scholarly journals Phytochemical composition and antimicrobial activity of Ochna thomasiana

2020 ◽  
Vol 18 (1) ◽  
Author(s):  
MBITHI JUSTUS MUEMA ◽  
ALEX K. MACHOCHO ◽  
NICHOLAS K. GIKONYO
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Antimicrobial Activity ◽  
Magnetic Resonance ◽  
High Activity ◽  
Dimethyl Ether ◽  
Proton Nuclear Magnetic Resonance ◽  
Root Bark ◽  
Phytochemical Composition ◽  
Crude Extracts ◽  
Nuclear Magnetic

Abstract. Muema MJ, Machocho AK, Gikonyo NK. 2018. Phytochemical composition and antimicrobial activity of Ochna thomasiana. Biofarmasi J Nat Prod Biochem 18: 29-41. Infectious diseases are the leading cause of mortality worldwide despite the vigorous campaigns that have been made to combat them. This study aimed at the determination and evaluation of the biological activities of Ochna thomasiana Engl. & Gilg ex Gilg. Here, we screened the plant extracts and tested for their antibacterial activity against Salmonella typhi (clinical isolate), Pseudomonas aeruginosa, Escherichia coli, Bacillus subtilis, and Staphylococcus aureus. Various chromatographic techniques separated and isolated the active compounds from this plant. The extracts were purified using silica gel, column chromatography (CC), Sephadex gel, and preparative thin-layer chromatography (PTLC). Structure characterization was determined using standard spectroscopic methods: Infrared (IR), ultraviolet (UV) spectroscopy, mass spectroscopy (MS) and proton nuclear magnetic resonance (1H NMR), distortionless enhancement by polarization transfer (DEPT), carbon-13 nuclear magnetic resonance (13C NMR), coherence spectroscopy (COSY), heteronuclear multiple bond coherence (HMBC) and heteronuclear single quantum coherence (HSQC). Compounds identified from the extracts are Lophirone A (18), afzelone D dimethyl ether (20), calodenone (17), a mixture of stigmasterol (74) and ?-sitosterol (23) and 3?-acetyl-24-ethylfriedelane (75). The stem and root bark of methanol crude extracts showed high activity against the Gram-positive bacteria. Lophirone A, afzelone D dimethyl ether, and 3?-acetyl-24- ethylfriedelane showed high activity against S. aureus. The results showed the root of O. thomasiana contains biflavonoids, and some sterols as its constituents and their antimicrobial activity are significant and is a lead towards the development of antimicrobial agents. The essential bioactive compounds and the antimicrobial activity of the crude extracts of this plant confirms its use in traditional medicine. However, there is a need to test the effectiveness of the crude extracts and isolated compounds via in vivo and in vitro evaluation. The plant species should be cultivated using good agricultural practices for medicinal plants for the future assessment of their activity against pathogens.

scholarly journals Synthesis, characterization, and antimicrobial activity of 4-imidazolecarboxaldehyde thiosemicarbazone and its Pt(II) and Pd(II) complexes

2021 ◽  
Vol 12 (1) ◽  
pp. 56-59
Author(s):  
Mohammed Bahreldin Hussein ◽  
Muna Mahdi Mohammed ◽  
Abdalla Gobara ◽  
Asha Fadllallah Wady ◽  
Awad Salim Ibrahim Holy
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Antimicrobial Activity ◽  
Magnetic Resonance ◽  
Free Ligand ◽  
Proton Nuclear Magnetic Resonance ◽  
Azomethine Nitrogen ◽  
Primary Amines ◽  
Complexing Agent ◽  
Nuclear Magnetic

