A comprehensive review on Covid-19 Omicron (B.1.1.529) variant.

The world has been combating different variants of SARS-COV-19 since its first outbreak in Wuhan city. SARS-COV-19 is caused by the coronavirus. The corona virus mutates and becomes more transmissible than earlier variants as the day passes. Till 24 November 2021, SARS-COV-19 has four variants Alpha, Beta, Gamma, and Delta, respectively. Among them, the delta variant caused severe havoc across the world. South Africa registered a new variant with the World Health Organization (WHO) on 24 November 2021, which is much more transmissible than previous variants. The WHO classified it as a variant of concern (VOC) on 26 November 2021 and called it the Greek letter Omicron (B.1.1.529), the fifteenth letter in the alphabet. Here a serious attempt was made to comprehend the omicron variant's origin, nomenclature, characteristics, mutations, the difference between delta and omicron variant, epidemiology, transmission, clinical features, impact on immunity, immune evasion, vaccines efficacy, etc.

Facile synthesis of silver modified zinc oxide nanocomposite: An efficient visible light active nanomaterial for bacterial inhibition and dye degradation.

The present study reports the synthesis of silver (Ag) decorated zinc oxide (ZnO) nanocomposite via green synthesis method by using Acacia arabica plant leaves extract as both reducing and capping agent. The results clearly indicate a uniform distribution of Ag nanoparticles (NPs) over ZnO surface. Various analytical and spectroscopic techniques were used for investigating the formation and morphology of as-synthesized Ag/ZnO nanocomposites. Emergence of SPR at 424 and 378 nm confirmed the synthesis of AgNPs and ZnO respectively. The confirmation of elemental composition and crystal structure of prepared nanomaterials (NMs) was carried out via EDX and XRD analysis. Results obtained from HRTEM and SEM analysis indicated small sized spherically shaped NMs. The as-synthesized was checked for its photocatalytic activity towards degradation of MB in the presence as well as absence of light irradiation. Results of degradation study revealed that Ag/ZnO exhibits remarkable photocatalytic activity in the presence of light whereby removing 90% of MB within 80 min. Moreover, the antibacterial activity of synthesized nanocomposite was examined in both visible light and dark conditions. The experiment showed that nanomaterial depicts enhanced antibacterial activity in light in comparison to dark. The results showed that the inhibition diameter of Ag/ZnO nanocomposite in light was found to be 18 (±0.2), 22 (±0.3) against E. coli and S. aureus respectively. The inhibition zone of the said nanomaterial against E. coli and S. aureus in dark was 11 (±0.3), 14 (±0.5) respectively. These results conclude that activity is delivered both in the presence of visible light and dark but efficiency of antibacterial activity is found to be more in visible light in comparison.

Synthesis, Antibacterial, and Antioxidant Evaluation of Novel Series of Condensed Thiazoloquinazoline with Pyrido, Pyrano, and Benzol Moieties as Five- and Six-Membered Heterocycle Derivatives.

A novel synthesis of thiazolo[2,3-b]quinazolines 4(a-e), pyrido[2',3':4,5]thiazolo[2,3-b]quinazolines {5(a-e), 6(a-e), and 7(a-e)}, pyrano[2',3':4,5]thiazolo[2,3-b]quinazolines 8(a-e), and benzo[4,5]thiazolo[2,3-b]quinazoloine9(a-e) derivatives starting from 2-(Bis-methylsulfanyl-methylene)-5,5-dimethyl-cyclohexane-1,3-dione 2 as efficient α,α dioxoketen dithioacetal is reported and the synthetic approaches of these types of compounds will provide an innovative molecular framework to the designing of new active heterocyclic compounds. In our study, we also present optimization of the synthetic method along with a biological evaluation of these newly synthesized compounds as antioxidants and antibacterial agents against the bacterial strains, like S. aureus, E. coli, and P. aeruginosa. Among all the evaluated compounds, it was found that some showed significant antioxidant activity at 10 µg/mL while the others exhibited better antibacterial activity at 100 µg/mL. The results of this study showed that compound 6(c) possessed remarkable antibacterial activity, whereas compound 9(c) exhibited the highest efficacy as an antioxidant. The structures of the new synthetic compounds were elucidated by elemental analysis, IR, 1H-NMR, and 13C-NMR.

A survey on usage of personal care products especially cosmetics among university students in Saudi Arabia.

