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The green alga Spirogyra varians accumulated antioxidative compounds in response to cold stress. When the algae were transferred from 20°C to 4°C, the amount of phenolic contents and flavonoids in the cell increased 17 times and 30 times, respectively, in 2 months. At this time, the radical scavenging activity of the methanolic extract of S. varian...
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... analyses were performed using a Gilson HPLC sys- tem (Gilson, USA) equipped with a UV – vis detector. Brief- ly, analyses of methanolic extracts were performed on a Phenomenex Luna C18 column (5 μ m, 100 Å, 4.6 × 100 mm; Phenomenex, USA) at room temperature using a 20- μ L injection volume. The mobile phase consisted of ddH 2 O (A) and acetonitrile (B, 0.05% TFA). Gradient elu- tion separation programs at a flow rate of 700 μ L min − 1 were as follows: 5% acetonitrile for 5 min, 5 – 100% for 20 min, and 100% for 5 min. Data were collected using a UV detector at 210 nm. The amounts of produced compounds were calculated by the integration of peak area with standards using the provided software (Gilson). HPLC analyses for the determination of amounts of phenolic compounds were repeated three times. For preparative isolation, a Phenomenex C18 column (5 μ m, 100 Å, 21×150 mm) was used at room temperature. The following solvent gradient was applied: ddH 2 O and acetonitrile (0.05% TFA); 5% acetonitrile for 10 min, 5 – 100% for 40 min, and 100% for 10 min with 3 mL min − 1 flow rate. Compounds shown with peaks increased during cold acclimation were collected and stored at − 80°C until use. The structures of the compounds were determined using hydrogen nuclear magnetic resonance ( 1 H NMR) spectroscopy. NMR spectra were recorded on CD OD and D O molecules at 27.4°C on a Delta 2 ECA 500 NMR spectrometer (JEOL, Japan; 1 H, 500 MHz), and chemical shifts in ppm were referenced to tetramethylsilane as an internal standard. Spyrogyra varians (Hassall) Kützing grows from late winter when water temperature ranges 4 – 6°C through early summer when the water temperature is over 25°C in shallow waters of Korea. It grows best in late spring when the water temperature is over 15°C. S. varians grew very slowly at 4° C, and the culture did not attain stationary phase until 60 days after it was transferred from 20°C. The total phenolic content in methanolic extracts of S. varians continuously increased when the algae were grown under cold stress (Fig. 1). Initially, the total phenolic content was 28.5 μ g mg − 1 methanolic extract. The total phenolic content showed little change when the samples were continuously grown at 20°C, but increased to 500.6 μ g (about 17 times) when the algae were transferred to 4°C for 60 days (Fig. 1). The accumulation of phenolic compounds was strictly proportional ( R 2 0 0.981) to the incubation time at 4°C. The result of the flavonoid assay was similar to that for the total phenolic compounds (Fig. 2). Low flavonoid content was observed in the algae grown at 20°C. Often, it was even lower than the detection limit ( − 0.77±0.57 μ g mg − 1 ). When the algae were transferred to 4°C, the flavonoid content increased more than five times in a day, and then their accumulation occurred proportional ( R 2 0 0.734) to the incubation time at 4°C (Fig. 2). When S. varians was cultured at 4°C for 60 days, the total amounts of flavonoids reached 23 g mg methanolic extract, which is about six times more than that