Benzoylcyclopropane Derivatives from Hypoxis hemerocallidea Corms

Planta Medica ◽  
2021 ◽  
Author(s):  
Fazila Zulfiqar ◽  
Pankaj Pandey ◽  
Siddharth K. Tripathi ◽  
Zulfiqar Ali ◽  
Amar G. Chittiboyina ◽  
...  

AbstractTwo monobenzoylcyclopropane (hypoxhemerol A (1) and hypoxhemeroloside G (2)) and three dibenzoylcyclopropane (hypoxhemerol B (3), hypoxhemeroloside H (4), and hypoxhemeroloside I (5)) derivatives were isolated from the hydro-alcoholic extract of Hypoxis hemerocallidea corms. This is the first instance where benzoylcyclopropane analogs were isolated from any natural source. Structure elucidation was mainly based on 1D- and 2D-NMR and HRESIMS data. The absolute configuration (2R, 4R) of 1 was determined via NOESY NMR and experimental and calculated ECD data analyses. Compounds 1–5 and 11 recently reported metabolites (hypoxoside, obtuside A, interjectin, acuminoside, curcapicycloside, and hypoxhemerolosides A – F) were screened for in vitro antimicrobial activity against various bacterial and fungal strains. Curcapicycloside and acuminoside exhibited antibacterial activity against Escherichia coli with 78 and 79% inhibition at 20 µg/mL, respectively. Hypoxhemeroloside A showed mild antifungal activity against Cryptococcus neoformans with 63% inhibition at 20 µg/mL.

2015 ◽  
Vol 51 (4) ◽  
pp. 861-867 ◽  
Author(s):  
Roosevelt Albuquerque Gomes ◽  
Yanna Carolina Ferreira Teles ◽  
Fillipe de Oliveira Pereira ◽  
Luis Alberto de Sousa Rodrigues ◽  
Edeltrudes de Oliveira Lima ◽  
...  

abstract Sidastrum micranthum (A. St.-Hil.) Fryxell, a member of the Malvaceae family, is called malva preta in Brazil. As this species is commonly used to treat bronchitis, cough, and asthma, better knowledge of its chemical compounds is important. The phytochemical study of its hexane extract, using chromatographic techniques, led to isolation of six compounds: the triterpene isoarborinol, a mixture of sitosterol and stigmasterol, sitosterol-3-O-β-D-glucopyranoside, pheophytin a, and 132-hydroxy-(132-S)-pheophytin a. Structural identification of these compounds was carried out using spectroscopic methods such as IR and 1D and 2D NMR (HOMOCOSY, HMQC, HMBC, and NOESY). Compounds isolated from S. micranthum were screened for their in vitro antifungal and antibacterial activity against twenty fungal and bacterial standard strains. Pheophytin a exhibited antimicrobial action against all microorganisms tested.


Antibiotics ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 1158
Author(s):  
Abdelsamed I. Elshamy ◽  
Tarik A. Mohamed ◽  
Eman M. Elkady ◽  
Ibrahim A. Saleh ◽  
Ahmed A. El-Beih ◽  
...  

The organic extracts of the Red Sea soft coral Paralemnalia thyrsoides has led to the identification of two neolemnane-type sesquiterpenoids: paralemnolins X and Y (1, 2). In addition to these newly characterized compounds, ten known metabolites (3–12) were isolated. Previously reported compounds were elucidated by literature comparison of spectroscopic data (1D and 2D NMR as well as MS data). In vitro antimicrobial activity was investigated for compounds (1–12) against Staphylococcus aureus, Escherichia coli, Candida albicans and Aspergillus niger. Compound 5 showed antimicrobial activity against all assayed microorganisms.


