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"Ahmed, Dildar"
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Comparative Analysis of Phenolics, Flavonoids, and Antioxidant and Antibacterial Potential of Methanolic, Hexanic and Aqueous Extracts from Adiantum caudatum Leaves
by
Ahmed, Dildar
,
Saeed, Ramsha
,
Khan, Muhammad
in
Adiantum caudatum
,
antibacterial
,
antioxidant
2015
In the quest for new medicines, the methanolic, hexanic, and aqueous extracts of Adiantum caudatum leaves, obtained by Soxhlet extraction, were analyzed for phenolic and flavonoid contents, and antioxidant and antimicrobial potential. TPCs (total phenolic content) of the methanolic, aqueous and hexanic extracts were 27.7, 21.1, and 16.7 μg of gallic acid equivalents per mL, respectively, while TFCs (total flavonoid content) were 13.2, 11.6, and 10.0 μg of rutin equivalents per mL, respectively. Antioxidant activities of the extracts in reducing power, FRAP (ferric reducing antioxidant power), phosphomolybdate and ABTS assays follow the same order of methanolic ˃ aqueous ˃ hexanic. In the DPPH assay, however, the aqueous extract exhibited a slightly higher antioxidant activity than the methanolic one. Methanol is therefore a better solvent to extract most of the antioxidant components from A. caudatum leaves. In lipid peroxidation inhibitory assay, the extracts showed almost similar behavior and their activity decreased gradually with time. The aqueous extract was the strongest inhibitor after two days, but the hexanic became the most potent after about three days. The antibacterial potential of the extracts was determined against Bacillus subtilis, Escherichia coli and Pseudomonas aeruginosa. Towards all the microbes, the aqueous extract was the most potent and the hexanic the least. P. aeruginosa was the most susceptible strain, while the aqueous and methanolic extracts exhibited a slightly higher efficacy against this pathogen than the drug amoxicillin. In conclusion, A. caudatum can potentially provide a remedy against disorders caused by oxidative stress and infections.
Journal Article
Extraction and Characterization of Microcrystalline Cellulose from Lagenaria siceraria Fruit Pedicles
by
Qamar, Muhammad Tariq
,
Alruwaili, Nabil K.
,
Ahmed, Dildar
in
Biopolymers
,
Bleaching
,
Caustic soda
2022
Microcrystalline cellulose (MCC) is a versatile polymer commonly employed in food, chemical, and biomedical formulations. Lagenaria siceraria (bottle gourd) fruit is consumed in many parts of the world, and its pedicle is discarded as waste. In the quest for a novel renewable source of the MCC, the present study investigates the extraction and characterization of MCC from the pedicle of Lagenaria siceraria fruits. The MCC was extracted by sequentially treating pedicles with water, alkali, bleaching (sodium chlorite), and dilute sulfuric acid (acid hydrolysis). The removal of associated impurities from pedicle fibers was confirmed by Fourier transform infrared analyses. The extracted MCC exhibited a characteristic crystalline structure of cellulose in X-ray diffraction with a 64.53% crystallinity index. The scanning electron microscopy (SEM) showed the variation in the morphology of the fibers and the formation of MCC of approximately 100 µm. The thermogravimetric analysis (TGA) indicated higher thermal stability of MCC. MCC production from biowaste (pedicle) holds potential for application as an emulsifier, stabilizer, and thickener in the chemical, pharmaceutical, and food industries.
Journal Article
Green extraction of bioactive compounds from Azadirachta indica in aqueous glycerol and modelling and optimisation by response surface methodology
by
Ahmed, Dildar
,
Anis, Nida
,
Anis, Mahnoor
in
2,2-diphenyl-1-picrylhydrazyl
,
antioxidant
,
Antioxidants
2022
Development of efficient and green methods for extracting bioactive phytochemicals has great industrial value. Increasing environmental sensitivity at the global level has tremendously enhanced the demand for such methods.
