Ginkgo, also known as ginkgo, is a special resource of China, accounting for more than 70% of the world's total. Ginkgo biloba is one of the key first-class protected plants in China and one of the ancient relict plants in the world. Studies have shown that Ginkgo biloba leaves and their extracts (GBE) contain various active substances such as flavonoids, lactones, phenols, terpenoids, polysaccharides, etc., which have antioxidant, bacteriostatic, immune, anti-inflammatory, anti-viral,.It has various biological activities such as blood sugar lowering, blood fat lowering, anti-tumor and anti-cancer. Among them, there are 40 kinds of flavonoids, which is one of the active ingredients of Ginkgo biloba. It is widely used in food, medicine, health care products, cosmetics and other fields.
1 The main antibacterial active ingredients and mechanism of Ginkgo biloba extract
Polysaccharide compounds are one of the important functional factors in Ginkgo biloba. They are mainly found in Ginkgo biloba leaves, which have strong antibacterial activity, scavenging active free radicals and anti-lipid oxidation. At present, more and more researches tend to replace chemical preservatives with plant polysaccharides to promote human health, food safety and future medical development. Studies have shown that the mechanism of bacteriostatic action of polysaccharides is mainly on cell membrane permeability, nucleic acid. It inhibits protein synthesis, interferes with cell wall formation, and acts as an anti-metabolite on the energy metabolism system to achieve bacteriostatic effects. There are also studies to detect the release of lactate dehydrogenase in cells by transmission electron microscopy, and to explore whether the essential oil of Litsea cubeba can damage the cell membrane of Vibrio. The results show that the essential oil of Litsea cubeba can destroy the cell membrane of Vibrio. It has certain reference value for the antibacterial mechanism of Ginkgo biloba polysaccharides.
The main active ingredient in Ginkgo biloba extract is flavonoids, most of which are present in the leaves, about 40 species, mainly including monoflavonoids, biflavonoids and catechins. Among them, kaempferol in monoflavonoids, The highest content of quercetin and isorhamnetin is considered to be a truly active substance in the total flavonoids of Ginkgo biloba. Flavonoids have the function of effectively removing toxic peroxygen free radicals, lowering blood lipids, promoting blood circulation and cerebral circulation. Flavonoids have good antibacterial action, and the mechanism of bacteriostatic action is flavonoids, which are polyphenolic compounds, pH value. The acidity is biased, which can degenerate the fungus protein or destroy the integrity of the cell membrane, thereby causing the microbial to have a functional disorder, thereby exerting a bacteriostatic effect. Combined with the structure and antibacterial mechanism of flavonoids in Ginkgo biloba extract, it is speculated that the mechanism of GBE inhibition is the combination of flavonoids and sugars into flavonoid glycosides, which hydrolyze the glycosidic bonds in bacterial cell walls and destroy the structure of bacterial cell walls. This causes the bacteria to die.
1.3 Ginkgo phenolic acid
Ginkgo phenolic acid lacquers are widely found in ginkgo leaves, seed kernels, and outer seed coats. Most of them are found in the outer seed coat of Ginkgo biloba. They can be divided into three categories: ginkgolic acid, ginkgo phenol, and ginkgo biloba. Ginkgo phenolic acid is considered to be a toxic and harmful substance in ginkgo because of its sensitization, mutagenicity and immunotoxicity. However, studies have shown that ginkgo also has many pharmacological effects such as anti-tumor, antibacterial and bactericidal, anti-oxidation and killing. Insects, etc. The study found that it has antibacterial activity against 9 plant pathogenic fungi, 10 animal pathogenic bacteria, 2 kinds of bacteria and 4 kinds of fungi.