2012 ◽  
Vol 36 (0E) ◽  
pp. 1-7
Author(s):  
Hassan A. Abdul-Ratha

The antimicrobial activity of Lactobacilli has been widely exploited for prevention offood –borne pathogens e.g.: Escherichia coli being the major cause of diarrhea especially inchildren, because of bacteriocin activity and the importance of herbal drugs, hence this studywas designed to evaluate the synergistic effect of plant extract and bacteriocin produced byLactobacillus on the growth and pathogenesis of Enteropathogenic Ecoli.1. The Plantaricin production was induced by adding the mutagenic agent Mitomycin C.2. Purification of Plantaricin was made by heating crude plantaricin at 80ºC for 10min andthen purified by two steps method including extraction with n-butanol followed by gelfiltration chromatography on Sepharose 6B column. The results showed that the specificactivity was 1600 AU/mg protein with 8 purification folds and 12% recovery yield.3. The antibacterial activity of Quercus infectoria with concentration 300 mg/ml wasshowed highly antibacterial activity in vitro and in vivo.4. The result showed synergistic effect of Plantaricin with Quercus infectoria extract afterexperimental infection that induced by orally dosing with Escherichia coli in vivo. A result ofhistopathological study was recorded recovery of tissue.


2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
B. A. Baviskar ◽  
S. S. Khadabadi ◽  
S. L. Deore

A new series ofN-{4-methyl-5-[4-(4-oxo-2-phenyl(1,3-thiazolidin-3-yl)]-5-sulfanyl(1,2,4-triazol-3-yl)-1,3-thiazol-2-yl }acetamide (7a-l) was synthesized in order to determine their antimicrobial activity and feasible structure–activity relationships. The compounds were synthesized in good yield and the structures of all newly synthesized compounds were established on the basis of their IR,1HNMR, and elemental analysis. The synthesized compounds were testedin vitroantibacterial activity againstStaphylococcus aureus,Escherichia coli,Pseudomonas aeruginosaandSalmonella typhiand antifungal activity againstAspergillus niger,Candida albicansby measuring the zone of inhibition in mm.


2019 ◽  
Vol 13 (2) ◽  
pp. 120-128
Author(s):  
Amal Thebti ◽  
Ines Chniti ◽  
Med Abderrahmane Sanhoury ◽  
Ikram Chehidi ◽  
Hadda Imene Ouzari ◽  
...  

Background:The widespread occurrence of resistance to current antibiotics has triggered increasing research efforts to design and develop innovative antibacterial and antifungal agents that could overcome such antimicrobial resistance.Objective:The aim of this work was the in vitro evaluation of twelve highly fluorinated Nmonosubstituted thiocarbamates and dithiocarbamates and six non-fluorinated analogs against nine bacterial strains and three fungal species.Methods:The in vitro antimicrobial activity against the tested microrganisms was evaluated using the microdilution broth method.Results:Escherichia coli ATCC 8739, Salmonella sp., Staphylococcus aureus 6539 and all the three fungi (Aspergillus niger, Aspergillus flavus and Penicillium expansum) exhibited the highest rate of susceptibility, whilst Enterococcus faecuim ATCC 19436 and particularly Escherichia coli DH5α were less susceptible. Thiocarbamate (1i) and dithiocarbamate (2i) showed both the lowest MIC values (3.9 µg/mL) and the widest spectrum of antibacterial activity. Furthermore, the N-ethyl derivatives inhibited more efficiently the growth of bacteria than N-aryl analogs.Conclusion:The fluorinated compounds showed, in general, a relatively more potent antibacterial activity than non-fluorinated counterparts. The results indicate that these thiocarbamates and dithiocarbamates could be promising candidates as potential antimicrobial agents.


2002 ◽  
Vol 57 (5-6) ◽  
pp. 483-488 ◽  
Author(s):  
Moacir G. Pizzolatti ◽  
Andreia F. Venson ◽  
Artur Smânia Júnior ◽  
Elza de F. A. Smânia ◽  
Raimundo Braz-Filho

A mixture of flavalignan cinchonains Ia and Ib was isolated from the bark of Trichilia catigua. The structures were established on the basis of spectroscopic data of the natural products and their methylated derivatives including 2D NMR experiments, and compared with data in the literature. These flavalignans exhibited antibacterial activity against Bacillus cereus, Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus.


Molecules ◽  
2021 ◽  
Vol 26 (9) ◽  
pp. 2597
Author(s):  
Birutė Sapijanskaitė-Banevič ◽  
Vykintas Palskys ◽  
Rita Vaickelionienė ◽  
Jūratė Šiugždaitė ◽  
Povilas Kavaliauskas ◽  
...  

