European Journal of Chemistry

The 4-fluoro-N-(1,3-dioxoisoindolin-2-yl)benzamide was synthesized by the reaction of 4-fluorobenzohydrazide with phthalic anhydride in acetic acid. The compound was characterized by analytical instruments like FT-IR and NMR. The three-dimensional structure of the title compound was further confirmed by single-crystal X-ray diffraction study. In addition to the experimental study, theoretical calculations were performed to explore the molecular structure in order to analyze experimental and theoretical findings. The title compound crystallizes in the monoclinic space group P2₁/n as determined by the X-ray diffraction investigation, crystal data for C₁₅H₉FN₂O₃·H₂O: a = 14.094(6) Å, b = 7.248(3) Å, c = 14.517(6) Å, β = 105.116(14)°, V = 1431.6(10) Å³, Z = 4, T = 298(2) K, μ(MoKα) = 0.112 mm^-1, Dcalc = 1.402 g/cm³, 37521 reflections measured (4.684° ≤ 2Θ ≤ 60.6°), 4225 unique (R_int = 0.0517, R_sigma = 0.0311) that were used in all calculations. The final R₁ was 0.0537 (I > 2σ(I)) and wR₂ was 0.1501 (all data). The N-H···O and O-H···O hydrogen bonds linking molecules in the crystal form a three-dimensional framework structure. The electronic states and molecular properties of the title compound were determined using computational studies, like density functional theory and Hirshfeld surface analysis.

The current research includes the synthesis and crystallographic characterization of 2-phenylaminotetrahydro-1,3-thiazepine hydrochloride (HPAT) and 2-phenyliminohexa- hydro-1,3-thiazepine (PIT) compounds. 2-Phenylaminotetrahydro-1,3-thiazepine hydro-chloride was synthesized by cyclization of 1-(4-hydroxybutyl)-3-phenylthiourea in an acidic condition. The second compound, 2-phenyliminohexahydro-1,3-thiazepine, was obtained by neutralizing 2-phenylaminotetrahydro-1,3-thiazepine hydrochloride with sodium hydrocarbonate. Both compounds were characterized by the single-crystal X-ray diffraction method. Crystal data for C₁₁H₁₇N₂OClS (HPAT): orthorhombic, space group P2₁2₁2₁ (no. 19), a = 4.97183(14) Å, b = 15.1169(4) Å, c = 17.7376(5) Å, V = 1333.14(6) Å³, Z = 4, μ(CuKα) = 3.859 mm^-1, Dcalc = 1.299 g/cm³, 9243 reflections measured (7.684° ≤ 2Θ ≤ 152.042°), 2749 unique (R_int = 0.0314, R_sigma = 0.0255) which were used in all calculations. The final R₁ was 0.0351 (I > 2σ(I)) and wR₂ was 0.0911 (all data). Crystal data for C₁₁H₁₄N₂S (PIT): monoclinic, space group P2₁/n (no. 14), a = 9.6303(9) Å, b = 9.8938(6) Å, c = 11.5627(9) Å, β = 103.419(8)°, V = 1071.62(14) Å³, Z = 4, μ(CuKα) = 2.357 mm^-1, Dcalc = 1.279 g/cm³, 3938 reflections measured (10.798° ≤ 2Θ ≤ 152.328°), 2172 unique (R_int = 0.0288, R_sigma = 0.0330) that were used in all calculations. The final R₁ was 0.0431 (I > 2σ(I)) and wR₂ was 0.1219 (all data). The asymmetric unit of HPAT contains one protonated amine, one chlorine anion, and one water molecule. Chlorine anion and water molecules play the role of the bridge in chain formation along the a- and b-axis through H-bonds with N-H hydrogen atoms. Furthermore, the Hirshfeld surface analyses are performed to determine the nature of the intermolecular contacts stabilizing the crystal structures of 2-phenylaminotetrahydro-1,3-thiazepine hydrochloride and 2-phenyliminohexahydro-1,3-thiazepine.