is a well-known medicinal tree. As glycerol has emerged as a green and safe extraction solvent for bioactive phytochemicals, this study aimed to investigate the efficacy of a glycerol–water solvent system to extract bioactive compounds from
leaves. Modelling and optimisation were carried out by using response surface methodology (RSM) as per the Box–Behnken design with three variables, namely, solvent concentration, time and temperature. The responses were total phenolic content (TPC), total flavonoid content (TFC), 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity and metal chelating activity (MCA). The optimum conditions found by numerical optimisation were a solvent concentration of 69.713%, a time period of 38.328 min and a temperature of 32.114 °C with the predicted values of TPC, TFC, %DPPH and %MCA as 5.27 mg gallic acid equivalents · g
DW (dry weight), 9.869 mg rutin equivalents · g
DW, 73.8% and 54.366%, respectively. The validation experiments showed almost the same results for each response with very low% errors (5.431–7.661). Increasing glycerol concentration in the extracting medium favoured the extraction of TPC, TFC and antioxidant phytochemicals, but for MCA, the trend was the opposite. In conclusion, 70% aqueous glycerol is an effective medium for the extraction of polyphenolic and antioxidant phytochemicals from
leaves. Extraction models suggested by RSM have high prospects to be used on a large industrial scale.
Journal Article
In Vitro Antidiabetic, Anti-Obesity and Antioxidant Analysis of Ocimum basilicum Aerial Biomass and in Silico Molecular Docking Simulations with Alpha-Amylase and Lipase Enzymes
2019
The present study explored phytochemicals, porcine pancreatic α-amylase (PPA) and lipase (PPL) inhibitory activities and antioxidant potential of polar and nonpolar extracts of the leaves and flowers of Ocimum basilicum and the in-silico mode of interaction between these enzymes and the major chemical constituents of the herb. The hexane extract (HE) and hydro-ethanolic extract (EE) obtained sequentially were used to estimate PPA and PPL inhibitory and antioxidant activities, total phenolic content (TPC) and total flavonoid content (TFC). Chemical constituents of the essential oils and HE were determined by GC-MS (Gas Chromatography-Mass Spectrometry). For PPA inhibition, IC50 (µg/mL) of the extracts were 0.27–0.37, which were close to 0.24 of acarbose, while for PPL inhibition, IC50 (µg/mL) of the extracts were 278.40–399.65, and that of Orlistat 145.72. The flowers EE was most potent antioxidant followed by leaves EE. The leaves EE had highest TPC and TFC followed of flowers EE. The essential oil of flowers had higher estragole (55%) than linalool (37%), while the essential oil of the leaves had higher linalool (42%) than estragole (38%). The HE of the flowers contained higher estragole (42%) than linalool (23%), while of the HE of the leaves too had higher estragole (65%) than linalool (18%). The in-silico molecular docking study showed linalool and estragole to have considerable PPA and PPL binding potential, which were further investigated through molecular dynamics simulations and binding free energy calculations. The PPA and PPL inhibitory activities of O. basilicum extracts and their notable antioxidant potential propose the herb as a multi-target complimentary medicine for diabetes, obesity and oxidative stress.
