• ALGAE
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• v.23 no.3
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• pp.231-240
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• 2008

The species composition and variation of benthic marine algae at Daejin and Jukbyeon on the mid-east coast of Korea were investigated seasonally from August 2006 to April 2007. As a result, the total of 85 species, including 8 chlorophytes, 26 phaeophytes, 50 rhodophytes and 1 sea grass were identified. 52 species were found at Daejin and 74 species at Jukbyeon. Dominant species in importance value were Corallina pilulifera, Chondrus ocellatus, melobesioidean algae, Sargassum horneri, Sargassum yezoense and Phyllospadix japonica at Daejin, and Corallina pilulifera, melobesioidean algae, Phyllospadix japonica, Acrosorium polyneurum, Sargassum siliquastrum and Hizikia fusiformis at Jukbyeon, respectively. The vertical distribution of algae were characterized by Corallina pilulifera, Hizikia fusiformis, Sargassum spp. (S. siliquastrum, S. yezoense) and Symphyocladia latiuscula at intertidal zone, Sargassum spp. (S. horneri, S. serratifolium, S. yezoense), melobesioidean algae, Phyllospadix japonica and Corallina pilulifera at 1 m depth, melobesioidean algae, Phyllospadix japonica and Sargassum spp. (S. horneri, S. yezoense) at 5 m depth and melobesioidean algae, Phyllospadix japonica and Sargassum spp. (S. horneri, S. micracanthum, S. yezoense) at 10 m depth.

• ALGAE
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• v.23 no.4
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• pp.327-334
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• 2008

Seaweed biomass was estimated using a nondestructive sampling method in the rocky intertidal and subtidal zone in Daejin on the mid-east coast of Korea from August 2006 to April 2008. Seasonal sampling were done at the depth of 0, 1, 5, 10 m using 50 x 50 cm quadrat. A total of 95 species, including 11 chlorophytes, 26 phaeophytes, 57 rhodophytes and one sea grass were identified. Mean biomass was comprised of 1,292 g wet wt m$^{-2}$ and the biomass values varied seasonally from 904 g to 1,945 g. Dominant species in biomass were Sargassum spp. (S. horneri, S. yezoense), Corallina pilulifera, Phyllospadix japonica, Symphyocladia latiuscula, Hizikia fusiformis, Codium arabicum and Chondrus ocellatus at Daejin. The vertical distribution of algae were characterized by Corallina pilulifera, Symphyocladia latiuscula, Sargassum spp. (S. confusum, S. yezoense), Hizikia fusiformis and Grateloupia elliptica at intertidal zone, Sargassum spp. (S. fulvellum, S. horneri, S. yezoense), Phyllospadix japonica, Codium arabicum, Undaria pinnatifida and Corallina pilulifera at 1 m depth, Sargassum spp. (S. horneri, S. micracanthum, S. yezoense), Phyllospadix japonica, Grateloupia elliptica, Gelidium amansii and Codium arabicum at 5 m depth and Phyllospadix japonica, Codium arabicum, Sargassum spp. (S. horneri, S. micracanthum, S. yezoense) and Undaria pinnatifida at 10 m depth.

• Preventive Nutrition and Food Science
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• v.22 no.3
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• pp.166-171
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• 2017

In this study, we investigated whether Sargassum yezoense extract (SYE) could inhibit ${\alpha}-glucosidase$ and ${\alpha}-amylase$ activities, and alleviate postprandial hyperglycemia in streptozotocin (STZ)-induced diabetic mice. Freeze-dried S. yezoense was extracted with 80% ethanol and concentrated for use in this study. The hypoglycemic effect was determined by evaluating the inhibitory activities of SYE against ${\alpha}-glucosidase$ and ${\alpha}-amylase$ as well as its ability to decrease postprandial blood glucose levels. The half-maximal inhibitory concentrations of SYE against ${\alpha}-glucosidase$ and ${\alpha}-amylase$ were $0.078{\pm}0.004$ and $0.212{\pm}0.064mg/mL$, respectively. SYE was a more effective inhibitor of ${\alpha}-glucosidase$ and ${\alpha}-amylase$ activities than the positive control, acarbose. The increase in postprandial blood glucose levels was significantly alleviated in the SYE group compared with that in the control group of STZ-induced diabetic mice. Furthermore, the area under the curves significantly decreased with SYE administration in STZ-induced diabetic mice. These results suggest that SYE is a potent inhibitor of ${\alpha}-glucosidase$ and ${\alpha}-amylase$ activities and alleviates postprandial hyperglycemia caused by dietary carbohydrates.

