scholarly journals Preparation and Antioxidant Activity of Chitosan Dimers with Different Sequences

Marine Drugs ◽  
2021 ◽  
Vol 19 (7) ◽  
pp. 366
Author(s):  
Wentong Hao ◽  
Kecheng Li ◽  
Yuzhen Ma ◽  
Rongfeng Li ◽  
Ronge Xing ◽  
...  

As a popular marine saccharide, chitooligosaccharides (COS) has been proven to have good antioxidant activity. Its antioxidant effect is closely related to its degree of polymerization, degree of acetylation and sequence. However, the specific structure–activity relationship remains unclear. In this study, three chitosan dimers with different sequences were obtained by the separation and enzymatic method, and the antioxidant activity of all four chitosan dimers were studied. The effect of COS sequence on its antioxidant activity was revealed for the first time. The amino group at the reducing end plays a vital role in scavenging superoxide radicals and in the reducing power of the chitosan dimer. At the same time, we found that the fully deacetylated chitosan dimer DD showed the strongest DPPH scavenging activity. When the amino groups of the chitosan dimer were acetylated, it showed better activity in scavenging hydroxyl radicals. Research on COS sequences opens up a new path for the study of COS, and is more conducive to the investigation of its mechanism.


Author(s):  
YOHANES TANDORO ◽  
PAINI SRI WIDYAWATI ◽  
TARSISIUS DWI WIBAWA BUDIANTA ◽  
GRACE SUMARGO

Objective: The objective of this study was to compare the phytochemical composition and antioxidant activity of Passiflora foetida fruits and leaves extract. Methods: The parameters observed in this study were phytochemical compounds including alkaloid, flavonoid, phenolic, sterol, triterpenoid, saponin, tannin, and cardiac glycoside, total phenolic content Folin Ciocalteu method is based on reduction of Folin Ciocalteu reagent in alkaline medium; the metal complex produced measured at λmax: 760 nm; total flavonoids content with AlCl3 Colorimetric method based on complex formation of AlCl3 and flavonoid content in alkaline medium, the AlCl3-flavonoid complex produced measured at λmax: 510 nm; free radical DPPH scavenging activity; and ferric reducing power based on reduction of Fe3+ion into Fe2+ion that reacted with FeCl3 to form a ferric-ferrous complex that measured at λmax: 700 nm. Results: Passiflora leaves extract has phytochemical compound such as alkaloids, phenolics, flavonoids, saponins, and cardiac glycosides, total phenol was 22.92±0.18 mg GAE/g sample dry base, total flavonoid was 7.01±0.10 mg CE/g sample dry base, DPPH scavenging activity was 2.77±0.02 mg GAE/g sample dry base and ferric reducing power was 3.20±0.04 mg GAE/g sample dry base meanwhile Passiflora fruits extract had phytochemical compounds such as alkaloid, phenolic, flavonoids, cardiac glycosides, total phenol was 6.53±1.02 mg GAE/g sample dry base, total flavonoids were 1.56±0.27 mg CE/g sample dry base, DPPH free radical scavenging activity was 1.00±0.15 mg GAE/g sample dry base, and ferric reducing power was 1.12±0.17 mg GAE/g sample dry base. Conclusion: Passiflora leaves extract has higher total phenol, total flavonoid and antioxidant activity measured by DPPH scavenging activity and ferric reducing power value compared with Passiflora fruits extract.



Author(s):  
Amanda Cristina Ramos Koike

The edible flowers are increasingly used in culinary preparations, which require new approaches to improve their conservation and safety. Irradiation treatment is safe and an effective alternative for food conservation. Indeed, it can also guarantee food quality, increasing shelf-life and disinfestation of it. This technology gives us a versatile way to get good quality food, reducing post-harvest losses. Dianthus chinensis flowers, popularly known as Chinese pink, are widely used in culinary preparations, being also acknowledged for their bioactive components and antioxidant properties. The purpose of this study was to evaluate the antioxidant activity of D. chinensis flowers submitted to electron beam and gamma irradiation at 0, 0.5, 0.8 and 1 kGy. The antioxidant properties were evaluated through 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity, reducing power and β-carotene bleaching inhibition assays. Total phenolics were also determined by the Folin-Ciocalteu assay. The antioxidant activity was higher for irradiated samples, especially those treated with 0.8 and 1 kGy, independently of the radiation source, which showed the highest capacity to inhibit β-carotene bleaching. Accordingly, the applied irradiation treatments seemed to represent feasible technology to preserve the quality of edible flower petals, being able to improve the antioxidant activity