A new class of probes was synthesized using a simple and efficient synthetic protocol. These compounds (PTZ-6(a-e)) have the phenothiazine (PTZ) moiety as the electron donor (D) and substituted aldehydes along with the acrylonitrile group, which acts as the electron acceptor (A), thus making D-π-A push-pull system. The structures of the newly synthesized series of small organic target molecules PTZ-6(a-e) were investigated and confirmed by spectros-copic techniques. The optical/solvatochromic properties were studied in detail by UV-vis absorption and fluorescence spectroscopy, because the molecules have shown good solubility in organic solvents. The density functional theory (DFT) model with the CAM-B3LYP function is utilized to study the photophysical properties of the probes, as these probes exhibited orange-to-red emission. Optical band gap values ranged from 2.32 to 2.50 eV, and these probes exhibited good thermal stability with a melting temperature of 136 to 198 °C and a T_5d temperature range from 335 to 354 °C. The cyclic voltammetry study confirms that the E_ox^onset values of the target compounds are 0.80 eV. The quantum yields (Φ) of the probes are measured experimentally in ethanol and the Stokes shifts are observed to be in the range of 4846-9430 cm^-1. The results displayed that novel (D-A-D) chromophores could play an important role in organic optoelectronics.

The novel coronavirus (COVID-19) has triggered a major human turmoil worldwide by posing challenges regarding infection prevention, disease diagnosis, and treatment. Several drugs including remdesivir (RDV), hydroxychloroquine (HCQ), and others are being used to treat COVID-19, although these are not specifically proven drugs. Thus, it is very critical to understand COVID-19 drug targets and their interactions with candidate drugs. Here, we attempted in silico screening of ten quinoline analogs (Q1-Q10) against the five main proteases of SARS-CoV-2 by docking and dynamics analysis. The prediction of the ADMET profile showed that the best docked quinolines are safe and possess drug-like properties. The molecular interaction and binding affinity of these small molecules were determined with respect to the five protease (M^pro) targets of SARS-CoV-2 (PDB ID: 6LU7, 6W63, 6M03, 6Y84 and 6YB7). The study indicated that the quinoline ligands Q4, Q5, Q6, Q7, Q8, Q9, and Q10as probable inhibitors against SARS-CoV-2 M^pro and showed favorable binding interaction with the amino acid Glu166 of 6Y84, 6LU7and 6M03. Furthermore, Q9 has a highly significant docking score and binding affinity with all fiveCOVID-19 receptors having a minimum of two H-bonds, which is remarkable compared to HCQ, RDV, and other quinolines. The dynamics simulation analysis of this potent drug candidate Q9 with 6LU7 indicated high stability of the complex. In conclusion, our findings indicate that all of these quinolines in general possess good binding affinity and Q9 can serve as a good quinoline scaffold for the design of new antiviral agents to target the active site of SARS-CoV-2 M^Pro.

Density-functional theory (DFT) calculations at the LC-wHPBE/6-311++G(d,p) level found that the textbook three-step nitration mechanism of benzene in mixed acids was seriously wrong. Step 1 of generating nitronium ion (NO₂⁺) is not spontaneous, the NO₂⁺ is generated by Lewis collision, and needs to overcome a barrier E_a = 18 or 22 kcal/mol in mixed acid or in nitric acid. Obtaining the E_a of the Lewis collision by quantum chemical calculations is a highlight of the study. The reaction system (NO₂⁺ + H₂O) + HSO₄^⎺ or + NO₃^⎺ or + nH₂O (n ≥ 1) can make NO₂⁺ spontaneously change to HNO₃ through a poly(≥3)-molecular acidification. Sulfuric acid can greatly reduce [H₂O] and increase [NO₂⁺]. Therefore, the nitration rate in mixed acid is much faster than that in nitric acid. Step 2, C₆H₆ + NO₂⁺, is an electrophilic addition, follows the transition state theory, and needs to overcome a low barrier, ΔE* = 7 kcal/mol. The product of Step 2 is the σ-complex C₆H₆-NO₂⁺. The essence of the electrophilic addition is the transfer of HOMO-1 electrons of C₆H₆ to LUMO of NO₂⁺. Step 3 is a spontaneous Lewis acid-base neutralization without any barrier, and generates the target product nitrobenzene C₆H₅NO₂. NO₂⁺ and σ-complex are the two active intermediates in nitration. The benzene nitration rate control step is not Step 2 of generating σ-complex, but is Step 1 to generate NO₂⁺. The DFT calculation obtains the barriers E_a and ΔE*, the reaction heats ΔH_σ and ΔH_p of each step of the nitration, resulting in the total nitration reaction heat ΔH = -35 kcal/mol. It is consistent with the experimental ΔH = -34 kcal/mol. Based on the results, a corrected benzene nitration three-step mechanism proposed.

