DEPT-135 Spectra Research Articles

Pharmacokinetics, drug-likeness, antibacterial and antioxidant activity of secondary metabolites from the roots extracts of Crinum abyssinicum and Calotropis procera and in silico molecular docking study

Crinum abyssinicum and Calotropis procera were traditionally used for the treatment of different diseases such as hypertension, diabetes, hepatitis B, skin infection, anticancer, asthma, fever, and diarrhea. The structures of the compounds were characterized by 1H NMR, 13C NMR, and DEPT-135 spectra. Compounds 1-3 were reported herein for the first time from the species of C. abyssinicum. The DCM/MeOH (1:1) and MeOH roots extracts of C. abyssinicum showed significant inhibitory activity against S. aureus and P. aeruginosa with a mean inhibition zone of 16.67 ± 1.20 and 16.33 ± 0.33 mm, respectively. Compounds 4 and 5 showed promising activity against E. coli with a mean inhibition zone of 17.7  0.8 and 17.7  1.2 mm, respectively. The results of DPPH activity showed the DCM: MeOH (1:1) and MeOH roots extracts of C. abyssinicum inhibited the DPPH radical by 52.86  0.24 % and 45.6  0.11 %, respectively, whereas compound 5 displayed 85.7 % of inhibition. The drug-likeness analysis showed that compounds 2-4 satisfy Lipinski’s rule of five with zero violations. Compounds 2, and 6 showed binding affinities of −6.0, and −6.7 kcal/mol against E. coli DNA gyrase B, respectively, while 3 and 5 showed −5.0 and −5.0 kcal/mol, respectively against human peroxiredoxin 5. Therefore, the in vitro antibacterial, radical scavenging activity along with the molecular docking analysis suggest the potential use of the extracts of C. abyssinicum and compounds 2, 5, 6, and 3, 5 can be considered as promising antibacterial agents and free radical scavengers, respectively.

Insight into the Mechanism of Water-Promoted Hydrogenation of Maleic Acid to Succinic Acid on Pd/C Catalyst

Solvent provides additional degrees of freedom to regulate catalyst reactivity in liquid-phase heterogeneous catalysis, but it is still a challenge to have insight into the multifaceted solvent effects. Herein, a remarkable promotional effect of water in maleic acid (MAc) hydrogenation to succinic acid (SAc) was observed. Kinetic studies showed that the apparent activation energy in water was much lower than in organic solvents. A series of isotope-labeling experiments were designed, and the products were analyzed by NMR (1H, 13C, 2H, and DEPT135 spectra). The results showed that D2O participated in MAc C═C hydrogenation and 34.7% of SAc was deuterated. The structures of these deuterated compounds were further confirmed by electrospray mass spectrometry (ESI-MS). The detailed mechanism of water participating in MAc C═C hydrogenation was studied by quasi-in situ mass spectrometry experiments. The results showed that H2 exchanged with D2O and formed the HD2O* transition state over the active site of Pd. Quantitative 13C NMR demonstrated that 46.2% of SAc was generated through the HD2O* transition state pathway. Based on these results, a rational mechanism of MAc hydrogenation in aqueous solution was proposed. Finally, a recyclability experiment showed that Pd/C had much better stability in water than in organic solvents.

Isolation and Structural Elucidation of 20 Hydroxyecdystone from Vitex doniana Sweet Stem bark (Black plum) Mustapha

