Levels Of Phenolic Acids Research Articles

Bazı Dicranum Hedw. Türlerinin Biyokimyasal Özellikleri

In this study, the fatty acid compositions, lipid-soluble vitamins, sterols, flavonoids, and phenolic acid levels, as well as the DPPH radical scavenging activity of five different Dicranum species (D. majus, D. fuscencens, D. polysetum, D. scoparium and D. tauricum) were examined. While lipid-soluble vitamins, sterols, flavonoids, and phenolic acids were evaluated by HPLC, fatty acid compositions were assessed by gas chromatography. Based on study findings, it was determined that the examined Dicranum species exhibit low levels of flavonoids and lipid-soluble vitamins. However, it was seen that the species under study were high in terms of phenolic acids. Particularly, it was determined that the examined species have substantial levels of gallic acid (52.96-63.1 g/g) and vanilic acid (11.96-44.83 g/g). Cinnamic acid concentration was lowest in the examined samples. The radical scavenging capacity of the examined species was found to range from 48.92% to 86.89% in 250 µl in this study. Additionally, it was discovered that the investigated species' stigmasterol contents ranged from 35.3 to 46.05 g/g. The lowest levels of ergosterol and beta-sitosterol were discovered in D. majus and D. fuscescens. Based on the results of fatty acid composition, it was discovered that oleic acid (C18:1 n9), linoelic acid (C18:2 n6), and -linolenic acid (C18:3 n3) were the predominant unsaturated fatty acids and that palmitic acid (C16:0) and behenic acid (C22:0) was the major saturated fatty acid.

Phytochemical Profile and Selective Cytotoxic Activity of a Solanum bulbocastanum Dun. Methanolic Extract on Breast Cancer Cells

Solanum bulbocastanum is a wild potato species, intensively used in potato breeding programs due to its resistance to environmental factors. Thus, its biochemical profile and putative human health-related traits might be transferred into potato cultivars aimed for consumption. This study aims to assess the phytochemical profile and the selective cytotoxicity of an S. bulbocastanum extract against breast cancer cells. Dry leaves were subjected to ultrasonication-assisted extraction in methanol [70%]. The phenolic and glycoalkaloid profiles were determined by HPLC-PDA/-ESI+-MS. The volatile profile was investigated by nontargeted ITEX/GC-MS. The extract was tested against three breast cancer cell lines (MCF7, MDA-MB-231, HS578T) and a healthy cell line (HUVEC) by the MTT assay, to assess its selective cytotoxicity. The phenolic profile of the extract revealed high levels of phenolic acids (5959.615 µg/mL extract), and the presence of flavanols (818.919 µg/mL extract). The diversity of the volatile compounds was rather low (nine compounds), whereas no glycoalkaloids were identified, only two alkaloid precursors (813.524 µg/mL extract). The extract proved to be cytotoxic towards all breast cancer cell lines (IC50 values between 139.1 and 356,1 µg/mL), with selectivity coefficients between 1.96 and 4.96 when compared with its toxicity on HUVECs. Based on these results we conclude that the exerted cytotoxic activity of the extract is due to its high polyphenolic content, whereas the lack of Solanaceae-specific glycoalkaloids might be responsible for its high selectivity against breast cancer cells in comparison with other extract obtained from wild Solanum species. However, further research is needed in order to assess the cytotoxicity of the individual compounds found in the extract, as well as the anti-tumor potential of the S. bulbocastanum tubers.

The content of biologically active compounds in potato tubers of Ismena (yellow flesh) and Provita (purple flesh) varieties – A comparison

The quality of potatoes intended for consumption or food processing depends primarily on their variety and chemical composition, which can be modified by growing conditions, place of cultivation, type of soil, amount of rainfall, as well as fertilization and plant protection products. This study aims to investigate the content of biologically active compounds in new varieties of potatoes with purple and yellow flesh, harvested in different cultivation locations. The content of the basic chemical composition and biologically active compounds in the raw material depended primarily on their variety, and to a lesser extent on the place of cultivation. Higher levels of kynurenic acid (KYNA), phenolic acids, and amino acids were found in potatoes of the new variety with purple-fleshed Provita compared to potatoes with yellow-fleshed Ismena. Potatoes with purple-flesh were characterized by over 40% lower amount of total glycoalcaloids (TGA). Most of the determined biologically active compounds, i.e. anthocyanins, phenolic acids, KYNA, and TGA varied depending on the place of origin of the potatoes, at the level of 40–66%. The biggest differences were found in the content of flavonols and amino acids, in the case of these substances the differences between potatoes from different places of cultivation ranged from 88% to 99%.

