Antioxidant Activity of Zyzzyanones and Makaluvamines from the Marine Sponge Zyzzya fuliginosa

Antioxidant activities of zyzzyanones A-D (1–4) and makaluvamines C (8), E (5), G (6), H (9), and L (7) isolated from the marine sponge Zyzzya fuliginosa (Carter, 1879) were evaluated using 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonate) (ABTS) scavenging assay and AAPH (2,2′-azobis(2-amidinopropane) dihydrochloride) induced autoxidation of linoleic acid. Zyzzyanones A, B (1, 2; TE = 0.3), C, D (3, 4; TE = 0.24) and makaluvamines 5–7 (TE = 0.6) displayed moderate activities in the ABTS assay and in the autoxidation of linoleic acid (61–66 % inhibition at concentrations of 0.1 mM). Makaluvamines C (8) and H (9) were essentially inactive in the both assays. Structure-activity relationships showed that antioxidant activities of tested compounds depended on the presence of a phenolic function in molecules. Makaluvamines 5–7 possessing a p-hydroxystyryl moiety were more active than zyzzyanones 1–4 possessing a p-hydroxyphenyl fragment. The presence of a charged side chain in 1 and 2 slightly increases their ABTS scavenging activity in comparison with compounds 3 and 4. Structural variations in a pyrroloquinoline skeleton of 5–7 and in a dipyrroloquinone core of 1–4 have no effect on activities.

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Structure─activity relationships in semi-synthetic penicillins

Proceedings of the Royal Society of London Series B Biological Sciences ◽

10.1098/rspb.1971.0102 ◽

1971 ◽

Vol 179 (1057) ◽

pp. 357-367 ◽

Cited By ~ 10

Keyword(s):

Antibacterial Activity ◽

Chemical Nature ◽

Side Chain ◽

Structural Variations ◽

Present Survey ◽

Structure Activity Relationships ◽

Structure Activity ◽

Large Numbers ◽

The Relationship

Investigation of the relationship between the antibacterial activity of penicillins and the chemical nature of the side chain began in earnest in 1957, when the isolation of 6-aminopenicillanic acid (6-APA) made possible the preparation of large numbers of N -substituted derivatives. Since that time some 1800 different penicillins have been prepared and studied in Beecham Research Laboratories, and the number examined throughout the world must amount to several thousands. The purpose of the present survey is to try to summarize the general patterns of structure-activity relationships which have emerged from these studies. 6-APA itself has only a low order of antibacterial activity, and the same applies to derivatives in which the amino group at position 6 is substituted by radicals other than acyl groups (figure 1). Hence it soon became clear that no advantage was to be gained from such considerable structural variations, and efforts were concentrated on preparing true penicillins containing acyl side-chains. Virtually all of these show considerable activity in vitro against at least some bacteria, but the spectrum of activity varies widely.

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Antioxidant Activity in Rheum emodi Wall (Himalayan Rhubarb)

Molecules ◽

10.3390/molecules26092555 ◽

2021 ◽

Vol 26 (9) ◽

pp. 2555

Author(s):

Sang Koo Park ◽

Yoon Kyung Lee

Keyword(s):

Antioxidant Activity ◽

Ethyl Acetate ◽

Radical Scavenging Activity ◽

Radical Scavenging ◽

Ethyl Acetate Fraction ◽

Total Phenolic ◽

Scavenging Activity ◽

Polyphenol Content ◽

Abts Assay ◽

Ic50 Values

Using natural products as antioxidant agents has been beneficial to replace synthetic products. Efforts have been made to profile the antioxidant capacities of natural resources, such as medicinal plants. The polyphenol content of Himalayan rhubarb, Rheum emodi wall, was measured and the antioxidant activity was determined using DPPH and ABTS+ assay, and the oxidative stress was assessed using SOD enzymatic assay. Five different solvent fractions, n-hexane, n-butanol, ethyl acetate, dichloromethane, and water, were used for screening the antioxidant capacity in effort to determine the optimum extraction solvent. The total phenolic contents for R. emodi fractions ranged from 27.76 to 209.21 mg of gallic acid equivalents (GAE)/g of dry weight. DPPH and ABTS+ assay results are presented into IC50 values, ranged from 21.52 to 2448.79 μg/mL and 90.25 to 1718.05 μg/mL, respectively. The ethyl acetate fraction had the highest antioxidant activity among other fractions. Also, n-butanol and water fractions showed significantly lower IC50 values than the positive control in DPPH radical scavenging activity. The IC50 values of SOD assay of fractions ranged from 2.31 to 64.78 μg/mL. A similar result was observed with ethyl acetate fraction showing the highest SOD radical scavenging activity. The study suggests that the ethyl acetate fraction of R. emodi possess the strongest antioxidant activity, thus the most efficient in extracting antioxidant contents. Moreover, a highly significant correlation was shown between total polyphenol content and antioxidant activity screening assays. The compounds related to the antioxidant activity of R. emodi were identified to myricitrin, myricetin 3-galloyl rhamnoside, and myricetin, which have not been reported in studies about R. emodi before.

