Synthesis, characterization, computational studies and DPPH scavenging activity of some triazatetracyclic derivatives

Author(s):  
F. Odame ◽  
Eric C. Hosten ◽  
R. Betz ◽  
J. Krause ◽  
Carminita L. Frost ◽  
...  
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.


Foods ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 59
Author(s):  
Janusz Malarz ◽  
Klaudia Michalska ◽  
Anna Stojakowska

The objective of the present study was to characterize chemical composition of hitherto unexamined aerial parts of Lactuca sativa var. angustana cv. Grüner Stern. In contrast to leafy and head varieties of the lettuces, asparagus lettuce grown in Europe is much less studied. Fractionation of a methanolic extract from leaves of L. sativa cv. Grüner Stern, supported with HPLC/DAD and 1H NMR analysis, led to the isolation and/or identification of numerous terpenoid and phenolic compounds, including five apocarotenoids—(-)-loliolide, (+)-dehydrovomifoliol, blumenol A, (6S,9S)-vomifoliol, and corchoionoside C; three sesquiterpene lactones; two lignans—((+)-syringaresinol and its 4-O-β-glucoside); five caffeic acid derivatives; and three flavonoids. Some of the compounds, to the best of our knowledge, have never been isolated from L. sativa before. Moreover, monolignols, phenolic acids and a tryptophan-derived alkaloid were found in the analyzed plant material. Stems, leaves and shoot tips of the asparagus lettuce were examined to assess their phenolics and sesquiterpene lactone content as well as DPPH scavenging activity. Another stem lettuce—L. sativa var. angustana cv. Karola, two cultivars of leafy lettuces and one species of wild lettuce—L. serriola, were also examined as a reference material using HPLC/DAD. The results have been discussed regarding our previous studies and the literature data available.


2018 ◽  
Vol 47 (4) ◽  
pp. 953-959
Author(s):  
Kishwar Jahan Shethi ◽  
Mohammad Zashim Uddin

To evaluate the antioxidant potential of less valued green leafy vegetables of Bangladesh, the methanolic extracts of Alternanthera sessilis, A. philoxeroides, A. paronychioides, Glinus oppositifolius and Portulaca oleracea were subjected to assay for total phenolic content, total flavonoid content and DPPH free radicle scavenging activity. Among the studied materials, A. sessilis showed the highest phenolic and flavonoid content. However, G. oppositifolius presented the lowest phenolic content (14.53 ± 0.48 mg of GAE/g of sample) and P. oleracea exhibited minimum (7.005 ± 0.25 mg of RUE/g of sample) flavonoid content. DPPH radical scavenging activity was found to increase with increase in the concentration of each individual material. A. philoxiroides (IC50 = 6.07 ± 0.27 μg/ml) was found as the most active in DPPH radical percentage inhibition, which was followed by A. sessilis (IC50 = 7.17 ± 0.67 μg/ml). Interestingly, A. paronychioides, in spite of having good amount of total phenolic and flavonoid content, showed less DPPH scavenging activity. No linear relationship was found to exist in case of the total phenolic, flavonoid content and DPPH scavenging activity among G. oppositifolius, P. oleracea and A. paronychioides. The results from different methods may differ substantially because each complex chemical reaction generates unique values. However, all the five plants exhibited creditable antioxidant activity and thus consumption of these vegetables may play important role in combating oxidative stresses and thereby help in retaining good health.


Author(s):  
Chaleeda Borompichaichartkul ◽  
Desi Sakawulan ◽  
Richard Archer

This study is aimed to improve the antioxidant property of instant coffee by using microencapsulation technique and spray drying. Concentrated coffee extract was mixed with Konjac glucomannan hydrolysate (KGMH) and Maltodextrin (MD). The mixture of coating material and coffee extract was then spray dried at 160 - 180 °C inlet air temperature and at 85-90 °C outlet air temperature. KGMH can preserve retention of phenolic compounds, DPPH scavenging activity and antioxidant activity of FRAP (p<0.05 of instrant coffee better than other treatment. Keywords: Hydrolysed Konjac Glucomannan; Spray Drying; Microencapsulation; Instant Coffee, Antioxidant 


Antioxidants ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 535 ◽  
Author(s):  
Francesco Gai ◽  
Magdalena Karamać ◽  
Michał A. Janiak ◽  
Ryszard Amarowicz ◽  
Pier Giorgio Peiretti

