蜂胶因其有益的健康特性而广受欢迎，例如抗菌活性和抗氧化作用。由于其有趣的化学多样性和治疗特性，它是人类最古老的传统药物之一。蜂胶样品的详细化学信息对于保证其安全性并被医疗保健系统接受是非常必要的。使用 HPLC-DAD 测定氢乙醇提取物的酚谱，并使用五种补充方法评估抗氧化剂。使用柱色谱法分离三萜类化合物，并使用1 H NMR 和13 C NMR 进行表征。评估了提取物和分离的化合物对细菌中群体感应介导的过程和生物膜形成的影响。原儿茶酸 (40.76 ± 0.82 µg/g)、4-羟基苯甲酸 (24.04 ± 0.21 µg/g)、香草酸 (29.90 ± 1.05 µg/g)、槲皮素 (43.53 ± 1.10 µg/g) 和木犀草素 (4.44 ± 1.10 µg/g) 0.48 µg/g）被鉴定和量化。该提取物在DPPH • 、ABTS •+ 、CUPRAC 和金属螯合试验中显示出良好的抗氧化活性，并且这种抗氧化作用通过循环伏安法得到证实。在 MIC 处从抗群体感应活性中分离出 27-羟基芒果酸 (1)、安博酸 (2) 和芒果酸 (3)，表明最活跃的样品是抑菌直径区为 18.0 ± 的提取物。 1.0mm，而化合物1、2和3的抑菌圈分别为12.0±0.5mm、9.0±1.0mm和12.3±1.0mm。样品抑制了P. 铜绿假单胞菌 PA01 在三个测试浓度（50、75 和 100 μg/mL）下的集群运动呈剂量依赖性。蜂胶提取物能够在 MIC 浓度下抑制金黄色葡萄球菌、大肠杆菌、铜绿假单胞菌、白色念珠菌和热带念珠菌形成生物膜。化合物1在 MIC 和 MIC/2 条件下对金黄色葡萄球菌、单核细胞增生李斯特菌、粪肠球菌、大肠杆菌和热带念珠菌具有生物膜抑制作用；化合物2抑制金黄色葡萄球菌、粪肠球菌、大肠杆菌、伤寒沙门氏菌、白色念珠菌和热带念珠菌的生物膜形成。化合物3抑制粪肠球菌、大肠杆菌、白色念珠菌和热带念珠菌的生物膜形成，并在MIC/4和MIC/8下进一步抑制大肠杆菌的生物膜。研究的蜂胶样品显示出大量的环阿麻烷型三萜酸，这表明可能由于附近的特定菌群而存在显着的区域内差异。结果表明，蜂胶及其化合物可以降低病原菌的毒力因子。
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Antibiofilm and Anti-Quorum Sensing Potential of Cycloartane-Type Triterpene Acids from Cameroonian Grassland Propolis: Phenolic Profile and Antioxidant Activity of Crude Extract
Propolis is very popular for its beneficial health properties, such as antimicrobial activity and antioxidant effects. It is one of the most long-serving traditional medicines to mankind due to its interesting chemical diversity and therapeutic properties. The detailed chemical information of propolis samples is very necessary to guarantee its safety and for it to be accepted into health care systems. The phenolic profile of the hydroethanolic extract was determined using HPLC-DAD, and the antioxidant was evaluated using five complementary methods. Triterpenoids were isolated using column chromatography and characterized using 1H NMR and 13C NMR. The effects of the extract and the isolated compounds on quorum sensing mediated processes and biofilm formation in bacteria were evaluated. Protocatechic acid (40.76 ± 0.82 µg/g), 4-hydroxybenzoic acid (24.04 ± 0.21 µg/g), vanillic acid (29.90 ± 1.05 µg/g), quercetin (43.53 ± 1.10 µg/g), and luteolin (4.44 ± 0.48 µg/g) were identified and quantified. The extract showed good antioxidant activity in the DPPH•, ABTS•+, CUPRAC, and metal chelating assays, and this antioxidant effect was confirmed by cyclic voltammetry. 27-Hydroxymangiferonic acid (1), Ambolic acid (2), and Mangiferonic acid (3) were isolated from anti-quorum sensing activity at MIC, and it was indicated that the most active sample was the extract with inhibition diameter zone of 18.0 ± 1.0 mm, while compounds 1, 2, and 3 had inhibition zones of 12.0 ± 0.5 mm, 9.0 ± 1.0 mm, and 12.3 ± 1.0 mm, respectively. The samples inhibited the P. aeruginosa PA01 swarming motility at the three tested concentrations (50, 75, and 100 μg/mL) in a dose-dependent manner. The propolis extract was able to inhibit biofilm formation by S. aureus, E. coli, P. aeruginosa, C. albicans, and C. tropicalis at MIC concentration. Compound 1 proved biofilm inhibition on S. aureus, L. monocytogenes, E. faecalis, E. coli, and C. tropicalis at MIC and MIC/2; compound 2 inhibited the formation of biofilm at MIC on S. aureus, E. faecalis, E. coli, S. typhi, C. albicans, and C. tropicalis; and compound 3 inhibited biofilm formation on E. faecalis, E. coli, C. albicans, and C. tropicalis and further biofilm inhibition on E. coli at MIC/4 and MIC/8. The studied propolis sample showed important amounts of cycloartane-type triterpene acids, and this indicates that there can be significant intra-regional variation probably due to specific flora within the vicinity. The results indicate that propolis and its compounds can reduce virulence factors of pathogenic bacteria.
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