Department of Pharmacognosy, University of Innsbruck, Innrain 80-82, 6020 Innsbruck, Austria.
Institute of Hygiene and Medical Microbiology, Medical University of Innsbruck, Schöpfstraße 41, 6020 Innsbruck, Austria.
Mar Drugs. 2019 Nov 29;17(12):675. doi: 10.3390/md17120675.
Bromophenols are a class of compounds occurring in red algae that are thought to play a role in chemical protection; however, their exact function is still not fully known. In order to investigate their occurrence, pure standards of seven bromophenols were isolated from a methanolic extract of the epiphytic red alga collected in Brittany, France. The structures of all compounds were determined by NMR and MS. Among the isolated substances, one new natural product, namely, 2-amino-5-(3-(2,3-dibromo-4,5-dihydroxybenzyl)ureido)pentanoic acid was identified. An HPLC method for the separation of all isolated substances was developed using a Phenomenex C8(2) Luna column and a mobile phase comprising 0.05% trifluoroacetic acid in water and acetonitrile. Method validation showed that the applied procedure is selective, linear (R 0.999), precise (intra-day ≤ 6.28%, inter-day ≤ 5.21%), and accurate (with maximum displacement values of 4.93% for the high spikes, 4.80% for the medium spikes, and 4.30% for the low spikes). For all standards limits of detection (LOD) were lower than 0.04 μg/mL and limits of quantification (LOQ) lower than 0.12 μg/mL. Subsequently, the method was applied to determine the bromophenol content in samples from varying sampling sites and collection years showing values between 0.678 and 0.005 mg/g dry weight for different bromophenols with significant variations between the sampling years. Bioactivity of seven isolated bromophenols was tested in agar diffusion tests against and bacteria. Three compounds showed a small zone of inhibition against both test organisms at a concentration of 100 µg/mL.
溴酚类化合物是红藻中一类存在的化合物，被认为在化学保护中发挥作用；然而，它们的确切功能仍不完全清楚。为了研究它们的存在，从法国布列塔尼采集的附生红藻的甲醇提取物中分离出七种溴酚类化合物的纯标准品。所有化合物的结构均通过 NMR 和 MS 确定。在所分离的物质中，鉴定出一种新的天然产物，即 2-氨基-5-(3-(2,3-二溴-4,5-二羟基苄基)脲基)戊酸。开发了一种使用 Phenomenex C8(2) Luna 柱和包含 0.05%三氟乙酸的水和乙腈作为流动相的 HPLC 方法，用于分离所有分离的物质。方法验证表明，所应用的程序具有选择性、线性（R 0.999）、精确（日内≤6.28%，日间≤5.21%）和准确（高浓度点的最大位移值为 4.93%，中浓度点为 4.80%，低浓度点为 4.30%）。对于所有标准，检测限（LOD）均低于 0.04 μg/mL，定量限（LOQ）均低于 0.12 μg/mL。随后，该方法应用于测定来自不同采样地点和采集年份的 样品中的溴酚含量，结果表明不同溴酚的含量在 0.678 至 0.005 mg/g 干重之间，采样年份之间存在显著差异。在琼脂扩散试验中，测试了七种分离的溴酚类化合物对 和 细菌的生物活性。三种化合物在 100 µg/mL 的浓度下对两种测试生物均显示出较小的抑菌区。