Hydrolysable tannins, physicochemical properties, and antioxidant property of wild-harvested Terminalia ferdinandiana (exell) fruit at different maturity stages.

Terminalia ferdinandiana Exell., also known as Kakadu plum, is a wild-harvested native Australian fruit with limited information on how maturity is affecting the phytonutritional properties and bioactivities of the fruit. Thus, this study investigated changes in hydrolysable tannins, phenolic acids, sugar profile, standard physicochemical parameters, and antioxidant-scavenging capacity of wild-harvested Kakadu plum fruits at four different maturity stages, from immature to fully mature. Fruits harvested <25, 25–50, 50–75, and 75–100% degree of fullness were classified as highly immature (stage 1), immature (stage 2), semi-mature (stage 3), and fully mature (stage 4), respectively. Results showed that chebulagic acid, geraniin, chebulinic acid, castalagin, punicalagin, and gallic acid continuously decreased during fruit maturity, while elaeocarpusin, helioscopin B, corilagin, 3,4,6-tri-O-galloyl-S-glucose, and ellagic acid increased at the beginning of fruit growth (from stage 1 to 2), but decreased when the fruits reached their full maturity (stage 4). The levels of hydrolysable tannins and phenolic acids in fully mature fruits (stage 4) were significantly (p ≤ 0.05) lower than that in their immature counterparts (stages 1 and 2). Total phenolic content (TPC) and DPPH antioxidant radical-scavenging activity did not vary significantly between different maturity stages. Pearson's correlation coefficient test indicated that TPC and DPPH positively (p ≤ 0.05) correlate with most of the studied tannin compounds. Sugars (glucose, fructose, and sucrose), total soluble solid content, and titratable acidity increased during the fruit development. Furthermore, principal component analysis (PCA) revealed the difference between the immature and mature samples, based on their nutritional profile and bioactive compounds. The PCA results also suggested a considerable variability between the individual trees, highlighting the challenges of wild-harvest practice.

Metabolic Analyses and Evaluation of Antioxidant Activity in Purple Kohlrabi Sprouts after Exposed to UVB Radiation.

Various metabolites act as plant defense molecules due to their antioxidant abilities. This study aimed to investigate the influence of UVB irradiation on the accumulation of metabolites, including primary metabolites (sugar, sugar alcohols, amino acids, organic acids, and an amine) and secondary metabolites (anthocyanins, fatty acids, and phenolic acids), and its synergistic antioxidant ability, in purple kohlrabi sprouts. Metabolite analyses revealed a total of 92 metabolites in the sprouts. Specifically, the levels of most amino acids increased after 24 h of UVB treatment, and then slightly decreased in the kohlrabi sprouts. The levels of most sugars and sugar alcohols increased after 24 h of UVB treatment and then decreased. The levels of TCA cycle intermediates and phenolic acids gradually increased during the UVB treatment. Furthermore, the levels of some fatty acids gradually increased during the UVB treatment, and the levels of the other fatty acids increased after 6 h of UVB treatment and then decreased. In particular, the levels of most anthocyanins, known to be strong antioxidants, gradually increased after 24 h of UVB treatment. In the in vitro ABTS scavenging assay, UVB-treated purple kohlrabi sprouts showed increased scavenging ability. This may be attributed to the increased accumulation of metabolites acting as antioxidants, in response to UVB treatment. This study confirmed that UVB irradiation induced the alteration of primary and secondary metabolism in the kohlrabi sprouts.

