Three New Abietane-Type Diterpenoids from Plectranthus africanus and Their Antibacterial Activities

Planta Medica ◽  
2017 ◽  
Vol 84 (01) ◽  
pp. 59-64 ◽  
Author(s):  
Raïssa Nzogong ◽  
Blaise Nganou ◽  
Alex Tedonkeu ◽  
Maurice Awouafack ◽  
Mathieu Tene ◽  
...  

AbstractThree new abietane-type diterpenoids, plectranthroyleanones A – C (1 – 3), together with five known compounds (4 – 8) were isolated from the methanol extract of the whole plant of Plectranthus africanus using column chromatography techniques. The structures of the new compounds were elucidated using a combination of 1D and 2D NMR and HRESIMS analyses. Compound 1 exhibited weak activities with minimal inhibitory concentration values of 75 µg/mL against gram-positive bacteria, Bacillus subtilis and Staphylococcus aureus, and 150 µg/mL against two gram-negative bacteria, Pseudomonas aeruginosa and Klebsiella pneumoniae, respectively, while 2 and 3 had moderate antibacterial activity against K. pneumoniae with a minimal inhibitory concentration value of 37.5 µg/mL.

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Serkan Yavuz ◽  
Hilal Yıldırım

In the present study, some novel ferrocene derivatives carrying urea, thiourea, and sulfonamide groups were synthesized, and all compounds were characterized by spectral and elemental analyses. These compounds were screened for their antibacterial activities and also their minimum inhibitory concentration (MIC) against Gram-positive bacteria (Staphylococcus aureusandBacillus subtilis) and Gram-negative bacteria (Klebsiella pneumoniaandEscherichia coli) and antifungal activities againstSaccharomyces cerevisiaeandCandida albicans. Amongst the tested compounds,4b,4c,5b, and6bdisplayed excellent antimicrobial activity.


Marine Drugs ◽  
2020 ◽  
Vol 18 (10) ◽  
pp. 522
Author(s):  
Eunji Cho ◽  
Oh-Seok Kwon ◽  
Beomkoo Chung ◽  
Jayho Lee ◽  
Jeongyoon Sun ◽  
...  

A marine-derived actinomycete (Streptomyces sp. MBTI36) exhibiting antibacterial activities was investigated in the present study. The strain was identified using genetic techniques. The 16S rDNA sequence of the isolate indicated that it was most closely related to Streptomyces microflavus. Furthermore, a new chromomycin A9 (1), along with chromomycin Ap (2), chromomycin A2 (3), and chromomycin A3 (4), were isolated from the ethyl acetate extract. Their structures were determined using extensive spectroscopic methods including 1D and 2D NMR, and HRMS, as well as comparisons with previously reported data. Compounds 1–4 showed potent antibacterial activities against Gram-positive bacteria including methicillin-resistant Staphylococcus aureus (MRSA). During a passage experiment, minimum inhibitory concentration (MIC) values for compounds 1–4 showed no more than a 4-fold increase from the starting MIC value, indicating that no resistance was detected over the 21 passages.


2021 ◽  
Vol 37 ◽  
pp. e37061
Author(s):  
Tabinda Nowsheen ◽  
Ali Hazrat ◽  
Sayed Wadood Ali Shah ◽  
Shabana Bibi ◽  
Afshan Begum ◽  
...  

The current study was carried out to explore the phytochemical, antioxidant potential and antibacterial activities of the crude methanolic extract of A. santolinifolia Turcz. Ex Besser. The antioxidant activity was carried out by using 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2’-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid (ABTS) assay, while methanolic extract displayed the highest scavenging activity (DPPH) was 61.31µg/ml on Artemisia santolinifolia root and the lowest (51.05µg/ml) was record for their leaves. Similarly, in (ABTS) the highest activity (89.16µg/ml) was recorded for roots of A. santolinifolia followed by leaves (68.14µg/ml). In low inhibitory concentration assay, the crude methanolic extracts showed significant inhibition against all tested microbes on different concentrations like 25 µg/ml, 50 µg/ml, and 100 µg/ml. The leaves extract of A. santolinifolia AsL showed MIC of 12.5µg/ml for B. subtilis, a gram-positive bacterium, 50µg/ml for gram positive bacteria S. aureus and 37.5 µg/ml for gram negative bacteria P. aeruginosa that is almost equal to the response of standard ciprofloxacin. Our current study revealed that Artemisia santolinifolia root (AsR) exhibited a significant antioxidant potential while AsL showed good antibacterial effect which is suggested to be used for treatment and management of different infectious diseases.


