Bioassay-Guided Isolation and Identification of Antibacterial and Antifungal Component from Methanolic Extract of Green Tea Leaves (Camellia sinensis)

Chakraborty, Devjani; Chakraborti, Sunanda

doi:10.3923/rjphyto.2010.78.86

Cited by 27 publications

(17 citation statements)

References 14 publications

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“…The individual theaflavins and catechins (and few further compounds above GC) were detected to be radical scavenging compounds (DPPH ∙ assay), antibacterials against Gram-positive B. subtilis bacteria, and inhibitors of tyrosinase, α-glucosidase and AChE. These findings were in accordance with literature reporting strong antioxidant [ 25 , 26 ], antibacterial [ 21 , 22 , 23 , 24 ] activities as well as protective effects against diabetes [ 27 ] and Alzheimer’s disease [ 28 , 29 ]. All 8 flavan-3-ols showed almost comparable radical scavenging, α-glucosidase and AChE inhibiting effects, whereas the antibiotic activity against Gram-positive bacteria was pronounced in the following order: EGC, GC > EGCG > T > ECG > C, EC > CG.…”

Section: Resultssupporting

confidence: 88%

“…These and further oxidation products like theasinensins and (epi)theaflagallins [ 18 ] can react further during processing into more complex brown–red thearubigins of dimeric to polymeric acidic structures [ 19 , 20 ]. The strong antimicrobial, antiviral, antifungal, anticarcinogenic [ 21 , 22 , 23 , 24 ] and antioxidant [ 25 , 26 ] effects of tea and tea extracts are mainly attributed to the catechins, but also partially to the theaflavins. Thus, tea consumption can reduce the risk of cardiovascular diseases, protect against diabetes [ 27 ] and Alzheimer’s disease [ 28 , 29 ], reduce skin diseases, help with digestive disorders and respiratory diseases [ 18 ].…”

Section: Introductionmentioning

confidence: 99%

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Effect-Directed Profiling of Powdered Tea Extracts for Catechins, Theaflavins, Flavonols and Caffeine

et al. 2021

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The antioxidative activity of Camelia sinensis tea and especially powdered tea extracts on the market, among others used as added value in functional foods, can considerably vary due to not only natural variance, but also adulteration and falsification. Thus, an effect-directed profiling was developed to prove the functional effects or health-promoting claims. It took 3–12 min per sample, depending on the assay incubation time, for 21 separations in parallel. Used as a fast product quality control, it can detect known and unknown bioactive compounds. Twenty tea extracts and a reference mixture of 11-bioactive compounds were investigated in parallel under the same chromatographic conditions by a newly developed reversed phase high-performance thin-layer chromatographic method. In eight planar on-surface assays, effect-directed tea profiles were revealed. Catechins and theaflavins turned out to be not only highly active, but also multi-potent compounds, able to act in a broad range of metabolic pathways. The flavan-3-ols acted as radical scavengers (DPPH∙ assay), antibacterials against Gram-positive Bacillus subtilis bacteria, and inhibitors of tyrosinase, α-glucosidase, β-glucosidase, and acetylcholinesterase. Further effects against Gram-negative Aliivibrio fischeri bacteria and β-glucuronidase were assigned to other components in the powdered tea extracts. According to their specifications, the activity responses of the powdered tea extracts were higher than in mere leaf extracts of green, white and black tea. The multi-imaging and effect-directed profiling was not only able to identify known functional food ingredients, but also to detect unknown bioactive compounds (including bioactive contaminants, residues or adulterations).

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Section: Resultssupporting

confidence: 88%

Section: Introductionmentioning

confidence: 99%

Effect-Directed Profiling of Powdered Tea Extracts for Catechins, Theaflavins, Flavonols and Caffeine

et al. 2021

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“…Aspergillus niger has various industrial applications. It can rarely cause external otitis and allergic aspergillosis [ 13 ].…”

Section: Introductionmentioning

confidence: 99%

Antimicrobial, Optical and Mechanical Properties of Chitosan–Starch Films with Natural Extracts

Lozano-Navarro

Díaz-Zavala

Velasco‐Santos

et al. 2017

IJMS

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Natural extracts possess several kinds of antioxidants (anthocyanins, betalains, thymol, carvacrol, and resveratrol) that have also demonstrated antimicrobial properties. In order to study these properties, extracts from cranberry, blueberry, beetroot, pomegranate, oregano, pitaya, and resveratrol (from grapes) were obtained. Growth inhibition tests of mesophilic aerobes, coliforms, and fungi were conducted in films prepared from the extracts in accordance with Mexican Official Norms (NOM). Optical properties such as transparency and opacity, mechanical properties, and pH were also analyzed in these materials. The films with beetroot, cranberry, and blueberry extracts demonstrated the best antimicrobial activity against various bacteria and fungi in comparison with unmodified chitosan–starch film. This study shows that the addition of antioxidants improved the antimicrobial performance of these films. It was also found that antimicrobial properties are inherent to the films. These polymers combined with the extracts effectively inhibit or reduce microorganism growth from human and environmental contact; therefore, previous sterilization could be unnecessary in comparison with traditional plastics. The presence of extracts decreased transmittance percentages at 280 and 400 nm, as well as the transparency values, while increasing their opacity values, providing better UV–VIS light barrier properties. Despite diminished glass transition temperatures (Tg), the values obtained are still adequate for food packaging applications.

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“…Like fungicide, weedicide, insecticide; viricides are lacking in the control of plant viruses. Botanical extracts have been known to combat bacterial and fungal diseases and thus gaining attraction in crop protection [32]. Endogenous viral inhibitors that are proteinaceous antiviral substances extracted from plants and used against plant viral infections [88,152,153].…”

Section: Plant Extractsmentioning

confidence: 99%

Emerging threats of begomoviruses to the cultivation of medicinal and aromatic crops and their management strategies

Saeed

Samad

2017

VirusDis.

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Begomoviruses (family Geminiviridae) are responsible for extreme yield reduction in a number of economically important crops including medicinal and aromatic plants (MAPs). Emergence of new variants of viruses due to recombination and mutations in the genomes, modern cropping systems, introduction of susceptible plant varieties, global trade in agricultural products, and changes in climatic conditions are responsible for aggravating the begomovirus problems during the last two decades. This review summaries the current research work on begomoviruses affecting MAPs and provides various traditional and advanced strategies for the management of begomoviruses and vector in MAPs.

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Bioassay-Guided Isolation and Identification of Antibacterial and Antifungal Component from Methanolic Extract of Green Tea Leaves (Camellia sinensis)

Cited by 27 publications

References 14 publications

Effect-Directed Profiling of Powdered Tea Extracts for Catechins, Theaflavins, Flavonols and Caffeine

Effect-Directed Profiling of Powdered Tea Extracts for Catechins, Theaflavins, Flavonols and Caffeine

Antimicrobial, Optical and Mechanical Properties of Chitosan–Starch Films with Natural Extracts

Emerging threats of begomoviruses to the cultivation of medicinal and aromatic crops and their management strategies

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