Antibacterial and Antioxidant Compounds from Root Extracts of Gloriosa superba Linn: A Combined Experimental and Computational Study

Throughout history, medicinal plants have globally served as remedies for various ailments, and diseases. The roots of Gloriosa superba are traditionally used to treat antitumor, antimicrobial, and anti-inflammatory diseases. In this study, the roots of G. superba (320 g) were successively extracted with n-hexane, chloroform, and methanol to afford 530 mg (0.17%), 2.89 g (0.90%), and 17.78 g (5.56%) yields, respectively. Silica gel column chromatographic separation of the combined chloroform and methanol extracts gave 4-methoxy caffeic acid heptyl ester (1), desmosterol (2), 3-hydroxymethyl phenol (3), 3-Hydroxy-5-methoxy-benzoic acid (4), sucrose (5) and rutinose (6). In vitro antibacterial study revealed promising zone of inhibition value by chloroform extract against Klebsiella pneumoniae (13±0.00 mm) compared to gentamicin (15.86±4.67 mm). Desmosterol (2), 3-hydroxymethyl phenol (3), and 3-Hydroxy-5-methoxy-benzoic acid (4) displayed promising zone of inhibition against K. pneumonia (12.33±0.58, 11.33±1.53 and 11.33±1.15 mm, respectively) at 1000 μg/mL compared to gentamycin (15.86±4.67 mm at 100 μg/mL). Promising inhibition zone values were also displayed by desmosterol (2) and 3-Hydroxy-5-methoxy-benzoic acid (4) against Pseudomonas aeruginosa (14±1.00 and 14±1.73 mm, respectively) compared to gentamycin (25±2.52 mm).Chloroform extract displayed 95.14% DPPH radical scavenging value compared to ascorbic acid (96.11%) at 200 μg/mL. Compounds 2 and 4 displayed binding affinities of -7.8 and -6.5 Kcal/mol, respectively, against PqsA protein of P. aeruginosa, compared to amoxicillin (-7.3 kcal/mol). Therefore, the in vitro antibacterial and radical scavenging activity results suggest the potential uses of the root extracts of G. superba as promising antibacterial agents and free radical scavengers

Chemical composition and antibacterial activity of essential oils from various parts of Gladiolus candidus, Ranunculus multifidus, Artemisia abyssinica and Crinum abyscinicum

ABSTRACT. The essential oil compositions of Gladiolus candidus, Ranunculus multifidus, Artemisia abyssinica and Crinum abyscinicum were analyzed with gas chromatography-mass spectrometry (GC-MS). The principal components in the leaves, stems and rhizomes of G. candidus were eudesmol, 1-naphthalenepropanol and oleic acid, respectively. α-Terpineol, alloocimene  and p-menth-2-en-1-ol from leaves, bulbs and roots were respectively the major constituents of C. abyscinicum. The aerial part of R. multifidus furnished p-mentha-2,8-dien-1-ol. Linalool and terpinenol were identified as the major constituents of A. abyssinica. The essential oils were evaluated for their antibacterial activity. Essential oil from leaves of G. candidus displayed zone of inhibition (IZ) of 15.1±0.3 and 16.7±0.9 mm against E. coli and S. aureus, respectively. Leaves essential oil of C. abyscinicum exhibited IZ of 17.9±1.1 and 15.6±1.1 mm against E. coli and P. aeruginosa, respectively, whereas essential oil from aerial part of R. multifidus displayed IZ of 18.8±0.8 and 19.4±0.6 mm against S. aureus and S. pyogens, respectively. At the same concentration, ceftriaxone showed IZ of 15.1±0.1, 16.2±0.8, 14.3±0.9 and 16.1±2.5mm against E. coli, P. aeruginosa, S. aureus, and S. pyogens, respectively. The findings presented herein support the ethnobotanical uses of these plants against bacteria.     KEY WORDS: G. candidus, R. multifidus, A. abyssinica, C. abyscinicum, Antibacterial activity, Essential oil   Bull. Chem. Soc. Ethiop. 2022, 36(4), 865-878.                                                              DOI: https://dx.doi.org/10.4314/bcse.v36i4.12                                                     &nbsp

Antibacterial Activity of Coumarins and Carbazole Alkaloid from Roots of Clausena anisata

