Kinetic studies of the removal of methylene blue from aqueous solution by biochar derived from jackfruit peel.

Kinetic studies play an instrumental role in determining the most appropriate reaction rate model for industrial-scale applications. This study focuses on the kinetics of methylene blue (MB) adsorption from aqueous solutions by biochar derived from jackfruit peel. Various kinetic models, including pseudo-first-order (PFO), pseudo-second-order (PSO), intra-diffusion, and Elovich models, were applied to study MB adsorption kinetics of jackfruit peel biochar. The experiments were performed with two initial concentrations of MB (24.23 mg/L and 41.42 mg/L) over a span of 240 min. Our findings emphasized that the Elovich model provided the best fit of the experimental data for MB adsorption. When compared to other materials, biochar from jackfruit peel emerges as an eco-friendly adsorbent for dye decolorization, with potential applications in the treatment of environmental pollution.

Correction to "Simple Two-step Procedure for the Synthesis of Memantine Hydrochloride from 1,3-Dimethyl-adamantane".

[This corrects the article DOI: 10.1021/acsomega.0c01589.].

Simple Two-step Procedure for the Synthesis of Memantine Hydrochloride from 1,3-Dimethyl-adamantane.

Memantine hydrochloride is a medicine used for the treatment of Alzheimer's disease. A number of methods for the preparation of memantine hydrochloride have been reported. These procedures started from 1,3-dimethyl-adamantane by as many as using three or four reaction steps to produce memantine hydrochloride with overall yields ranging from 54 to 77%. In this article, a simple, concise two-step synthesis of memantine hydrochloride from 1,3-dimethyl-adamantane via N-formamido-3,5-dimethyl-adamantane with an improved overall yield of 83% was developed. In step 1, 3,5-dimethyl-adamantane was reacted with formamide and nitric acid to afford 1-formamido-3,5-dimethyl-adamantane in 98% yield, followed by hydrolysis of 1-formamido-3,5-dimethyl-adamantane with aq hydrochloride to give memantine hydrochloride in 85% yield. The procedure can be easily deployed at an industrial scale.

Synthesis and Bioactivity of Thiosemicarbazones Containing Adamantane Skeletons.

Reaction of 4-(1-adamantyl)-3-thiosemicarbazide (1) with numerous substituted acetophenones and benzaldehydes yielded the corresponding thiosemicarbazones containing adamantane skeletons. The synthesized compounds were evaluated for their in vitro activities against some Gram-positive and Gram-negative bacteria, and the fungus Candida albicans, and cytotoxicity against four cancer cell lines (Hep3B, HeLa, A549, and MCF-7). All of them showed good antifungal activity against Candida albicans. Compounds 2c, 2d, 2g, 2j and 3a, 3e, 3g displayed significant inhibitory activity against Enterococcus faecalis. Compounds 2a, 2e, 2h, 2k and 3j had moderate inhibitory potency against Staphylococcus aureus. Compounds 2a, 2e and 2g found so good inhibitory effect on Bacillus cereus. Compounds 2d and 2h, which contain (ortho) hydroxyl groups on the phenyl ring, were shown to be good candidates as potential agents for killing the tested cancer cell lines, i.e., Hep3B, A549, and MCF-7. Compounds 2a-c, 2f, 2g, 2j, 2k, 3g, and 3i were moderate inhibitors against MCF-7.

Synthesis and Bioactivity of Hydrazide-Hydrazones with the 1-Adamantyl-Carbonyl Moiety.

Reaction of 1-adamantyl carbohydrazide (1) with various substituted benzaldehydes and acetophenones yielded the corresponding hydrazide-hydrazones with a 1-adamantane carbonyl moiety. The new synthesized compounds were tested for activities against some Gram-negative and Gram-positive bacteria, and the fungus Candida albicans. Compounds 4a, 4b, 5a, and 5c displayed potential antibacterial activity against tested Gram-positive bacteria and C. albicans, while compounds 4e and 5e possessed cytotoxicity against tested human cancer cell lines.