.

Plant geographic distribution influences chemical defences in native and introduced Plantago lanceolata populations

Abstract Plants growing outside their native range may be confronted by new regimes of herbivory, but how this affects plant chemical defence profiles has rarely been studied. Using Plantago lanceolata as a model species, we investigated whether introduced populations show significant differences from native populations in several growth and chemical defence traits. Plantago lanceolata (ribwort plantain) is an herbaceous plant species native to Europe and Western Asia that has been introduced to numerous countries worldwide. We sampled seeds from nine native and 10 introduced populations that covered a broad geographic and environmental range and performed a greenhouse experiment, in which we infested half of the plants in each population with caterpillars of the generalist herbivore Spodoptera littoralis. We then measured size‐related and resource‐allocation traits as well as the levels of constitutive and induced chemical defence compounds in roots and shoots of P. lanceolata. When we considered the environmental characteristics of the site of origin, our results revealed that populations from introduced ranges were characterized by an increase in chemical defence compounds without compromising plant biomass. The concentrations of iridoid glycosides and verbascoside, the major anti‐herbivore defence compounds of P. lanceolata, were higher in introduced populations than in native populations. In addition, introduced populations exhibited greater rates of herbivore‐induced volatile organic compound emission and diversity, and similar chemical diversity based on untargeted analyses of leaf methanol extracts. In conclusion, the geographic origin of the populations had a significant influence on morphological and chemical plant traits, suggesting that P. lanceolata populations are not only adapted to different environments in their native range, but also in their introduced range. Read the free Plain Language Summary for this article on the Journal blog.

Integrated metabolic phenotypes and gene expression profiles reveal enzymatic browning mechanism in postharvest chrysanthemum

Chrysanthemum (Chrysanthemum morifolium Ramat) is a valuable crop mainly used for medicine, beverages and ornament. Enzymatic browning causes serious postharvest flower deterioration of chrysanthemum, but the mechanism remains unclear. To clarify the mechanism involved, the cellular ultrastructure, metabolites, browning products, and differentially expressed genes of chrysanthemum were studied systematically. During the browning process, cellular compartmentalization was severely disrupted and the contents of chlorogenic acid derivatives and flavonoid glycosides decreased significantly. A browning product with a dihydrobenzofuran skeleton was purified and identified for the first time from a simulated browning reaction of chlorogenic acid catalyzed by peroxidase. Moreover, six differentially expressed genes were for the first time identified to be involved in the regulation of oxidase by transcriptome and qPCR, and one of which (c76073_g1) was validated using in vitro enzyme activity determination. This research elucidates the inherent mechanism of enzymatic browning, provides a scientific explanation for the steam-treated processing of chrysanthemums and lays the foundation for the molecular breeding of anti-browning chrysanthemum varieties.

Effect of UV Stress on the Antioxidant Capacity, Photosynthetic Activity, Flavonoid and Steviol Glycoside Accumulation of Stevia rebaudiana Bertoni

Lighting conditions are an important controller of plant growth and development, and they affect secondary metabolite synthesis. In this research, we explored the effect of additional UV irradiation of various ranges in addition to the main one at PPFD 160 µmol m−2 s−1 on the accumulation of some secondary metabolites of stevia (Stevia rebaudiana Bertoni). The fresh weight of leaves was slightly higher under additional UV-A and UV-B irradiation compared with the control variant, and the leaf surface area was significantly larger, respectively, by 23.3 and 20.7% than in the control variant, while the rate of photosynthesis did not decrease. Plants under additional UV-B and UV-C irradiation were under the greatest light stress, as evidenced by a decrease in antioxidant capacity by an average of 30% compared to the control and UV-A. The total flavonoid content was significantly higher (by 74%) under UV-B irradiation. The highest concentration of steviol glycoside was observed during budding and flowering under UV-B and UV-C irradiation (by 13.2 and 11.3%, respectively). Analysis of hyperspectral images, chlorophyll fluorescence, and vegetation indices showed light stress increasing under UV-C irradiation, which caused an increase in the relative chlorophyll content, scorches, leaf morphology changes, a CO2 absorption rate decrease, and plant growth inhibition. UV-B irradiation can be used as an optimal type of irradiation based on a set of indicators.

Transcriptomic Analyses Reveal Insights into the Shared Regulatory Network of Phenolic Compounds and Steviol Glycosides in Stevia rebaudiana.

