Document Details
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Document Type |
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Thesis |
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Document Title |
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MARINE NATURAL PRODUCTS FROM RED SEA ORGANISMS - CHEMICAL AND BIOLOGICAL CHARACTERIZATION الخصائص الكيميائية والبيولوجية للمنتجات الطبيعية البحرية من كائنات البحر الاحمر |
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Subject |
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Faculty of Marine Sciences |
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Document Language |
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Arabic |
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Abstract |
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In this study, Four Red Sea organisms Avrainvillea amadelpha (algae), Holothuria atra (sea cucumber), Sarcocornia fruticosa (coastal plant), and Emericella nidulans (fungi) were chemically and biologically investigated. A total of 26 metabolites were isolated and identified from the crude extracts of these organisms, using chromatographic techniques and spectral analyses. The compounds were identified as four steroidal compounds sitostenone, β-sitosterol, β-sitosterol 3-O-sulfate, sitosterol 3-O-β-glucoside, and sulfonyglycolipid from A. amadelpha; three fatty acids palmitic acid, 9-hydroxypalmitic acid, 9-palmitoleic acid; nucleobase thymine, nucleosides thymine 2'-deoxyriboside, uracil 2'-deoxyriboside, uracil β-ribofuranoside, two steroids β-sitosterol and sitosterol 3-O-β-glucoside, and two triterpene glycosides echinoside B and echinoside B 12-O-methyl ether from H. atra; six flavonoids isorhamnetin, isorhamnetin 3-O-(6''-O-α-rhamnosyl)-β-galactoside, isorhamnetin 3-O-(2'',6''-O-α-di-rhamnosyl)-β-galactoside, rhamnazin 3-O-(6''-O-α-rhamnosyl)-β-galactoside, rhamnazin 3-O-rutinoside, and rhamnazin 3-O-(2'',6''-O-α-di-rhamnosyl)-β-glucoside as a new natural compound, along with known nitrogenous compound allantoin from S. fruticosa; and known fungal metabolites emericellin, shamixanthone and arugosin C from E. nidulans.
The biological activities of the compounds compared to their total extracts were evaluated as antimicrobial, anticancer, antioxidant and antiviral. The antifungal screening displayed that sitostenone and sulfonoglycolipid at 50 µg/disc have strong ability to inhibit Aspergillus niger with inhibition zone diameter 17.97 and 12.03 mm, respectively, as well as significant cytotoxic activity against MCF-7 cancer cells with IC50 values 5.42 and 6.72 μM, respectively. Sulfonoglycolipid displayed the highest cell line activity against colorectal cancer (HCT116) cells with IC50 3.61 μM. The results showed that the crude extract of S. fruticosa and the new rhamnazin tri-glycoside have HCV protease inhibitory with IC50 10.5 µg/ml and IC50 8.9 μM, respectively. Isorhamnetin di- and tri-glycosides effectively scavenged DPPH radicals with IC50 values 3.8 and 4.3 μM, respectively. E. nidulans extract at 100 µg/disc and arugosin C at 50 µg/disc had selective antimicrobial activity against Gram-positive strain Staphylococcus aureus with inhibition zone diameters 14 and 15 mm, respectively. Shamixanthone was a potent antibacterial metabolite against Bacillus cereus (13 mm inhibition) at 50 µg/disc. Moreover, emericellin exhibited a good antibacterial activity against Gram-negative bacterial strain Escherichia coli with inhibition zone 12 mm compared to the inhibition of antibiotic reference.
Chloroform (as non-polar) fractions of A. amadelpha, H. atra, S. fruticosa were investigated for their lipoidal constituents (using GC-MS analyses) and antifouling activity (using antibiofilm bacterial test). The GC-MS analysis of fatty acids (FAs) content of A. amadelpha revealed the dominance of palmitic acid (26.76%) with considerable amounts of oleic acid (C18:1, n-9) and arachidonic acid (C20:4, n-6) at 9.74 and 6.66%, respectively. Quantities of unsaturated FAs (58.86%) of H. atra were detected where palmitoleic acid (C16:1, n-7) and arachidonic acid (20:4, n-6) were the major components represented by 17.33 and 13.6%, respectively. Costal plant S. fruticosa was dominated by conjugated C18 FAs (linoleic acid, n-6 and α-linolenic acid, n-3) at approximately same ratio with a total amount of 33.65%. The unsaponifiable matter (USM) of both A. amadelpha and H. atra comprised of five chemical classes of hydrocarbons, ketones, esters, terpenes and steroidal compounds while n-Alkanes were the main grouped components of the unsaponifiable fraction of H. atra. The crude extracts and their lipoidal fractions were found to exhibit antifouling activity against three biofilm-bacterial strains isolated from the Red Sea, where alga A. amadelpha extracts displayed highest percentage of biofilm inhibition. S. fruticosa and A. amadelpha showed growth inhibitory activity against the biofilm-forming bacterial strains where USM, FAs and FAs-methyl ester fractions exhibited a strong activity at 100 µg ml-1 against Planomicrobium sp.
Total extract of H. atra and S. fruticosa proved to have cytotoxic activity against in vitro Ehrlich ascites carcinoma cells with inhibition of 86 and 52%, respectively at concentration 2.5 mg/ml. The animal model assay indicated that intraperitoneally injection and orally treatment decreased the tumor volume of the tested rats to 71 and 54%, respectively, for H. atra extract, and to 71 and 78%, respectively, for S. fruticosa extract compared to the untreated control animals (45%). Moreover, H. atra and S. fruticosa extracts exhibited larvicidal effects on Aedes aegypti mosquito vector of dengue fever virus by LC50 188 and 58 ppm, respectively. These findings showed that S. fruticosa proved to be a potent larvicidal which is more effective than reported results on S. brachiata. |
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Supervisor |
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Prof. Dr. Usama Wahid Abd El-Atty Hawas |
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Thesis Type |
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Doctorate Thesis |
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Publishing Year |
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1440 AH
2019 AD |
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Added Date |
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Sunday, September 15, 2019 |
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Researchers
| فكري مرشد شاهر | Shaher, Fekri Murshed | Researcher | Doctorate | |
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