Research of chemical components of some seaweed species in con co island – quang tri province

Journal of Science and Technology 54 (2C) (2016) 493-501 RESEARCH OF CHEMICAL COMPONENTS OF SOME SEAWEED SPECIES IN CON CO ISLAND – QUANG TRI PROVINCE Le Tat Thanh1, *, Nguyen Van Tuyen Anh1, Vu Thi Oanh1, Pham Thu Hue3, Nguyen Thi Cam Binh3, Dam Duc Tien2 1Institute of Natural Products Chemistry, VAST, 18 Hoang Quoc Viet, Cau Giay, Hanoi 2Institute of Marine Environment and Resources, VAST, 246 Da Nang, Ngo Quyen, Hai Phong 3Vietnam Naval Academy- Ministry of Defence, 30 Tran Phu, Nha Trang, Khanh Hoa *Email: thanh.biotech@gmail.com Received: 15 July 2016; Accepted for publication: 29 October 2016 ABSTRACT 11 samples of 8 seaweed families were collected at Con Co – Quang Tri and determined of the chemical compositions. The analysis results showed that these seaweed samples in Con Co contain high content of trace elements and low content of heavy metals. Many samples have good lipid quality to meet the requirements of safe food, as well as being good for the human health (such as CC1, N9, N4, and N6 samples). Especially, some seaweed samples were found to contain long-chain fatty acids with many double bonds presenting high bioactivity in their lipid composition, such as C20: 4n-6 (AA) up to 22.35% (Hypnea flagelliformis Grev., sample N6), C20: 5n-3 (EPA) 16.36 % (Grateloupia lithophila, sample N9), C22: 6n-3 (DHA) 1.07 % (Hypnea esperi, sample N2), C22: 5n-3 (DPA) 1.82% (Liagora spl., samples N4). Keywords: lipid, fatty acid, trace element, heavy metal, seaweed in Con Co. 1. INTRODUCTION Con Co Island, Quang Tri province is a place converging typical ecosystems of tropical waters with seaweed and coral ecosystems. This is the area spawning ground of valuable and endemic seafood species, with high economic values [1]. Aggregate survey results showed that from 1975 to 2005, one grass species (Halophila ovalis - an oval grass species) and 56 other species of seaweeds belonging to 3 branches and 24 families have been found at Con Co coastal island. Among them, the brown seaweeds Phaeophyta have 17 species belonging to 6 families and accounting for 30.36 %, the red seaweeds Rhodophyta have 26 species belonging to 11 families and accounting for 46.43 %, and the green seaweeds have 13 species belonging to 7 families and accounting for 23.18 % [2]. They distribute in rocks, sands with gravel, shell of mollusks, corals. Growth and development of these species take place in winter and spring when the sea water has high and stable salinity Le Tat Thanh, Nguyen Van Tuyen Anh, Vu Thi Oanh 494 (salinity from 25-32 ‰), low rainfall, clear water and without alluvial. Seaweeds fade away when water temperature is above 30 oC and salinity is low. These are two decisive factors that influence seaweeds crop in Con Co island area [3]. The study of the chemical composition of the seaweed species in Con Co - Vietnam almost have not had any publication. 2. MATERIALS AND METHODS 2.1. Materials The name of samples, time of collections and location of samples are presented in Table 1. The samples were collected in Con Co island and identified scientific name by Dr. Dam Duc Tien, Institute of Marine Environment and Resources. Samples were stored at standard conditions at the Institute of Natural Products Chemistry. Table 1. List of research samples. No Name of samples Time of collections Collecting coordinates Sign of samples Family Hypneaceae 1 Hypnea esperi 22.5.2012 17O09’03’’N-107O20’11’’E N2 2 Hypnea flagelliformis Grev. 23.5.2012 17O09’03’’N -107O20’11’’E N6 Family Ceramiaceae 3 Laurencia tropica Yamada 23.5.2012 17O09’03’’N – 107O20’17’’E N5 4 L. heteroclada Harvey 28.5.2013 17O09’03’’N – 107O20’17’’E CC2 Family Bangiaceae 5 Liagora sp1. 