Stevia rebaudiana (Bertoni) is a highly valuable crop for the steviol glycoside content in its leaves, which are no-calorie sweeteners hundreds of times more potent than sucrose. The presence of health-promoting phenolic compounds, particularly flavonoids, in the leaf of S. rebaudiana adds further nutritional value to this crop. Although all these secondary metabolites are highly desirable in S. rebaudiana leaves, the genes regulating the biosynthesis of phenolic compounds and the shared gene network between the regulation of biosynthesis of steviol glycosides and phenolic compounds still need to be investigated in this species. To identify putative candidate genes involved in the synergistic regulation of steviol glycosides and phenolic compounds, four genotypes with different contents of these compounds were selected for a pairwise comparison RNA-seq analysis, yielding 1136 differentially expressed genes. Genes that highly correlate with both steviol glycosides and phenolic compound accumulation in the four genotypes of S. rebaudiana were identified using the weighted gene co-expression network analysis. The presence of UDP-glycosyltransferases 76G1, 76H1, 85C1, and 91A1, and several genes associated with the phenylpropanoid pathway, including peroxidase, caffeoyl-CoA O-methyltransferase, and malonyl-coenzyme A:anthocyanin 3-O-glucoside-6″-O-malonyltransferase, along with 21 transcription factors like SCL3, WRK11, and MYB111, implied an extensive and synergistic regulatory network involved in enhancing the production of such compounds in S. rebaudiana leaves. In conclusion, this work identified a variety of putative candidate genes involved in the biosynthesis and regulation of particular steviol glycosides and phenolic compounds that will be useful in gene editing strategies for increasing and steering the production of such compounds in S. rebaudiana as well as in other species.

HPLC-UV Analysis of Flavonoid Glycosides in the Herb of <i>Astragalus</i> (<i>A. dasyanthus</i>, <i>A. varius</i>, <i>A. testiculatus</i>, <i>A. henningii</i>), Growing in the Volga Region

Introduction. The search for new promising sources of biologically active substances is one of the tasks of modern pharmacognosy. Among the huge variety of species of the genus Astragalus L., only a few of them have been studied. In addition, none of them is included in the current edition of the State Pharmacopoeia of the Russian Federation. In our opinion, the study of four species of this genus of Astragalus L. (A. dasyanthus, A. varius, A. testiculatus, A. henningii) growing in the Volga region is of interest.Aim. Study of the glycoside composition of flavonoids in the astragalus herb of four species (A. dasyanthus, A. varius, A. testiculatus, A. henningii) by HPLC-UV using external standards.Materials and methods. The material was samples of astragalus grass (A. dasyanthus, A. varius, A. testiculatus, A. henningii), collected on the territory of the Saratov region in accordance with the basic rules of collection and preparation and dried to an air-dry state. Aqueous-alcoholic extracts (1 : 50) were analyzed. Qualitative and quantitative analysis of flavonoid glycosides was carried out on an Agilent 1260 chromatograph (Agilent Technologies, USA) equipped with a diode array detector, manual sample injection (Agilent G1328C manual injector, Agilent Technologies USA) and an Agilent Open Lab CDS system for collecting and processing chromatographic data. The elution gradient was selected individually using 0.1 % phosphoric acid/acetonitrile solution as solvents. Compounds were identified by retention times and UV spectra of reference standards (RS). The quantitative content of each detected component was expressed in mg/g of dry raw material. All studies were repeated five times, the results were statistically processed using MS Exсel 2010.Results and discussion. The chromatographic profiles of aqueous-alcoholic extracts from the herbs of four types of astragalus were studied. Differences were found in both the qualitative composition and quantitative content of flavonoid glycosides in the grass of the analyzed species. The largest number of compounds was found in the herb of A. varius (6 compounds), 4 compounds were identified in the herb of A. dasyanthus and A. henningii, and 3 compounds were identified in the herb of A. testiculatus. The dominant components in the herb of A. henningii are orientin and rutin, in the herb of A. testiculatus and A. varius it is cynaroside, and in A. dasyanthus it is rutin.Conclusion. A HPLC-UV method was developed for determining the quantitative content of flavonoid glycosides in extracts from the herbs of four species of astragalus (A. dasyanthus, A. varius, A. testiculatus, A. henningii) and the chromatographic profiles of the analyzed samples were studied.