The electronic absorption spectra of morpholine and its five morpholine complexes have been studied in different solvents of various polarities. The regression and correlation coefficients have been calculated with the SPSS program. Solvation energy relationships were deduced from spectral shifts and correlated with solvent parameters α (solvent hydrogen bond donor acidity), β (solvent hydrogen bond acceptor basicity), and π* (dipolarity/polarizability). The percentage contributions of the calculated solvatochromic parameters show that classic solvation effects play a major role in explaining the spectral shifts in all investigated complexes. The blue shift of [Fe(MOR)₃Cl₃]·4H₂O, [Ni(MOR)₄Cl₂]·4H₂O, and [Cu(MOR)₄Cl₂]·6H₂O complexes is due to the formation of hydrogen bonds, which suggests the stabilization of the ground electronic state compared with the excited state. [CuNi(MOR)₂Cl₄]·4H₂O and [CuZn(MOR)₃Cl₄]·2H₂O are mixed metal complexes that suffer a red shift due to the solute-solvent interactions, which causes stabilization of the excited solute state with increasing solvent polarity. The bands are affected by specific solute-solvent interactions including hydrogen bond donor ability (acidity) and hydrogen bond acceptor ability (basicity) and nonspecific solute-solvent interactions including electromagnetic interaction between the dipole moments of solute and polar solvents.

A new fast and simple selective method for the simultaneous determination of lisinopril dihydrate and amlodipine in combined drugs was developed using the fourth derivative spectrum method, based on the zero-crossing-point technique for the determination of compounds in drugs. The wavelength values for lisinopril dihydrate and amlodipine in solvent medium were found to be (203, 207, and 231 nm) and (215, 254, and 277 nm), respectively, with the average obeying Beer’s law in the range of lisinopril dihydrate 2.0 to 45.0 µg/mL and amlodipine 2.0 to 35.0 µg/mL. Lisinopril dihydrate has molar absorptivity regions (9227.76-11700.28 L/mol.cm, 203 nm), (15320.74-20795.59 L/mol.cm, 207 nm), and (2207.60-3311.40 L/mol.cm, 231 nm), while amlodipine (5886.72-10914.96 L/mol.cm, 215 nm), (5518.8-6418.16 L/mol.cm, 254 nm) and (1676.08-1921.36 L/mol.cm, 277 nm). The recovery rate of lisinopril dihydrate in the pharmaceutical dosage forms range was 95.13 to 102.60% and amlodipine 95.14 to 102.80%. The results of the relative error showed that the interferences did not affect the method of estimating these compounds. The proposed method has been successfully applied to estimate pharmaceutical dosage forms.