23.5.2012 17O09’20’’N – 107O20’51’’E N4 6 Liagora sp2. 24.5.2012 17O09’20’’N – 107O20’51’’E N7 Family Hylamaniaceae 7 Grateloupia lithophila 24.5.2012 17O09’20’’N – 107O20’51’’E N9 Family Bonnemaisoniaceae 8 Asparagopsis taxiformis (Delile) Coll/ et Herv. 22.5.2012 17 O09’27’’N – 107O19’51’’E N1 Family Phyllophoraceae 9 Gymnogongrus flabellifotmis Harvey 28.5.2013 17 O09’04’’N – 107O20’36’’E CC1 Family Rhodymeniaceae 10 Coelarthrum opuntia (Endlicher) Boergesen 22.5.2012 17 O09’04’’N – 107O20’36’’E N3 Family Halymeniaceae 11 Halymenia dilitata Zanerdini 28.5.2013 17O09’27’’N – 107O19’51’’E CC4 2.2. Methods Determination of humidity: Desiccating samples until their mass are constant follow to the standard of TCVN 7035:2002 [4]. Research some chemical components of some seaweed species in Con Co island, Quang Tri 495 Determination of total ash: following to standard of TCVN 5253:1990 [5]. Determination of heavy metals: Following to standard of pharmacopoeia Vietnam IV [6]. Determination of content of trace elements and heavy metals are realized by atomic absorption spectrometer: Thermo Elemental - Model Solaar M6 Dual Zeeman Atomic Absorption Spectrometer. Determination of total lipid content: Following to method of E.G. Bligh, W. J. Dyer [7]. Determination of fatty acid composition: Following to standard of ISO 659:2009 [8]. 3. RESULTS AND DISCUSSION 3.1. Humidity and total ash content The research results are shown in Table 2. Table 2. Water content and ash content of seaweeds. No Sign Water content (%) Ash content (%) No Sign Water content (%) Ash content (%) 1 N2 85.67 2.47 7 N9 82.86 1.81 2 N6 83.60 0.80 8 N1 84.53 3.74 3 N5 83.24 1.08 9 CC1 84.02 1.34 4 CC2 83.26 1.32 10 N3 83.40 1.63 5 N4 85.21 1.78 11 CC4 84.43 1.68 6 N7 86.45 2.97 Humidity: The obtained results show that the water content in seaweeds range from 82.86 % to 86.45 % of fresh weight, average content is 83.92 %. There were no significant differences in water content between different samples. There are some variations in ash content between different samples within the range from 0.80 % to 3.74 % of fresh weight, average content is 1.88 %. The samples has the highest content of ash is N1 and the lowest content belong to N6. 3.2. Content of trace elements The research results are shown in Table 3. Table 3. Content of trace elements. (Unit: ppm) No Sign I2 Fe Zn Mn No Sign I2 Fe Zn Mn 1 N2 26.06 6095.44 42.12 163.46 7 N9 21.73 7296.48 52.10 656.80 2 N6 42.02 1987.86 32.74 215.74 8 N1 17.06 4391.35 35.08 570.45 3 N5 30.74 7233.65 52.60 717.97 9 CC1 37.82 4464.06 26.33 150.57 4 CC2 31.28 1472.26 55.83 446.40 10 N3 26.55 3712.79 70.09 452.19 5 N4 23.85 1551.39 57.06 881.42 11 CC4 38.43 2981.27 46.73 239.97 6 N7 25.75 6198.72 63.43 121.98 Average 29.21 4307.75 48.56 419.72 The obtained results show that the seaweed samples contain high content of trace elements, detail as below: Le Tat Thanh, Nguyen Van Tuyen Anh, Vu Thi Oanh 496 Content of iodine (I2): The sample has the highest content is N6 (42.02 ppm), the lowest content belong to sample N1 (17.06 ppm), average content is 29.21 ppm. Content of Iron (Fe): ranges of 1987.86 - 7233.65 ppm, average is 4307.75 ppm. Samples have iron content higher than the average content are samples N9, N5, N7, N2. Conten of Zinc (Zn): achieves from 26.33 ppm (CC1) to 70.09 ppm (N3), average content is 48.56 ppm. Content of Manganese (Mn): Manganese is one of elements that has high content. The sample has the highest content is sample N4 (881.42 ppm) and the lowest content belong to sample N7 (121.98 ppm), average content is 419.72 ppm. Comment: Seaweeds in Con Co island accumulate quite