The p-aminobenzoic acid was applied for the synthesis of substituted 1-phenyl-5-oxopyrrolidine derivatives containing benzimidazole, azole, oxadiazole, triazole, dihydrazone, and dithiosemicarbazide moieties in the structure. All the obtained compounds were evaluated for their in vitro antimicrobial activity against Staphylococcus aureus, Bacillus cereus, Listeria monocytogenes, Salmonella enteritidis, Escherichia coli, and Pseudomonas aeruginosa by using MIC and MBC assays. This study showed a good bactericidal activity of γ-amino acid and benzimidazoles derivatives. The antimicrobial activity of the most promising compounds was higher than ampicillin. Furthermore, two benzimidazoles demonstrated good antimicrobial activity against L. monocytogenes (MIC 15.62 µg/mL) that was four times more potent than ampicillin (MIC 65 µg/mL). Further studies are needed to better understand the mechanism of the antimicrobial activity as well as to generate antimicrobial compounds based on the 1-phenyl-5-oxopyrrolidine scaffold.


2020 ◽  
Vol 22 (1) ◽  
pp. 43 ◽  
Author(s):  
Т.V. Kharlamova ◽  
R.B. Seidakhmetova ◽  
K.D. Praliyev

The present study is a continuation of the scientific research works for the synthesis of anthraquinonе-containing derivatives with cyclic ring systems by the interaction of 1,2,4-trihydroxyanthraquinone (purpurin) with cyclic carboxylic acid chlorides. Series of purpurin esters containing a saturated cyclic fragment was studied for antibacterial activity about museum strains of microorganisms. The effects of these preparations in vitro about Staphylococcus aureus ATCC 6538, Bacillus subtilis ATCC 6633, Escherichia coli ATCC 25922, Pseudomonas aeruginosa АТСС 27853 and fungus Сandida albicans АТСС 10231 were studied. It has been found that the compounds with the cyclohexane fragment have possess an antimicrobial activity with strains of microorganisms Staphylococcus aureus АТСС 6538 for which the MIC value was 31.25 μg/ml.


Author(s):  
О.В. Шамова ◽  
М.С. Жаркова ◽  
П.М. Копейкин ◽  
Д.С. Орлов ◽  
Е.А. Корнева

