scholarly journals Antimicrobial Activity and Ellagitannins from Terminalia Ferdinandiana

Proceedings ◽  
2020 ◽  
Vol 36 (1) ◽  
pp. 81
Author(s):  
Akter ◽  
Hong ◽  
Netzel ◽  
Tinggi ◽  
Osborne ◽  
...  

Extracts were prepared from Terminalia ferdinandiana (Kakadu plum) fruits, leaves, seedcoats, and barks using accelerated solvent extraction with methanol, ethanol, water, acetone, and hexane. Antioxidant activity was assessed using the 2, 2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging assay and by determining the total phenolic content (TPC). Methanol fruit extracts had the strongest free radical scavenging activity and the highest TPC (12 g/100 g DW). The antimicrobial activity of all extracts (except hexane) was analysed by agar disc diffusion. Fruits and leaves showed larger inhibition zones against foodborne bacteria Listeria monocytogenes, Bacillus cereus, methicillin resistant Staphylococcus aureus, and clinical isolates of Pseudomonas aeruginosa compared to seedcoats and barks. The minimum inhibitory and minimum bactericidal concentration of the extracts ranged from 1.0 to 3.0 mg/mL against the tested microorganisms. Scanning electron microscopy images of bacteria treated with the extracts showed morphological changes consistent with cell death. A new UHPLC-MS/MS method for the determination of punicalagin and castalagin, bioactive ellagitannins, was developed and validated. Punicalagin contents in the fruits and leaves were 74 and 49 mg/100 g DW whilst castalagin contents were 1.1 and 0.8 mg/100 g DW. To the best of our knowledge, this is the first report about punicalagin and castalagin concentrations in Kakadu plum fruits and leaves. These initial findings are very promising in regards to the potential use of Kakadu plum fruit and leaf extracts as natural preservatives in the food industry.

Foods ◽  
2019 ◽  
Vol 8 (8) ◽  
pp. 281 ◽  
Author(s):  
Saleha Akter ◽  
Michael E. Netzel ◽  
Ujang Tinggi ◽  
Simone A. Osborne ◽  
Mary T. Fletcher ◽  
...  

Terminalia ferdinandiana (Kakadu plum) is a native Australian plant containing phytochemicals with antioxidant capacity. In the search for alternatives to synthetic preservatives, antioxidants from plants and herbs are increasingly being investigated for the preservation of food. In this study, extracts were prepared from Terminalia ferdinandiana fruit, leaves, seedcoats, and bark using different solvents. Hydrolysable and condensed tannin contents in the extracts were determined, as well as antioxidant capacity, by measuring the total phenolic content (TPC) and free radical scavenging activity using the 2, 2-diphenyl-1-picrylhydrazyl (DPPH) assay. Total phenolic content was higher in the fruits and barks with methanol extracts, containing the highest TPC, hydrolysable tannins, and DPPH-free radical scavenging capacity (12.2 ± 2.8 g/100 g dry weight (DW), 55 ± 2 mg/100 g DW, and 93% respectively). Saponins and condensed tannins were highest in bark extracts (7.0 ± 0.2 and 6.5 ± 0.7 g/100 g DW). The antimicrobial activity of extracts from fruit and leaves showed larger zones of inhibition, compared to seedcoats and barks, against the foodborne bacteria Listeria monocytogenes, Bacillus cereus, Methicillin resistant Staphylococcus aureus, and clinical isolates of Pseudomonas aeruginosa. The minimum inhibitory concentration and minimum bactericidal concentration in response to the different extracts ranged from 1.0 to 3.0 mg/mL. Scanning electron microscopy images of the treated bacteria showed morphological changes, leading to cell death. These results suggest that antioxidant rich extracts of Terminalia ferdinandiana fruits and leaves have potential applications as natural antimicrobials in food preservation.


Proceedings ◽  
2020 ◽  
Vol 70 (1) ◽  
pp. 48
Author(s):  
Anh Dao Thi Phan ◽  
Maral Seidi Damyeh ◽  
Saleha Akter ◽  
Mridusmita Chaliha ◽  
Michael E. Netzel ◽  
...  

