Browsing by Author "Sahini, M. G."

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    Chemical profiling of Cannabis sativa from eleven Tanzanian regions
    (Elsevier, 2023) Mhando, H. B.; Sahini, M. G.; Makangara, J. J.
    The aim of this research was to investigate the chemical profiles of Cannabis sativa from 11 Tanzanian regions using preliminary tests as well as instrumental analyses with GC-MS and LCMS. Generally, all the seized samples tested positive for the presence of (Δ9-THC. The preliminary test with Duquenois method followed by chloroform addition revealed the presence of Δ9-tetrahydrocannabinol (Δ9-THC) in all the samples. GC-MS analyses of the samples revealed the presence of nine cannabinoids including Δ9-THC, Δ8-THC, cannabidivarol, cannabidiol, Δ9-tetrahydro cannabivarin (Δ9-THCV), cannabichromene, cannabinol, caryophyllene, and cannabicouramaronone, whereas LC-MS chemical profiling revealed the presence 24 chemical substances, including 4 cannabinoids, 15 different types of drugs and 5 amino acids. The Pwani region had the highest percentage composition of Δ9-THC (13.45%), the main psychoactive ingredient of Cannabis sativa, followed by Arusha (10.92%) and Singida (10.08%). The sample from Kilimanjaro had the lowest percentage of Δ9-THC (6.72%). Apart from cannabinoids, the majority of other chemical substances were found in the Dar es Salaam region sample, which could be attributed to the fact that the city is the epicenter of business rather than the cultivation area, implying that the samples were obtained from different sources and blended as a single package.
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    Extraction, phytochemistry, nutritional, and therapeutical potentials of rice bran oil: a review
    (Elsevier, 2023) Sahini, M. G.; Mutegoa, E.
    Background Rice is the third-most-produced crop in the world after corn and sugarcane, and due to its widespread production, its byproduct, rice bran, is widely available. One option to add value to this agricultural waste is by utilizing the potential phytochemicals in rice bran oil (RBO). Rice bran oil contains vital chemicals with medicinal and nutritional benefits. This paper examines the numerous ways that rice bran oil is extracted, the various phytochemicals that are present, as well as their potential for use in nutrition and medicine. Method A review of literatures released from 1996 to 2023 was done, with just one more item of literature from 1973. The search was performed in various online platforms such as Google Scholar, PubMed, Science Direct, Springer, Research4Life, Web of Science, SciFinder, Science Open etc. The more recent literatures were given more consideration, and the older literatures were only taken into account when they were absolutely essential in light of the subject at hand. Results Literature survey has revealed that the essential phytochemical components of RBO includes phenolic acids, flavonoids, γ-oryzanol and ferulic acids and vitamin E which constitutes tocopherols and tocotrienols as well as other unique fatty acids. Numerous therapeutical potentials, including antioxidant, anti-inflammatory, antidiabetic, and anticancer activities have been evidenced, thanks to these significant phytochemical ingredients. Additionally, numerous nutritional potentials of RBO have been researched and reported. Conclusions This review consolidates information on the developments in RBO extraction techniques, phytochemical components, and their nutritional and medicinal benefits. Also included are the approach towards processing of rice bran. Considering the abundance and potential of this agrowaste, the use of RBO based phytochemicals for nutritional and therapeutic purpose is worthy pursuing further.
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    High temperature X-ray diffraction and thermo-gravimetrical analysis of the cubic perovskite Ba0.5Sr0.5Co0.8Fe0.2O3−δ under different atmospheres
    (Royal Society of Chemistry, 2015) Sahini, M. G.; Tolchard, J. R.; Wiik, K.; Grande, T.
    Ba0.5Sr0.5Co0.8Fe0.2O3−δ (BSCF) with the cubic perovskite structure is known to be metastable at low temperature under an oxidizing atmosphere. Here, the thermal and chemical expansion of BSCF were studied by in situ high temperature powder X-ray diffraction and thermo-gravimetrical analysis (TGA) in partial pressure of oxygen ranging from an inert atmosphere (∼10−4 bar) to 10 bar O2. The BSCF powder, heat treated at 1000 °C and quenched to ambient temperature prior to the analysis, was shown to oxidize under an oxidizing atmosphere before thermal reduction took place. With decreasing partial pressure of oxygen the initial oxidation was suppressed and only reduction of Co/Fe and loss of oxygen were observed under an inert atmosphere. The thermal expansion of BSCF under different atmospheres was determined from the thermal evolution of the cubic unit cell parameter, demonstrating that the thermal expansion of BSCF depends on the atmosphere. Chemical expansion of BSCF was also estimated based on the diffraction data and thermo-gravimetrical analysis. A hexagonal perovskite phase, coexisting with the cubic BSCF polymorph, was observed to be formed above 600 °C during heating. The phase separation leading to the formation of the hexagonal polymorph was driven by oxidation, and the unit cell of the cubic BSCF was shown to decrease with increasing amounts of the hexagonal phase. The hexagonal phase disappeared upon further heating, accompanied with an expansion of the unit cell of the cubic BSCF.
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    In silico study of the inhibition of SARS-COV-2 viral cell entry by neem tree extracts
    (The Royal Society of Chemistry, 2021) Shadrack, D. M.; Vuai, S. A.; Sahini, M. G.; Onoka, I.
    The outbreak of COVID-19, caused by SARS-COV-2, is responsible for higher mortality and morbidity rates across the globe. Until now, there is no specific treatment of the disease and hospitalized patients are treated according to the symptoms they develop. Efforts to identify drugs and/or vaccines are ongoing processes. Natural products have shown great promise in the treatment of many viral related diseases. In this work, using in silico methods, bioactive compounds from the neem tree were investigated for their ability to block viral cell entry as spike RBD-ACE2 inhibitors. Azadirachtin H, quentin and margocin were identified as potential compounds that demonstrated viral cell entry inhibition properties. The structural re-orientation of azadirachtin H was observed as the mechanism for viral cell entry inhibition. These compounds possessed good harmacodynamic properties. The proposed molecules can serve as a starting point towards developing effective anti-SARS-COV-2 drugs targeting the inhibition of viral cell entry upon further in vitro and in vivo validation.