Антимикробные пептиды (АМП) системы врожденного иммунитета - соединения, играющие важную роль в патогенезе инфекционных заболеваний, так как обладают свойством инактивировать широкий спектр патогенных бактерий, обеспечивая противомикробную защиту живых организмов. В настоящее время АМП рассматриваются как потенциальные соединения-корректоры инфекционной патологии, вызываемой антибиотикорезистентными бактериями (АБР). Цель данной работы состояла в изученим механизмов антибактериального действия трех пептидов, принадлежащих к семейству бактенецинов - ChBac3.4, ChBac5 и mini-ChBac7.5Nb. Эти химически синтезированные пептиды являются аналогами природных пролин-богатых АМП, обнаруженных в лейкоцитах домашней козы Capra hircus и проявляющих высокую антимикробную активность, в том числе и в отношении грамотрицательных АБР. Методы. Минимальные ингибирующие и минимальные бактерицидные концентрации пептидов (МИК и МБК) определяли методом серийных разведений в жидкой питательной среде с последующим высевом на плотную питательную среду. Эффекты пептидов на проницаемость цитоплазматической мембраны бактерий для хромогенного маркера исследовали с использованием генетически модифицированного штамма Escherichia coli ML35p. Действие бактенецинов на метаболическую активность бактерий изучали с применением маркера резазурина. Результаты. Показано, что все исследованные пептиды проявляют высокую антимикробную активность в отношении Escherichia coli ML35p и антибиотикоустойчивых штаммов Escherichia coli ESBL и Acinetobacter baumannii in vitro, но их действие на бактериальные клетки разное. Использован комплекс методик, позволяющих наблюдать в режиме реального времени динамику действия бактенецинов в различных концентрациях (включая их МИК и МБК) на барьерную функцию цитоплазматической мембраны и на интенсивность метаболизма бактериальных клеток, что дало возможность выявить различия в характере воздействия бактенецинов, отличающихся по структуре молекулы, на исследуемые микроорганизмы. Установлено, что действие каждого из трех исследованных бактенецинов в бактерицидных концентрациях отличается по эффективности нарушения целостности бактериальных мембран и в скорости подавления метаболизма клеток. Заключение. Полученная информация дополнит существующие фундаментальные представления о механизмах действия пролин-богатых пептидов врожденного иммунитета, а также послужит основой для биотехнологических исследований, направленных на разработку на базе этих соединений новых антибиотических препаратов для коррекции инфекционных заболеваний, вызываемых АБР и являющимися причинами тяжелых внутрибольничных инфекций. Antimicrobial peptides (AMPs) of the innate immunity are compounds that play an important role in pathogenesis of infectious diseases due to their ability to inactivate a broad array of pathogenic bacteria, thereby providing anti-microbial host defense. AMPs are currently considered promising compounds for treatment of infectious diseases caused by antibiotic-resistant bacteria. The aim of this study was to investigate molecular mechanisms of the antibacterial action of three peptides from the bactenecin family, ChBac3.4, ChBac5, and mini-ChBac7.5Nb. These chemically synthesized peptides are analogues of natural proline-rich AMPs previously discovered by the authors of the present study in leukocytes of the domestic goat, Capra hircus. These peptides exhibit a high antimicrobial activity, in particular, against antibiotic-resistant gram-negative bacteria. Methods. Minimum inhibitory and minimum bactericidal concentrations of the peptides (MIC and MBC) were determined using the broth microdilution assay followed by subculturing on agar plates. Effects of the AMPs on bacterial cytoplasmic membrane permeability for a chromogenic marker were explored using a genetically modified strain, Escherichia coli ML35p. The effect of bactenecins on bacterial metabolic activity was studied using a resazurin marker. Results. All the studied peptides showed a high in vitro antimicrobial activity against Escherichia coli ML35p and antibiotic-resistant strains, Escherichia coli ESBL and Acinetobacter baumannii, but differed in features of their action on bacterial cells. The used combination of techniques allowed the real-time monitoring of effects of bactenecin at different concentrations (including their MIC and MBC) on the cell membrane barrier function and metabolic activity of bacteria. The differences in effects of these three structurally different bactenecins on the studied microorganisms implied that these peptides at bactericidal concentrations differed in their capability for disintegrating bacterial cell membranes and rate of inhibiting bacterial metabolism. Conclusion. The obtained information will supplement the existing basic concepts on mechanisms involved in effects of proline-rich peptides of the innate immunity. This information will also stimulate biotechnological research aimed at development of new antibiotics for treatment of infectious diseases, such as severe in-hospital infections, caused by antibiotic-resistant strains.


Marine Drugs ◽  
2021 ◽  
Vol 19 (2) ◽  
pp. 46
Author(s):  
Karolina Subko ◽  
Sara Kildgaard ◽  
Francisca Vicente ◽  
Fernando Reyes ◽  
Olga Genilloud ◽  
...  

The marine-derived fungus Stilbella fimetaria is a chemically talented fungus producing several classes of bioactive metabolites, including meroterpenoids of the ascochlorin family. The targeted dereplication of fungal extracts by UHPLC-DAD-QTOF-MS revealed the presence of several new along with multiple known ascochlorin analogues (19–22). Their structures and relative configuration were characterized by 1D and 2D NMR. Further targeted dereplication based on a novel 1,4-benzoquinone sesquiterpene derivative, fimetarin A (22), resulted in the identification of three additional fimetarin analogues, fimetarins B–D (23–25), with their tentative structures proposed from detailed MS/HRMS analysis. In total, four new and eight known ascochlorin/fimetarin analogues were tested for their antimicrobial activity, identifying the analogues with a 5-chloroorcylaldehyde moiety to be more active than the benzoquinone analogue. Additionally, the presence of two conjugated double bonds at C-2′/C-3′ and C-4′/C-5′ were found to be essential for the observed antifungal activity, whereas the single, untailored bonds at C-4′/C-5′ and C-8′/C-9′ were suggested to be necessary for the observed antibacterial activity.


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