In this study, an analysis of pesticide residues was performed using a gas chromatography/ electron impact mass spectrometer (GC/EI-MS) to qualitatively assess and characterize pesticide residues in khat leaves sampled from selected agricultural farms in Meru County, Kenya. A solid-phase microextraction (SPME) procedure followed by GC/EI-MS analysis led to the detection and identification of six pesticide compounds from the sample-ion chromatograms. They include cypermethrin, acephate, cyhalothrin, cyfluthrin, chlorpyrifos, and chlorfenvinphos. The prevalence rate of pesticide contamination was determined to be 54.5% of the sample size. Of the identified pesticide residues, 50% were compounds based on pyrethroids and the other 50% were based on organophosphate. Four of the six identified pesticides were chlorinated compounds. A quick, easy, cheap, effective, rugged, and safe UV-vis double beam spectrophotometric technique based on copper (II) chelation reactions leading to colored copper pesticide complexes was developed, validated, and applied to quantify and compare the levels of selected pesticide compounds found in the khat samples. UV-vis wavelength-scan measurements performed on pesticide compounds chelated with copper (II) ions revealed maximum absorption of Cu-cypermethrin and Cu-acephate at 321 and 207 nm, respectively. The standards calibration curves developed from the UV-Vis quantitation technique showed excellent linearity in the concentration range of 0.5-10.0 µg/L (R² = 0.99) for both cypermethrin and acephate standards. The estimated limits of quantification (LOQ) were 0.25-0.26 µg/L, respectively. The UV-Vis quantitation results from the selected samples (in which residues were confirmed to be present) revealed that acephate (an organophosphate residue) occurred at higher concentration levels (range 2.897-7.978 µg/L) than cypermethrin (2.145 µg/L). For the pesticides quantitatively analysed in the selected samples, the levels were below the maximum residue limit (MRL). The hazard quotients (HQ) were in the range of between 0.247-0.797.

The thermal degradation of model polystyrene (MPS) and waste polystyrene (WPS) was performed in a thermobalance system at four heating rates (β) i.e., 5, 10, 15 and 20 °C/min  in an inert atmosphere. The apparent activation energy (E_a) and frequency factor (A) for the MPS and the WPS were calculated using Ozawa-Flynn-Wall (OFW), Kissinger-Akahira-Sunose (KAS), and Augis-Bennetis (AB) methods. It has been determined that E_a and A vary according to fraction conversion, heating rates, and applied models. The activation energy determined for MPS was found to be in the range of 91-106, 90-105, and 114-133 kJ/mol, while, for WPS, E_a was determined in the range of 82-160, 79-159 and 102-202 kJ/mol by applying OFW, KAS, and AB models, respectively. From the results obtained, it was concluded that the E_a determined by all of these methods increases with fraction conversion, indicating that the decomposition of polystyrene follows a complex mechanism of the solid-state reaction. Hence, the kinetic parameters, i.e., E_a and A, seem to play a key role in investigating the mechanism of solid-state reactions and will provide an opportunity to develop the mechanism of the industrial decomposition reactions. The results show that the MPS has a lower activation energy compared to WPS. This high E_a of WPS may be due to the additives used in the manufacturing of different polystyrene products. Pyrolysis GC/MS of WPS indicates that the main components of pyrolysis oil are 1-hydroxy-2-propanone, styrene, α-methyl styrene, toluene, and 1,2-dimethyl benzene. The presence of some oxygenated compounds in the fuel oil of WPS may be due to contamination or additives used during polystyrene processing, as the WPS samples were collected from a garbage dump near a local market. WPS can be utilized as fuel if the fuel oil collected from the pyrolysis of WPS is properly upgraded to make it equivalent to commercial fuel oil.

4-(tert-Butyl)-4-nitro-1,1-biphenyl has been synthesized, and its structure has been characterized by using some spectroscopic and single-crystal X-ray diffraction techniques. It crystallizes in a monoclinic crystal system with space group P2₁/n and unit cell parameters: a = 6.4478(3) Å, b = 9.2477(4) Å, c = 23.4572(9) Å, β = 95.114(4)°, V = 1393.11(10) Å³, Z = 4. The molecular structure has been solved by using the intrinsic phasing method. The crystal structure is stabilized by C-H···O interactions. Computational studies were performed using density functional theory (DFT) and Hartree-Fock (HF) methods. The optimized geometry obtained from DFT and HF in the gas phase was compared with solid-phase experimental data retrieved from single-crystal X-ray diffraction results. Frontier molecular orbitals, such as the HOMO/LUMO energy gap, the molecular electrostatic potential, and Mulliken atomic charges, have been investigated. The HOMO LUMO energy gap of 3.97 eV indicates that the molecule is soft and highly reactive. The Hirshfeld surface analysis and their associated fingerprint plots have been used to quantitatively validate the interactions. Further insilico molecular docking studies have been performed with the molecular target Type-II topoisomerase (PDB ID: 1JIJ) and their results suggest that 4-(tert-butyl)-4-nitro-1,1-biphenyl could be considered an anticancer drug.