Content of selected polyphenolic compounds in four Sambucus nigra l. cultivars in relation to their antimicrobial activity

European elderberry (Sambucus nigra L.) fruits constitute a valuable source of biologically active compounds useful in the pharmaceutical industry. We aimed to determine the content of chosen polyphenolic compounds in fruit extracts from four cultivars of elderberry (Alleso, Korsor, Sampo, Samyl) and their relation to antibacterial and antifungal activity. The content of polyphenols was determined with the use of high-performance liquid chromatography (HPLC), while antimicrobial activity, including minimum inhibitory concentration (MIC), minimum bactericidal (MBC) or fungicidal (MFC) concentration, was studied with the use of microbroth dilution method. HPLC analysis revealed the presence of concentrations of cyanidin glycosides, caffeic and quercetin derivatives depending on the plant cultivar. The extracts exhibited the highest antibacterial activity against Staphylococcus spp. (MIC = 0.313 – 0.625 mg/mL) and Helicobacter pylori (MIC = 0.313 – 1.25 mg/mL) and antifungal against Candida albicans and C. parapsilosis (MIC = 0.313 – 2.5 mg/mL). Results showed that the concentration of cyanidin glycosides, caffeic and quercetin derivatives depended on the analyzed S. nigra L. cultivar and pointed towards a correlation between their high content and antimicrobial activity. These results support the idea that elderberry fruits contain bioactive compounds providing them significant antimicrobial potential.

Holistic quality evaluation method of Epimedii Folium based on NIR spectroscopy and chemometrics.

There are some problems in the quality control of Epimedii Folium (leaves of Epimedium brevicornum Maxim.), such as the mixed use of Epimedii Folium from different harvesting periods and regions, incomplete quality evaluation, and time-consuming analysis methods. Near-infrared (NIR) spectroscopy was conducted to establish a rapid overall quality evaluation method for Epimedii Folium. Quantitative models of the total solid, moisture, total flavonoid, and flavonol glycoside (Epimedin A, Epimedin B, Epimedin C, Icariin) contents of Epimedii Folium were established by partial least squares regression (PLSR). The root mean square error (RMSE) and correlation coefficient (R) were used to evaluate the performance of models. The qualitative models of Epimedii Folium from different geographic origins and harvest periods were established based on K-nearest neighbor (KNN), back-propagation neural network (BPNN), and random forest (RF). Accuracy and Kappa values were used to evaluate the performance of models. A new multivariable signal conversion strategy was proposed, which combines NIR spectroscopy with the PLSR model to predict the absorbance values of retention time points in the high-performance liquid chromatography (HPLC) fingerprint to obtain the predicted HPLC fingerprint. The Pearson correlation coefficient and cosine coefficient were used to evaluate the similarity between real and predicted HPLC fingerprints. Qualitative models, quantitative models, and the similarity between real and predicted HPLC fingerprints are satisfactory. The method serves as a fast and green analytical quality evaluation method of Epimedii Folium and can replace traditional methods to achieve the overall quality evaluation of Epimedii Folium.

Brassica microgreens cabbage (Brassica oleracea), radish (Raphanus sativus) and rocket (Eruca vesicaria) (L.) Cav: application of red‐light emitting diodes lighting during postharvest storage and in vitro digestion on bioactive compounds and antioxidant activity

SummaryMicrogreens grow best under light‐emitting diodes (LED), an artificial light source. In this study, LED lights (red, blue and far‐red) were tested on brassica microgreens to see if they induced an increase in bioactive compounds (glucosinolates and phenolics). In vitro digestion also measured bioavailable bioactive compounds in the intestinal phase. LED lights (red, blue and far‐red) were applied for 6 h in storage at 5 °C and 85% RH for 5 days on cabbage (Brassica oleracea), radish (Raphanus sativus) and rocket (Eruca vesicaria (L.) Cav). Red light significantly enhanced ascorbic acid, total phenols, kaempferol and quercetin glycoside concentrations in all three Brassica microgreens and antioxidant activities. Exposure to red LED light increased 4‐methoxyglucobrassicin (cabbage), glucoraphenin (radish), glucoraphanin A and glucoerucin (rocket). Red light stress may have resulted in secondary metabolite production in immature plants. An in vitro digestion showed higher concentrations of phenolic compounds, glucosinolate components and antioxidants in the intestinal phase. Red LED light is recommended as a postharvest treatment for improving cabbage, rocket and radish bioactive compounds.

The increase of steviol glycosides in stevia (Stevia rebaudiana Bertoni) through artificial polyploidy

Stevia rebaudiana is a plant that produces secondary metabolites with diterpene glycosides, commonly called steviol glycosides, the Steviol glycosides as a low-calorie sweetener. Rebaudioside A and stevioside are steviol glycosides that are abundant in stevia leaves. Apart from being a sweetener, stevioside in stevia leaves has the potential as an anticancer. The obstacle to developing Stevia in Indonesia is the availability of stevia seeds of low quality, so a strategy is needed to improve the plants and increase the availability of quality stevia seeds. Artificial polyploid is one strategy for plant improvement, including increasing the production of secondary metabolites. This study aims to increase the content of steviol glycosides through artificial polyploidy using colchicine in tissue culture. The treatment was immersed in the explants in 100 mg.L-1 colchicine for 0, 24, 48, 72, and 96 hours. The results showed that soaking for 24 hours produced 13.63% mixoploid explants. The mixoploid explants produced the highest levels of rebaudioside A at 4.286% and the highest stevioside at 13.047%.

