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This study investigates the photocatalytic degradation of Acid Blue Dye using zinc oxide nanoparticles synthesized from Senna siamea flower extracts (ZnO-S.S.). The synthesized nanoparticles were investigated using Transmission Emission Spectroscopy (TEM) and Scanning Electron Microscope (SEM), which made it possible to reveal the spherical shape of ZnO-S.S. nanoparticles. Themogravimetric Analysis – Differential Thermal Analysis (TGA-DTA) revealed high thermal stability of ZnO-S.S. with an insignificant weight loss as temperature increases from 600 °C to 846.9 °C. While Energy Dispersive X-ray analysis (EDX) reveals the elemental composition and atomic weight percentage as C (4.8%), O (11%), S (6%) and Zn (78.2%). The synthesized nanoparticles ZnO-S.S. used to degrade Acid Blue dye contaminated waste water under visible light irradiation. Exhibits an optimum degradation efficiency of 99% achieved in 150 minutes using a catalyst dosage of 150 mg at an initial acid blue concentration of 10 mg/L. The degradation process best conformed to the pseudo first order kinetics pathway. In conclusion the study established that the synthesized catalyst exhibits good efficiency and utility in degrading dye contaminated wastewater. However, further studies are recommended on the influence of other indicators such as light intensity, temperature and pH on the degradation process.

Green synthesis of metal oxide nanoparticles has gained prominence in recent years, resulting from the absence of toxic chemicals, low energy requirement, and eco-friendliness. This paper reports the green synthesis of zinc oxide nanoparticles (ZnO-NPs) using plant extract as a reducing agent. The ZnO-NPs were synthesized using Corchorus olitorius leaf extract and zinc acetate dihydrate, Zn (CH3COO)2.2H2O as precursor. The synthesized ZnO-NPs were characterized by the application of UV–Vis spectroscopy, Transmission Electron Microscopy (TEM), X-ray diffraction (XRD), Energy Dispersive X-ray Spectroscopy (EDX) and Fourier Transform Infrared Spectroscopy (FTIR). UV-vis indicated the reduction of zinc acetate dihydrate into ZnO-NPs by the leave extract. XRD and TEM revealed that the average size of the synthesized ZnO-NPs was 22 nm. The XRD pattern showed the hexagonal wurtzite crystalline nature of the synthesized ZnO-NPs. The elemental composition obtained from EDX showed that the synthesized ZnO-NPs are primarily composed of three elements: Zn (75.20 %), O (20.48.7%), and C (4.32). Examination of stretching and bonding in the ZnO-NPs using FT-IR revealed the presence of Zn-O bonding at 430.37–403.93 cm-1.

Abstract Background The increase in resistance of pathogenic organisms to the available chemotherapeutic agents are critical challenges in drug design and development, motivating researchers to look for novel compounds that can combat multidrug-resistant organisms. Recently, chalcones have been proved to be attractive moieties in drug discovery. Results Eight novel triphenylamine chalcones with different substitution patterns were successfully synthesized via the conventional Claisen–Schmidt condensation reaction in an alkaline medium at room temperature, and recrystallized using ethanol, the percentage yield of the compounds were between 30 and 92%. The structures of the synthesized chalcones were successfully characterized and confirmed using FT-IR, NMR spectroscopic and GC–MS spectrometric techniques. Conclusions The results of the biological studies showed that all the synthesized chalcones possess remarkable activities against the tested microbes, by showing a significant zone of inhibitions relative to that of the standard drugs used. The investigation revealed that 1b showed highest ZOI (30 mm), lowest MIC (12.5 µg/ml) and MBC/MFC (50 µg/ml) on Aspergillus niger. Therefore, displayed better antifungal potential as compared to the rest of the compounds, and can be a potential antifungal drug candidate.