Terminalia ferdinandiana (Kakadu plum), belonging to the family Combretaceae, is endemic to Australia and has a long history of traditional medicinal applications and food cuisine by the Australian Indigenous people. This study investigated the effects of maturity stages on the morphology, physicochemical parameters (total soluble solids (TSS), total acid content (TAC), and pH), soluble sugar profile and antioxidant capacity of Kakadu plum (KP) fruits that were wild harvested from different trees and classified into four different maturity stages (immature to mature). TSS and TAC were determined by standard assays/procedures, main sugars by UHPLC–MS/MS and antioxidant capacity (total phenolic content (TPC) and DPPH free radical scavenging capacity) by spectrophotometry. The results showed that soluble sugars (glucose, sucrose and fructose) ranging from 1.3 to 17.7% dry weight (DW), TSS (17.0–52.7% DW) and TAC (1.3–6.7% DW) increased with maturity. However, antioxidant capacity (TPC in the range of 7.4–21.9% DW and DPPH free radical scavenging capacity from 22 to 76% inhibition at the extract concentration of 20 g·L−1) did not follow the same trend as the one observed for soluble sugars, TSS and TAC. These differences were associated with the tree-to-tree variability as a consequence of the wild harvest condition. This study provides important information to both the KP industry and Indigenous enterprises regarding the selection of the appropriate maturity stage to harvest KP fruit to target for different markets (e.g., low-sugar vs. high-sugar fruit).


Medicines ◽  
2019 ◽  
Vol 6 (2) ◽  
pp. 70 ◽  
Author(s):  
Kusum Sai ◽  
Rashmi Thapa ◽  
Hari Prasad Devkota ◽  
Khem Raj Joshi

Background: More than 700 plants are reported to be used for medicinal purposes in Nepal; however, many of them are not studied for their scientific evidences. The aims of the present study were the estimation of the total phenolic and flavonoid contents, and the evaluation of the free radical scavenging and α-amylase inhibitory activities of five selected medicinal plants from western Nepal: Aeschynanthus parviflorus Wall. (Gesneriaceae), Buddleja asiatica Lour. (Loganiaceae), Carica papaya L. (Caricaceae), Drepanostachyum falcatum (Nees) Keng f. (Gramineae) and Spondias pinnata (L. f.) Kurz (Anacardiaceae). Methods: The total phenolic content (TPC) and total flavonoid content (TFC) were measured using Folin-Ciocalteu’s phenol reagent and aluminium chloride methods, respectively. A 1,1–diphenyl–2–picrylhydrazyl (DPPH) free radical scavenging assay was used to evaluate the free radical scavenging activity and an α-amylase inhibitory assay was carried out to determine the in vitro antidiabetic activity. Results: The phytochemical screening of five hydroalcoholic plant extracts revealed the presence of various secondary metabolites, including alkaloids, flavonoids, reducing sugars, saponins, terpenoids and tannins. The amounts of total phenolics and flavonoids were found to be the highest in B. asiatica leaf extract, which also showed the most potent free radical scavenging activity. Extract of C. papaya fruits showed the highest α-amylase inhibitory activity, whereas the extracts of B. asiatica leaves and S. pinnata leaves exhibited moderate activity. Conclusions: Some of the medicinal plants selected in this study showed high TPC and TFC values and potent bioactivities. These results may provide the scientific evidences of the traditional uses of these plants. However, further detailed studies on bioactive compounds isolation and identification and evaluation of in vivo pharmacological activities should be performed in future.


Foods ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1617
Author(s):  
Tina Kostka ◽  
Johanna Josefine Ostberg-Potthoff ◽  
Karlis Briviba ◽  
Seiichi Matsugo ◽  
Peter Winterhalter ◽  
...  