Mycorrhization of strawberry plantlets potentiates the synthesis of phytochemicals during ex vitro acclimatization

Ex vitro strawberry plantlets from micropropagation and coinoculated with arbuscular mycorrhizal fungi (AMF) and biochar can provide beneficial health effects. In the present study, we evaluated the effects of different proportions of biochar in the presence and absence of AMF on the production of secondary metabolites in the leaves and roots of strawberry plantlets during ex vitro acclimatization. Additionally, the enzymatic activity of the substrate enriched with AMF and biochar was analyzed. The experiment consisted of the control (absence of the mycorrhizal community) and four biochar proportions (0, 3, 6, and 9% of the volume of the container) coinoculated with AMF. Plantlets produced on substrates enriched with AMF showed higher levels of polyphenols, flavonoids, phenolic acids, and tannins in the tissues analyzed than control plantlets. The combination of AMF and 9% biochar increased the content of total flavonoids in the leaves of strawberry plantlets and increased the activity of phosphatase. The substrate with up to 6% biochar and mycorrhizae showed increased β-glucosidase activity. In conclusion, mycorrhizae are excellent tools to improve the phytochemical quality of strawberry plantlets acclimatized ex vitro. The association between host plants, mycorrhizal symbionts, and bioactivators of these fungi potentiates properties beneficial to health, which can be exploited efficiently in sustainable agriculture.

Molecular mechanisms associated with microbial biostimulant-mediated growth enhancement, priming and drought stress tolerance in maize plants

Microbial-based biostimulants are emerging as effective strategies to improve agricultural productivity; however, the modes of action of such formulations are still largely unknown. Thus, herein we report elucidated metabolic reconfigurations in maize (Zea mays) leaves associated with growth promotion and drought stress tolerance induced by a microbial-based biostimulant, a Bacillus consortium. Morphophysiological measurements revealed that the biostimulant induced a significant increase in biomass and enzymatic regulators of oxidative stress. Furthermore, the targeted metabolomics approach revealed differential quantitative profiles in amino acid-, phytohormone-, flavonoid- and phenolic acid levels in plants treated with the biostimulant under well-watered, mild, and severe drought stress conditions. These metabolic alterations were complemented with gene expression and global DNA methylation profiles. Thus, the postulated framework, describing biostimulant-induced metabolic events in maize plants, provides actionable knowledge necessary for industries and farmers to confidently and innovatively explore, design and fully implement microbial-based formulations and strategies into agronomic practices for sustainable agriculture and food production.

Polyphenols Sourced from Ilex latifolia Thunb. Relieve Intestinal Injury via Modulating Ferroptosis in Weanling Piglets under Oxidative Stress.

Polyphenols sourced from Ilex latifolia Thunb. (PIT) contain high levels of phenolic acids, tannic acids, triterpenoids and so on, which play important roles in antioxidant function. This study was conducted to investigate the effects of PIT against intestinal injury in piglets under oxidative stress. Thirty-two weanling piglets were arranged by a 2 × 2 factorial experiment with diets (basal diet vs. PIT diet) and oxidative stress (saline vs. diquat). All piglets were injected with saline or diquat on d 21, respectively. After 7 days, all pigs were slaughtered and intestinal samples were collected. PIT enhanced jejunal villus heights and crypt depth in the piglets under oxidative stress. PIT increased the activities of intestinal mucosal lactase, sucrase and maltase in the challenged piglets. PIT also increased the jejunal ratio of protein to DNA and ileal protein content. PIT increased the jejunal activities of GSH-PX and GSH content and reduced the ileal MDA amounts. Furthermore, PIT regulated the expression of ferroptosis mediators, such as TFR1, HSPB1, SLC7A11 and GPX4. These results indicate that dietary PIT supplementation enhances the histological structure and function of the intestinal mucosa, which is involved in modulating antioxidant capacity and ferroptosis.

