Synthesis, Characterization, Crystal Structure and Quantum Chemical Calculations of 2-oxo-2H-chromen-3-yl Acetate
Akoun Abou,
Siaka Sosso,
Affiba Florance Kouassi,
Thouakesseh Jeremie Zoueu,
Abdoulaye Djande,
Olivier Ouari
Issue:
Volume 9, Issue 2, April 2021
Pages:
29-44
Received:
14 March 2021
Accepted:
6 April 2021
Published:
16 April 2021
Abstract: This paper is focused on a combined experimental and theoretical study of 3-substituted coumarin derivative, the 2-oxo-2H-chromen-3-yl acetate (I). The compound was synthesized by reacting chroman-2,3-dione and acetic anhydride in dried diethyl ether in the presence of dried pyridine and crystallized in the orthorhombic crystal system with Pbca space group. The lattice parameters of the structure are a=14.6770 (1), b=7.1079 (1), c=17.6767 (2) Å, α=β=γ=90° with 8 molecules per unit cell (Z=8). The compound has been characterized structurally by Spectroscopy utilizing 1H NMR, 13C NMR and IR techniques and by crystallography using the X-Ray diffraction (XRD) analysis. In the crystallographic study, the positions of the atoms were determined by direct methods and refined to a final R value of 0.038 for 1768 independent reflections. The stabilization of the structure is provided by intermolecular C-H•••O hydrogen bonds extending along [010] direction. Likewise, the presence and nature of intermolecular contacts are determined by the 3-D molecular Hirshfeld surface and 2-D fingerprint plot analysis which indicate the main contributions to the Hirshfeld surface, 38.7% for O ••• H and 28.7% for H •• H. Moreover, the molecular geometry of (I) was as well minimized utilizing density functional theory (DFT/RB3LYP), the frequency calculations with RB3LYP method, the basic ab initio model i.e the restricted Hartree-Fock (RHF) and the exchange component of Perdew and Wang’s 1991 functional B3PW91 methods with the 6-311++G(d, p) basis set in ground state. The derived structural parameters highlight very good correlation with the crystallographic results. Frontier molecular orbitals (HOMO-LUMO), their energy gap, the non-linear optical effects (NLO) and related reactive parameters were also computed to better apprehend the properties of the molecule.
Abstract: This paper is focused on a combined experimental and theoretical study of 3-substituted coumarin derivative, the 2-oxo-2H-chromen-3-yl acetate (I). The compound was synthesized by reacting chroman-2,3-dione and acetic anhydride in dried diethyl ether in the presence of dried pyridine and crystallized in the orthorhombic crystal system with Pbca spa...
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Dextrose Equivalent Analysis of Acid Hydrolysed Corn and Cassava Starch Sourced from Ghana
Odum Bismark,
Owusu Kwaku Michael,
Odoom Kwesi Justice,
Ebenezer Otoo,
Norgbey Eyram,
Kwakye Danso Benjamin
Issue:
Volume 9, Issue 2, April 2021
Pages:
45-53
Received:
17 November 2020
Accepted:
14 December 2020
Published:
23 April 2021
Abstract: The use of acid hydrolysis to convert starch into dextrose can be difficult and time-consuming. The process requires high acidic medium and temperature which tends to contaminate the end-product hydrolysate. Therefore, this research was carried out to obtain optimum conditions necessary to produce a high and quality Dextrose Equivalent by varying the initial starch concentration and acid volume. The mass of corn and cassava starch and the total hydrochloric acid volume used for the hydrolysis ranged from 100 to 400 g and 1-3 liters respectively. The results showed that the optimum conditions for hydrolyzing the two starch types to Dextrose were within a temperature range of 100°C-120°C, 12 w/w% starch concentration, 4 atmospheric pressure and 30 minutes operating time. The optimum conditions produced a Dextrose Equivalent of 79.80% and 78.66% for cassava and corn starch respectively. The amount of dextrose produced in the process is a function of temperature, pressure, acid volume, operating time and initial starch concentration. Experimental results also confirmed an increase in pH of the hydrolysate with a temperature rise, and this influenced the Dextrose quality. The outcomes provided new findings to complement existing outcomes on how initial starch concentration and acid volume affect Dextrose Equivalent by acid-type hydrolysis.
Abstract: The use of acid hydrolysis to convert starch into dextrose can be difficult and time-consuming. The process requires high acidic medium and temperature which tends to contaminate the end-product hydrolysate. Therefore, this research was carried out to obtain optimum conditions necessary to produce a high and quality Dextrose Equivalent by varying t...
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Antioxidant Screening of Various Solvent Extracts of Cuminum cyminum Cultivated in Bangladesh
Fardushi Rahman,
Sabina Easmin,
Shahed Zaman,
Hamidul Haq,
Rezaul Haque Ansary,
Subed Chandra Dev Sharma,
Suganya Murugesu,
Vikneswari Perumal
Issue:
Volume 9, Issue 2, April 2021
Pages:
54-61
Received:
11 March 2021
Accepted:
2 April 2021
Published:
23 April 2021
Abstract: Cuminum cyminum is a widely used spice and most valuable medicinal plant in South Asian countries to enhance vitality. This herb has been reported to be used as conventional remedy for many years. In this research, C. cyminum cultivated in Bangladesh was focused on exploring the scavenging ability using different solvents with green extraction technique. This study aims to screen the suitable solvent for the effective C. cyminum extraction followed by the phytochemical analysis and identification of its chemical constituents. The solvents, methanol and n-hexane, were used for the extraction using sonication extraction technique to screen the antioxidant activity of C. cyminum. Moreover, the different solvent ratios (0, 20, 40, 60, 80 and 100%) of ethanol and water were used to investigate the best combination of extracting solvents that can produce C. cyminum extracts with the most desirable and potent antioxidant activities. The metabolites were identified using gas chromatography-mass spectrometry. The methanol extract showed maximum yield (5.32±2.86%) and IC50 (3.02±1.97) value concerning n-hexane (3.02±0.78%, 5.08±0.95). However, the range of different solvent ratios (100% ethanol-0% ethanol) yield was 4.11±0.59-14.47±5.36%. On the other hand, the 60% ethanol exhibited the highest inhibitory potential (1.39±1.42µg/ml), and aqueous extract exhibited the lowest inhibitory potential (5.79±3.43µg/ml). Phytochemical investigation showed that tannin and glycosides were present in both extracts. Flavonoids showed a positive result in methanol extract, while anthraquinones and steroids showed a positive result in n-hexane extract. The identified metabolites using GCMS are D-carvone, 1, 3-benzodioxole, squalene, 2H, 6H-benzo [1, 2-b: 5, 4-b'] dipyran-2, 6-dione, D-limonene and apiol. Cuminum cyminum can reduce oxidative damage by potently inhibiting free radicals and can be utilized as natural compounds to scavenge free radical activity.
Abstract: Cuminum cyminum is a widely used spice and most valuable medicinal plant in South Asian countries to enhance vitality. This herb has been reported to be used as conventional remedy for many years. In this research, C. cyminum cultivated in Bangladesh was focused on exploring the scavenging ability using different solvents with green extraction tech...
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