BACKGROUND: The harmful health effects of personal care products especially cosmetics have engulfed many societies of the world especially the female section without an alarm. OBJECTIVES: To estimate the prevalence of cosmetic usage and to assess the experiences of Saudi female undergraduate students in Wadi Al Dawasir province in an attempt to arouse general awareness among Saudi students about the harmful effects of the chemicals present therein. METHODOLOGY: It is a cross-sectional study carried out with a total of randomly selected 106 college students (female) at undergraduate level. Two colleges for girls of Prince Sattam Bin Abdul Aziz University at Wadi Al Dawasir region were included. Standard questionnaire was set in Arabic and English both. T test and data was analyzed using SPSS version 20. Chi-square/Fisher's exact tests and a P value of <0.05 were considered statistically significant. RESULTS: The overall prevalence of using cosmetics (makeup) and average age of first use of the cosmetics was found to be quite high. Statistical analysis shows that 69.8% students applied daily and 23.6% students applied twice to thrice daily. Consequently, this makes a gross percentage of 93.4% among college going Saudi students who applied makeup on daily basis. The findings have shown that 93.2% female and married medical students use cosmetics twice/thrice daily. Similarly, 6.8% female and married medical students use cosmetics once daily. The findings have shown that 82.9% female and unmarried medical students possess knowledge about cosmetics. Similarly, 17.1% female and married medical students possess knowledge about cosmetics. CONCLUSION: The usage of cosmetics was found to be extremely high among the college going Saudi students in Wadi Al Dawasir Region, Kingdom of Saudi Arabia. Un-awareness regarding the harmful effects of cosmetics was found to be high among these students.

New Pd(II) complexes of the synthesized 1-N-substituted thiosemicarbazones of 3-indole carboxaldehyde: characterization and antiamoebic assessment against E. histolytica.

Reaction of 3-indole carboxaldehyde with aminothiocarbonyl hydrazines resulted in the formation of 3-indole carboxaldehyde thiosemicarbazones (TSCs) 1-13. The synthesized thiosemicarbazones were used as ligands in the formation of [Pd(TSC)Cl2] complexes with palladium(II) metal ion precursor, [Pd(DMSO)2Cl2]. The chemical structures of all the compounds were established by electronic, IR, 1H NMR and 13C NMR spectral data. The structure of the complexes was further established by FABMS and DTA. It is concluded that the thione sulphur and the azomethine nitrogen atom of the ligands are bonded to the metal ion. The testing of the antiamoebic activity of these compounds against the protozoan parasite Entamoeba histolytica suggests that compounds 5, 3a, 5a and 8a-13a might be endowed with important antiamoebic properties since they showed less IC50 values than metronidazole. Moreover, compound 12a displays remarkable antiamoebic activity than metronidazole (IC50 values of 0.29 vs 1.81 microM, respectively). MTT assay showed that the compounds are non-toxic to human kidney epithelial cell line.

Novel Pd(II) complexes of 1-N-substituted 3-phenyl-2-pyrazoline derivatives and evaluation of antiamoebic activity.

Cyclization of Mannich base with N(4)-substituted thiosemicarbazides by different aliphatic, aromatic and cyclic amines afforded a series of new 1-N-substituted cyclised pyrazoline analogues of thiosemicarbazones (PYZ-TSC) 1-10. Reaction of [Pd(DMSO)(2)Cl(2)] with pyrazoline derivatives led to new palladium(II) complexes [Pd(PYZ-TSC)Cl(2)] 1a-10a. The structures of all the compounds were characterized by spectroscopic methods. It was concluded that the pyrazoline thiosemicarbazone derivatives have two chelating arms, one attached at the 2-position of the pyrazole ring (that is, N donor) and other (S donor) linked to the thiosemicarbazone branch. The determination of antiamoebic activity of all the compounds was done using HM1:IMSS strain of Entamoeba histolytica, among all the complexes, 8a showed the most promising IC(50)=0.37 microM vs. IC(50)=1.81 microM of metronidazole, the reference drug. MTT assay showed that the compounds are non-toxic to human kidney epithelial cell line.

Synthesis, characterization and antiamoebic activity of new indole-3-carboxaldehyde thiosemicarbazones and their Pd(II) complexes.