Molecules ◽  
2019 ◽  
Vol 24 (4) ◽  
pp. 805 ◽  
Author(s):  
Liang-Bo Li ◽  
Guang-Da Xiao ◽  
Wei Xiang ◽  
Xing Yang ◽  
Ke-Xin Cao ◽  
...  

Three new substituted bithiophenes (1–3), and one new sulf-polyacetylene ester, ritroyne A (16) were isolated from the whole plant of Echinops ritro together with twelve known substituted thiophenes. The structures were elucidated on the basis of extensive spectroscopic analysis including 1D and 2D NMR as well as MS. Furthermore, the absolute configuration of ritroyne A (16) was established by computational methods. In bioscreening experiments, four compounds (2, 4, 12, 14) showed similar antibacterial activity against Staphylococcus aureus ATCC 2592 with levofloxacin (8 µg/mL). Five compounds (2, 4, 9, 12, 14) exhibited antibacterial activities against Escherichia coli ATCC 25922, with minimum inhibitory concentration (MIC) values of 32–64 µg/mL. Three compounds (2, 4, 12) exhibited antifungal activities against Candida albicans ATCC 2002 with MIC values of 32–64 µg/mL. However, compound 16 did not exhibit antimicrobial activities against three microorganisms.


Author(s):  
A.A.J.P. Kumara ◽  
D. L. Jayratne ◽  
G. V. Samaranayake

Euphorbia antiquorum is a large shrub or small tree belonging to the largest and the most diverse family in the plant kingdom, Euphorbiaceae. E. antiquram latex was used as a classical binding agent for the kshara sutra in the management of the anal fistula. In the present study, an attempt was made to evaluate the antimicrobial properties of latex of E. antiquorum on certain microbes. The methanolic extract of the latex was prepared. The fractions of methanol extract were tested for their antibacterial activity against the Gram positive bacteria, Streptococus agalactiae and Staphylococcus aureus and Gram negative bacteria Escherichia coli and P. aeruginosa. The results revealed that the latex showed minimum inhibition only to E. coli and S. aureus. Latex did not posses antibacterial activity against S. agalactiae and P. aeruginosa. The results suggest that the E. antiquorum latex extract account for the antibacterial properties and has a potential for use as an antimicrobial agent.


Crystals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 789
Author(s):  
Shih-Fu Ou ◽  
Ya-Yun Zheng ◽  
Sin-Jen Lee ◽  
Shyi-Tien Chen ◽  
Chien-Hui Wu ◽  
...  

Graphene quantum dots, carbon nanomaterials with excellent fluorescence characteristics, are advantageous for use in biological systems owing to their small size, non-toxicity, and biocompatibility. We used the hydrothermal method to prepare functional N-doped carbon quantum dots (N-CQDs) from 1,3,6-trinitropyrene and analyzed their ability to fluorescently stain various bacteria. Our results showed that N-CQDs stain the cell septa and membrane of the Gram-negative bacteria Escherichia coli, Salmonellaenteritidis, and Vibrio parahaemolyticus and the Gram-positive bacteria Bacillus subtilis, Listeria monocytogenes, and Staphylococcus aureus. The optimal concentration of N-CQDs was approximately 500 ppm for Gram-negative bacteria and 1000 ppm for Gram-positive bacteria, and the exposure times varied with bacteria. N-Doped carbon quantum dots have better light stability and higher photobleaching resistance than the commercially available FM4-64. When excited at two different wavelengths, N-CQDs can emit light of both red and green wavelengths, making them ideal for bioimaging. They can also specifically stain Gram-positive and Gram-negative bacterial cell membranes. We developed an inexpensive, relatively easy, and bio-friendly method to synthesize an N-CQD composite. Additionally, they can serve as a universal bacterial membrane-staining dye, with better photobleaching resistance than commercial dyes.