of 1 day after transfer. Analysis of the radical scavenging activity showed that the accumulation of antioxidative compounds was associated with cold acclimation and was proportional to the increase of total phenolic and flavonoid contents (Fig. 3). Radical scavenging activity increased strongly 1 day after transfer to 4°C (twice higher than at 20°C). The initial IC 50 value of methanolic extracts was 11.9 μ g mL − 1 , but became 5.21 μ g mg − 1 1 day after transfer to 4°C, which showed a 2.28 times increase of the antioxidative activity. The IC 50 value decreased to 0.05 μ g mL − 1 when samples were incubated at 4°C for 30 days, which showed 238 times increase of antioxidative activity from the initial state. Simultaneously, the methanolic extracts of S. varians grown at 20°C and 4°C were analyzed using HPLC. In total, six compounds were newly produced (peaks 2, 3, and 4) or increased (peaks 1, 5, and 6) when the algae were grown at 4°C (Fig. 4). The amount of each compound increased two to five times in a week and continued to increase over time (Fig. 5). Four compounds were successfully purified using chromatography and analyzed by 1 H NMR (Fig. 6). Accumulated secondary metabolites were isolated from methanolic extracts of S. varians using phase separation (re- covery of the aqueous phase), followed by semi-preparative C18 chromatography. With this approach, 0.5 – 2 mg of each compound was isolated and identified as follows: 1- O -Galloyl- β - D -glucose (1) (Majeed et al. 2009); pro- posed structure: yellow, amorphous/powder/crystalline solid; 1 H-NMR (500 MHz, D 2 O) δ 7.18 (2H, s, Galloyl-H), glucose moiety, 5.66 (1H, d, J 0 7.9 Hz, H-1), 3.82 (1H, dd, J 0 12.5, 2.0 Hz, H-6), 3.67 (1H, dd, J 0 12.6, 5.0 Hz, H-5), 3.59 – 3.3.54 (3H, m, H-3, H-4, and H-6), 3.42 (1H, t, J 0 9.65 Hz, H-2). Methyl gallate (2) (Kuroyanagi et al. 1982): yellow, amorphous/powder/crystalline solid; 1 H NMR (500 MHz, D 2 O) δ 7.09 (2H, s, Galloyl-H), 3.80 (3H, s, – OCH 3 ). 1,2,3,6-Tetra- O -galloyl- β - D -glucose (3) (Duan et al. 2004): white, amorphous/powder/crystalline solid; 1 H NMR (500 MHz, Methanol-D3) δ 7.11, 7.02, 701, 6.92 (each 2H, s, Galloyl-H), glucose moiety, 6.08 (1H, d, J 0 8.3 Hz, H-1), 5.56 (1H, t, J 0 9.5 Hz, H-3), 5.41 (1H, dd, J 0 9.8, 8.3 Hz, H-2), 4.60 (1H, dd, J 0 12.3, 2.0 Hz, Ha-6), 4.51 (1H, dd, J 0 12.0, 4.3 Hz, Hb-6), 3.99 (1H, m, H-5) and 3.94 (1H, t, J 0 9.5 Hz, H-3). 1,2,3,4,6-Penta- O -galloyl- β - D -glucose (4) (Duan et al. 2004): white, amorphous/powder/crystalline solid; 1 H-NMR (500 MHz, Methanol-D3) δ 7.10, 7.04, 6.97, 6.94, 6.89 (each 2H, s, Galloyl-H), glucose moiety, δ 6.22 (1H, d, J 0 8.3 Hz, H-1), 5.89 (1H, t, J 0 9.5 Hz, H-3), 5.61 (1H, t, J 0 9.7, Hz, H- 6), 5.57 (1H, dd, J 0 9.8, 8.3 Hz, H-2), 4.5 (1H, bd, J 0 Hz, H- 4), 4.38 (2H, m, H-5, and H-6). HRTOF-ESIMS m/z 963.4166 [M+Na] (calculated for C 41 H 32 O 26 +Na, 963.1079). Isolated compounds were identified as 1- O -galloyl- β - D glucose (peak 1), methyl gallate (peak 2), 1,2,3,6-tetra- O -galloyl- β - D -glucose (peak 3), and 1,2,3,4,6-penta- O -Galloyl- β - D glucose (peak 4) through an analyses of their physical, spec- troscopic, and literature data. Due to the small amount of the sample (0.2 – 0.5 mg), only 1 H NMR analysis was carried out, except for peak 4. Further analysis of peak 4 using NMR also identified it as 1,2,3,4,6-penta- O -galloyl- β - D -glucose (Fig. 6). Our results showed that large amounts of phenolic and flavonoid antioxidants were accumulated when S. ...