Secondary plant metabolites, e.g., polyphenols, are widely known as health-improving compounds that occur in natural functional foods such as pomegranates. While extracts generated from these fruits inhibit oxidative stress, the allocation of these effects to the different subgroups of substances, e.g., anthocyanins, “copigments” (polyphenols without anthocyanins), or polymeric compounds, is still unknown. Therefore, in the present study, polyphenols from pomegranate juice were extracted and separated into an anthocyanin and copigment fraction using adsorptive membrane chromatography. Phenolic compounds were determined by high performance liquid chromatography with photodiode array (HPLC–PDA) detection and HPLC-PDA electrospray ionization tandem mass spectrometry (HPLC–PDA–ESI–MS/MS), while the free radical scavenging activity of the pomegranate XAD‑7 extract and its fractions was evaluated by the Trolox equivalent antioxidant capacity (TEAC) assay and electron spin resonance (ESR) spectroscopy. Compared to juice, the total phenolic content and free radical scavenging potential was significantly higher in the pomegranate XAD-7 extract and its fractions. In comparison to the anthocyanin and copigment fraction, pomegranate XAD-7 extract showed the highest radical scavenging activity against galvinoxyl and DPPH radicals. Moreover, the enriched XAD-7 extract and its fractions were able to protect human hepatocellular HepG2 cells against oxidative stress induced by hydrogen peroxide. Overall, these results indicated that anthocyanins and copigments act together in reducing oxidative stress.


2015 ◽  
Vol 15 (1) ◽  
pp. 53-60 ◽  
Author(s):  
Bedraj Pandey ◽  
Meena Rajbhandari

Quercetin was isolated from ethyl acetate fraction of a methanol extract of the outer scale of onion by repeated sephadex LH-20 column chromatography. Methanol, 50% aqueous methanol and 70% aqueous acetone extracts of different parts of four medicinal plants, Ficus benghalensis, Elaeocarpus sphaericus, Ipomea carnea and Azeratum conyzoides were prepared and screened for total phenolic and flavonoid contents and free radical scavenging activity. The total phenolics contents were measured spectrophotometrically by using Folin-Ciocalteu reagent and total flavonoids content by using aluminum chloride colorimetric method. Free radical scavenging activity was evaluated using 2,2-diphenyl-1-picryl-hydrazyl (DPPH) assay. All the investigated medicinal plant extracts contained high amount of phenolics. The highest amount was detected in 70% aqueous acetone extract of E. sphaericus (298.8±9.03 mg GAE/g extract) and lowest amount in 50% aqueous methanol extract of F. benghalensis (6.7±0.73 mg GAE/g extract). The highest amount of flavonoid was found in methanol extract (78.2±2.72 mg quercetin/g extract) and the lowest amount was detected in 50% aqueous methanol extract (2.1±0.25 mg quercetin/g extract) of F. benghalensis. DPPH free radical scavenging assay was carried out only in 70% acetone extracts. The highest IC50 value was observed for E. sphaericus (34.0 μg/ml). A strong linear correlation between total phenolic content and antioxidant activity was found indicating that the major antioxidants are phenolics.DOI: http://dx.doi.org/10.3126/njst.v15i1.12010  Nepal Journal of Science and Technology Vol. 15, No.1 (2014) 53-60


Author(s):  
ISHFAQ KHAN ◽  
NEHA CHAUHAN ◽  
CHAUHAN PK ◽  
MOHD. AZHAR KHAN

Objectives: The main focus of the present study was to evaluate the antimicrobial efficacy (against oral pathogenic bacteria), free radical scavenging activity, and total phenolic and flavonoids content (TPC and TFC) of methanolic extract (ME) of J. regia obtained from Kashmir region. Methods: The plant part was collected and its ME was prepared. ME was subjected to antibacterial activity against oral bacteria such as Staphylococcus aureus, Streptococcus mutans, and Pseudomonas aeruginosa. The free radical scavenging activity was determined using 2,2-diphenyl- 1-picrylhydrazylhydrate (DPPH) assay. TPC and TFC were also determined using a standard curve equation of gallic acid and quercetin. A standard curve using different concentrations of gallic acid and quercetin was drawn from which the concentration of phenols in the test sample was calculated and expressed in mg/g. Results: The ME of J. regia was found effective against all the strains of microorganisms responsible for oral infection understudy. It was also observed that scavenging of DPPH increased with the increase in concentration for both standard ascorbic and methanolic bark extract of J. regia showing its antioxidant potential. The TPC and TFC of ME was found to be 43.35±0.079 and 17.28±0.125. Conclusions: The results obtained from the study clearly indicate that the walnut bark from Kashmir region can be a good candidate for employment as an antibacterial against oral pathogens. J. regia bark was found to be a good source of healthy compounds such as phenolic and flavonoids, suggesting that its bark could be useful to prevent diseases in which free radicals are present.


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