scholarly journals Synthesis of Kojic Ester Derivatives as Potential Antibacterial Agent

2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Carolynne Zie Wei Sie ◽  
Zainab Ngaini ◽  
Nurashikin Suhaili ◽  
Eswaran Madiahlagan

The search for lead product with beneficial pharmacological properties has become a great challenge and costly. Extraction and synthetic modification of bioactive compounds from natural resources has gained great attention and is cost effective. In this study, kojic acid was produced from fungal fermentation, using sago waste as substrate, and chemically incorporated with chalcones and azobenzene to form a series of kojic ester derivatives and evaluated for antibacterial activities. Kojic ester bearing halogenated chalcone demonstrated active inhibition against Staphylococcus aureus compared to that of standard ampicillin. The inhibition increased as the electronegativity of halogens decreased, while incorporation of azobenzene derivatives on kojic acid backbone demonstrated fair antibacterial activity against Escherichia coli with minimum inhibitory concentration (MIC) of 190–330 ppm. The presence of C=C and N=N reactive moieties in both chalcone and azo molecules contributed to the potential biological activities of the kojic acid ester.

2021 ◽  
Vol 33 (3) ◽  
pp. 545-550
Author(s):  
P. Siripipatthana ◽  
P. Srihanam ◽  
A. Sangdee

A hydromethanolic root extract of Ampelocissus martinii Planch. (A. martinii) was analyzed by standard methods for its phytochemical content, antioxidant activity, α-amylase and α-glucosidase inhibitions and antibacterial activities. The root extract exhibited the highest content of saponins, followed by phenols, proanthocyanidin and flavonoids, respectively. It showed high antioxidant activity in FRAP and CUPRAC assays. The root extract and standard Trolox had similar antioxidant activities in the DPPH and ABTS assay. It also showed much higher α-amylase and α-glucosidase inhibitory activity compared to standard acarbose. Moreover, the root extract inhibited all tested Gram-positive bacteria with the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of 6.25 mg/mL. These results indicate that A. martinii root can be pharmaceutically used as active ingredients to prevent bacterial infection and radical-related diseases especially diabetes.


Polymers ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 1979
Author(s):  
Lin Song ◽  
Wancui Xie ◽  
Yukun Zhao ◽  
Xinyao Lv ◽  
Huanbin Yang ◽  
...  

Kojic acid (KA) with antibacterial activities produced by fermentation was grafted onto konjac glucomannan oligosaccharide (KGO) composed of glucose and mannose linked by β-1,4 glycosidic bonds. A novel KGO derivative, konjac glucomannan oligosaccharide kojic acid (KGOK) possessing both moisture retention and antibacterial activities was synthesized. The structure of KGOK was characterized and analyzed by thermogravimetric analysis (TG), XRD, UV–vis absorption, FTIR, and 1H NMR. The analysis results suggest that KA was linked to the KGO molecular chain through a covalent bond, and the reaction site of KA was the methylol group. The studies demonstrate that KGOK maintained the excellent moisture absorption and retention properties of KGO and the good antibacterial activities of KA. The minimum inhibitory concentration (MIC) of KGOK is 2 mg/mL for Staphylococcus aureus, Staphylococcus epidermidis, Shewanella putrefaciens, and Salmonella enterica, while its MIC is 3 mg/mL for Escherichia coli. The multi-functionality of the KGOK synthesized from natural sources provides a theoretical foundation for their potential applications in the preservation of food, beverage, aquatic, and cosmetic products.


2019 ◽  
Vol 5 (3) ◽  
pp. 1-10
Author(s):  
Puspa Julistia Puspita ◽  
Mega Safithri ◽  
Nirmala Peni Sugiharti

Piper crocatum is one of medicinal herbal plants with a large number of benefits. Usually herbal plants have activity as antibacterial agent. Therefore, the objectives of this research were to obtain information on antibacterial activities of the leaf extracts of Piper crocatum againts four types of bacteria, in that Staphylococcus, Bacillus substilis, Escherichia coli, and Pseudomonas aeruginosa and then to analyze the phytochemistry of the leaf extracts of Piper crocatum. The leaves of Piper crocatum were extracted by maceration and reflux using ethanol 30%. The assays of the antibacterial activities and phytochemistry on the extracts were carried out using the method of Maria Bintang. Results showed that the yield of the extraction using ethanol by maceration method was 20.8%. Meanwhile, using the reflux method, the yield was obtained about 26.25%. The phytochemistry analysis showed that the leaf extracts of Piper crocatum contained alkaloid, steroid and tanin. According to this study, it was found that the leaf extract of Piper crocatum can be used to inhibit the growth of B. subtilis and P. aeuruginosa, but can not inhibit the growth of E.coli and S. aureus.