• Korean Journal of Pharmacognosy
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• v.40 no.2
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• pp.150-154
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• 2009

We examined ethanol extracts prepared from the Korean marine algae belonging to the Sargassaceae family for their inhibitory effects on ${\alpha}$-glucosidase activity and free radicals in vitro. Among five marine algae, the extracts of Sargassum yezoense were found to possess strongly ${\alpha}$-glucosidase inhibition and free radicals scavenging activities. Two compounds were isolated via bioactivity guided isolation and tested for their effects on ${\alpha}$-glucosidase, DPPH, $ABTS^{+}$ and $Photochem^{(R)}$ analysis. Their chemical structures were elucidated by spectral analysis and direct comparison with authentic compounds; their structures were identified as sargaquinoic acid (1) and sargahydroquinoic acid (2). The inhibitory effects of compound 1 and 2 ($IC_{50}$ value:14.2 and 12.8 ${\mu}M$, respectively) on ${\alpha}$-glucosidase were more potent that of deoxynojirimycin as a positive control ($IC_{50}$ value:18.0 ${\mu}M$). All compounds displayed antioxidative activity which was measured by DPPH, $ABTS^{+}$ and $Photochem^{(R)}$ apparatus.

• ALGAE
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• v.21 no.4
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• pp.393-405
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• 2006

Eight species of Sargassum subgenus Bactrophycus section Halochloa and Repentia were collected from the coasts of Korea: Sargassum coreanum J. Agardh, Sargassum sagamianum Yendo, Sargassum micracanthum (Kützing) Endlicher, Sargassum macrocarpum C. Agardh, Sargassum autumnale Yoshida, Sargassum siliquastrum (Mertens ex Turner) C. Agardh, Sargassum serratifolium (C. Agardh) C. Agardh, Sargassum yezoense (Yamada) Yoshida et Konno. These species were investigated on morphological variations and geographical distributions in Korea. The valuable taxonomic characters between similar species of these section were discussed with special reference to types of holdfasts, shape of main branch, leaves and vesicles.

• ALGAE
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• v.23 no.4
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• pp.301-310
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• 2008

The marine benthic algal flora and biomass of Chuja Island, southern coast of Korea, was investigated. The collections of intertidal marine algae were made at two sites, Yecho of Hachujado and Hupo of Sangchujado, from October 2006 to July 2007. A total of 162 species, including 15 green, 47 brown and 100 red algae, were identified in this study. The occurrence of species according to season was abundant during spring to summer and less in autumn. The vertical distribution of intertidal zone in Chujado was characterized by Gloiopeltis spp., Myelophycus simplex, Ishige okamurae, Chondrus ocellatus, Grateloupia elliptica, Hizikia fusiformis and Sargassum spp. The average biomass of macroalgae was measured as 400 g wet wt m$^{-2}$. The dominant species based on the biomass were Sargassum yezoense, S. coreanum and Hizikia fusiformis. ESG II (ecological state group) as an opportunistic species, including sheet form, filamentous form, and coarsely branched form, occurred 85.8% in the intertidal seaweeds. These results provide a baseline for future monitoring studies in the Chuja Island.

• Journal of the Korean Society of Marine Environment & Safety
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• v.21 no.2
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• pp.119-129
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• 2015