Citations
... The high temperature (36.1°C) significantly increased the accumulation of phenolic compounds in biomass of Nannochloropsis oculata [75]. Han et al. [76] reported that when Spirogyra varians was transferred from 20°C to 4°C the amount of phenolic and flavonoid compounds increased 17 times and 30 times, respectively, to cope up against the cold stress. Hanachi et al. [77] reported that high temperature (28°C) increases the content of antioxidant phenolic compounds in axenic cultures of Monoraphidium species. ...
Microalgae are regarded as a rich trove of diverse secondary metabolites that exert remarkable biological activities. In particular, microalgae-derived bioactive phenolic compounds (MBPCs) are a boon to biopharmaceutical and nutraceutical industries due to their diverse bioactivities, including antimicrobial, anticancer, antiviral, and immunomodulatory activities. The state-of-the-art green technologies for extraction and purification of MBPCs, along with the modern progress in the identification and characterization of MBPCs, have accelerated the discovery of novel active pharmaceutical compounds. However, several factors regulate the production of these bioactive phenolic compounds in microalgae. Furthermore, some microalgae species produce toxic phenolic compounds that negatively impact the aquatic ecosystem, animal, and human life. Therefore, the focus of this review paper is to bring into light the current innovations in bioprospection, extraction, purification, and characterization of MBPCs. This review is also aimed at a better understanding of the physicochemical factors regulating the production of MBPCs at an industrial scale. Finally, the present review covers the recent advances in toxicological evaluation, diverse applications, and future prospects of MBPCs in biopharmaceutical industries.
... The biosynthetic pathway to similar compounds in brown algae (Heterokonts), green algae, and red algae has been established (Richards et al. 2006), and one of the key genes required, shikimate dehydrogenase, has been identified in green algae (Carrington et al. 2018). The phenolics produced range from glycosylated monomers through to red/purple pigments that resemble the hydrolysable tannins/ gallotannins of land plants (Han et al. 2012;Aigner et al. 2013;Holzinger and Pichrtová 2016). These may perform similar functions to flavonoids in land plants. ...
Bryophytes is the collective name for the nonvascular land plant group comprised of the liverworts, hornworts, and mosses, which together total over 20000 species. They represent the basal group of land plants, and are thus thought to be the extant species most similar to the first land plant ancestors. In comparison to flowering plants there are relatively few studies on the molecular genetics of the flavonoid pathway in bryophytes, although this is changing with the advent of new model systems in recent years. Here we review the literature on the flavonoid pathway in bryophytes and discuss what this may indicate with regard to the evolution of this pathway.
... Valledor et al. (2013) investigated the lipid profiles in the chlorophyte Chlamydomonas reinhardtii upon cold stress and found an increase in polyunsaturated fatty acids that is likely occurring to maintain membrane fluidity. The streptophyte Spirogyra varians ) accumulated antioxidants at 4 • C suggesting an accelerated ROS generation ( Han et al., 2012). ...
Biological soil crusts (BSCs) are complex communities of autotrophic, heterotrophic, and saprotrophic (micro)organisms. In the polar regions, these biocrust communities have essential ecological functions such as primary production, nitrogen fixation, and ecosystem engineering while coping with extreme environmental conditions (temperature, desiccation, and irradiation). The microalga Klebsormidium is commonly found in BSCs all across the globe. The ecophysiological resilience of various Klebsormidium species to desiccation and other stresses has been studied intensively. Here we present the results of transcriptomic analyses of two different Klebsormidium species, K. dissectum and K. flaccidum, isolated from Antarctic and Arctic BSCs. We performed desiccation stress experiments at two different temperatures mimicking fluctuations associated with global change. Cultures grown on agar plates were desiccated on membrane filters at 10% relative air humidity until the photosynthetic activity as reflected in the effective quantum yield of photosystem II [Y(II)] ceased. For both species, the response to dehydration was much faster at the higher temperature. At the transcriptome level both species responded more strongly to the desiccation stress at the higher temperature suggesting that adaptation to cold conditions enhanced the resilience of both algae to desiccation stress. Interestingly, the two different species responded differently to the applied desiccation stress with respect to the number as well as function of genes showing differential gene expression. The portion of differentially expressed genes shared between both taxa was surprisingly low indicating that both Klebsormidium species adapted independently to the harsh conditions of Antarctica and the Arctic, respectively. Overall, our results indicate that environmental acclimation has a great impact on gene expression and the response to desiccation stress in Klebsormidium.
