Plant Source Foods
Chuong Pham-Huy, Bruno Pham Huy in Food and Lifestyle in Health and Disease, 2022
There are numerous chemical compounds present in Ginkgo biloba leaf. The two main pharmacologically active groups of compounds contained in Ginkgo leaf extract are the flavonoids and the terpenoids (281–283). Only two types of terpenoids are found in Ginkgo leaf: ginkgolides and bilobalide. Ginkgolides are diterpene trilactones with five types (A, B, C, J, and M), while bilobalide is a unique sesquiterpene trilactone (281, 283). Flavonoids frequently present in Ginkgo leaf extract are: flavones, biflavones (bilobetol, amentoflavone, 5 methoxybilobetol, ginkgetin, isoginkgetin and sciadopitysin), flavonols, tannins, and glycosides of quercetin and kaempferol (283). The standardized preparation of Ginkgo leaf extract made from the dried green leaves is named EGb 761 and contains two main bioactive constituents, flavonoid glycosides (about 24%) and terpene lactones (ginkgolides and bilobalide about 6%), along with less than five ppm of the allergenic component, ginkgolic acid (281, 283). Terpenoids such as ginkgolides and bilobalide help vasodilation, blood circulation, platelet anti-aggregation, and more.
Phytotherapeutic Agents in Epilepsy
Vikas Kumar, Addepalli Veeranjaneyulu in Herbs for Diabetes and Neurological Disease Management, 2018
Two biflavones, agathisflavone, and amentoflavone have been isolated and characterized from the ethanolic extract of the leaves from South African plant Rhus pyroides (Fam. Anacardiaceae).39R. pyroides has been used in the traditional system of medicine for the treatment of epilepsy and it has shown good activity in the 3H-Ro 15-1788 (FLU) binding assay.40 Bioassay-guided fractionation of R. pyroides leaves showed that the two biflavonoids are present in the fractions exhibited good displacing activity in the binding assay 3H-Ro 15-1788 (FLU) binding assay. The two biflavones demonstrated a much higher potency than the corresponding monomer apigenin.41,42 Molecular modelling studies with apigenin, agathisflavone, and amentoflavone with respect to the BZD receptor developed suggest that the low affinity of apigenin is most probably due to its inability to fill up the L2 lipophilic pocket which is important for high affinity binding of flavone derivatives.43 Further, the significantly higher affinity of the two biflavonoids is also attributable to the affinity increasing interactions of one of the monomers with amino acid residues in the “subunit interface” area or the L3 lipophilic area of the receptor. Amentoflavone shows a higher affinity to the GABAA/BZD receptor than agathisflavone.
Medicinal Plants Against COVID-19
Hanadi Talal Ahmedah, Muhammad Riaz, Sagheer Ahmed, Marius Alexandru Moga in The Covid-19 Pandemic, 2023
The ethanolic extract of leaves of T. nucifera were checked for their effect as anti SARS coronavirus 3CL(pro) agent by using a FRET method and reported to contain four bioflavonoids including ginkgetin, amentoflavone, bilobetin, and sciadopitysin. Although, the extract of T. nucifera also have eight diterpenoids exhibiting IC50 value ranging from 49.6 µM to 283.5 µM, but the inhibitory effect of bioflavonoids (IC50 = 8.3–72.3 µM) was stronger which made them competitive inhibitors towards SARS-CoV-3CL(pro). Amentoflavone was the utmost effective prohibitor exhibiting IC50 = 8.3 ± 1.2 µM followed by luteolin (IC50 = 20.0 ± 2.2 µM), quercetin (IC50 = 23.8 ± 1.9 µM) and apigenin (IC50 = 28.8 ± 21.4 µM). Molecular docking revealed that amentoflavone formed strong hydrogen bonds with SARS-CoV-3CL(pro), thus inhibiting its activity [26].
