National Institute of Technology, Durgapur, West Bengal 713209, India.
College of Engineering, National University of Science and Technology, P.O Box 2322, CPO Seeb 111, Al hail, Oman.
J Photochem Photobiol B. 2019 Nov;200:111622. doi: 10.1016/j.jphotobiol.2019.111622. Epub 2019 Sep 10.
Seaweeds are considered to be one of the richest bio-reserves, comprising of numerous bioactive compounds with versatile properties and multiple activities. The present study examined the antibacterial activity of two types of seaweeds, Ulva lactuca (green) and Stoechospermum marginatum (brown) collected from Oman Coastal region against five multidrug-resistant bacteria. The aqueous extracts of the seaweeds showed better antibacterial activity compared to methanol extracts. The results of the antibacterial assay revealed the excellent inhibitory effects of U.lactuca with the maximum activity against E.coli(8 mm) followed by K.pneumonia(4 mm) and S.typhi(2 mm). S.marginatum formed a clear zone of inhibition only against E.coli(3 mm).The major phytochemical constituents identified in both the types of seaweeds were Alkaloids, Terpenoids, Saponins, Flavonoids, and Steroids. Fourier transform infrared spectroscopy (FTIR) results confirmed the presence of alcoholic/phenolic groups, and amide groups in the seaweed extracts. Gas chromatography-mass spectrometry (GC-MS) results evidenced the presence of bioactive compounds such as 5-Octadecenal, 1-Tricosanol, Neophytadiene, Lactaropallidin, Phytol, Fenretinide, Lucenin, Vincadifformine in U.lactuca. Additionally, U.lactuca displayed better antioxidant activity (33.05%) in the DPPH free radical scavenging activity test compared to the S.marginatum (21.51%). Thus, the green seaweed U.lactuca could be considered as a potential source of natural antioxidant and antibacterial agents for food and pharmaceutical products.
海藻被认为是最丰富的生物资源之一，其中包含许多具有多种特性和多种活性的生物活性化合物。本研究考察了两种来自阿曼沿海地区的海藻，即绿藻（Ulva lactuca）和缘管浒苔（Stoechospermum marginatum）的水提物和甲醇提物对五种多重耐药菌的抗菌活性。与甲醇提取物相比，海藻的水提取物表现出更好的抗菌活性。抗菌活性测定结果表明，绿藻对大肠杆菌（8mm）的抑制效果最好，其次是肺炎克雷伯菌（4mm）和伤寒沙门氏菌（2mm）。缘管浒苔仅对大肠杆菌（3mm）形成抑菌圈。两种海藻中鉴定的主要植物化学成分是生物碱、萜类、皂苷、类黄酮和甾体。傅里叶变换红外光谱（FTIR）结果证实了海藻提取物中存在醇/酚基团和酰胺基团。气相色谱-质谱联用（GC-MS）结果表明，绿藻中存在生物活性化合物，如 5-十八碳烯醛、1-二十三烷醇、新 Phytadiene、乳香 Pallidin、叶绿醇、芬维仑、叶黄素、长春地辛。此外，绿藻在 DPPH 自由基清除活性试验中表现出更好的抗氧化活性（33.05%），而缘管浒苔（21.51%）。因此，绿藻可以被认为是天然抗氧化剂和抗菌剂的潜在来源，可用于食品和制药产品。