Phenolic Profiling of Berries Waste and Determination of Their Antioxidant Potential

Berries waste is a major issue in Australia’s annual food wastage, which can reach 7.3 million tonnes. This study assessed the phenolic content and antioxidant potential of four fruit berry wastes, including blueberries (Vaccinium corymbosum), blackberries (Rubus spp.), raspberries (Rubus idaeus), and strawberries (Fragaria spp.), followed by their characterization and quantification. Blueberry wastes were high in phenolic content (total phenolic content: 1.97 ± 0.16 mg GAE/gF.W; total flavonoid content: 220.43 ± 13.15 μg QE/gF.W; total tannins content: 16.47 ± 0.98 μg CE/gF.W), and antioxidant potentials are 2,2′-diphenyl-1-picrylhydrazyl: 2.23 ± 0.17 mg AAE/gF.W; 2,2′-azino-bis-(3-ethylbenzothiazoline-6-sulphonic acid): 1.79 ± 0.09 mg AAE/gF.W; ferric reducing antioxidant power: 68.71 ± 11.11 μg AAE/gF.W (total antioxidant capacity: 1.22 ± 0.03 mg AAE/gF.W). The LC-ESI-QTOF-MS/MS analysis identified 87 compounds from blueberry (57), strawberry (40), raspberry (47), and blackberry wastes (27). Indicated by HPLC quantification, blueberry wastes had higher levels of phenolic acid (syringic acid and coumaric acid) and flavonoid (kaempferol and kaempfero l-3-glucoside). Our study reported that phenolics from berry wastes could be utilized in different food, feed, pharmaceutical, and nutraceutical industries.

Metabolic Profiling of White and Green Radish Cultivars (Raphanus sativus)

Radish (Raphanus sativus) is a Brassica vegetable important for human nutrition and health because it is rich in diverse metabolites. Although previous studies have evaluated various metabolites, few studies have comprehensively profiled the primary and secondary metabolites in the roots of white- and green-colored radishes. Thus, this study aimed to provide information about the contents of metabolites beneficial for human health in both cultivars and to investigate the relationships between the various metabolites detected. In particular, among the 55 metabolites detected in radish roots, the levels of most amino acids and phenolic acids, vital to nutrition and health, were higher in green radish roots, while slightly higher levels of glucosinolates were observed in white radish roots—information which can be used to develop an effective strategy to promote vegetable consumption. Furthermore, glutamic acid, as a metabolic precursor of amino acids and chlorophylls, was positively correlated with other amino acids (cysteine, tryptophan, asparagine, alanine, serine, phenylalanine, valine, isoleucine, proline, leucine, beta-alanine, lysine, and GABA), and chlorophylls (chlorophyll a and chlorophyll b) detected in radish roots and phenylalanine, a metabolic precursor of phenolic compounds, were positively correlated with kaempferol, 4-hydroxybenzoate, and catechin. In addition, strong positive correlations between carbohydrates (sucrose and glucose) and phenolics were observed in this study, indicating that sucrose and glucose function as energy sources for phenolic compounds.

Accumulation of anthocyanins and phenolic acids and antioxidant activity of lettuce cultivars grown hydroponically and in the open ground

We assess the level of anthocyanins and phenolic acids accumulated in the leaves of lettuce cultivars grown hydroponically and in the open ground. In addition, the antioxidant activity of the cultivars under study was determined. The plant material was macerated overnight using a selected extractant. The anthocyanin concentration was determined by spectrophotometry, while the composition of anthocyanins and phenolic compounds was determined by reverse-phase high performance liquid chromatography. In general, anthocyanins in the extracts of all red-leaved lettuce cultivars were represented by cyanidin-3-(6″- malonylglucoside) with a small amount of its isomer – cyanidin-3-(3″-malonylglucoside). The highest level of anthocyanins was detected in the leaves of c.v. Thurinus, amounting up to 0.200 g per 100 g of fresh product for the intensively painted leaf areas. The cultivation of lettuce under the green-house conditions (hydroponically) leads to a significant reduction in the anthocyanin concentration in its leaves. The loss of anthocyanins during leaf drying was established to exceed 50%. Along with anthocyanins, the derivatives of caffeic acid, including chlorogenic (5-caffeoylquinic) acid, 5CQA, chicoric (3,4-caffeoyltartaric) acid, and 3,5- dicaffeoylquinic acid are important water-soluble compounds with antioxidant effects. The 5CQA accumulation was the highest, comprising 140 mg per 100 g of fresh weight (Red Thurinus). Antioxidant properties correlating with the level of anthocyanin accumulation were determined using the Folin-Ciocalteu method. In comparison with green-leaved cultivars, red-leaved lettuce was found to exhibit a greater antioxidant activity, thus representing a more valuable and functional food product. According to the obtained results, a system of additional illumination is required for intensification of the anthocyan biosynthesis aimed at obtaining highquality products cultivated hydroponically in green-house facilities.