2020 ◽  
Vol 24 (4) ◽  
pp. 354-401 ◽  
Author(s):  
Keisham S. Singh

Marine natural products (MNPs) containing pyrone rings have been isolated from numerous marine organisms, and also produced by marine fungi and bacteria, particularly, actinomycetes. They constitute a versatile structure unit of bioactive natural products that exhibit various biological activities such as antibiotic, antifungal, cytotoxic, neurotoxic, phytotoxic and anti-tyrosinase. The two structure isomers of pyrone ring are γ- pyrone and α-pyrone. In terms of chemical motif, γ-pyrone is the vinologous form of α- pyrone which possesses a lactone ring. Actinomycete bacteria are responsible for the production of several α-pyrone compounds such as elijopyrones A-D, salinipyrones and violapyrones etc. to name a few. A class of pyrone metabolites, polypropionates which have fascinating carbon skeleton, is primarily produced by marine molluscs. Interestingly, some of the pyrone polytketides which are found in cone snails are actually synthesized by actinomycete bacteria. Several pyrone derivatives have been obtained from marine fungi such as Aspergillums flavus, Altenaria sp., etc. The γ-pyrone derivative namely, kojic acid obtained from Aspergillus fungus has high commercial demand and finds various applications. Kojic acid and its derivative displayed inhibition of tyrosinase activity and, it is also extensively used as a ligand in coordination chemistry. Owing to their commercial and biological significance, the synthesis of pyrone containing compounds has been given attention over the past years. Few reviews on the total synthesis of pyrone containing natural products namely, polypropionate metabolites have been reported. However, these reviews skipped other marine pyrone metabolites and also omitted discussion on isolation and detailed biological activities. This review presents a brief account of the isolation of marine metabolites containing a pyrone ring and their reported bio-activities. Further, the review covers the synthesis of marine pyrone metabolites such as cyercene-A, placidenes, onchitriol-I, onchitriol-II, crispatene, photodeoxytrichidione, (-) membrenone-C, lihualide-B, macrocyclic enol ethers and auripyrones-A & B.


2021 ◽  
Author(s):  
Luke D Geoffrion ◽  
David Medina Cruz ◽  
Matthew Kusper ◽  
Sakr Elsaidi ◽  
Fumiya Watanabe ◽  
...  

Bismuth oxide is an important bismuth compound having applications in electronics, photo-catalysis and medicine. At the nanoscale, bismuth oxide experiences a variety of new physico-chemical properties because of its increased...


Antibiotics ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 893
Author(s):  
Olufunto T. Fanoro ◽  
Sundararajan Parani ◽  
Rodney Maluleke ◽  
Thabang C. Lebepe ◽  
Jose R. Varghese ◽  
...  

We herein report a facile, green, cost-effective, plant-mediated synthesis of gold nanoparticles (AuNPs) for the first time using Combretum erythrophyllum (CE) plant leaves. The synthesis was conducted at room temperature using CE leaf extract serving as a reducing and capping agent. The as-synthesized AuNPs were found to be crystalline, well dispersed, and spherical in shape with an average diameter of 13.20 nm and an excellent stability of over 60 days. The AuNPs showed broad-spectrum antibacterial activities against both pathogenic Gram-positive (Staphylococcus epidermidis (ATCC14990), Staphylococcus aureus (ATCC 25923), Mycobacterium smegmatis (MC 215)) and Gram-negative bacteria (Proteus mirabilis (ATCC 7002), Escherichia coli (ATCC 25922), Klebsiella pneumoniae (ATCC 13822), Klebsiella oxytoca (ATCC 8724)), with a minimum inhibition concentration of 62.5 µg/mL. In addition, the as-synthesized AuNPs were highly stable with exceptional cell viability towards normal cells (BHK- 21) and cancerous cancer cell lines (cervical and lung cancer).