highly content of trace elements. This area can be considered as potential area for the exploitation of these seaweed species to make raw materials for the supplement foods with micro-nutrients and for serving life. 3.3. Content of heavy metals The research results in Table 4 show that the content of heavy metals in seaweed samples have considerable disparities between different species: Content of copper (Cu) ranges from 4.24 ppm (sample N6) to 23.6 ppm (sample N3); Content of lead (Pb) is 3.49 - 22.35 ppm, sample N4 has the lowest content and the highest content belong to sample N3; Content of cadmium (Cd) is from 0.27 ppm (sample CC1) to 5.88ppm (sample N3); Content of arsenic (As) is 1.07- 4.11ppm, sample N9 contains the lowest content while the highest content belong to N6. Table 4. Content of heavy metals. (Unit: ppm) No Sign Cu Pb Cd As No Sign Cu Pb Cd As 1 N2 7.29 11.99 2.34 3.03 7 N9 11.80 7.39 0.16 1.07 2 N6 4.24 5.29 0.63 4.11 8 N1 11.10 7.72 0.46 1.10 3 N5 8.70 5.32 0.79 4.02 9 CC1 8.77 9.78 0.27 1.61 4 CC2 11.60 8.71 0.83 3.85 10 N3 23.60 22.35 5.88 3.70 5 N4 4.52 3.49 0.36 3.80 11 CC4 17.80 9.14 4.41 2.10 6 N7 9.55 7.11 0.48 4.10 Compare with Vietnamese standards, QCVN 8-2: 2011/BYT, heavy metal limits in food for Cu (27 ppm), Pb (25 ppm), Cd (7 ppm) and As (15 ppm), research seaweed samples in Con Co have the heavy metal contents are much lower than the standards. Specially, species Opuntia Coelarthrum (sample N3) has the highest content in all four heavy metal targets but they are still lower than the standards. 3.4. Lipid content, composition and content of fatty acids The obtained results are shown in Table 5. Total lipid contents of 11 samples range from 0.12 to 0.50 % in comparison with the weight of fresh seaweed. These results are compared with previous publication and show that the total lipid contents of seaweed species collected in Con Co are equivalent to the species of families Gracilariaceae and Ceraminaceae belonging to red seaweed phylum but still lower than those of species of brown seaweed phylum and green seaweed phylum [9]. Research some chemical components of some seaweed species in Con Co island, Quang Tri 497 Table 5. Content of lipid and fatty acids. Name N2 N6 N5 CC2 N4 N7 N9 N1 CC1 N3 CC4 Total lipid (% weight of fresh seaweed) 0.13 0.17 0.41 0.28 0.13 0.12 0.18 0.31 0.34 0.50 0.41 Fatty acids (% total fatty acids) 12:0 0.28 - - - - - 0.4 - - - - 13:0 0.41 - - - - 0.45 - - - 0.26 - 14:0 11.81 - 12.13 3.55 7.45 - 2.37 13.14 10.82 0.45 5.77 14:1n-9 0.7 - - - - - 2.26 - - - - i-15:0 - 3.06 - 0.41 - - 0.21 - - - - 15:0 1.63 1.02 1.34 0.52 0.53 2.24 0.51 0.8 0.41 - 15:1n-7 - - 0.37 - - - 0.31 - - - - 15:1n-5 0.2 - 0.38 - - - 0.31 - - 1.03 - i-16:0 - - - - 1.77 0.87 0.78 - - - - 16:0 54.88 43.08 48.43 45.73 66.86 68.86 32.69 55.69 40.98 54.34 53.26 16:1n-7 2.65 1.03 2.1 5.86 2.95 3.71 3.36 3.62 1.27 0.92 2.29 16:1n-5 2.85 - 0.56 - - - 0.23 - - 0.82 - i-17:0 - 0.93 - - - 1.03 - 0.62 - 0.23 - 17:0 0.43 - - 1.25 - - - 0.36 1.31 - 1.49 17:2n-6 - 0.79 0.66 - - - 0.18 - - - - 17:1n-9 - 0.62 - - - - 0.37 - - - - 17:1n-7 0.63 - - - - 0.54 - - - 0.21 - 18:0 2.95 7.67 1.74 2.04 3.14 1.93 1.29 2.31 1.09 1.91 2.1 18:1n-9 7.44 - 7.0 13.46 6.32 6.06 7.48 8.27 1.52 11.5 11.57 18:1n-7 1.6 1.35 - 8.79 - 2.02 4.05 3.88 7.15 - 5.33 18:3n-6 - - - - - 0.43 0.47 - - - - 18:2n-6 1.59 - 1.68 4.37 1.64 1.35 1.79 1.55 7.08 1.26 4.1 18:4n-3 - - 0.65 - - - - - - - - 19:0 0.37 3.42 2.13 - - - 0.95 - - - - 19:5n-3 - - - - - - 0.54 0.36 - - - 19:4n-3 1.92 6.78 - - - - 0.2 - - - - 19:1n-9 0.32 - - - - - 0.22 - - 0.58 - 20:3n-6 - - - 1.03 - 0.32 1.45 - 0.91 1.27 1.43 20:4n-6 - 22.35 1.68 7.92 1.7 - 14.45 2.24 5.55 7.98 6.99 Le Tat Thanh, Nguyen Van