Journal Article
Phytochemical profiling, biological potential and In Silico identification of anticancerous compound from Pakistani pomegranate Peel
by
Hussain, Jamshid
,
Lin, Kuen-Song
,
Syed, Wajid
in
Anti-Bacterial Agents - chemistry
,
Anti-Bacterial Agents - pharmacology
,
antidiabetic
2025
The increasing antimicrobial resistance and recurrence is a major public health concern leading to high rates of morbidity and mortality worldwide. Furthermore, free radicals induced damage led to oxidative diseases such as cancer and diabetes.Therefore, finding safe and effective antimicrobial and antioxidant agents is vital. Pomegranate peel, constituting 60% of the total fruit's weight, is largely disposed despite its known benefits in traditional medicine. The current study aimed to determine the chemical constituents and biological activities of the methanolic extracts of peels of three pomegranate varieties [wild (PPE-1), white (PPE-2), and red (PPE-3)]. Phytochemicals analysis were performed using UV-vis spectrophotometry, gas chromatography-mass spectroscopy (GC-MS), and high-performance liquid chromatography (HPLC). The antioxidant potentials were determined via 2,2-diphenyl-1-picrylhydrazyl scavenging and phosphomolybdate (ABTS) assay and In Vitro antidiabetic activity was assessed by α-amylase inhibition assay. The antibacterial activity was assesed against three most dominant pathogens including E. coli, Staphylococcus aureus and Staphylococcus epidermidis by disc diffusion. The total phenolics, flavonoid, and tannin contents were highest in PPE-1 followed by PPE-2 and PPE-3. Among the polyphenol, chlorogenic acid was found in substantial concentration in all extracts. The GC-MS analysis identified 13 distinct compounds with the notable presence of 5-(hydroxymethyl) furan-2-carbaldehyde. All varieties exhibited significant antioxidants, antibacterial and antidiabetics, but the PPE-1 showed the highest activities. Docking studies revealed that chlorogenic acid was a strong inhibitor of Cyclooxygenase-II (COX-II) indicating anti-inflammatory and anticancerous potential. The study revealed that pomegranate peels have promising biological potentials such as antioxidants, antidiabetic, and antimicrobial, suggesting their role in drug developments.
Journal Article
Examining the Impact of External Debt, Natural Resources, Foreign Direct Investment, and Economic Growth on Ecological Sustainability in Brazil
by
Saleem, Saleem Haji
,
Samour, Ahmed
,
Ahmed, Dildar Haydar
in
Agreements
,
Alternative energy sources
,
Brazil
2024
Although some recent papers have explored the impacts of external debt on environmental sustainability, the impacts of external debt on the load capacity factor (LCF) have been ignored. In this regard, this work aims to examine the influence of renewable energy, FDI, and external debt on the LCF in Brazil over the period 1970–2021; this indicator implies the country’s strength to promote the population based on current lifestyles. This paper uses the novel augmented autoregressive distributive lag (A-ARDL) technique. The findings from the A-ARDL show that renewable energy positively influenced ecological sustainability by promoting the LCF by 0.451% in the short run and 0.038% in the long run. In addition, the findings show that an increase in the rent of natural resources promotes the LCF. In contrast, the outcomes illustrate that an increase in the external debt led to an adverse impact on ecological sustainability by decreasing the level of LCF by 0.093% in the short run and 0.162% in the long run. Furthermore, the findings demonstrated that FDI negatively affects the ecological sustainability quality by reducing the LCF in the country. The study provides beneficial recommendations to policymakers in Brazil for achieving sustainable development in Brazil.
Journal Article
Use of Neem leaves as soil amendment for the control of collar rot disease of chickpea
by
Javaid, Arshad
,
Al-Taie, Azher Hameed
,
Ahmed, Dildar
in
Azadirachta indica
,
Bioassays
,
Biomass
2020
Chickpea (
Cicer arietinum
L.) is an important grain legume that is attacked by the fungal pathogen,
Sclerotium rolfsii
, responsible for collar rot disease. In the present study, the pathogen was isolated from diseased chickpea seedlings and identified on molecular basis using internal transcribed spacer (ITS) and β-tubulin markers. To control this pathogen, an in vivo study was carried out, using Neem (
Azadirachta indica
A. Juss.) leaf dry biomass (1, 2, and 3%) as soil amendment
.
A broad-spectrum fungicide mancozeb was selected as a reference and the data regarding plant growth and mortality rates were calculated. In positive control, the highest seedling mortality (56%) was recorded in comparison to negative control (0%) after 30 days of sowing. In 1, 2, and 3% concentrations of
A. indica
dry leaf biomass, the seedling mortalities were 49, 38, and 38%, respectively. On the other hand, the mancozeb-treated seedlings showed the lowest plant mortality rate (28%). Soil treatments with mancozeb as well as with 1 and 2% leaf biomass concentrations showed marked differences in root and shoot dry biomasses over positive control. In a laboratory bioassay, methanolic leaf extract of Neem of 0.5 to 3.5% concentrations reduced biomass of
S. rolfsii
by 86–90% over control. The present study concluded that 2%
A. indica
leaf amendment was the most useful concentration for management of collar rot disease of chickpea.