In continuation of our research on thiosemicarbazones and their metal complexes as antiamoebic agents, a new series of indole-3-carboxaldehyde thiosemicarbazones (TSC) 1-7 were prepared by condensing indole-3-carboxaldehyde with cycloalkylaminothiocarbonyl hydrazines. Their palladium(II) complexes of the [Pd(TSC)Cl2] type, were synthesized upon coordination with [Pd(DMSO)2Cl2]. The chemical structures of all the compounds were established by elemental analyses, electronic, IR, (1)H NMR and (13)C NMR spectral data. The structure of the complexes was further established by thermogravimetric analysis and FAB MS. Spectroscopic data revealed that thiosemicarbazones act as bidentate ligands, making use of thione sulphur and azomethine nitrogen atom for coordination to the Pd(II) ion. Among all the compounds evaluated for antiamoebic activity using HM1:IMSS strain of Entamoeba histolytica, all palladium complexes were found to be more active than their respective ligands. Moreover, ligand 5 and complexes 1a-3a, 5a and 7a showed antiamoebic activity, at lower IC(50) doses when compared to the reference drug metronidazole with IC(50)=1.81 microM.

Synthesis and antiamoebic activity of new oxime ether derivatives containing 2-acetylpyridine/2-acetylfuran.

Various oxime ether derivatives of 2-acetylpyridine and 2-acetylfuran series have been synthesised. O-Alkylation of the oximes by various alkylaminoethyl halides gave the corresponding oxime ether derivatives. The structures of these compounds were elucidated by UV, IR, 1H NMR, 13C NMR spectroscopic methods and elemental analyses. All the compounds were screened in vitro against the HM1:IMSS strain of Entamoeba histolytica. Based on the 50% inhibitory concentration (IC50) data of the 12 compounds evaluated, two of the 2-acetylpyridine series and two in the 2-acetylfuran series showed better IC50 values in vitro when compared with the standard amoebicidal drug, metronidazole. Moreover, one compound showed the most promising antiamoebic activity (IC50=0.5 microM vs IC50=1.9 microM of metronidazole).

Synthesis and antiamoebic activity of 3,7-dimethyl-pyrazolo[3,4-e][1,2,4] triazin-4-yl thiosemicarbazide derivatives.

A series of 3,7-dimethyl-pyrazolo[3,4-e][1,2,4]triazin-4-yl thiosemicarbazide derivatives 3-22 were prepared and evaluated in vitro against HM1:1MSS strain of Entamoeba histolytica, to identify the compounds for antiamoebic activity. They exhibited antiamoebic activity in the range (IC50=0.81-7.31microM). The results were compared to the activity of known drug metronidazole. It is inferred from the in vitro studies that the compounds 10, 11, 17 and 18 were found to be significantly better inhibitors of E. histolytica since IC50 values in the muM range elicited by these compounds are much lower than metronidazole. Besides, compounds 11 and 17 have shown the most promising antiamoebic activity (IC50=0.81microM of 11, IC50=0.84 microM of 17 versus IC50=1.81microM of metronidazole). The study suggests the possibility of developing triazine analogues as potential drug candidates for antiamoebic activity.

Synthesis and anti-amoebic activity of gold(I), ruthenium(II), and copper(II) complexes of metronidazole.

A series of Au, Ru, and Cu complexes of metronidazole (= [1-(2-hydroxyethyl)-2-methyl-5-nitro-1H-imidazole; 1) were prepared as highly potent anti-amoebic drugs. The complexes [Au(PPh3)(1)]PF6 (2), [Ru(1)2(Cl)2(H2O)2] (3), and [Cu(1)2(mu-Cl)(H2O)]2Cl2 (4) were readily synthesized from [Au(PPh3)Cl], RuCl3 x 3 H2O, and CuCl2 x 2 H2O, respectively. All complexes were thoroughly characterized by IR, UV/VIS, 1H-NMR, FAB-MS, elemental and thermogravimetric analyses, and, in the case of 4, also by X-ray crystallography (Fig. 1). All complexes were evaluated in vitro as growth inhibitors of Entamoeba histolytica (HM1:IMSS strain). Their IC50 values were in the range of 0.10-0.51 microM (Table 2), which makes these drugs, especially the Cu(II) complex 4, considerably more potent than uncomplexed metronidazole (1; IC50 = 1.81 microM), the current standard drug for the worldwide treatment of amoebiasis.

Synthesis and in vitro antiprotozoal activity of 5-nitrothiophene-2-carboxaldehyde thiosemicarbazone derivatives.

Several thiosemicarbazone derivatives of 5-nitrothiophene-2-carboxaldehyde were prepared by the simple process in which N(4)-thiosemicarbazone moiety was replaced by aliphatic, arylic and cyclic amine. Among these thiosemicarbazones compound 11 showed significant antiamoebic activity whereas compound 3 was more active antitrichomonal than the reference drug.