Benthic marine algal flora and community structure at Chuksan on the mid-east coast of Korea were investigated seasonally from July 2007 to May 2009. Ninety-eight seaweed species were identified, including 13 green, 23 brown and 62 red algal species. The number of species found ranged between 33 and 63 among seasons. Two green (Ulva australis and Codium arabicum), three brown (Dictyota dichotoma, Sargassum fusiforme and Sargassum yezoense), and eleven red algae (Corallina pilulifera, Lithophyllum okamurae, Pachymeniopsis elliptica, Grateloupia filicina, G. cornea, Hildenbrandia rubra, Chondrus ocellatus, Acrosorium polyneurum, Chondria crassicaulis, Polysiphonia morrowii and Symphyocladia latiuscula) were observed throughout the survey period. Average marine algal biomass was $629.68g\;dry\;wt\;m^{-2}$ and it ranged seasonally from 119.30 to $1,660.96g\;dry\;wt\;m^{-2}$. The vertical distribution of marine algae was characterized by Corallina pilulifera and Sargassum spp. in the intertidal zone; Sargassum spp. at 1 m depth; Sargassum spp. and melobesioidean algae at 5 m depth; and melobesioidean algae at 10 m depth.

• Food Science and Biotechnology
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• v.17 no.3
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• pp.613-622
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• 2008

Cancer chemopreventive effects can be exerted through the induction of phase II detoxification enzymes and the inhibition of inflammatory responses. In this study, the cancer chemopreventive effects and anti-inflammatory responses of 30 seaweed extracts were examined. The extracts of Dictyota coriacea and Cutleria cylindrica exhibited the high chemoprevention index, having 4.36 and 4.66, respectively. They also activated antioxidant response element at $100\;{\mu}g/mL$ by about 3-fold while did not activate xenobiotic response element. Seven seaweed extracts, Ishige okamurae, Desmarestia ligulata, Desmarestia viridis, Dictyopteris divaricata, D. coriacea, Sargassum horneri, and Sargassum yezoense, showed significant inhibition on nitric oxide (NO) and prostaglandin $E_2$ ($PGE_2$) production in a dose-dependant manner in $5-20\;{\mu}g/mL$. These seaweed extracts could be used as food materials for cancer chemoprevention. D. coriacea could contain potential chemopreventive agents not only that regulate genes via an ARE-dependent mechanism but also prevent the inflammation through inhibition of NO and $PGE_2$ production.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.54 no.6
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• pp.1007-1016
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• 2021

This study examined the characteristics and seasonal distribution patterns of subtidal marine algal communities along the east coast of Korea, from 2016 to 2017, and recorded the coverage ratio (%) by the algal type. During the study period, 134 marine algae species (16 green, 29 brown, and 89 red) were identified at the survey sites. The maximum number of species was observed at the Nagok site (70 species), and the minimum at the Gisamoon site (50 species). The total average biomass (dry weight) during the survey period was 66.22 g/m², including green algae (2.19 g/m²), brown algae (38.10 g/m²), and red algae (25.94 g/m²). The dominant seaweeds in the vertical distribution based on coverage rates (%) were Sargassum yezoense and Dictyopteris divaricata at the upper, Symphyocladia latiuscula and Undaria pinnatifida at the middle, and Agarum clathratum subsp. yakishiriense and Plocamium telfairiae at the lower sections of the distribution. Richness, evenness, and diversity index, calculated based on the biomass of the abundant species, were estimated to be 6.36, 0.55, and 1.98, respectively, over the entire sea area. Based on the evaluation of the environmental states using community indices, the ecological evaluation index (EEI-c) of subtidal marine algal communities along the east coast of Korea was marked as 'good-moderate'.

• Korean Journal of Plant Resources
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• v.26 no.5
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• pp.526-532
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• 2013

In this study, we investigated the effect of 88 marine algae extracts on melanin synthesis to develop new whitening agents. Among varieties of marine algae tested, the ethyl acetate extracts from Endarachne binghamiae (EB), Scytosiphon lomentaria, Sargassum yezoense, Ecklonia cava and Sargassum fusiforme inhibited melanin synthesis in melan-a cells. EB treatment showed the strongest inhibitory activity in melanin synthesis, compared with that of other extracts. EB-mediated inhibition of melanin synthesis appeared to be associated with inhibition of ${\alpha}$-glucosidase-dependent glycosylation of tyrosinase in melan-a cells. In addition, EB treatment did not affect mushroom tyrosinase or cell-extracted tyrosinase activity in vitro. Taken together, our findings suggest that anti-browning effect of EB on skin is mediated through regulation of ${\alpha}$-glucosidase activity and subsequent inhibition of tyrosinase activity and melanin synthesis, and further development of EB as a potential agent for skin whitening.