... Spirogyra containing polyunsaturated fatty has been reported to have a good antioxidative effect (Ivanova et al. 2002). In Spirogyra varians, it has been reported that antioxidative secondary metabolites including methyl gallate, 1-O-galloyl-ß-D-glucose, 1, 2,3,6-tetra-O-galloyl-ß-D-glucose, and 1,2,3,4,6-penta-O- galloyl-ß-D-glucose were increased by various environment conditions such as cold stress and gamma-radiation (Han et al. 2012; Lee et al. 2012). The methyl gallate and galloyl derivatives isolated from land plants have been shown to have antioxidant activity, neuroprotective effect, and anticancer activity (Lu et al. 2006; Dodoa et al. 2008; Yu et al. 2012). ...
... Spirogyra neglecta activates antioxidative enzymes such as catalase as well as glutathione-reductase and glutathioneperoxidase in rats (Thumvijit et al. 2013). Galloyl derivatives, strong antioxidants, were accumulated in cold stressed S. varians (Han et al. 2012). AAPH is a water-soluble azo compound largely used as a source of peroxyl radicals (ROO⋅) (Niki 1990). ...
... showed better peroxyl radicals scavenging effects than dieckol from E. cava (2.77 and 0.88 μg mL −1 , respectively). Gallic acid is a trihydroxybenzoic acid found in land plants such as galluts, sumac, witch hazel, tea leaves, oak bark, and other plants, and is also found in the freshwater plant, Myriophyllum spicatum (Nakai et al. 2000), but has not been reported to isolate from Spirogyra sp. until now.. Methyl gallate has been previously isolated from various algae and plants included the green alga, S. varians, and the land plant, Acer ginnala (Han et al. 2004Han et al. , 2012). Furthermore, gallic acid and many galloyl derivatives from land plants and aquatic plants have been reported not only for their antioxidative activity but also for various biological activities such as α-glucosidase inhibition and anticancer and anti-inflammatory effects (Cannell et al. 1988; Hsieh et al. 2004; Masuoka et al. 2006). ...
A freshwater alga, Spirogyra sp., collected in shallow ponds in South Korea, was evaluated for its antilipid peroxidative effect against 2,2′-azobis (2-amidinopropane) dihydrochloride (AAPH)-induced in vivo zebrafish, and antioxidative compounds from the alga were efficiently identified using 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS+) online high-performance liquid chromatography (HPLC) and preparative centrifugal partition chromatography. The ethyl acetate fraction of Spirogyra sp. (SPE) in each fraction showed the strongest 2,2-diphenyl-1-picrylhydrazyl scavenging activity and significantly scavenged 2′,7′-dichlorodihydrofluorescein diacetate and diphenyl-1-pyrenylphosphine fluorescence, respectively, in AAPH-induced zebrafish embryo without any cytotoxicity in the concentrations between 25 and 50 μg mL−1. The two main antioxidative compounds in SPE were confirmed by ABTS+ online HPLC and were identified as gallic acid and methyl gallate, respectively, by HPLC-diode array detection (DAD)-electrospray ionization (ESI)/mass spectrometry (MS), 1H- and 13C-NMR. We conclude therefore that Spirogyra sp. is rich in gallic acid and methyl gallate, and it might be useful as a strong antilipid peroxidation material.
