GC/MS identification and applications of bioactive seaweed extracts from Mediterranean coast of Egypt

Abstract

The antibacterial activity of different seaweed species against five fish pathogens (A. hydrophila, V. parahaemolyticus, V. alginolyticus, V. damsela and Vibrio sp.) has been evaluated. The ethanolic extract of C. sinuosa (CSE1) and dichloromethane extract of C. officinalis (COM) exhibited the highest antibacterial activity with activity index (AI) = 1.4 ±0.74 and 1.2 ±0.71, respectively. When the extracts were encapsulated into calcium alginate beads their antibacterial activity against the most susceptible bacterial pathogens showed that the significant growth inhibition was against V. parahaemolyticus after 5 min post addition of the beads recording 1.4 and 2 fold decrease in the growth, respectively. Recycling of the (CA/COM) beads was carried out for 7 successive cycles with success in elimination of V. parahaemolyticus. The potential applications of encapsulated extracts for elimination of microbial load in fish rearing water and antifouling activity were proved in the current investigation. The chemical composition of the bioactive extracts (CSE1) and (COM) was determined using GC/MS analysis which revealed the presence of several constituents that have been reported to exhibit antimicrobial activity. Additionally, the dichloromethane extract (COM) produced six major components including n-nonadecane, 1,2,3propanetricarboxylic acid, 2-(acetyloxy)-, tributyl ester, 2-methylhexadecan-1-ol, 1-docosene, 1-eicosanol and chloroacetic acid, octadecyl ester. However, the ethanolic extract (CSE1) was characterized by the presence of fatty acids, fatty acids ethyl esters and aromatic hydrocarbon where the most abundant compound was n-tridecanoic acid ethyl ester.

The Potential of a New Commercial Seaweed Extract in Stimulating Morpho-Agronomic and Bioactive Properties of Eruca vesicaria (L.) Cav.

“…Rhodopin, as a carotenoid compound in seaweeds, has antioxidant activity [49,51]. Nonadecane reported in many red, brown, and green seaweeds displayed antioxidant and antimicrobial activities [48][49][50]. This finding reflects the key role of these bioactive compounds as a protective effect against plant pathogens and invaders.…”

“…Phytol is one of the chlorophyll products that has been reported to have significant antioxidant effects [45,75]. Rhodopin, as a carotenoid compound in seaweeds, has antioxidant activity [49,51]. Nonadecane reported in many red, brown, and green seaweeds displayed antioxidant and antimicrobial activities [48][49][50].…”

Impact of Seaweed Liquid Extract Biostimulant on Growth, Yield, and Chemical Composition of Cucumber (Cucumis sativus)

“…Nonadecane is also a natural alkane hydrocarbon that was recorded in different brown, red, and green seaweeds, collected from the Alexandrian coast. However, nonadecane showed different biological properties such as antimicrobial and antioxidant activities [32][33][34][35][36]. Milbemycin B, 5-demethoxy-5-one-6,28-anhydro-25-ethyl-4-methyl-13-chloro-oxime (milbemycin oxime), was also reported in TAM [13,59,60].…”

Gas Chromatography-Mass Spectroscopy and Fourier Transform Infrared Profiling of the Bioactive Compounds Present in Methanol Leaf Extract of Solanum Aethiopicum from Imo State, Nigeria

“…Heptadecane (0.31%) also has strong anti-inflammatory properties (Kim et al, 2013) Decanoic/Capric acid (0.15%) has been known to be antibacterial, antiinflammatory, anti-seizure and reduce oxidative stress, regulate signaling pathways (Yang et al, 2018:Chang et al, 2016: Huang et al, 2014. 1-Docosene (5.98%), 2methylhexacosane(0.49%) and Dibutyl phthalate (0.05%) possess antibacterial properties (Togashi et al, 2007;Sahar & Aida, 2018;Khatiwora, Adsul, Kulkarni, Deshpande & Kashalkar, 2012). Aspidospermidine-17-ol,1-acetyl,19,21-epoxy-15,16-dimethoxy (0.41%) has antimicrobial properties (Olubunmi & Anthony, 2017;Safwat, Hamed & Moatamed, 2018).…”