The aim of this study was to evaluate the differences in the antioxidant activity and phenolic profile of sunflower (Helianthus annuus L.) extracts obtained from the aerial parts of plants harvested at five growth stages. In vitro assays were used to determine the antioxidant activity, i.e., ABTS•+ and DPPH• scavenging activity, the ferric-reducing antioxidant power (FRAP) and the ability to inhibit β-carotene–linoleic acid emulsion oxidation. Phenolic compounds, such as mono- and dicaffeoylquinic acid isomers and caffeic acid hexose, were identified using the LC–TOF–MS/MS technique. The predominant compound during the growth cycle of the plant was 3,5-di-O-caffeoylquinic acid, whose content was the highest at the mid-flowering stage. The total phenolic content was also the highest in sunflowers at the mid-flowering stage. The main phenolic compound contents were closely correlated with ABTS•+ and DPPH• scavenging activity and FRAP. No significant correlation was found between the total phenolic content and the antioxidant activity in the emulsion system. The highest antiradical activity and FRAP were generally determined in older plants (mid-flowering and late flowering stages). In conclusion, the aerial parts of sunflowers, in particular those harvested at the mid-flowering stage, are a good plant material from which to obtain phenolic compound extracts, albeit mainly of one class (esters of caffeic acid and quinic acid), with high antioxidant activity.


2019 ◽  
Vol 2019 ◽  
pp. 1-9
Author(s):  
Enqin Xia ◽  
Lu Zhai ◽  
Zhigang Huang ◽  
Hairong Liang ◽  
Hui Yang ◽  
...  

DPPH• scavenging peptides (<3kDa) from underutilized Dunaliella salina protein were obtained by the following successive treatment, i.e., ultrasound extraction, simulated in vitro gastrointestinal digestion hydrolyzation, and membrane ultrafiltration classification. The optimal condition for ultrasound-assisted extraction was an ultrasound wave with 800 W of power treating a mixture of 60 mL of 1.0 mol L−1 NaOH and 2 g algae powder for 15 min. A high correlation (r=0.8146) between DPPH• scavenging activity and yield of the intact peptides showed their antioxidant capacity. Simulated in vitro digestion assay resulted in excellent DPPH• scavenging activity of the total peptide, amounting to (86.5 ± 10.1)%, comparing with the nondigestion samples at (46.8 ± 6.5)%. After fractionation, the 500-1000 Da fraction exhibited the highest DPPH• scavenging activity (81.2 ± 4.0)%, increasing 1.5 times due to digestion. Then, the 500-1000 Da fraction was analyzed by RPLC-Q Exactive HF mass spectrometer, and 4 novel peptides, i.e., Ile-Leu-Thr-Lys-Ala-Ala-Ile-Glu-Gly-Lys, Ile-Ile-Tyr-Phe-Gln-Gly-Lys, Asn-Asp-Pro-Ser-Thr-Val-Lys, and Thr-Val-Arg-Pro-Pro-Gln-Arg, were identified. From these amino acid sequences, hydrophobic residues accounted for 56%, which indicated their high antioxidant property. The results indicated that underutilized protein of Dunaliella salina could be a potential source of antioxidative peptides through simulated in vitro gastrointestinal digestion.


Molecules ◽  
2012 ◽  
Vol 17 (11) ◽  
pp. 12910-12924 ◽  
Author(s):  
Pu Jing ◽  
Shu-Juan Zhao ◽  
Wen-Jie Jian ◽  
Bing-Jun Qian ◽  
Ying Dong ◽  
...  

2020 ◽  
Vol 850 ◽  
pp. 230-235
Author(s):  
Inese Mieriņa ◽  
Darja Kostjuņina ◽  
Dārta Zelma Skrastiņa ◽  
Mara Jure

The most common cinnamoyl anilines are avenanthramides, which are natural antioxidants found in oats. This is a rather uncommon and not well-investigated group of antioxidants. This paper deals with 2-arylidenemalonic acid dianilides – cinnamoyl anilines which are decorated with an additional arylaminocarbonyl moiety at α-position of double bond. The DPPH scavenging activity of the title compounds is slightly lower in comparison to the corresponding cinnamoyl anilines. On the other hand, the title dianilides are more active than cinnamic acid anilides containing an additional carboxylic group in the α-position of double bond.


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.


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