... The isolation of flavogallonic acid dilactone (8) was reported for the first time among plants belonging to the family Tamaricaceae. This report describes the isolation and identification of these hydrolyzable tannin-related phenolics (6)(7)(8), four known hydrolyzable tannins (9)(10)(11)(12), and the structural elucidation of six new hydrolyzable tannins (13)(14)(15)(16)(17)(18). All of the isolated hydrolyzable tannins showed structural features analogous to those reported for hydrolyzable tannins of the tamaricaceous plants [15,17]. ...
... The structures of the known ellagitannins 9-11 were identified as gemin D (9) [15d], remurin A (10) [15d], and 1,3-di-O-galloyl-4,6-O-(S)-hexahydroxydiphenoyl-β-D-glucose (11) [15d], based on comparisons of their 1 H NMR spectroscopic data with those of the authentic samples. A simple gallotannin 1,2,3,6-tetra-O-galloyl-β-D-glucose (12) was also identified by comparison of its 1 H NMR spectroscopic data with reported values [18]. ...
... The structures of the new hydrolyzable tannins were determined based on chromatographic, physicochemical, and spectroscopic data, and sometimes chemical evidence. The new hydrolyzable tannins (13)(14)(15)(16)(17)(18) were given a new series name: phyllagallin followed by a capital letter to indicate the degree of oligomerization (M for monomer and D for dimers). According to the acylation level of the sugar core(s) with the HHDP unit, the new tannins (13)(14)(15)(16)(17)(18) were subdivided into an ellagitannin, phyllagallin M1 (13), a gallo-ellagitannin, phyllagallin D1 (14), and gallotannins, phyllagallin M2 (15), and phyllagallins D2-D4 (16)(17)(18). ...
Chromatographic separation of an aqueous acetone extract of the galls from Tamarix aphylla using gels resulted in isolation of an ellagitannin, phyllagallin M1 (13), a gallo-ellagitannin, phyllagallin D1 (14), and four gallotannins, phyllagallin M2 (15) and phyllagallins D2-D4 (16-18), in addition to four known ellagitannins and three phenolics of lower molecular weight structurally related to hydrolyzable tannins. The structures of the six new tannins were elucidated based on spectroscopic and chemical data. Among the phenolics, flavogallonic acid dilactone (8), which is presumed to be biogenetically produced by C-C oxidative coupling of an ellagic acid unit with a galloyl residue, shows an exceptional oxidative pattern of gallic acid residues in plants of the family Tamaricaceae. Although the ellagitannin tamarixellagic acid (4) has been reported to be a constituent of the galls of Tamarix aphylla, such compounds with anomalous location of the DHDG moiety at O-3 on the glucopyranose core have not previously been observed among the tannins of tamaricaceous plants.
Copyright © 2015. Published by Elsevier B.V.
... Some strong antioxidants including the red wine polyphenol resveratrol (Leikert et al., 2002), flavones (Chen et al., 2010b), and green tea (−)epicatechin (Huang et al., 1999) have been found to induce vasorelaxation via a mechanism related to nitric oxide (NO) production. According to the previous study, Spirogyra sp., a green alga commonly found in freshwater, contains various antioxidant galloyl derivatives such as gallic acid and methyl gallate (Han et al., 2012;Lee et al., submitted for publication). Especially, gallic acid (GA) is a common polyphenol, and because of its simple phenolic structure and antioxidant activity, it is used as a standard in assays of polyphenol content (Fig. 1). ...
... GA and methyl gallate isolated from Spirogyra sp. have been shown to exhibit strong antioxidant activities in zebrafish embryos without any evidence for cytotoxicity at concentrations between 25 and 50 g/ml (Lee et al., submitted for publication). Spirogyra varians undergoes cold stress in winter at water temperatures of 4-6 • C and produces large amounts of phenolic and flavonoid antioxidants (Han et al., 2012). Therefore, we predicted that antioxidant materials purified from Spirogyra sp. would exhibit a vasorelaxant effect. ...