2006 ◽  
Vol 50 (6) ◽  
pp. 2261-2264 ◽  
Author(s):  
Hee-Soo Park ◽  
Hyun-Joo Kim ◽  
Min-Jung Seol ◽  
Dong-Rack Choi ◽  
Eung-Chil Choi ◽  
...  

ABSTRACT DW-224a showed the most potent in vitro activity among the quinolone compounds tested against clinical isolates of gram-positive bacteria. Against gram-negative bacteria, DW-224a was slightly less active than the other fluoroquinolones. The in vivo activities of DW-224a against gram-positive bacteria were more potent than those of other quinolones.


2021 ◽  
Author(s):  
Lin Yang ◽  
Jinge Sun ◽  
Qiuting Ren ◽  
Xu Ma ◽  
Yaya Wang ◽  
...  

Abstract Background With the development of aquaculture, fish and shrimp diseases have been paid more and more attention in the world. How to improve the immunity of aquatic animals was an urgent problem to be solved. Duckweed (Lemnacecae), as a eukaryote, could be an ideal feedstock for the production of antimicrobial peptides. Result Penaeidins 3a (Pen 3a) from Litopenaeus vannamei was expressed under the control of CaMV-35S promoter in duckweed, Lemna turionifera 5511. Bacteriostatic test by Pen3a duckweed extract showed the antibacterial activity against Escherichia coli and Staphylococcus aureus. Transcriptome analysis of WT and Pen3a duckweed showed different results, and the protein metabolic process was the most up-regulated DEGs. In Pen 3a transgenic duckweed, the expression of sphingolipid metabolism and phagocytosis process-related genes have been significantly up-regulated. Quantitative proteomics suggested a remarkable difference in protein enrichment in metabolic pathways. Conclusion Our study provide a novel solution on aquaculture and water purification. The Pen 3a transgenic duckweed extraction inhibit the growth of gram-negative bacteria, gram-positive bacteria, which could be applied to control the bacteria in lake. The results could lay the foundation for the subsequent production of antibiotics.


2011 ◽  
Vol 11 ◽  
pp. 2237-2242 ◽  
Author(s):  
S. C. Sati ◽  
Savita Joshi

The antibacterial activity of methanol, ethanol, chloroform, and hexane extracts of the leaves of Himalayan gymnospermous plantGinkgo bilobaL. was assessed against five animal and plant pathogenic strains (Agrobacterium tumefaciens, Bacillus subtilis, Escherichia coli, Erwinia chrysanthemi, and Xanthomonas phaseoli) employing disc-diffusion and broth-dilution assays. The methanol extract showed the highest activity (zone of inhibition of 15–21 mm) followed by ethanol (14–19 mm), chloroform (15–20 mm), and hexane (14–19 mm) extracts at 250 μg/mL. A minimum inhibitory concentration (MIC) of 7.8 μg/mL was found for the methanol extract against most of the pathogens tested.


2017 ◽  
Vol 12 (7) ◽  
pp. 1934578X1701200 ◽  
Author(s):  
Soumia Mouffouk ◽  
Laurence Marcourt ◽  
Mohammed Benkhaled ◽  
Kaouthar Boudiaf ◽  
Jean-Luc Wolfender ◽  
...  

Two new prenylated isoflavonoids, namely Erinasone A and Erinasone B along with 19 known secondary metabolites, including twelve isoflavonoids, three polyphenols, one flavonol, two flavanones and three steroids, were isolated from the whole plant (roots and aerial parts) of Erinacea anthyllis. Structures of all isolated compounds were elucidated by spectroscopic analysis, including 1D and 2D NMR (1H, 13C, COSY, HSQC, TOCSY, HMBC and NOESY), mass spectrometry (ESI-MS), UV-Vis, measurement of optical rotation [α]D and by comparison with the literature data. The total phenolic and flavonoid contents were determined in this study. Furthermore, the antioxidant and antibacterial activities of the EtOAc and n-BuOH extracts of E. anthyllis were evaluated. These extracts exhibited moderate antibacterial and antioxidant activities. Their IC50 values were approximately 0.04 mg/mL ( n-BuOH) and 0.037 mg/mL (EtOAc). Consequently, Erinacea anthyllis is a rich source of polyphenolic compounds particularly isoflavonoids used as chemotaxonomic markers for the subfamily Papilionoideae of the family Fabaceae.


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