Journal Article
Optimization of solvent-free microwave-assisted extraction of antioxidant compounds from Lagenaria siceraria fruit by response surface methodology
by
Aydar, Alev Yüksel
,
Tariq Qamar, Muhammad
,
Ahmed, Dildar
in
2,2-diphenyl-1-picrylhydrazyl
,
antioxidant
,
antioxidant activity
2022
(bottle gourd) fruit is highly celebrated for its nutritional as well as therapeutic properties. The present study was undertaken with the aim of exploring an efficient green solvent-free microwave-assisted extraction method for bioactives from this fruit. Optimization was done according to response surface methodology (RSM), where microwave power (W) and time (s) were independent factors, and percent extraction yield, total phenolic content (TPC), total flavonoid content (TFC), 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity, ferric reducing antioxidant potential (FRAP) and iron chelating activity (ICA) were the responses. TPC, TFC, DPPH radical scavenging activity, FRAP and ICA were highest at 480 W and 60 s. The TPC was 288.9 mg GAE · g
DW (milligram gallic acid equivalent per gram dry weight), TFC was 214.1 mg RE · g
(rutin equivalent per gram DW), anti-radical activity was 32.96%, FRAP was 289.7 mg AAE · g
(mg ascorbic acid equivalents per gram) and ICA was 19.52%. The results of the study thus demonstrate that the solvent-free microwave-assisted extraction method, which utilised an optimum power of 480 W and a time of 60 s, is an effective and green method for extraction of antioxidant compounds from bottle gourd fruit.
Journal Article
Fiscal Policy, Oil Price, Foreign Direct Investment, and Renewable Energy—A Path to Sustainable Development in South Africa
by
Maarof, Mamon Adam
,
Samour, Ahmed
,
Ahmed, Dildar Haydar
in
Alternative energy sources
,
Carbon dioxide
,
Causality
2023
Since South Africa is in pursuit of accomplishing the 2030 Sustainable Development Goals, it has become pertinent to accelerate the desired energy transition. Against this background, this work aims to evaluate the effects of oil prices, fiscal policy, and foreign direct investment on renewable energy consumption in South Africa from 1979 to 2019. Using the novel Augmented Autoregressive Distributed Lag approach, this study finds that economic growth and taxation revenues positively promote renewable energy in South Africa. In contrast, the findings show that an increase in oil prices has a negative impact on renewable energy in both short and long periods. Likewise, the research shows that foreign direct investment was not found to enhance renewable energy. The findings from fully modified-OLS, dynamic ordinary least squares, and canonical cointegrating regression models corroborate the findings of the Autoregressive Distributed Lag method. For the Granger causality inference, the findings demonstrate that there is a one-way causal connection detected from economic growth to the consumption of renewable energy. Based on these outcomes, a policy framework has been offered to help South Africa to attain the sustainable development goals.
Journal Article
Adapting multilingual vision language transformers for low-resource Urdu optical character recognition (OCR)
by
Shaiq, Mohammad Daniyal
,
Naeem, M. Asif
,
Cheema, Musa Dildar Ahmed
in
Computational linguistics
,
Data Mining and Machine Learning
,
Data Science
2024
In the realm of digitizing written content, the challenges posed by low-resource languages are noteworthy. These languages, often lacking in comprehensive linguistic resources, require specialized attention to develop robust systems for accurate optical character recognition (OCR). This article addresses the significance of focusing on such languages and introduces ViLanOCR, an innovative bilingual OCR system tailored for Urdu and English. Unlike existing systems, which struggle with the intricacies of low-resource languages, ViLanOCR leverages advanced multilingual transformer-based language models to achieve superior performances. The proposed approach is evaluated using the character error rate (CER) metric and achieves state-of-the-art results on the Urdu UHWR dataset, with a CER of 1.1%. The experimental results demonstrate the effectiveness of the proposed approach, surpassing state of the-art baselines in Urdu handwriting digitization.
Journal Article