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In Vitro Antioxidant Activity Metaplexis Japonica Makino Extract and Derivatives

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.955-959.387 ◽

2014 ◽

Vol 955-959 ◽

pp. 387-389 ◽

Cited By ~ 2

Author(s):

Bao Qing Wang

Keyword(s):

Antioxidant Activity ◽

Linoleic Acid ◽

Ethyl Acetate ◽

Antioxidant Activities ◽

Radical Scavenging ◽

Acid Test ◽

Acetone Extracts ◽

Β Carotene ◽

Ethyl Acetate Extracts

Antioxidant activities of acetone and ethyl acetate extracts from Metaplexis japonica Makino, one of famous medicine plants in the eastnorth region of China, named luomo in Chinese, were examined by a DPPH (1,1-Diphenyl-2-picrylhydrazyl) radical-scavenging assay and a β-carotene-linoleic acid test. In DPPH, the antioxidant activity of the acetone extracts, ethyl acetate extracts and derivative were IC50 were 313.21, 266.92 and 118.78μg/mL, respectively. In the β-carotene-linoleic acid test, IC50 were 285.09, 351.57 and 123.89μg/mL. It was concluded that Metaplexis japonica Makino and its derivatives might be a potential natural source of antioxidants .

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Antioxidant and Anticancer Activities of Wampee (Clausena lansium(Lour.) Skeels) Peel

Journal of Biomedicine and Biotechnology ◽

10.1155/2009/612805 ◽

2009 ◽

Vol 2009 ◽

pp. 1-6 ◽

Cited By ~ 29

Author(s):

K. Nagendra Prasad ◽

Jing Hao ◽

Chun Yi ◽

Dandan Zhang ◽

Shengxiang Qiu ◽

...

Keyword(s):

Antioxidant Activity ◽

Ethyl Acetate ◽

Antioxidant Activities ◽

Radical Scavenging Activity ◽

Radical Scavenging ◽

Reducing Power ◽

Total Phenolic ◽

Liver Carcinoma ◽

Scavenging Activity ◽

Anticancer Activities

Antioxidant activities of wampee peel extracts using five different solvents (ethanol, hexane, ethyl acetate, butanol and water) were determined by using in-vitro antioxidant models including total antioxidant capability, 1,1-diphenyl-2-picryl hydrazyl (DPPH) radical scavenging activity, reducing power, and superoxide scavenging activity. Ethyl acetate fraction (EAF) exhibited the highest antioxidant activity compared to other fractions, even higher than synthetic antioxidant butylated hydroxyl toluene (BHT). In addition, the EAF exhibited strong anticancer activities against human gastric carcinoma (SGC-7901), human hepatocellular liver carcinoma (HepG-2) and human lung adenocarcinoma (A-549) cancer cell lines, higher than cisplatin, a conventional anticancer drug. The total phenolic content of wampee fraction was positively correlated with the antioxidant activity. This is the first report on the antioxidant and anticancer activities of the wampee peel extract. Thus, wampee peel can be used potentially as a readily accessible source of natural antioxidants and a possible pharmaceutical supplement.

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Structure-activity relationships for glucocorticoids—III. Structural and conformational study of the rings and side-chain of steroids which bind to the glucocorticoid receptor

Journal of Steroid Biochemistry ◽

10.1016/0022-4731(78)90051-1 ◽

1978 ◽

Vol 9 (10) ◽

pp. 909-920 ◽

Cited By ~ 25

Author(s):

Jean-Pierre Schmit ◽

Guy G. Rousseau

Keyword(s):

Glucocorticoid Receptor ◽

Side Chain ◽

Conformational Study ◽

Structure Activity Relationships ◽

Structure Activity

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Potential antitumor agents. 63. Structure-activity relationships for side-chain analogs of the colon 38 active agent 9-oxo-9H-xanthene-4-acetic acid

Journal of Medicinal Chemistry ◽

10.1021/jm00113a027 ◽

1991 ◽

Vol 34 (9) ◽

pp. 2864-2870 ◽

Cited By ~ 41

Author(s):

Gordon W. Rewcastle ◽

Graham J. Atwell ◽

Bruce C. Baguley ◽

Maruta Boyd ◽

Lindy L. Thomsen ◽

...