Improved solubility, dissolution rate, and oral bioavailability of main biflavonoids from Selaginella doederleinii extract by amorphous solid dispersion
Published in Drug Delivery, 2020
Bing Chen, Xuewen Wang, Yanyan Zhang, Kangping Huang, Hao Liu, Dafen Xu, Shaoguang Li, Qicai Liu, Jianyong Huang, Hong Yao, Xinhua Lin
TBESD was obtained from S. doederleinii using the reported methods (Yao et al., 2017); 103.82 mg/g, 37.52 mg/g, 44.40 mg/g, 53.36 mg/g, and 35.12 mg/g of amentoflavone, robustaflavone, 2″,3″-dihydro-3′,3‴-biapigenin, 3′,3‴-binaringenin, and delicaflavone were respectively used. Chrysin (purity ≧98%, internal standard, IS) was acquired from Shanghai Winherb Medical Technology Co., Ltd. (Shanghai, China). Reference standards for amentoflavone, robustaflavone, 2″,3″-dihydro-3′,3‴-biapigenin, 3′,3‴-binaringenin, and delicaflavone (purity ≧98%) were isolated from S. doederleinii and their structures were fully elucidated by UV, MS, 1H NMR, and 13C NMR and confirmed by comparison to the literature (Li et al., 2014). The chemical structures of amentoflavone, robustaflavone, 2″,3″-dihydro-3′,3‴-biapigenin, 3′,3‴-binaringenin, and delicaflavone are shown in Figure S1.
Extensive metabolism of flavonoids relevant to their potential efficacy on Alzheimer’s disease
Published in Drug Metabolism Reviews, 2021
Amentoflavone (3′,8ʺ-biapigenin) is a biflavone with C-3′ in one apigenin linked to C-8 of another. Apigenin conjugates were observed after rats were orally administered amentoflavone, suggesting bond cleavage should occur (Wang et al. 2020), however, in another study, amentoflavone was dominantly oxidated, but no apigenin was detected (Feng et al. 2020), probably due to rapid conjugation of apigenin after released in vivo. In addition, amentoflavone was also directly conjugated in rats following intravenous, intraperitoneal or intragastric administration (Wang et al. 2020), and oral dosing resulted in higher levels of conjugation (Liao et al. 2015), indicating it was absorbed intact. Furthermore, mono-hydroxylated or hydrogenated amentoflavone was formed in rat liver (RLMs) and intestinal (RIMs) microsomes (Wang et al. 2020), while amentoflavone conjugates, rather than its oxidative metabolites, were found in human liver microsomes (HLMs), RLMs or RIMs from duodenum, jejunum and ileum in vitro by others (Gan et al. 2020). Moreover, amentoflavone was glucuronidated faster in HLMs and RLMs than in RIMs, which was basically mediated by human UGTs 1A1 and 1A3 (Gan et al. 2020). In addition, amentoflavone was mono-hydroxylated, methylated, hydrogenated or glucuronidated in Caco-2 cells, however, its colonic metabolism might be limited (Wang, Lu, Wang et al. 2020). Amentoflavone could be also mono-methylated and/or hydroxylated by human intestinal bacteria in vitro (Qian et al. 2017).
Preparation, evaluation and metabolites study in rats of novel amentoflavone-loaded TPGS/soluplus mixed nanomicelles
Published in Drug Delivery, 2020
Xue Feng, Yuting Chen, Luya Li, Yuqian Zhang, Lantong Zhang, Zhiqing Zhang
Ginkgo is a deciduous tree of ginkgo family and ginkgo genus. It is an ancient gymnosperm with a growth history of several hundred million years (Gong et al., 2008). Ginkgo biloba leaves are rich in more than 200 kinds of compounds such as lactones, polysaccharides, flavones, organic acids and phenolic acids (Ude et al., 2013). Biflavonoids as special flavonoids, their activities are higher than that of monoflavonoids in some aspects. Therefore, a more detailed study on biflavonoids has a good application prospect and significance. As a kind of biflavonoids in ginkgo biloba leaves, amentoflavone (AMF) has many biological activities, such as antioxidant (Zhang et al., 2015; Lee & An, 2016), anti-inflammatory (Zhang et al., 2015), antifungal (Hwang et al., 2012), antiviral (Coulerie et al., 2013), hypoglycemic (Su et al., 2019), anti-tumor (Guruvayoorappan & Kuttan, 2008), and inducing apoptosis (Pei et al., 2012; Zhaohui et al., 2018).