Tuyen Anh, Vu Thi Oanh 498 20:5n-3 - - - 0.92 6.34 - 16.35 - 13.47 - - 20:3n-3 - - - - - 1.25 0.58 - - - - 20:0 0.22 0.64 0.54 0.3 - - 2.68 - - - - 21:1n-11 - 5.55 - - - 0.34 - 0.44 - - - 21:4n-3 - - - - - - - - - 0.23 - 21:4n-6 0.5 - - - - - - 0.47 - - - 21:3n-6 - - 4.5 - - - - - - - - 21:2n-6 - - 3.62 - - - - - - - - i:22:0 0.22 - - - - - - - - - - 22:6n-3 1.07 - - - - - - - - - - 22:5n-3 - - - - 1.82 - - - - - - 22:0 - - 3.34 - - - - 2.49 - 11.32 - 24:0 0.87 1.02 - - - 0.83 - - - - - Other 4.46 0.69 7.15 3.85 0.01 9.48 1.79 4.05 8.05 5.28 5.67 SFA 74.07 59.91 69.65 53.8 79.22 73.47 43.61 74.5 55 68.69 62.62 PUFA 5.08 29.92 12.79 14.24 11.5 3.35 36.01 4.62 27.01 10.74 12.52 Omega-3 2.99 6.78 0.65 0.92 8.16 1.25 17.67 0.36 13.47 0.23 0 Omega-6 2.09 23.14 12.14 13.32 3.34 2.1 18.34 4.26 13.54 10.51 12.52 Omega-9 8.46 0.62 7 13.46 6.32 6.06 10.33 8.27 1.52 12.08 11.57 PUFA/SFA 0.24 0.76 0.55 0.34 0.55 0.20 0.66 0.22 0.73 0.41 0.39 n3/n6 1.43 0.29 0.05 0.07 2.44 0.60 0.96 0.08 0.99 0.02 0.00 The composition and content of fatty acids: Comment: When analysis the composition and content of fatty acids from research samples, we have identified 42 fatty acids that have 12 to 24 carbon atoms in their structures. Saturated fatty acids (SFA) accounted for high content from 43.61 % to 79.22 %, in which the fatty acid C16:0 mainly occupies (from 43.08 % to 68.86 % of total fatty acids), the acid C18:0 has low content from 1.09 % to 7.76 %. There are appearances of long chain saturated fatty acids 20:0, 22:0, 24:0 in some samples with low contents, about 1 %. Specially, sample N3 contains fatty acid 22:0 with high content 11.32 %, this variation may be created by biochemical or environmental conditions, nutrition. They have affected the accumulation of these fatty acids excessly. Polyunsaturated fatty acids (PUFA) have content from 3.35 % (sample N7) to 35.83 % (sample N9) of total fatty acids. These are the essential fatty acids which have high biological activity, they have a positive effect on animals in juvenile stage. In PUFA group we are interested in fatty acids C20, especially C20: 4n-6 (arachidonic acid - AA) that has the highest content of 22.35 % (sample N6), C20: 5n-3 (eicosapentaenoic acids - EPA) has content reaching 16.35 % (sample N9) and C20: 3n-6 (eicosatrienoic acid) has content reaching 1.43 % (sample CC4). They are the fatty acid precursors for the biosynthesis of eicosanoids and have extremely important role in modulating inflammatory processes in muscle. Research some chemical components of some seaweed species in Con Co island, Quang Tri 499 Omega 3 fatty acids (or n-3) have found out 8 fatty acids, omega-3 content ranges from 0 to 17.67%. Particularly, fatty acid C20: 5n-3 (EPA) presented very high content in 3 samples N9, CC1, N4 (16.35 %, 13.47% and 6.34 %, respectively); this fatty acid is rarely found in other marine organisms. Acid C22:5n-3 (docosahexaenoic acid - DHA) only appears in sample N4 with content is 1.82 %, it is very rare to see in the seaweeds. The omega-3 fatty acids only appear in some samples with very low contents, less than 1 %. Particularly, sample CC4 does not contain the fatty acids of omega-3 group, which are considered diffirent from researches on seaweed samples ago. Because these fatty acids of this group are always the characteristic elements of the general marine organisms and particular seaweeds [10]. The omega-6 fatty acids (or n-6): the majority of the research samples have content of omega-6 fatty acids higher than content of omega-3 fatty acids. We have identified 8 fatty acids whose content ranged from 2.09 % - 23.14 %. The omega-6 fatty acids appear mainly such as C20: 4n-6 (AA) has a quite high