Synthesis of Zinc Oxide Nanoparticles using Extract of Cynodon dactylon and Assessment of their Biological Activity against Staphylococcus aureus and Escherichia coli

Nanotechnology is a groundbreaking technology that that has been widely applied in creating materials which are useful in various fields. It's important to maintain eco-friendly approaches for synthesis of nanoparticles by diversifying the substrate sources. In this study, the researchers used aqueous extract of Cynodon dactylon to synthesize zinc oxide nanoparticles (ZnONPs). Quantitative phytochemical analysis of the extract showed high concentrations of alkaloids, flavonoids, carbohydrates, proteins, amino acids, and phenolic compounds. In contrast, moderate concentrations of tannins, oils, and fats, and low concentrations of phlorotannins, saponin, triterpenoids, and cardiac glycosides were found. Sterols, anthraquinone glycosides, gums, and mucilages were not detected in the extract. The synthesized ZnONPs showed absorbance ranging from 293 nm to 336 nm, with a peak at 307 nm. Fourier transform infrared (FTIR) spectroscopy revealed that the surface of the ZnONPs contained alcohol (intermolecular bonded), alkyne, amine salt, alkane, alkyne, aromatic compounds, conjugated alkene, amine, nitro compound, sulfonyl chloride, alkylaryl ether, and sulfoxide. Dynamic light scatering (DLS) analysis of the ZnONPs showed that its average size was 35.34±1.64 nm, and the polydispersity index was 0.6335. Spectrum of X ray diffraction indicated that peaks formed at 2θ and their corresponding orientation planes are 31.92o (100), 34.62o (002), 36.44o (101), 47.64o (102), 56.84o (110), 63.3o (200), and 68.16o (112). Transmission electron micrograph revealed the spherical shape, and nonuniform sizes of ZnONPs, which ranged from 0.52 nm to 8.32 nm. Antibacterial analysis of biosynthesized ZnONPs recorded 16±3.2 mm and 6.0±2.2 mm; 6.7±2.1 mm and 4.33±1.3 mm, 0.0±0.0 mm and 1.0±1.41 mm, against Staphylococcus aureus and Escherichia coli, at 53.3 mg/mL, 26.7 mg/mL and 13.3 mg/ml concentrations, respectively. At sub-inhibitory concentrations, biosynthesized ZnONPs demonstrated effective dose-dependent antibiofilm formation activity against E. coli and S. aureus. Consequently, extract of Cynodon dactylon is suitable for biosynthesis of ZnONPs with effective antibacterial and antibiofilm formation activities.

Qualitative and quantitative phytochemical analysis of brown seaweed Sargassum polycystum collected from Bangladesh with its antioxidant activity determination

Seaweeds possess considerable potential for developing and enhancing pharmaceutical drugs because of their wide variety as abundant sources of numerous bioactive secondary metabolites, making them well-suited for developing and enhancing pharmaceutical drugs. This study evaluated the antioxidant, secondary metabolites, total phenolic content, and total flavonoid content of various crude extracts (methanol, ethanol) and their fractions (50 % and 70 %) of Sargassum polycystum. Fourier transform infrared (FT‐IR) analysis was also performed to identify the active chemical composition of the crude extracts. The results showed that various extracts contained varying concentrations of terpenoid, saponin, phlobatannin, cardiac glycosides, phenolic, and flavonoid. FT-IR analysis confirmed the presence of phenols, carboxylic acid, ketones, ethers, aromatics, amides, and sulfonates. 100 % methanolic extract contained the maximum concentrations of total phenols (80.13 mg of GAE/g) and total flavonoids (38.33 mg of quercetin/g). 100 % methanol extracts exhibited higher antioxidant activity in the DPPH assay (78.32 %, IC50 = 1.59 mg/ml) and ABTS assay (69.82 %, IC50 = 2.39 mg/ml). The bio-functional activity of crude extracts depended on their extract and concentration. The present study demonstrates that the macroalgae S. polycystum contains noteworthy secondary metabolites and natural antioxidants, indicating their potential utilization in various pharmacological and functional food applications.