Clausena anisata is one of the medicinal plants used traditionally for treatment of parasitic infections, irritation (boils, ringworm, and eczema), flatworm infestations, influenza, abdominal cramps, and constipation. Phytochemical screening test of dichloromethane/methanol (1 : 1) roots extract revealed the presence of flavonoids, phytosterols, coumarins, phenols, alkaloids, tannins, terpenoids, and free reducing sugars and the absence of saponins. Silica gel column chromatographic separation of the dichloromethane/methanol (1 : 1) extract afforded a carbazole alkaloid derivative of heptazoline (1) and three coumarins (2–4), including the known coumarins imperatorin (3) and chalepin (4). Structures of the compounds were elucidated by spectroscopic techniques (IR, 1H NMR, 13C NMR, and DEPT-135). Antibacterial activity of the crude extracts and isolated compounds was screened using agar diffusion method against strains of Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, and Bacillus substilis. The results of antibacterial test revealed derivative of heptaphylline (1) and imperatorin (3) exhibited comparable antibacterial activity against S. aureus and B. substilis (14 and 13 mm zone of inhibition, respectively) to that of ciprofloxacin (15 mm zone of inhibition) at a concentration of 20 µg/mL. Chalepin (4) revealed more antibacterial activity against B. substilis (16 mm zone of inhibition) compared to ciprofloxacin (15 mm)

Antibacterial Activity of Two Flavans from the Stem Bark of Embelia schimperi

Embelia schemperi Vatke is one of the medicinal plants used traditionally for treatment of intestinal tape worm, dysmenorrheal, bacterial, and fungal infections. Phytochemical screening test of the dichloromethane/methanol (1 : 1) and methanol extracts revealed the presence of phenols, alkaloids, tannins, and flavonoids whereas terpenoids, glycoside, and phytosterols were absent. Silica gel column chromatographic separation of the methanol extract afforded 3,5,7,3′,4′-pentahydroxyflavan, named epicatechin (1), along with a close flavan derivative (2). Structures of the compounds were elucidated by spectroscopic techniques (1D and 2D NMR, FTIR, and UV-Vis). The crude extracts and isolated compounds were screened for in vitro antibacterial activity against strains of Klebsiella pneumoniae, Escherichia coli, Cryptococcus neoformans, Shigella dysentriae, and Staphylococcus aureus. Epicatechin (1) exhibited comparable antibacterial activity against S. aureus and E. coli (15 and 12 mm zone of inhibition, resp.) to that of the control antibiotic gentamicin, with zone of inhibition of 15 and 12 mm, respectively, at a concentration of 20 µg/mL

Iridoid glycosides from the root of Acanthus sennii

Context: Acanthus sennii is a plant traditionally used for the treatment of antifungal, cytotoxic, anti-inflammatory, antipyretic, antioxidant, insecticidal, hepatoprotective, immunomodulatory, anti-platelet aggregation and anti-viral potential. Aims: To investigate the phytochemical constituents of roots of Acanthus sennii. Methods: Phytochemical screening tests were conducted to identify the class of compounds present in the root extract. Silica gel column chromatographic technique was applied to separate the constituents of the extracts. Various spectroscopic techniques (IR, 1H NMR, 13C NMR, DEPT-135, COSY, gHSQC, and gHMBC) were applied to determine the structures of isolated compounds. Results: Phytochemical screening of the dichloromethane/methanol (1:1) and methanol (100%) root extract of the plant revealed the presence of phenolic compounds, steroids, flavonoids, and terpenes. Chromatographic separation of dichloromethane/methanol (1:1) root extract of Acanthus sennii yielded two iridoid glycosides (1, 2). Conclusions: The roots of Acanthus senni contain various class of constituents such as flavonoids, phenols, terpenoids, tannins, and iridoid glycosides identified through phytochemical screening test and purification process, which might be responsible for the traditional use of the plant. To the best of our knowledge, these compounds are isolated for the first time from this genus

Phytochemical investigation and antimicrobial activity of leaves extract of Vernonia auriculifera Hiern.

Context: The genus Vernonia is one of the largest groups in the family Compositae constituting more than 500 species distributed widely in tropical and sub-tropical regions of Africa, Asia, and America. Traditionally the genus is used for the treatment of schistosomiasis, amoebic dysentery, gastrointestinal problems, malaria, venereal diseases, wounds, hepatitis, and diabetes. Vernonia auriculifera Hiern is used for healing wounds as ointment around the injured areas. Aims: To investigate the phytochemical constituents and evaluate antimicrobial activity of leaves extract of Vernonia auriculifera Hiern. Methods: Phytochemical screening tests were conducted to identify the class of compounds present in the leaves extracts of V. auriculifera. Silica gel column chromatographic technique was applied to separate the constituents of the extracts. Various spectroscopic techniques (IR, 1H NMR, 13C NMR, DEPT-135, COSY, gHSQC, and gHMBC) were applied to determine the structures of isolated compounds. Results: Phytochemical screening of the methanol leaf extract revealed the presence of tannins, flavonoids, terpenoids, saponins and absence of anthraquinones, steroids, and alkaloids. Silica gel column chromatography of the methanol leaves extract yielded one compound. The hexane, chloroform, methanol and water extracts were tested against Staphylococcus aureus. The methanol and water extracts showed promising growth suppression at minimum inhibitory concentration of 200 mg/mL. Conclusions: The polar extracts of the leaves of Vernonia auriculifera Hiern possess antimicrobial activity