content from 1.68 % to 22.35 % of the total fatty acids, acid C18: 2n-6 has content from 1.26 % - 4.37 %, acid C20: 3n-6 has content from 0.32 % - 1.45 %. Omega 9 fatty acids (or n-9) have identified 4 fatty acids, C14 to C19 have contents from 0.62% - 13.46 %. In which mainly fatty acid is C18:1n-9 presenting in 10 per 11 research samples with average content is 8.06 %, the remaining fatty acids only appear in some samples with the negligible content. Index of PUFA/SFA ranged from 0.20 to 0.76. According to recommendations of World Health Organization (WHO), requirements for healthy food are index of PUFA/SFA>0.4. In 11 research samples there are 6 samples that achieve the requirements of this index, arranged in order from high to low as samples N6, CC1, N9, N5, N4, N3. Index of n3/n6 ranged from 0 to 2.44. According to recommendations WHO, the food has the index n3/n6 > 0.1 is good for human health. We see that there are 6 satisfactory samples arranged in order from high to low as samples N4, N2, CC1, N9, N7, N6. From the index of PUFA/SFA and n3/n6 above we may find out samples CC1, N9, N4, N6 with lipid components to meet the requirements of healthy food and good for the body. 4. CONCLUSIONS We used modern analytical methods to analyze some chemical components of 11 seaweed samples collected in Con Co island - Quang Tri. The results are shown that: The water content ranged from 82.86 % to 86.45 %; The total ash content ranged from 0.8 % to 3.74 %; The content of trace elements: Iodine (17.06 - 42.02 ppm), Iron (1987.86 - 7233.65 ppm), Zinc (23.66 – 70.09 ppm), Manganese (121.98 to 881. 42 ppm); The content of heavy metals such as Cu, Pb, Cd and As are below the permissible standards; The total lipid content of 0.12- 0.50% weight of fresh seaweed and there are 42 different fatty acids in samples have been identified. In which some long-chain fatty acids that have high bioactivity such as C20:4n-6 (AA) exhibited the highest content up to 22.35 % (Hypnea flagelliformis Grev., sample N6), C20:5n-3 (EPA) 16.36 % (Grateloupia lithophila, sample N9), C22: 6n-3 (DHA) 1.07 % (Hypnea esperi, sample N2), C22: 5n-3 (DPA) 1.82 % (Liagora sp1., sample N4). Acknowledgements. 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TÓM TẮT NGHIÊN CỨU MỘT SỐ THÀNH PHẦN HÓA HỌC TỪ CÁC LOÀI RONG BIỂN KHU VỰC ĐẢO CỒN CỎ Lê Tất Thành 1, *, Nguyễn Văn Tuyến Anh 1, Vũ Thị Oanh 1, Phạm Thu Huế 3, Nguyễn Thị Cẩm Bình 3, Đàm Đức Tiến 2 1Viện Hoá học các hợp chất thiên nhiên, Viện HLKHCNVN, 18 Hoàng Quốc Việt, Hà Nội 2Viện Tài nguyên và Môi trường biển, Viện Hàn lâm Khoa học và Công nghệ Việt Nam 246 đường Đà Nẵng, Ngô Quyền, Hải Phòng 3Học Viện Hải Quân – Bộ Quốc Phòng, 30 Trần Phú, Nha Trang, Khánh Hoà *Email: thanh.biotech@gmail.com Chúng tôi đã tiến hành thu 11 mẫu của 8 họ thuộc ngành rong đỏ (Rhodophyta) ở khu vực đảo Cồn Cỏ - Quảng Trị và xác định một số thành phần hoá học của chúng. Kết quả phân tích cho thấy các mẫu rong biển ở Đảo Cồn Cỏ có chứa hàm lượng cao các nguyên tố vi lượng, hàm lượng kim loại nặng thấp, nhiều mẫu có chất lượng lipit tốt đáp ứng yêu cầu thực phẩm an toàn và tốt cho cơ thể như CC1, N9, N4, N6. Đặc biệt trong thành phần lipit của rong biển đã phát Research some chemical components of some seaweed species in Con Co island, Quang Tri 501 hiện một số axit béo mạch dài nhiều nối đôi có hoạt tính sinh học cao như C20:4n-6 (AA) có hàm lượng cao nhất lên đến 22,35 % (loài Hypnea flagelliformis Grev., mẫu N6), C20:5n-3 (EPA) 16,36 % (loài Grateloupia lithophila, mẫu N9), C22:6n-3 (DHA) 1,07 % (loài Hypnea esperi, mẫu N2), C22:5n-3 (DPA) 1,82 % (loài Liagora sp1., mẫu N4). Từ khóa: lipit, axit béo, nguyên tố vi lượng, nguyên tố kim loại nặng, rong Cồn Cỏ.