Schiff bases are versatile ligands, synthesized via condensation of primary amines with carbonyl compounds. In this study, equimolar amounts of 4-imidazolecarboxaldehyde and thiosemicarbazide were combined and the Schiff base 4-imidazolecarboxaldehyde thiosemicarbazone was prepared as a new bidentate complexing agent. The synthesized ligand was reacted with palladium (II) and platinum (II) ions yielding air-stable complexes. For characterization purpose, infrared spectra, mass spectra, electronic spectra, thermal analysis, proton nuclear magnetic resonance and 13-carbon nuclear magnetic resonance spectra studies were carried out on the obtained complexes and ligand. The characterization data showed that the ligand acts as a bidentate coordinate to the metal ions through azomethine nitrogen and sulfur atoms. An in vitro antimicrobial investigation was also carried out for the free ligand and its metal complexes against four bacteria; Bacillus cereus, Staphylococcus aureus (Gram-positive), Escherichia coli and Salmonella typhimurium (Gram-negative) and one Fungi; Candida albicans, to assess their antimicrobial properties by disc diffusion technique. Antimicrobial activity of the prepared complexes showed higher activity than the free ligand.

scholarly journals N-[7-Chloro-4-[4-(phenoxymethyl)-1H-1,2,3-triazol-1-yl] quinoline]-acetamide

Molbank ◽  
10.3390/m1213 ◽  
2021 ◽  
Vol 2021 (2) ◽  
pp. M1213
Author(s):  
Paolo Coghi ◽  
Jerome P. L. Ng ◽  
Ali Adnan Nasim ◽  
Vincent Kam Wai Wong
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Quantum Coherence ◽  
Biologically Active ◽  
Proton Nuclear Magnetic Resonance ◽  
Dipolar Cycloaddition ◽  
Heteronuclear Single Quantum Coherence ◽  
Pharmacokinetic Properties ◽  
Nuclear Magnetic

The 1,2,3-triazole is a well-known biologically active pharmacophore constructed by the copper-catalyzed azide–alkyne cycloaddition. We herein reported the synthesis of 4-amino-7-chloro-based [1,2,3]-triazole hybrids via Cu(I)-catalyzed Huisgen 1,3-dipolar cycloaddition of 4-azido-7-chloroquinoline with an alkyne derivative of acetaminophen. The compound was fully characterized by Fourier-transform infrared (FTIR), proton nuclear magnetic resonance (1H-NMR), carbon-13 nuclear magnetic resonance (13C-NMR), heteronuclear single quantum coherence (HSQC), ultraviolet (UV) and high-resolution mass spectroscopies (HRMS). This compound was screened in vitro with different normal and cancer cell lines. The drug likeness of the compound was also investigated by predicting its pharmacokinetic properties.

scholarly journals One-Pot Synthesis of 7, 7-Dimethyl-4-Phenyl-2-Thioxo-2,3,4,6,7, 8-Hexahydro-1H-Quinazoline-5-OnesUsing Zinc Ferrite Nanocatalyst and Its Bio Evaluation

Catalysts ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 431
Author(s):  
Tentu Nageswara Rao ◽  
Nalla Krishnarao ◽  
Faheem Ahmed ◽  
Suliman Yousef Alomar ◽  
Fadwa Albalawi ◽  
...  
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Zinc Ferrite ◽  
Large Scale ◽  
Cyano Group ◽  
Proton Nuclear Magnetic Resonance ◽  
Scale Production ◽  
One Pot ◽  
Antibacterial And Antifungal ◽  
Nuclear Magnetic

A simple and highly efficient protocol for the synthesis of derivatives 7, 7-dimethyl-4-phenyl-2-thioxo-2, 3, 4, 6, 7, 8-hexahydro-1H-quinazoline-5-one from 5, 5-dimethyl cyclohexane-1, 3-dione (4a–4h) (dimedone) has been described. The aryl aldehydes were substituted with thiourea in the presence of synthesized zinc ferrite nanocatalyst, which increased the yield under reflux through condensation, followed by cyclization to give desired products. The other advantages are that it is eco-friendly and economically affordable for large-scale production. Structural validation and characterization of all the newly synthesized compounds were evaluated by spectral analysis (mass spectrometry, proton nuclear magnetic resonance (1HNMR), and Carbon-13 nuclear magnetic resonance(13CNMR)spectroscopies. The structure of antibacterial and antifungal assays was performed with the newly synthesized compounds. The antimicrobial activity of title compounds possessing electron-withdrawing groups such as (4e–4h) (Cl, Br, and cyano group) exhibited more active potential than the electron-donating groups, C6H5,4-C6H4, 3-OC2H5-4OH-C6H3, etc., (4a–4d) containing moiety.

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