In this work, we have synthesized a novel dihydrazone-based fluorescent probe N'¹,N'²-bis{1-(2-hydroxyphenyl)propylidene}oxalohydrazide (H₂hpoh)for Al³⁺ ions by a simple condensation reaction. The prepared organic probe has been characterized by different physicochemical and spectroscopic techniques. The single-crystal structure of the receptor has also been reported. Crystal data for C₂₀H₂₂N₄O₄: monoclinic, space group P2₁/c (no. 14), a = 6.0747(15) Å, b = 11.621(5) Å, c = 13.453(4) Å, β = 94.61(3)°, V = 946.6(5) Å³, Z = 2, T = 293(2) K, μ(MoKα) = 0.096 mm^-1, Dcalc = 1.342 g/cm³, 4046 reflections measured (6.076° ≤ 2Θ ≤ 58.05°), 2149 unique (R_int = 0.0876, R_sigma = 0.2223) which were used in all calculations. The final R₁ was 0.0972 (I > 2σ(I)) and wR₂ was 0.2316 (all data). The ethanolic aqueous solution of the probe shows enhanced fluorescence in the presence of Al³⁺ ions, whereas no appreciable change in the spectral pattern is observed in the presence of other cations, i.e., Na⁺, K⁺, Ca²⁺, Ba²⁺, Mn²⁺, Fe³⁺, Co²⁺, Ni²⁺, Cu²⁺, Zn²⁺, Cr³⁺, Cd²⁺ and Hg²⁺. The binding mode of the receptor with Al³⁺ ions was studied using various spectral titration techniques such as UV-visible, fluorescence, and ¹H NMR. The receptor acts as a dibasic hexadentate ligand and interacts with two Al³⁺ ions with a high binding constant K_B = 8.99×10¹⁰ 1/M. The lowest detection limit for the Al³⁺ complex of H₂hpoh was determined to be 7.8×10⁻⁵ M. With the help of DFT calculations, the mechanism of fluorescence enhancement has been explained.

The new Cu(II) carboxylate complex, aqua(2,2'-bipyridine-κ²N,N')bis(4-methylbenzoato-κO)copper(II) [Cu(4-mba)₂(bipy)(H₂O)] (4-mba: 4-methylbenzoate, bipy: 2,2'-bipyridine) was synthesized, and the molecular structure of the complex was characterized by the single crystal X-ray diffraction technique. The X-ray diffraction analysis indicated that the asymmetric unit comprises an independent molecule. Crystal data for [Cu(4-meb)₂(2,2-bipy)(H₂O)]: Triclinic, space group P-1 (no. 2), a = 7.0452(13) Å, b = 11.260(2) Å, c = 16.635(3) Å, α = 103.543(7)°, β = 91.002(7)°, γ = 104.106(6)°, V = 1240.4(4) Å³, Z = 2, T = 296 K, μ(MoKα) = 0.918 mm^-1, Dcalc = 1.360 g/cm³, 51364 reflections measured (5.054° ≤ 2Θ ≤ 57.38°), 6258 unique (R_int = 0.0398, R_sigma = 0.0284) which were used in all calculations. The final R₁ was 0.0392 (I > 2σ(I)) and wR₂ was 0.1021 (all data). The Cu(II) ion was found to be coordinated with two nitrogen atoms of the 2,2'-bipyridine ligand, two oxygen atoms of the 4-methyl benzoate molecule, and one oxygen atom of the aqua ligand. In the three-dimensional supramolecular architecture, molecules are connected through pairs of O-H···O and C-H···O intermolecular interactions, consisting of chains. The molecule also demonstrates Cg···Cg intermolecular interactions between six-membered rings of 2,2'-bipyridine.