2020 ◽  
pp. 15-21
Author(s):  
Arindam Ghosh ◽  
Soumya Majumder ◽  
Sumedha Saha ◽  
Malay Bhattacharya

Beneficial properties of shade trees of tea plantations other than their medicinal properties have been extensively studied. This research was initiated to explore the properties of some shade trees with special emphasis on their antioxidant and antibacterial properties. Leaves from shade tree like Dalbergia sissoo (DS), Cassia siamea (CS), Derris robusta (DR), Leucaena leucocephala (LL), Acacia lenticularis (AL) and Melia azedarach (MA) were used for the study. Characterization of shade tree leaves by determination of moisture, crude fibre and ash content and tests of non polar – polar solvent extracts for steroid, tannins, cardiac glycosides and coumarin, free radical scavenging, ferric reducing power, NO scavenging activities, quantification of Flavonoids and antibacterial activity were conducted. The average moisture, crude fibre and ash percentage of shade tree plants were found to be 62.95, 11.28 and 1.86 respectively. Methanol, ethanol, acetone and ethyl acetate respectively proved to be the most potent solvent for various phytochemical extractions as it gave positive results for tests like tannin, steroid, cardiac glycosides and coumarin. AL (91.46%), DR (92.69%), LL (94.32%) and MA (93.34%) leaf extracts showed a high level of DPPH scavenging activity in their water extracts. In DS (88.11%) and CS (83.23%) maximum DPPH scavenging activity was observed in Diethyl ether and Methanol extracts respectively.  Acetone extracts were more active than the water extracts in exhibiting ferric reducing power and NO scavenging activity. Summation of the quantity revealed that DS showed maximum presence of flavonoids and acetone as most potential for isolation of flavonoids. The decreasing order of summative antibacterial activity was recorded in DS, followed by CS, DR, AL, MA and LL. Chloroform showed the highest summative inhibition zone followed by ethanol, ethyl acetate, diethyl ether, acetone, water,  hexane, benzene and methanol. The antioxidant and antibacterial potential of shade trees were established.



2019 ◽  
Author(s):  
Sven Basa ◽  
Malathi Nampally ◽  
Talita Honorato ◽  
Subha Narayan Das ◽  
Appa Rao Podile ◽  
...  

The biological activity of chitosans depends on their degree of polymerization (DP) and degree of acetylation (DA). However, information could also be carried by the pattern of acetylation (PA): the sequence of <i>β</i>-1,4-linked glucosamine (deacetylated/D) and <i>N</i>-acetylglucosamine (acetylated/A) units. To address this hypothesis, we prepared partially-acetylated chitosan oligosaccharides from a chitosan polymer (DA=35%, DP<sub>w</sub>=905) using recombinant chitosan hydrolases with distinct substrate and cleavage specificities. The mixtures were separated into fractions DP4–DP12, which were tested for elicitor and priming activities in rice cells. We confirmed that both activities were influenced by DP, <a>but also observed apparent DA-dependent priming activity, with the ADDD+DADD fraction proving remarkably effective</a>. We then compared all four mono-acetylated tetramers prepared using different chitin deacetylases and observed significant differences in priming activity. This demonstrates for the first time that PA influences the biological activity of chitosans, which can now be recognized as <i>bona fide</i> information-carrying molecules



2019 ◽  
Author(s):  
Sven Basa ◽  
Malathi Nampally ◽  
Talita Honorato ◽  
Subha Narayan Das ◽  
Appa Rao Podile ◽  
...  

The biological activity of chitosans depends on their degree of polymerization (DP) and degree of acetylation (DA). However, information could also be carried by the pattern of acetylation (PA): the sequence of <i>β</i>-1,4-linked glucosamine (deacetylated/D) and <i>N</i>-acetylglucosamine (acetylated/A) units. To address this hypothesis, we prepared partially-acetylated chitosan oligosaccharides from a chitosan polymer (DA=35%, DP<sub>w</sub>=905) using recombinant chitosan hydrolases with distinct substrate and cleavage specificities. The mixtures were separated into fractions DP4–DP12, which were tested for elicitor and priming activities in rice cells. We confirmed that both activities were influenced by DP, <a>but also observed apparent DA-dependent priming activity, with the ADDD+DADD fraction proving remarkably effective</a>. We then compared all four mono-acetylated tetramers prepared using different chitin deacetylases and observed significant differences in priming activity. This demonstrates for the first time that PA influences the biological activity of chitosans, which can now be recognized as <i>bona fide</i> information-carrying molecules



Author(s):  
Gerard Bessan Dossou-Agoin ◽  
Habib Ganfon ◽  
Fidèle Assogba ◽  
Adam Gbankoto ◽  
Joachim Gbenou ◽  
...  