Abstract Background Antibiotic resistance has risen as a result of a variety of conditions, prompting researchers to look for new compounds that can combat multidrug-resistant organisms. Over the last two decades, chalcones have been proved to be attractive moieties in drug discovery. Various substituted acetophenones, propiophenones and 4-(Diphenylamino) benzaldehyde were combined, using the Aldol condensation reaction to obtain eight novel triphenylamine chalcones. The compound’s antimicrobial properties were investigated (in vitro). With the non-mutant X-ray Human cytochrome P450 21A2 Hydroxyprogesterone retrieved from Protein Data Bank (PDB: 5VBU), molecular docking experiments were also carried out to analyse the most favourable conformation and find the orientation that maximizes interaction and minimize energy. Results Eight novel triphenylamine chalcones were successfully synthesized and recrystallized using ethanol, the percentage yield of the compounds were between 30 and 92%. The activity against different pathogens revealed that, all synthesized compounds showed marked antimicrobial activity against the tested microorganisms. (E)-3-(4-(diphenylamino)phenyl)-1-(3′-nitrophenyl)prop-2-en-1-one (1b) showed the highest zone of inhibition against Aspergillus niger, measuring 30 mm. The minimum inhibitory concentration (MIC) results revealed that (E)-1-(4′-bromophenyl)-3-(4-(diphenylamino)phenyl)prop-2-en-1-one (1a), (E)-3-(4-(diphenylamino)phenyl)-1-(3′-nitrophenyl)prop-2-en-1-one (1b), (E)-1-(4′-chlorophenyl)-3-(4-diphenylamino)phenyl)prop-2-en-1-one (1c), (E)-3-(4-diphenylamino)phenyl)-1-(4′-fluorophenyl)prop-2-en-1-one (1d) and (E)-4-(3-(diphenylamino)phenyl)-1-(4-fluorophenyl)-2-methylbut-3-en-1-one (2d) had the lowest MIC and inhibit Aspergillus niger growth at 12.5 µg/ml. All the synthesized compounds showed minimum bactericidal concentration and minimum fungicidal concentration (MBC/MFC) effect against Escherichia coli, Pseudomonas aeruginosa, Bacillus subtilis, Candida albicans and Aspergillus niger at 50 µg/ml. The docking studies of the synthesized chalcones with the binding site of the Human cytochrome P450 21A2 Hydroxyprogesterone (PDB: 5VBU) reveal that the binding affinity of the synthesized chalcones was in the range of − 11.2 to − 9.4 kcal/mol and showed highest binding score compared to that of the standard drugs (Fluconazole and Ciproflaxacin), with docking scores of − 7.9 and − 7.3 kcal/mol, respectively. Conclusions The investigation reveals that compound 1b showed the highest ZOI of 30 mm, least MIC and MBC/MFC of 12.5 and 50 µg/ml against Aspergillus niger, respectively. Therefore, displayed better antifungal potential as compared to the rest of the compounds. The outcome of the docking analysis revealed that (E)-4-(3-(diphenylamino)phenyl)-1-(4′-hydroxyphenyl)-2-methylbut-3-en-1-one (2a) showed a better binding affinity of -11.2 kcal/mol, which is higher than the remaining compounds and the control drugs (fluconazole and ciproflaxacin).

Abstract Background The unique and vast pharmacological activities of flavonoids have made them of research interest. This led to the use of various techniques to isolate and characterize them, intending to determine their potential health benefits. Main text The medicinal values of plant-based flavonoids that this literature review tends to summarize the pharmacological activities of these secondary metabolites from 22 selected plant families. The pharmacological shreds of evidence reported in the literature have proven that flavonoids have shown anti-cancer, anti-microbial, anti-oxidant, anti-inflammatory, anti-fungal, anti-ulcer, and anti-edematogenic activities. Out of these, 30% showed to have anti-oxidant activity, key in protecting the body against free radicals. Besides, 18% of the references showed anti-microbial and anti-cancer activities. Further literature reports indicated that flavonoids from these families exhibited anti-inflammatory and anti-edematogenic (9%), anti-viral and anti-ulcer (5%), anti-fungal, anti-nociceptive, and anti-histamine (2%). Conclusion The pharmacological activities of flavonoids from the various sources reviewed in this study show that the secondary metabolites could provide a scaffold for the development of potent anti-cancer drugs in the future.

This review aims at studying the phytochemistry and biological activities of some selected Apocynaceae plants. Eleven members of this family were reviewed for their phytochemistry and biological activities. Interestingly, the commonly isolated compounds reported from Mondia whitei (Hook.f.) Skeels, Secondatia floribunda A. DC, Carissa carandas, Tabernaemontana divaricate, Nerium oleander, Wrightia tinctoria, Tabernaemontana divaricate, Alstonia scholaris, Carrisa spinarum Linn, Thevetia peruviana and Caralluma lasiantha were triterpenoids, flavonoids, phytosterols, cardiac glycosides and lignans. All of them exhibited remarkable biological activities, mostly similar to each other. This review provides a detailed insight into the pharmacological activities of these selected members of this family.