The current study describes the analysis of the phytochemical composition and biological activities of various polarity extracts of the Anaphalis busua plant that was collected at an altitude of 1654 m in the Himalayan terrain of Uttarakhand, India. The extracts were prepared by the cold percolation method, which was then subjected to GC-MS for phytochemical analysis. A total of 31 compounds were identified that constituted 94.95% of the total methanolic extract. Mome inositol (31.03%) was identified as the main compound in the methanolic extract. Twenty-two compounds that comprise 68.24% of the total hexane extract were identified. Tetracontane (19.33%) was present in a significant proportion. The methanolic extract demonstrated potent antioxidant activity in terms of DPPH radical scavenging and metal chelating activity that have IC₅₀ values of 81.71±1.334 and 11.26±0.005 µg/mL, respectively, compared to standards ascorbic acid and EDTA that have IC₅₀ values at 12.71±0.02 and 11.36±0.06 µg/mL, respectively. The methanolic extract showed potent anti-inflammatory activity with an IC₅₀ value of 24.10±0.09 µg/mL in comparison to standard diclofenac potassium with an IC₅₀ value of 18.95±0.03 µg/mL. In vitro studies reveal that A. busua has a strong therapeutic potential and, if further explored, may prove to be a powerful antioxidant, anti-inflammatory, and cost-effective agent compared to synthetically derived agents from pharmaceutical industries.

Medicinal plants are used in folk medicine to cure several human diseases. This work was designed to evaluate the antioxidant and antimicrobial activities of different extracts of Globularia alypum, Dittrichia viscosa, Juniperus oxycedrus, and Retama sphaerocarpa. The total phenolic content (TPC), the total flavonoid content (TFC), and the condensed tannin content (CTC) were determined spectrophotometrically. The antioxidant activity was tested using TAC, DPPH and reducing power assays. The agar diffusion method was used to determine antimicrobial activity against four bacteria (Bacillus subtilis, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa) and one fungus (Candida albicans). J. oxycedrus acetone extract showed the highest extraction yield (35.56±0.45%), TPC (504.96±14.82 mg GAE/g DE) and TFC (43.91±0.87 mg QE/g DE). The same extract exhibited the highest TAC (350.67±6.05 mg GAE/g DE) and was the most effective against the DPPH free radical (IC₅₀ = 0.21±0.01 mg/mL). In contrast, the J. oxycedrus methanol extract showed the highest reducing power (A_0.5 = 0.39 ± 0.09 mg/mL). All extracts tested showed antibacterial and anticandidal activities at different concentrations. The best antimicrobial effect was also observed with the acetone extract of J. oxycedrus against P. aeruginosa (26.77±0.06 mm), B. cereus (17.16±0.08 mm), E. coli (15.84±0.04 mm), and C. albicans (21.36±0.11 mm), while the ethanol extract of D. viscosa was the most active against S. aureus (24.54±0.03 mm). The results of this study provide a scientific basis for the traditional use of these local plants and demonstrate their potential as sources of natural antioxidant and antimicrobial bioactive compounds.

The objectives of the present study were to investigate the phytochemical composition of essential oils (EO) from rhizomes of Acorus calamus collected from Jorhat, Assam; Munsyari and Pantnagar, Uttarakhand, India.  EOs were studied for different pesticidal activities viz; nematicidal, insecticidal, and herbicidal activity. To study the synergistic effect of EOs on pesticidal activity, four combinations of EOs were prepared. Phenylpropanoids with β-asarone as the main compound were identified in all collections with varying percentages. Its contribution was found to be 85.8% in Munsyari EOs followed by 74.3% in Pantnagar and 62.6% in Assam collections. All EOs exhibited dose-dependent in vitro nematicidal activity against Meloidogyne incognita in terms of immobility and inhibition of egg hatching. The activity was observed as maximum in the EO combination of all three collections (1:1:1) whereas minimum in the Assam collections. In insecticidal activity against Lipaphis erysimi and Selepa celtis, maximum mortality was observed in Munsyari collections. The oils were assessed for sprout inhibition activity in terms of seed germination inhibition, coleoptile growth of the shoot and root against Raphanus raphanistrum. Maximum seed germination inhibition, % shoot, and root growth inhibition were found in all collections EO combinations. To predict the possible mode of action and the structure-activity relationship between major compounds of EOs and biological activities, in silico molecular docking and ADME/Tox studies were performed. The docking results revealed the mode of action of proteins of insects, nematodes, and weeds and were found in support of in vitro experiments. The study may be helpful for the development of herbal-based pesticides after proper clinical trials.