Aims: The leafy stem and fruit of P.murex have been reported to be used in folk medicine to treat male reproductive system ailments. This study was undertaken to assess the antioxidant potential of the aqueous extracts of P.murex leafy stem and fruit. Methodology: Extracts were prepared by macerating the powder in water. Total phenolics amount were determined by Folin-Ciocalteu reagent, flavonoids were quantified by aluminum chloride method and total tannin content was estimated by hexacyanoferric method. The in vitro antioxidant activity of the extracts were assessed through 2,2´-diphenyl-1-picrylhydrazyl (DPPH) scavenging assay, reducing power assay, hydrogen peroxide (H2O2) inhibition assay and lipid peroxidation assay. Results: Total phenolic compounds, flavonoids and tannins content were respectively equal to 48.91± 1.67 µg/mg Gallic Acid Equivalents (GAE); 56.01± 0.90 µg/mg Rutin Equivalents (RUE); 16.92± 1.22 µg/mg Tannic Acid Equivalents (TAE) for the leafy stem extract while they were equal to 26.26± 0.54 µg/mg GAE; 47.88± 2.39 µg/mg RUE; 7.94± 0.31 µg/mg TAE for the fruit. The leafy stem extract exhibited a more pronounced DPPH scavenging activity, reducing power, hydrogen peroxide scavenging activity and lipid peroxidation activity than the fruit extract. Conclusion: The antioxidant activity of the leafy stem aqueous extract was significantly more potent than that of the fruit extract. Further studies will find out the extracts pharmacological efficacy and innocuity.



Author(s):  
Stanley Kanayochukwu Nnenne ◽  
Kingsley Ikechukwu Ubaoji ◽  
Uchechukwu Chibuzo Ogbodo ◽  
Victor Henry Azubuike Enemor ◽  
Adebayo Afees Oladejo

Aim: Citrullus lanatus is a fruit widely consumed for its pulp though incompletely, as its other parts (seed and rind) are discarded and may possibly offer bioactive compounds involved in ameliorating certain disease conditions. Hence, this study aimed at comparatively investigating the nutritional composition and antioxidant properties of the seed, pulp and rind of C. lanatus so as to inform the inclusion of these different parts into the fare of the people. Methodology: Standard analytical methods of Association of Official Analytical Chemists were used to determine proximate, phytochemical, vitamin, mineral and antioxidant aspects of the fruit parts. The results were analyzed using Student’s t-test at .05. Results: The proximate analysis showed a high moisture value in the pulp (93.34 +/- .82) followed by the rind (77.11 +/- 3.44) and the seed (10.00 +/- .48). High crude protein and fiber contents were both noted in the seed followed by the rind and pulp. Mineral determinations revealed potassium to be abundant in the rind (452.31mg/kg) than the seed (305.7mg/kg) and the pulp (100.5mg/kg), followed by calcium occurring more in the rind (292.61mg/kg) than in the pulp (257.21mg/kg) and seed (227.45mg/kg) and then manganese being the least concentrated among the minerals. The investigated phytochemical principles revealed the highest concentration of cardiac glycosides in the seed (14.82 +/- .66) than the rind (1.95 +/- 0.80) and pulp (1.10 +/- 0.17), followed by saponins occurring most in the rind (12.05 +/- 3.91) than the seed (10.17 +/- 0.63) and pulp (.13 +/- .01). The seed had the highest DPPH scavenging activity followed by the rind and pulp respectively. The seed also showed a higher reducing power and lipid peroxidation capacities than the other fruit parts suggesting a potent property for antioxidant activity in the fruit parts of C. lanatus. Conclusion: The findings imply that both seed and rind of C. lanatus can be good sources of nutritional, phytochemical and antioxidant components in addition to the pulp which is commonly consumed and these may be implicated in management of certain diseases with further evidential research.



2021 ◽  
Vol 11 (6) ◽  
pp. 42-51
Author(s):  
Kazi Layla Khaled ◽  
Rukshana Irani

