S. Okhale

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Papers by S. Okhale

Evaluation of the Inhibitive Properties of Silver Nanoparticles in Senna occidentalis Root Extract as Corrosion Inhibitor of Mild Steel

Tanzania Journal of Science

The use of nanoparticles as corrosion inhibitors has gained popularity because of its increased c... more The use of nanoparticles as corrosion inhibitors has gained popularity because of its increased corrosion efficiency due to increase surface to volume ratio. Nanoparticles which undergo physisorption/chemisorption to the corrosion metal surface and inhibit the corrosion efficiently also have low toxicity, low cost and easy production. In this research work, weight lost method was applied to study the inhibitive properties of silver nanoparticles (AgNPs) synthesized using Senna occidentalis root extract as environmentally benign corrosion inhibitor of mild steel in 0.5 M H2SO4 medium at 298 K and 308 K. It was observed that the corrosion rate of the steel sample decreases with increase in concentration of the silver nanoparticles but increased with rise in temperature. The highest inhibition efficiency of 65.59% was obtained at 308 K at the concentration of 5 gdm-3 and the least of 10.58% at the concentration of 1 gdm-3 at 308 K. The decrease in inhibition efficiency with rise in te...

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Leaf Epidermal Microscopy, Chemo-Microscopy and GC-MS Analyses of Three Ocimum Species from Nigeria

Asian Plant Research Journal

Comparative analyses of the leaf epidermal microscopy, chemo-microscopy and GCMS analysis of esse... more Comparative analyses of the leaf epidermal microscopy, chemo-microscopy and GCMS analysis of essential oils from three Ocimum species were analyzed. Ocimum belong to the family Lamiaceae. Leaf epidermal microscopy revealed anomocytic stomata in the species studied. Ocimum basilicum has anomocytic stomata on both surfaces but were more abundant on the lower surface; cell walls were wavy on the upper surface and had glandular trichomes on both surfaces. Ocimum canum had anomocytic stomata on both surfaces; cell walls were wavy and trichomes were glandular and non-glandular occurring on both surfaces but occurring more on the upper surface. The non-glandular trichomes are cone-shaped with pointed tip. Ocimum gratissimum has anomacytic stomata on both surfaces occurring more on the lower surface; the cell walls are curved on both surfaces and glandular trichomes occur on both surfaces which are more abundant on the lower surface. The glandular trichomes are radially flagellated in all t...

format_quoteThree Ocimum species were compared for microscopy and GC-MS analyses to support their pharmacological and culinary applications.format_quote

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Solid-liquid microwave-assisted extraction of bioactive extract recovery from Hunteria umbellata seeds: Non-mechanistic modelling, bi-objective optimization, HPLC finger printing and scale-up techno-economics with sensitivity analysis

Cleaner Chemical Engineering

Polyphenolic Extract Recovery from Azadirachta indica Leaves via Green Microwave-Assisted Extraction Technology: GA-ANFIS Prediction, Cuckoo Search Algorithm Optimization and ASPEN-Based Scale-Up Techno-economics

Process Integration and Optimization for Sustainability

This study presented hybrid genetic algorithm adaptive neuro-fuzzy inference system (GA-ANFIS) mo... more This study presented hybrid genetic algorithm adaptive neuro-fuzzy inference system (GA-ANFIS) modelling, cuckoo search algorithm optimization (CSAO), and scale-up techno-economics of Azadirachta indica leaves' microwave-assisted extraction (MAE). Box-Behnken design (BBD) of Design-Expert software was used to design MAE experiment using microwave power (520-1040 watts), extraction time (2-10 min), and solid-liquid ratio (0.4-1 g/ml) with two dependent variables: total phenolic content (TPC) and total extractible yield (TEY). Predictive GA-ANFIS and CSAO models for the MAE were implemented in Matlab 2019 environment. ASPEN base-case simulation and economic analysis for the phenolic extract recovery were achieved using CSAO optimal conditions. Process profitability uncertainty analyses were conducted with Monte Carlo simulation (MCS). BBD model results gave coefficient of determination (R 2) 0.949 and 0.952 for TEY and TPC, respectively. GA-ANFIS results gave training R 2 0.989, testing R 2 0.999 and training R 2 0.995, testing R 2 0.992 for the TEY and TPC prediction, respectively. CSA optimal region for the extract recovery gave microwave power 1040 W, extraction time 4 min, S/L ratio 0.4, TEY 33.3%, and TPC 10 mg GAE/g dw. ASPEN base-case techno-economic results gave batch size (1.49 kg), batch time (135 min), total capital investment ($211,172), annual production cost ($42,386), net present value ($150,298), payback time (5.84 years), and rate of return (17%). The MCS profitability risk analysis revealed that the associated uncertainty for the process is less than 1%. Therefore, this work shows that Azadirachta indica leaves extract production using green technology is feasible.

format_quoteTechno-economic analysis shows Azadirachta indica extract production is feasible, with a net present value of $150,298 and a payback time of 5.84 years.format_quote

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Evaluation Of Hplc-Uv-Dad And Antiproliferative Characteristics Of The Leaf Infusion Of Ximenia Americana Linn