Selected Phenolic Acids Inhibit the Initial Growth of Ambrosia artemisiifolia L.

Simple SummaryIn the context of international commitments to reduce the environmental impact of herbicides, ecologically more favorable control method approaches must be explored. This is particularly important for allergenic Ambrosia artemisiifolia L., one of the most harmful species in the world. Secondary plant metabolites and, in particular, some phenolic compounds are known to have a strong allelopathic effect on weed growth. In this study we investigated whether phenolic acids (chlorogenic acid, caffeic acid, ferulic acid, gallic acid, protocatechuic acid, p-hydroxybenzoic acid, syringic acid, vanillic acid, and p-coumaric acid) can inhibit the early growth of A. artemisiifolia. Phenolic acids were tested at five different dose levels that were up to 16 times than those naturally occurring in plants. The results show that the suppression of the early growth of A. artemisiifolia is strongly dependent on phenolic acid and its dose. Treating seeds with ferulic acid, vanillic acid, p-coumaric acid, p-hydroxybenzoic acid, or a mixture of all phenolic acids resulted in significantly better inhibition of early growth parameters than other phenolic acids. However, none of the phenolic acids tested were effective as bioherbicides at their naturally occurring doses in plants. Therefore, selected doses of phenolic acids with significantly reduced herbicide doses should be further explored to effectively control A. artemisiifolia.This study aimed to investigate whether different doses of specific phenolic acids (chlorogenic acid, caffeic acid, ferulic acid, gallic acid, protocatechuic acid, p-hydroxybenzoic acid, syringic acid, vanillic acid, and p-coumaric acid), alone or in combination, can inhibit the early growth of the common ragweed (Ambrosia artemisiifolia L., Asterales: Asteraceae). A seed bioassay was performed in Petri dishes and placed in a climate chamber to assess the effects of five dose levels of phenolic acids to radicle and shoot length, as well seedling biomass of A. artemisiifolia. The lowest dose of phenolic acid corresponded to the natural phenolic acid concentration previously reported in dry plant tissue samples from Brassicaceae cover crop plants. Results show that the inhibition of the early growth of A. artemisiifolia depends strongly on phenolic acid. Across different treatments, high doses of phenolic acids significantly shortened shoots and radicles, as well as reduced seedling biomass. Treating seeds with ferulic acid alone, vanillic acid alone, p-hydroxybenzoic acid alone, or a mixture of all phenolic acids significantly reduced all early growth parameters. The estimated effective dose for the 50% inhibition (ED50) of radicle growth in A. artemisiifolia seedlings was 368.39 ± 59.85 × 10−8 mol with ferulic acid, 135.41 ± 17.65 × 10−8 mol with p-coumaric acid, 810.36 ± 134.15 × 10−8 mol with p-hydroxybenzoic acid, and 160.11 ± 12.30 × 10−8 mol with the combination of all phenolic acids.

The use of widely targeted metabolite profiling to reveal the senescence changes in postharvest ‘Red Globe’ (Vitis vinifera) grape berries

Changes in the metabolites of table grapes (Vitis vinifera) reportedly occur during postharvest senescence. The aim of this study was to determine the metabolomic differences in postharvest table grapes (‘Red Globe’) after being subjected to different senescence periods. To this end, we used widely targeted metabolomics based on ultra-performance liquid chromatography and tandem mass spectrometry. A total of 135 differential metabolites were identified. During postharvest senescence, the levels of most differential flavonoids (e.g., pelargonidin 3-O-glucoside, quercetin-3-O-glucoside, and cyanidin 3-O-glucoside) and L-aspartic acid decreased, while the levels of phenolic acids (e.g., trans-4-hydroxycinnamic acid methyl ester) and pantothenol increased. During early and late senescence, the levels of most differential lipids, especially LysoPC, as well as those of nucleotides and their derivatives, such as uridine, decreased and increased, respectively. Collectively, the findings of this study provide fundamental insights into the reasonable control of table grape fruit postharvest senescence and lay a solid foundation for further research.