Keyword(s):

Acetic Acid ◽

Antitumor Agents ◽

Active Agent ◽

Side Chain ◽

Structure Activity Relationships ◽

Structure Activity ◽

Potential Antitumor

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HPLC Evaluation of Phenolic Profile, Nutritive Content, and Antioxidant Capacity of Extracts Obtained fromPunica granatumFruit Peel

Advances in Pharmacological Sciences ◽

10.1155/2013/296236 ◽

2013 ◽

Vol 2013 ◽

pp. 1-6 ◽

Cited By ~ 10

Author(s):

Sushil Kumar Middha ◽

Talambedu Usha ◽

Veena Pande

Keyword(s):

Antioxidant Activity ◽

Gallic Acid ◽

Antioxidant Activities ◽

Radical Scavenging Activity ◽

Radical Scavenging ◽

Water Extract ◽

Scavenging Activity ◽

Fruit Peel ◽

Phenolic Profile ◽

Antioxidant Power

This study revealed polyphenolic content, nutritive content, antioxidant activity, and phenolic profile of methanol and aqueous extracts ofPunica granatumpeel extract. For this, extracts were screened for possible antioxidant activities by free radical scavenging activity (DPPH), hydrogen peroxide scavenging activity and ferric-reducing antioxidant power (FRAP) assays. The total phenolics and flavonoid recovered by methanolic (MPE) and the water extract (AQPE) were ranged from 185 ± 12.45 to 298.00 ± 24.86 mg GAE (gallic acid equivalents)/gm and 23.05 ± 1.54 to 49.8 ± 2.14 quercetin (QE) mg/g, respectively. The EC50of herbal extracts ranged from 100 µg/ml (0.38 quercetin equivalents), for AQPE, 168 µg/ml (0.80 quercetin equivalents), for MPE. The phenolic profile in the methanolic extracts was investigated by chromatographic (HPLC) method. About 5 different flavonoids, phenolic acids, and their derivatives including quercetin (1), rutin (2), gallic acid (3), ellagic acid (4), and punicalagin as a major ellagitannin (5) have been identified. Among both extracts, methanolic extract was the most effective. This report may be the first to show nutritive content and correlation analysis to suggest that phenols and flavonoids might contribute the high antioxidant activity of this fruit peel and establish it as a valuable natural antioxidant source applicable in the health food industry.

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Structure–activity relationships of the peptide deformylase inhibitor BB-3497: modification of the methylene spacer and the P1′ side chain

Bioorganic & Medicinal Chemistry Letters ◽

10.1016/s0960-894x(03)00532-8 ◽

2003 ◽

Vol 13 (16) ◽

pp. 2709-2713 ◽

Cited By ~ 28

Author(s):

Stephen J. Davies ◽

Andrew P. Ayscough ◽

R.Paul Beckett ◽

Ryan A. Bragg ◽

John M. Clements ◽

...

Keyword(s):

Peptide Deformylase ◽

Side Chain ◽

Structure Activity Relationships ◽

Structure Activity

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Antioxidant Activity of 1’-Hydroxyethylnaphthazarins and their Derivatives

Natural Product Communications ◽

10.1177/1934578x1701201218 ◽

2017 ◽

Vol 12 (12) ◽

pp. 1934578X1701201

Author(s):

Natalia K. Utkina ◽

Natalia D. Pokhilo

Keyword(s):

Antioxidant Activity ◽

Radical Cation ◽

Radical Scavenging Activity ◽

Radical Scavenging ◽

Structure Activity Relationship ◽

Activity Relationship ◽

Hydroxyl Group ◽

Side Chains ◽

Scavenging Activity ◽

Structure Activity

The ABTS•+ radical cation scavenging activity of known (2-5, 9, 10) and new (6-8) 1’-hydroxyethylnaphthazarins and their products of esterification and etherification was evaluated and a structure-activity relationship was studied. It was shown, that the structure of side chains does not affect the radical scavenging activity of 1’-hydroxyethylnaphthazarins and their derivatives. The presence of methoxyl groups on the naphthazarin core slightly enhanced the antioxidant activity of compounds compared with compounds without methoxyl groups. The presence of the additional hydroxyl group on the naphthazarin moiety of isonorlomazarin (5) and its derivative (6) is essential for the activity.

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