Ximenia americana (X. americana) is reputable for the treatment of various ailments in Nigeria. T... more Ximenia americana (X. americana) is reputable for the treatment of various ailments in Nigeria. The hot aqueous extract of X. americana leaf (XA) was obtained by infusion. The antiproliferative potential of XA was evaluated employing Sorghum bicolor seed radicle as test subject over the period of 48-96 hours. The mean radicle lengths (mm), percentage inhibition and percentage growth were determined. XA was chemically characterized using colour reactions and high performance liquid chromatography with UV-diode array detector (HPLC-UV-DAD). Phytochemical investigation indicated the presence of tannins, saponins and flavonoids. HPLC analysis revealed thirteen peaks with rutin and ferullic acid eluting at 6.886 and 7.796 minute respectively. XA significantly (p < 0.0001) inhibited S. bicolor seed growth over a period of 48-96 h against the control seeds. At 96 h, XA dose-dependently inhibited seed growth, giving percentage inhibition of 23.24, 29.06, 30.68, 38.27, 49.57, 50.39, 64.60, 79.67 and 82.01% for seeds treated with 1 mg/ml, 2 mg/ml, 4 mg/ml, 8 mg/ml 16 mg/ml, 24 mg/ml, 32 mg/ml, 40 mg/ml and 48 mg/ml respectively with IC 50 of 24 mg/ml. Methotrexate 0.167 mg/ml used as positive control gave inhibition of 92.76% at 96 h. This result revealed the potential of XA to inhibit the growth of fast proliferating cells of S. bicolor seed radicle.

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Bioactive Extract Production from Citrullus Clocynthis Fruit via Microwave-Assisted Extraction: Experimental Optimization, Process Design and Economics with Uncertainty Quantification

Journal of Pharmaceutical Innovation

Pharmacognostic and Chromatographic Standardization of Calyptrochilum emarginatum (SW.) Schltr. (Orchidaceae)

Pharmacognostic and chromatographic evaluation of Calyptrochilum emarginatum (SW.) a potential dr... more Pharmacognostic and chromatographic evaluation of Calyptrochilum emarginatum (SW.) a potential drug plant belonging to the orchid family was carried out. High performance liquid chromatographic standardization of the methanol extract revealed sixteen compounds one of which had the same retention time 6.8 minutes as reference rutin. Thin layer chromatography of the hexane extract showed 11 spots one of which had Rf value of 0.5 same as β-sitosterol and the successive ethyl acetate extract gave 9 spots. Proximate analysis revealed moisture content of 11.9%, alcohol extractive value 1.4%, total ash 6.9%, water soluble ash 2.5% acid-insoluble ash 3.2% and water extractive value 13.8%. Microscopic evaluation of the leaf epidermis revealed anomocytic stomata which were only on the lower surface (hypostomatic), the epidermal cells were polygonal in shape on both adaxial (upper) and abaxial (lower) surfaces. Trichomes or trichome bases were not found on both surfaces. Keywords: Orchid, Caly...

Identification of Thymol as an Antitubercular Agent from Ocimum gratissimum Leaf Essential Oil

American Chemical Science Journal, 2015

Ocimum gratissimum consumed as a vegetable is used to treat cough, tuberculosis and dysentery in ... more Ocimum gratissimum consumed as a vegetable is used to treat cough, tuberculosis and dysentery in Nigeria. Hydro-distillation of the fresh leaves of O. gratissimum yielded a golden yellow essential oil 0.5% v/w which exhibited minimum inhibitory concentration (MIC) of 48 μg/ml against Mycobacterium bovis BCG strain. Activity-guided fractionation of the oil into neutral and acidic portions followed by column chromatography led to the isolation of a crystalline compound with MIC Original Research Article Okhale et al.; ACSj, 9(2): 1-6, 2015; Article no.ACSj.19141 2 of 9.8 μg/ml while the control drug isoniazid had MIC of 0.07 μg/ml. GC-MS and H NMR analyses revealed the bioactive crystalline compound to be thymol.

Annona senegalensis Persoon (Annonaceae): A review of its ethnomedicinal uses, biological activities and phytocompounds

Journal of Pharmacognosy and Phytochemistry, 2016

Annona senegalensis, also known as wild custard apple and wild soursop is a member of Annonaceae ... more Annona senegalensis, also known as wild custard apple and wild soursop is a member of Annonaceae family. It is a fruit tree native to Senegal and found in semi-arid to subhumid regions of Africa, with a long history of traditional use. Numerous ethnomedicinal uses have been attributed to different parts of A. senegalensis, as well as its use as food and food additives. All parts of the plant contain varying amounts of essential oils. Annogalene, annosenegalin, acetogenins, kaurenoic acid and (-)-roemerine are the major bioactive constituents of A. senegalensis. Biological activities of phytoconstituents from various parts of A. senegalensis include anticonvulsant, cytotoxic, antimicrobial, antispasmodic, anti-inflammatory and analgesic activities; others are antioxidant, antivenomous, hypnotic, anthelmintic, antiplasmodial, haemostatic, spermatogenic and insecticidal activities.

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Evaluation of chemical composition, cytostatic and anti-proliferative effects of ethanolic roots extract of Securidaca longepedunculata (Fresen)

Journal of Pharmacognosy and Phytochemistry