Sorbitol immersion accelerates the deposition of suberin polyphenolic and lignin at wounds of potato tubers by activating phenylpropanoid metabolism

Sorbitol is the primary product of photosynthesis and sugar metabolism in plants. However, the mechanism by which sorbitol treatment affects potato tuber wound healing remains unclear. This study showed that sorbitol treatment reduced weight loss and disease index (inoculated with Fusarium sulphureum) of tubers during healing. Sorbitol also facilitated the accumulation of suberin polyphenolic (SPP) and lignin at the wounded sites. Sorbitol treatment activated the activities of phenylalanine ammonia-lyase (PAL), 4-coumaryl-CoA ligase (4CL), cinnamic acid-4-hydroxylase (C4H), and cinnamyl alcohol dehydrogenase (CAD), and increased the levels of individual phenolic acids and lignin monomers. In addition, sorbitol treatment increased the H2O2 level and peroxidase (POD) activity. It was suggested that sorbitol treatment could activate phenylpropanoid metabolism, and promote SPP and lignin deposition at the wound sites of potato tubers.

Metabolomics reveals key resistant responses in tomato fruit induced by Cryptococcus laurentii

To investigate the mechanisms underlying inducible resistance in postharvest tomato fruit, non-targeted metabolome analysis was performed to uncover metabolic changes in tomato fruit upon Cryptococcus laurentii treatment. 289 and 149 metabolites were identified in positive and negative ion modes, respectively. A total of 59 metabolites, mainly including phenylpropanoids, flavonoids and phenolic acids, were differently abundant in C. laurentii-treated tomato fruit. Moreover, key metabolites involved in phenylpropanoid biosynthesis pathway, especially chlorogenic acid, caffeic acid and ferulic acid were identified through KEGG enrichment analysis. Enhanced levels of phenolic acids indicated activation of the phenylpropanoid biosynthesis pathway, which is a classic metabolic pathway associated with inducible resistance, suggesting that its activation and consequent metabolic changes contributed to inducible resistence induced by C. laurentii. Our findings would provide new understanding of resistance induction mechanism in tomato fruit from the metabolic perspective, and offer novel insights for new approaches reducing postharvest loss on tomato.

Daily dynamics of intermediate metabolite profiles lead to time-dependent phenylethanoid glycosides production in Scrophularia striata during the day/night cycle.

Phenylethanoid glycosides (PhGs) are important medicinal compounds found in Scrophularia striata, one of the plant species native to Iran. Since almost all aspects of plant life are controlled by night/light cycle, studying its relationship to valuable plant metabolites production will help us to determine the right time for their extraction. Therefore, the aim of this investigation is to figure out whether the diel light oscillations control PhGs production and how it relates to daily changes in upstream metabolic reactions and circadian clock in S. striata. For this, daily rhythms of metabolic pathways were examined every 4h during a day/night cycle in 3 groups of control (16h light/8h dark), continuous light and darkness. The results showed that acteoside and echinacoside levels in each group peaked during the night and day, respectively. Thus, the PhGs production follows a rhythmic behavior in S. striata, which is probably controlled by circadian clock. Also, the levels of photosynthetic pigments, carbohydrates, amino acids, phenolic acids, phytohormones and phenylalanine ammonia-lyase (PAL) and tyrosine ammonia-lyase (TAL) enzyme activities varied diel in a similar or different way among study groups. The observations revealed that light/dark cycle controls the carbon and energy flow from light reception to the production and consumption of starch, biosynthesis of phenylalanine, tyrosine, cinnamic acid and coumaric acid, activation of hormonal signaling pathways and enzymes involved in phenylpropanoid pathway. Overall, it can be concluded that PhGs accumulation time-dependent patterns is likely due to daily fluctuations in upstream metabolic reactions induced by light/dark cycle.