2 Antibacterial effect of Ginkgo biloba extract
2.1 Antibacterial effect of Ginkgo biloba extract o n plant pathogenic fungi
Many studies have shown that Ginkgo biloba extract is suitable for a variety of phytopathogenic fungi (such as P. persicae, Magnaporthe oryzae, Pear Rust, Corn Anthracnose, Citrus scab, Citrus Penicillium sp., etc.) has a bacteriostatic effect, and the size of the bacteriostatic action varies depending on the method for extracting the bacteriostatic active ingredient of Ginkgo biloba, and is related to the concentration of the bacteriostatic active ingredient in the ginkgo extract. In the preliminary study of antibacterial and insecticidal activities in the outer extract of Ginkgo biloba exocarp, an indoor bacteriostatic experiment was carried out, and eight major harmful bacteria of various plants (the anemone of Strelitzia repens, the amphibians, and the black spots of cabbage) were isolated. Pathogen, cabbage anthracnose, Capsicum annuum, Capsicum anthracis, eggplant white fungus, Brassica oleracea, and a certain gradient concentration of Ginkgo biloba exocarp medium, antibacterial effect on Ginkgo biloba extract research. The results showed that the Ginkgo biloba extract had antibacterial activity against 8 major pathogens, and the bacteriostatic effect of the stock solution and the 5-fold dilution of Ginkgo biloba exocarp extract was 100% (the growth rate of 8 pathogens was 0). The pathogen grows normally. At the same time, the eight kinds of pathogens in the Ginkgo biloba extract diluted 10 times the concentration of the medium, the antibacterial effect also reached 45% ~ 84%, which has the best antibacterial effect against Strychon anthracnose, reaching 84%, cabbage The antibacterial effect of anthrax was the weakest, which was 45%. The results showed that the petroleum ether extract and acetone extract of Ginkgo biloba had certain antibacterial effects on P. stipitis and R. rotifera, and the leaf extract had the strongest antibacterial activity. The ethanol extract of Ginkgo biloba fruit has the most obvious antibacterial effect on apple rot pathogen. The bacteriostatic effects of 10 times and 25 times extracts are 100% and 50%, respectively, followed by the antibacterial effect on apple dry rot, 10 times and The antibacterial effect of the 25-fold extract reached 68.5% and 44.4%, respectively. These studies have shown that Ginkgo biloba extract has a bacteriostatic effect on plant pathogenic fungi, and the bacteriostatic effect is closely related to the concentration of Ginkgo biloba extract: the higher the concentration of GBE, the more obvious the bacteriostatic effect, the lower the concentration, the antibacterial The smaller the effect.
2.2 Antibacterial effect of Ginkgo biloba extract on common pathogenic bacteria in animals
At present, the research on the antibacterial effect of Ginkgo biloba extract mostly focuses on the antibacterial effect on common pathogenic bacteria of animals. This is a hot spot in the research of GBE bacteriostasis, and most of them focus on the research on Staphylococcus aureus, Escherichia coli, Bacteriostatic action of bacteria such as Pasteurella multocida. A variety of studies have shown that GBE has a good antibacterial effect on common pathogenic bacteria in animals, and the antibacterial effect of Ginkgo biloba extract is the most studied.
2.3 In vitro antibacterial effect of Ginkgo biloba extract on Porphyromonas gingivalis
To study the antibacterial activity of Ginkgo biloba extract against Porphyromonas gingivalis in vitro, it can provide pharmacological basis for the study of new pure Chinese medicine for the purpose of treating periodontal pain. However, the antibacterial active ingredient of Ginkgo biloba extract is currently used for gingival porphyrin. The research on the antibacterial effect of cytobacteria is still relatively rare, which provides a good development prospect for the development and application of Ginkgo biloba extract. Studies have shown that the same concentration of Ginkgo biloba extract against B. gingivalis is more bacteriostatic than Escherichia coli and Staphylococcus aureus, which indicates that Ginkgo biloba extract is for porphyrin The bacteriostatic action of the bacterium is highly practicable.
Comparison of antibacterial effects of different methods for extracting active substances from Ginkgo biloba leaves
The antibacterial effects of different methods for extracting active substances from Ginkgo biloba leaves are different. Due to different extraction methods, the active ingredients and concentrations of Ginkgo biloba leaves have different antibacterial activities. Comparing the antibacterial effects of Ginkgo biloba extracts extracted by different methods, it can provide a basis for the study of the extraction method with the best antibacterial effect.
Company name: Shaanxi Yougu Biotechnology Co., Ltd
Address: No.1589#, Zhuque South Rd, Zip 710065, Xi`an, China,