The rapidly growing civilization and economy need the judicious usage of floral and faunal heritage. Acacia nilotica (Family: Fabaceae) is a beneficial plant species and each part of it exhibits numerous biological and pharmacological effects. The gum exudates of Acacia nilotica trees are underutilized plant products that can be explored for their potential as a therapeutic and curative agent. Its nutritional composition, interaction with anti-nutritional factors and antioxidants can determine its utility as a food. The present investigation was aimed to estimate the anti-nutritional factors and antioxidant activity of Acacia nilotica gum. It also focused on establishing a relationship of the obtained data with the ethnomedicinal and pharmacological properties claimed in the literature. The analysis was carried out using standard methods and protocols involving spectrophotometric and gravimetric principles. The anti-nutritional components like tannin, trypsin inhibitor, phytate, oxalate, total saponin, steroidal saponins, alkaloid content of Acacia nilotica gum was found to be 0.2369±0.0354 g tannic acid equivalent/100 g, 0.0108±0.0037 TIU/mg, 156.3333±9.4516 mg/100 g, 132.5±28.3152mg/100 g, 12.7183±6.7788 mg diosgenin equivalent /g, 0.0705±0.01 mg diosgenin equivalent /g, 0.1333±0.0577 g/100 g respectively. The amounts of total phenols and flavonoids was determined to be 8.0033±2.7211 mg of gallic acid equivalent/g sample, 0.0458±0.0186 mg quercetin equivalent /g sample respectively with a significant DPPH Scavenging activity. The results indicate that the quantity of anti-nutritional factors in gum is within the range of the contents of anti-nutritional factors found in commonly consumed foods. The substantial presence of phenol, flavonoids and DPPH activity in the gum indicates the presence of high antioxidant properties. The presence of anti-nutritional factors and antioxidants in favourable levels can impart diverse physiological responses. The present study concluded that Acacia nilotica gum can be used as a nutritious food commodity with a plethora of recuperative activities.



2021 ◽  
Vol 11 (6) ◽  
pp. 42-51
Author(s):  
Layla Khaled Kazi ◽  
Rukshana Irani

The rapidly growing civilization and economy need the judicious usage of floral and faunal heritage. Acacia nilotica (Family: Fabaceae) is a beneficial plant species and each part of it exhibits numerous biological and pharmacological effects. The gum exudates of Acacia nilotica trees are underutilized plant products that can be explored for their potential as a therapeutic and curative agent. Its nutritional composition, interaction with anti-nutritional factors and antioxidants can determine its utility as a food. The present investigation was aimed to estimate the anti-nutritional factors and antioxidant activity of Acacia nilotica gum. It also focused on establishing a relationship of the obtained data with the ethnomedicinal and pharmacological properties claimed in the literature. The analysis was carried out using standard methods and protocols involving spectrophotometric and gravimetric principles. The anti-nutritional components like tannin, trypsin inhibitor, phytate, oxalate, total saponin, steroidal saponins, alkaloid content of Acacia nilotica gum was found to be 0.2369±0.0354 g tannic acid equivalent/100 g, 0.0108±0.0037 TIU/mg, 156.3333±9.4516 mg/100 g, 132.5±28.3152mg/100 g, 12.7183±6.7788 mg diosgenin equivalent /g, 0.0705±0.01 mg diosgenin equivalent /g, 0.1333±0.0577 g/100 g respectively. The amounts of total phenols and flavonoids was determined to be 8.0033±2.7211 mg of gallic acid equivalent/g sample, 0.0458±0.0186 mg quercetin equivalent /g sample respectively with a significant DPPH Scavenging activity. The results indicate that the quantity of anti-nutritional factors in gum is within the range of the contents of anti-nutritional factors found in commonly consumed foods. The substantial presence of phenol, flavonoids and DPPH activity in the gum indicates the presence of high antioxidant properties. The presence of anti-nutritional factors and antioxidants in favourable levels can impart diverse physiological responses. The present study concluded that Acacia nilotica gum can be used as a nutritious food commodity with a plethora of recuperative activities.



Author(s):  
Is Fatimah ◽  
Putwi Widya Citradewi ◽  
Amri Yahya ◽  
Bambang Nugroho ◽  
Habibi Hidayat ◽  
...  

Abstract The composite of green synthesized gold nanoparticles (Au NPs)-doped hydroxyapatite (HA) has been prepared. The gold nanoparticles were produced via bioreduction of HAuCl4 with Clitoria ternatea flower extract, and utilized in the synthesis of hydroxyapatite using Ca(OH)2 and ammonium diphosphate as precursor. The aim of this research is to study the structural analysis of the composite and antibacterial activity test toward Eschericia coli, Staphylococcus aureus, Klebsiela pneumoniae, and Streptococcus pyogenes. In addition, the antioxidant activity was evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging method. The monitoring of gold nanoparticles formation was conducted by UV–vis spectroscopy and particle size analyses, meanwhile the synthesized composite was studied using X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. The results showed that homogeneously dispersed gold nanoparticles in HA structure was obtained with the particle size ranging at 5-80 nm. The nanocomposite demonstrated antibacterial activity against tested bacteria. The nanocomposite expressed an antioxidant activity as shown by the DPPH scavenging activity of 66 and 58% at the concentration of 100 μg/mL and 50 μg/mL, respectively.



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