Tea Plants With Gray Blight Have Altered Root Exudates That Recruit a Beneficial Rhizosphere Microbiome to Prime Immunity Against Aboveground Pathogen Infection.

Tea gray blight disease and its existing control measures have had a negative impact on the sustainable development of tea gardens. However, our knowledge of safe and effective biological control measures is limited. It is critical to explore beneficial microbial communities in the tea rhizosphere for the control of tea gray blight. In this study, we prepared conditioned soil by inoculating Pseudopestalotiopsis camelliae-sinensis on tea seedling leaves. Thereafter, we examined the growth performance and disease resistance of fresh tea seedlings grown in conditioned and control soils. Next, the rhizosphere microbial community and root exudates of tea seedlings infected by the pathogen were analyzed. In addition, we also evaluated the effects of the rhizosphere microbial community and root exudates induced by pathogens on the performance of tea seedlings. The results showed that tea seedlings grown in conditioned soil had lower disease index values and higher growth vigor. Soil microbiome analysis revealed that the fungal and bacterial communities of the rhizosphere were altered upon infection with Ps. camelliae-sinensis. Genus-level analysis showed that the abundance of the fungi Trichoderma, Penicillium, and Gliocladiopsis and the bacteria Pseudomonas, Streptomyces, Bacillus, and Burkholderia were significantly (p < 0.05) increased in the conditioned soil. Through isolation, culture, and inoculation tests, we found that most isolates from the induced microbial genera could inhibit the infection of tea gray blight pathogen and promote tea seedling growth. The results of root exudate analysis showed that infected tea seedlings exhibited significantly higher exudate levels of phenolic acids and flavonoids and lower exudate levels of amino acids and organic acids. Exogenously applied phenolic acids and flavonoids suppressed gray blight disease by regulating the rhizosphere microbial community. In summary, our findings suggest that tea plants with gray blight can recruit beneficial rhizosphere microorganisms by altering their root exudates, thereby improving the disease resistance of tea plants growing in the same soil.

Investigation of Antioxidant Activity and Analysis of Phenolic Compounds of some Asteraceae Plants by HPLC: A Comparison Between Methanol and Ethanol Extracts

Background: Medicinal and healing plants have been used in treating human diseases for centuries because of their therapeutic effects. They may assist in curing common ailments such as a multitude of skin problems, various disorders from muscle spasms to cuts and wounds. They can be used to relieve symptoms of different illnesses from cold to some forms of arthritis or some allergies as well. The Asteraceae plant is a strong source of antimicrobial and antioxidant agents and this paper focuses on its specifications. Objectives: The specific aim of this study was to investigate the antioxidant potential and radical scavenging of different solvents (Methanol and Ethanol) of five species i.e.Artemisia absinthium L., Arctium lappa L., Centaurea cyanus L., Silybum marianum L., and Echinops ritro L. belonging to the Asteraceae family. Methods: Methanol and ethanol extracts of the above plants were prepared. The obtained extracts were evaluated for total phenolic content (TPC), total flavonoid content (TFC), total antioxidant capacity (TAC), chain-breaking activity (CBA), thiobarbituric acid (TBA) and 2, 2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity. Also, Ferric reducing antioxidant power (FRAP), Nitric oxide (NO) radical scavenging, Hydrogen peroxide (H2O2) radical scavenging and Superoxide (O2 -) radical inhibition assay were measured. Phenolic compounds were determined and measured by high-performance liquid chromatography (HPLC) as well. Results: The collected and analyzed data showed that the highest values for the TPC, TFC, TBA, and DPPH were related to methanol extract of A. lappa L. Moreover, maximum values for the CBA, H2O2 and O2 - were observed in the ethanol extract of E. ritro L., while methanol extract of E. ritro L. showed the highest amount of FRAP and NO. Eventually, the highest value for TAC was related to A. absintium L. and it was also realized that methanol compared to ethanol solvent was more successful in the extraction procedure. Conclusions: These findings suggest that A. lappa L. and E. ritro L. extracts can be considered as excellent natural antioxidant agents and the type of the solvent can affect the extraction of phenolic compounds. Sinapic acid as the highest level of phenolic acid was found in S. marianum L.