Author(s):  
Olufunmiso O. Olajuyigbe ◽  
Morenike O. Adeoye-Isijola ◽  
Otunola Adedayo

Background: Black soap is a medicinal product that could be harnessed for economic purpose if properly packaged, and misconception about its traditional use by herbalists is thrown overboard.Aims: To promote the relevance of these soaps for economic development, this study compared the antibacterial activity of black soaps with medicated soaps widely used against bacterial infections.Methods: The antibacterial activities of these soap samples were determined by agar diffusion and macrobroth dilution methods.Results: In this study, the statistical analysis of the inhibition zones showed that black soaps were significantly (p < 0.05) more active than medicated soaps used against the test bacterial isolates. The black soaps inhibited and killed the isolates better than the medicated soaps at the different concentrations used. The minimum inhibitory concentration for Klebsiella pneumoniae and Enterococcus faecalis ranged between 0.125 mg/mL and 2 mg/mL, Staphylococcus aureus (0.25–4) mg/mL, Escherichia coli (0.125–4) mg/mL and Pseudomonas aeruginosa (1–4) mg/mL. The result showed that K. pneumoniae and E. faecalis were the most susceptible, followed by E. faecalis > E. coli > S. aureus > P. aeruginosa.Conclusion: As a valuable medicinal output derivable from organic waste product that could be converted to wealth, African black soap production, utilisation and commercialisation have tremendous economic potentials. These soaps showed significant antibacterial activity greater than those of the medicated soaps. Hence, their use could be a better option in place of commercially available medicated and antiseptic soaps because of the degree of antibacterial activities they exhibited.


2021 ◽  
Vol 28 ◽  
Author(s):  
Vishal Kumar ◽  
Sanjeev Dhawan ◽  
Pankaj Sanjay Girase ◽  
Paul Awolade ◽  
Suraj Raosaheb Shinde ◽  
...  

: Chalcones are an interesting class of compounds endowed with a plethora of biological activities beneficial to human health. These chemo types have continued to attract increased research attention over the years; hence, numerous natural and synthetic chalcones have found with interesting anticancer activities through the inhibition of various molecular targets including ABCG2, BCRP, P-glycoprotein, 5α-reductase, Androgen receptor (AR), Histone deacetylases (HDAC), Sirtuin 1, proteasome, Vascular endothelial growth factor (VEGF), Cathepsin-K, tubulin, CDC25B phosphatase, Topoisomerase, EBV, NF-κB, mTOR, BRAF and Wnt/β-catenin. Moreover, the study of intrinsic mechanisms of action, particularly relating to specific cellular pathways and modes of engagement with molecular targets, may help medicinal chemists to develop a more effective, selective, and cost-effective chalcone-based anticancer drugs. This review, therefore, sheds light on the effect of structural variations on the anticancer potency of chalcone hybrids reported in 2018-2019 alongside their mechanism of action, molecular targets, and potential impacts on effective cancer chemotherapy.


2012 ◽  
Vol 510 ◽  
pp. 757-761 ◽  
Author(s):  
Shu’e Duan ◽  
Yun Hui Zhai ◽  
Ying Juan Qu

In this paper a novel colorless and salt-tolerant silver-histidine complex doped montmorillonite (Na-MMT) antibacterial agent (SHMMT) power was synthesized by ion exchange reaction using silver-histidine complex ion [Ag (his)] + as precursor, and characterized by atomic absorption spectrophotometer (AAS) and power X-ray diffraction (XRD). The antibacterial activities against Pseudoalteromonas carrageenovora were examined by a modified broth dilution test and the plate counting method. The salt-tolerant property was determined by the antibacterial activities of the sea water soaked SHMMT. The results showed that the Ag loading amount of SHMMT powder reached 1.7mmol/g, far more than the cationic exchange capacity (CEC) of Na-MMT. SHMMT powder had high bacterial activity eventhough it was soaked in the sea water for 30 days. 1


Molecules ◽  
2020 ◽  
Vol 25 (23) ◽  
pp. 5679
Author(s):  
Qing-Wei Tan ◽  
Jian-Cheng Ni ◽  
Jian-Ting Shi ◽  
Jian-Xuan Zhu ◽  
Qi-Jian Chen

Phytochemistry investigations on Ailanthus altissima (Mill.) Swingle, a Simaroubaceae plant that is recognized as a traditional herbal medicine, have afforded various natural products, among which C20 quassinoid is the most attractive for their significant and diverse pharmacological and biological activities. Our continuous study has led to the isolation of two novel quassinoid glycosides, named chuglycosides J and K, together with fourteen known lignans from the samara of A. altissima. The new structures were elucidated based on comprehensive spectra data analysis. All of the compounds were evaluated for their anti-tobacco mosaic virus activity, among which chuglycosides J and K exhibited inhibitory effects against the virus multiplication with half maximal inhibitory concentration (IC50) values of 56.21 ± 1.86 and 137.74 ± 3.57 μM, respectively.


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