Vitex doniana Sweet, a plant commonly known black plum, in English, Prunier noir in French, dinya in Hausa, ucha koro in Igbo, oori-nla in yoruba and ngarmi in Kanuri is a medium-sized deciduous tree, 8-18 m high, with a heavy rounded crown and a clear bole up to 5 m. V. doniana is from Verbenaceae family and abundantly occurring in savannah regions. It can be found throughout tropical Africa. The ethanolic extract of Vitex doniana stem bark (11.9 g) was subjected to a silica gel accelerated column chromatography and eluents fractions (150 ml aliquots) obtained were collected and monitored with thin layer chromatography (TLC). Fractions with similar Rf values from same solvents system were poled together. Phytochemical test of all the fractions were perform. Complete elution yielded 48 fractions (150 ml/fraction) which were pooled to 24 fractions and finally to eight (8) eight fractions and coded. Fraction Vd8-a (56 mg) has gave a single spot a white crystal compound coded V1 on checking with TLC and observed under Ultraviolet lamp. The Rf values was calculated to be 0.433 and melting point was found to be 241-243°C uncorrected. The infrared spectrum of compound V1 shows prominent peaks that corresponds to OHstr (3365 cm-1) and C=0 (1652 cm-1). The 1H NMR (400 MHZ) spectrum of compound V1 in DMSO-d6 displayed five singlet signals. It further showed a broad singlet at δ 5.58 integrated for 1 H is due to an olefinic H-atom adjacent to the carbonyl carbon atom. Three signals at δ 3.10` (d, J = 9.0 Hz, H-22), 3.59 (m, 1H, 2H-a) and 3.72 (m, 1H, 3H-e) each integrating for one proton is due to an oxymethine protons indicating that three oxymethine H-atoms were present in the compound. The 13C-NMR spectrum showed the presence of 27 Carbon atoms, suggesting that may be steroid skeleton and the DEPT-135 spectra showed the presence of five CH3, eight CH2, and seven CH groups, and seven quaternary C-atoms. The Molecular formula was established as C27H44O7 by HRES-MS positive ion mode m/z 481.3179. Based on the spectral analysis, the compound V1 is thus concluded to have ecdysteriod skeleton and conclusively conforms with 2β, 3β 14α, 20R, 22R, 25- hexahydroxy-5 β cholest- 7-ene-6- one, commonly known as 20-hydroxyecdysone. This is the first time this compound was isolated from Vitex doniana sweet.

Synthesis, characterization and antimicrobial activity of some new azo flavones and azo flavanone derived from o-hydroxyacetophenone

Some new azo-flavones of 2-(substituted phenyl)-6-(p-tolyldiazenyl)-4 H -chromen-4-ones, have been synthesized in three consecutive main steps. 4-toluidine was used as a diazotizing agent and subjected to coupling reaction with 2-hydroxyacetophenone forming 2-(hydroxyl)-5-[4-methylphenylazo] acetophenone as a key substrate. The prepared starting material reacted with different substituted benzaldehydes affording new 2-hydroxy azo-chalcones which were cyclized by DMSO/I 2 giving the target biological active azo-flavone derivatives. The structures of the newly synthesized products were elucidated by using FT-IR, 1 H-NMR, 13 C-NMR and DEPT-135 spectra. The synthesized flavones were screened with two types of bacteria Escherichia coli gram negative and Staphylococcus aurous gram positive. The results observed a significant effect against gram negative bacteria.

1-(3-Iodopropyl)-4-methylquinolin-1-ium Iodide

A solvent-free “one-pot” synthetic approach to 1-(3-iodopropyl)-4-methylquinolin-1-ium iodide is reported in the present work. The title compound is derived from N-alkylation of 4-methylquinoline with 1,3-diiodopropane proceeded at room temperature. The target quinolinium salt is obtained in a highly pure form. It’s structure was evaluated by 1H-NMR, 13C-NMR, and DEPT135 spectra.

Synthesis and Characterization of Some New 4,5-Dihydropyrazolyl Thiazoles

The prepared starting material 2,4-bis (4-chlorobenzyloxy)acetophenone (1) has been reacted with different substituted benzaldehydes to give a series of new chalcones (2a-j). The prepared new chalcones were subjected to react with thiosemicarbazide according to the Michael addition reaction to afford new thiocarbamoylpyrazoline derivatives (3a-j). A thiocarbamoyl group in compounds (3a-j) was cyclized with p-bromophenacyl bromide to give a series of new 4,5-dihydropyrazolyl thiazoles (4a-j). The structures of the synthesized compounds were characterized by spectral methods: FT-IR, 1 H-NMR, 13 C-NMR and DEPT-135 spectra.