Changes in metabolism modulate induced by viroid infection in the orchid Dendrobium officinale

Dendrobium officinale is an important traditional Chinese medicinal herb, and the stem tissue is the main medicinal that is harvested from D. officinale. Recently, the first viroid was identified from D. officinale in China, and it has been named Dendrobium viroid (DVd). Whether DVd interferes with metabolic pathways in dendrobium plants and affects the medicinal value of the host is unknown. In this study, metabolomics data from stem tissues supported by transcriptome studies were used to investigate how metabolism modulate of D. officinale is altered by DVd infection. Our results show that metabolism of D. officinale is reprogrammed in many ways during DVd infection, and this is reflected by significant changes in the levels of flavonoids, alkaloids, and phenolic acids. Furthermore, we found that DVd infection significantly decreased the accumulation of flavonoids and alkaloid metabolites in infected stems, and the decreases in these metabolites appears to affect the medicinal components of the infected plants, weakening the host antiviral immune response as well. Conversely, phenolic acids occupy a larger proportion of the up-regulated metabolites from DVd infection in comparison with the mock-inoculated control, and the increase in the total phenolic acids may reflect the activation of the pathogen defense response in D. officinale. Taken together, our results provide an interesting overview and give a better understanding of the relationship between metabolism and DVd infection in the orchid D. officinale.

Reversed-Phase HPLC Characterization and Quantification and Antioxidant Capacity of the Phenolic Acids and Flavonoids Extracted From Eight Varieties of Sorghum Grown in Austria.

Sorghum is raising great interest as a grain for the future, for its agricultural advantages in times of climate change, and for the positive impact of its bioactive compounds on human health. These compounds comprise phenolic acids, in a free, conjugated, and bound form, and flavonoids. The most commonly used extraction methods require high volumes of chemicals and are non-practical when handling many samples at a time. The main aim of this study was to develop a microscale extraction procedure for both phenolic acids and flavonoids to improve yield and diversity, labor time, and chemicals usage. The improved protocols allowed to perform the extraction in 2-ml safe-lock tubes using around 60 times less chemical volume for phenolic acids and 6 times less for flavonoids. In addition, compared to the macroscale method, the microscale approach was effective in extracting a comparable amount of phenolic acids (between 0.99 and 1.57 mg ferulic acid/g) and even a higher quantity of flavonoids (between 1.10 and 2.24 mg ferulic acid/g). With the established methods, phenolic compounds were extracted from eight varieties of sorghum grown in Austria, previously shown to be promising for food processing. In all sorghum varieties, protocatechuic, vanillic, caffeic, syringic, P-coumaric, and ferulic acids were detected in free, conjugated and bound form, with the last being the most abundant. Arsky and Icebergg varieties presented the lowest (922.65 μg/g) and the highest (1,269.28 μg/g) levels of total phenolic acids, respectively, recorded using high-performance liquid chromatography (HPLC). Flavonoids, comprising luteolinidin, apigenidin, naringenin, apigenin, 5-methoxy-luteolinidin (5-MetO-Lut), and 7-methoxy-apigeninidin (7-MetO-Api), were detected in amounts between 27.03 (Kalatur variety) and 87.52 μg/g (Huggo variety). The red varieties, Huggo, Armorik, and Arsky, had the highest antioxidant activity measured as 2,2-Diphenyl-1-picrylhydrazyl (DPPH) [around 5.00 μg Trolox equivalent (TE)/g] and Azino-bis(3-ehtylbenzthiazoline-6-sulfonic acid) (ABTS) (around 3.00 μg TE/g) scavenging capacity for both phenolic acids and flavonoids. Ferric reducing antioxidant power (FRAP) was the highest for the phenolic acids extracted from a white Ggolden variety.