The production of secondary metabolites varies under the different environmental conditions. The aim of this study was to investigate the effects of pH and temperature on the content of antioxidant compounds in a species of microscopic algae. First, the microalgal strain Monoraphidium sp. was cultured under the different temperature and pH treatments. The biochemical assays were then performed on the compounds such as photosynthetic pigments, phenolic compounds, and total flavonoids. The total antioxidant activity was evaluated by FRAP and DPPH methods. The results of this study showed that the microalgae Monoraphidium sp. had the maximum growth and high content of antioxidant compounds at the acidic pH and temperature 28°C. The results indicated that the optimal conditions can be achieved for the high production of antioxidant compounds in microalgae by changing the environmental factors, which can be used in the pharmaceutical, medical, and production of nutritional supplements industries.
Silicon (Si) is the second most abundant element in the earth crust. Silicon has been shown to
ameliorate the adverse effects of heavy metals on plants. This research was aimed to investigate the
effects of silicon nano-fertilizer nutrition on growth and physiological characteristics of coriander
(Coriandrum sativum L.) under lead stress. The study was conducted in a factorial experiment
based on a completely randomized design with four replications in the research greenhouse of
Mohaghegh Ardabili University during 2016. Experimental treatments included soil contamination
by PbCl2 (0, 500, 1000 and 1500 mg/kg soil) and foliar spraying with silicon nano-fertilizer (0, 1.5
and 3 mM). Morphological studied traits including plant height, leaf number and area, fresh and dry
weight of root and plant, root and stem diameter, physiological parameters such as photosynthetic
pigments, electrolyte leakage, relative water contents, proline, carbohydrates, phenol, antioxidants
were measured. Results indicated that lead stress reduced the morphological characteristics such as
plant height, plant fresh and dry weight, and stem and root diameter, so that the increased content of
lead led to decrease of plant dry weight, root weight, root and stem diameter, root length, plant
height, leaf area and dry weight up to 57, 50, 20, 41, 15, 42 and 25%, respectively. Foliar spraying
with silicon (3mM) led to improve most of morphological traits of coriander. The content of
chlorophyll a, chlorophyll b, total chlorophyll, carotenoid and carbohydrate in leaves was increased
with increasing lead concentration in soil. However, silicon foliar spraying improved these traits
under lead stress. Proline, phenol, flavonoid and antioxidant capacity were significantly increased
with increasing concentration of lead up to 1500mg/kg. In general, it can be concluded that the use
of silicon nanoparticles for coriander can reduce the negative effects of lead stress to a satisfactory
level.
Desiccation tolerance is commonly regarded as one of the key features for the colonization of terrestrial habitats by green algae and the evolution of land plants. Extensive studies, focused mostly on physiology, have been carried out assessing the desiccation tolerance and resilience of the streptophytic genera Klebsormidium and Zygnema. Here we present transcriptomic analyses of Zygnema circumcarinatum exposed to desiccation stress. Cultures of Z. circumcarinatum, grown in liquid medium or on agar plates, were desiccated at ~86% relative air humidity until Y(II) ceased. In general, the response to dehydration was much more pronounced in Z. circumcarinatum, cultivated in liquid medium for 1 month, compared to filaments grown on agar plates for 7 and 12 months. Culture on solid medium enables the alga to acclimate to dehydration much better and an increase in desiccation tolerance was clearly correlated to increased culture age. Moreover, gene expression analysis revealed that photosynthesis was strongly repressed upon desiccation treatment in the liquid culture while only minor effects were detected in filaments cultivated on agar plates for 7 months. Otherwise, both samples showed an induction of stress protection mechanisms such as reactive oxygen species scavenging (Early light-induced proteins, glutathione metabolism) and DNA repair as well as the expression of chaperones and aquaporins. Additionally, Z. circumcarinatum, cultivated in liquid medium, upregulated sucrose-synthesizing enzymes and strongly induced membrane modifications in response to desiccation stress. These results corroborate the previously described hardening and associated desiccation tolerance in Zygnema in response to seasonal fluctuations in water availability.
Export Date: 14 May 2013, Source: Scopus, Article in Press