In this work, we develop the synthesis of selenium nanoparticles (B@SeNPs) using a green method using the aqueous extract of Hibiscus esculentus L. Various techniques were used to characterize bio-synthesized B@SeNPs. The mixture color was clearly changed to reddish at 45-50 °C and the extract pH = 6. According to Fourier transform infrared spectroscopy (FT-IR), the B@SeNPs were produced, capped, and stabilized using biomolecules found in plant extracts. The energy dispersive X-ray (EDX) analysis profile revealed an atomic Se signal (1.39 mV). The powder X-ray diffraction (PXRD) pattern confirmed the hexagonal phase crystalline form of B@SeNPs. The zeta potential for SeNPs was determined to be -51.3 mV. Scanning electron microscope (SEM) and transmission electron microscopy (TEM) micrographs revealed spherical Se particles with sizes of roughly 62 nm. Furthermore, B@SeNPs can degrade methylene blue dye by 98.3% at 21 min with a rate constant of 0.1023 min^-1 in the presence of NaBH₄. In biological evaluation, the synthesized nanoparticles have been proven to be effective against two human cancers (AGS and MCF-7 cells) with IC₅₀ values of 20.46 and 88.43 µg/mL, respectively. Additionally, B@SeNPs showed high safety in the Beas cell line (normal) at 123 µg/mL as the highest concentration. The biofabricated SeNPs had a moderate antibacterial effect against ATCC and multidrug-resistant clinical isolates. They had no antifungal activity against the tested fungus strains except C. albicans (IFRC 1873), with a MIC value of 138.75 µg/mL. Finally, the green-synthesized B@SeNPs could be a contender for further testing as a chemotherapeutic agent in the treatment of some human cancers.

The synthesis of many transition metal complexes containing 3,5-diamino-1,2,4-triazole (Hdatrz) as a ligand with different counter anions Br^⎺, Cl^⎺, ClO₄^⎺ and SO₄^2- has been studied extensively, but the chemistry of transition metal nitrate and acetate compounds and their reactivity are relatively unexplored. In this research work, two new series of metal(II) complexes (M = Ni, Co, and Zn) {[Ni₃(Hdatrz)₆(H₂O)₆](NO₃)₆ (1), [Co₃(Hdatrz)₆(H₂O)₆](NO₃)₆ (2), [Zn₃(Hdatrz)₆(H₂O)₆](NO₃)₆ (3), [Ni₃(Hdatrz)₆(H₂O)₆](OAc)₆ (4), [Co₃(Hdatrz)₆(H₂O)₆] (OAc)₆ (5) and [Zn₃(Hdatrz)₆(H₂O)₆](OAc)₆ (6)} have been synthesized. These synthesized complexes were characterized by various physicochemical techniques such as UV-vis spectroscopy, Fourier transform infrared spectroscopy, and magnetic susceptibility measurements. All six complexes were found to be trinuclear and bridged through the Hdatrz ligand. Spectral data suggested a distorted octahedral environment around the central metal ions in these complexes. It also revealed that the NH and OH groups are involved in hydrogen bonding. These complexes were tested against the fungal strains Colletotrichum gloeosporioides and Aspergillus niger. These synthesized complexes have not been observed to have antifungal activities. The machine learning K-nearest neighbours evaluates the analytical characteristics and solubility behavior of the metal complexes. Machine learning models provide results with 75% precision.