Phytochemical analysis and antibacterial activity on seed and pod extracts of Crotalaria incana.

Context: Crotalaria incana L. (Fabaceae) is used for various traditional medicinal treatments such as astringent, jaundice and palpitation, inflammation, skin disease and purgative. Aims: To investigate the phytochemical constituents and evaluate the antibacterial activity of seed and pod extracts of C. incana. Methods: Phytochemical screening tests were conducted to identify the class of compounds present in the dichloromethane/methanol (1:1) extracts of seed and pod. Silica gel column chromatographic technique was applied to separate the constituents of the extracts. Various spectroscopic techniques (IR, NMR (1H, 13C and DEPT-135) were applied to determine the structures of isolated compounds. Antibacterial activities were evaluated via disc diffusion method. Results: Preliminary phytochemical screening of seed and pod extracts of C. incana L. revealed the presence alkaloids, flavonoids, triterpenes, tannins and steroids and absence of anthraquinones. Silica gel column chromatography separation of the extract yielded a known steroid β-sitosterol (1) and 1-nonadecanol (2). Evaluation of antibacterial activity of crude extract via disc diffusion method against Escherichia coli, Staphylococcus aureus, Klebsiella pneumonia and Salmonella typhi showed moderate susceptibility of this selected Gram-positive and Gram-negative bacteria strains, comparable to the activity of the antibiotic (gentamicin). Conclusions: The compound (2) (1-nonadecanol) was isolated for the first time from the C. incana. These results proved that polar extracts of the seeds and pods of C. incana possess antibacterial activity

Antibacterial and Antioxidant Efficacies of Secondary Metabolites from the Roots of Cyphostemma adenocaule: A Combined In Vitro and In Silico Study

Cyphostemma adenocaule is a therapeutic plant traditionally used to treat rabies, snake bite, diarrhea, and wound healing. To address the bioactive compounds exhibiting these activities, we performed a comprehensive study on the roots of the plant. Thus, the present study aims to inspect the in vitro antioxidant and antibacterial efficacies of compounds isolated from the combined dichloromethane : methanol (1 : 1) and methanol extracts of C. adenocaule along with the in silico study of their interaction with selected protein targets. The silica gel column chromatography technique was used for the isolation of compounds, and the antibacterial and antioxidant activities were evaluated using agar disc diffusion and DPPH radical scavenging assays, respectively. Furthermore, in silico molecular docking screening, pharmacokinetics, and toxicity protocols of the compound isolates were performed to offer the potential applications of the compounds in developing novel medications. A BIOVIA Discovery Studio in combination with AutoDock Vina 4.2 software, SwissADME, and ProTox-II prediction web tools were used to generate the molecular docking, pharmacokinetics, and toxicity profiles, respectively. Notably, the chromatographic separation of the combined extracts yielded six known compounds, namely, β-sitosterol (1), 3-hydroxyisoagatholactone (2), ε-viniferin (3), myricetin (4), tricuspidatol A (5), and parthenocissin A (6). The in vitro antibacterial activities revealed the highest inhibition zone by tricuspidatol A (5) (16.67 ± 0.47), showcasing its potent activity against S. aureus at 2 mg/mL, compared to ciprofloxacin (21.50 ± 0.41). ε-Viniferin (3) (IC50: 0.32 μg/mL) exhibited greater antioxidant activity than the others and displayed promising results compared to ascorbic acid (0.075 μg/mL). The molecular docking study revealed the highest binding affinity by ε-viniferin (3) (−9.9 kcal/mol) against topoisomerase II α. 3-Hydroxyisoagatholactone (2) and ε-viniferin (3) fulfilled Lipinski’s rule with no violation, and the organ toxicity predictions revealed that all the compounds showed no cytotoxicity and hepatotoxicity effects. Thus, this study’s combined in vitro and in silico outcomes suggest the potential use of the isolated compounds in drug discovery and support the traditional relevance of C. adenocaule

Anthraquinones of the Roots of Pentas micrantha

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