Seasonal and pluviometric effects on the phenolic compound composition and antioxidant potential of Licania macrophylla Benth (Chrysobalanaceae), a medicinal plant from the Amazon rainforest

Abstract Licania macrophylla is a medicinal plant from the Amazon. It is mainly used in the form of a decoction and has been reported to contain several phenolic compounds. However, the effect of seasonality on the phenolic composition and antioxidant potential of this plant has not been well studied, especially in the Amazon region, an area affected by the rainy and less-rainy seasons. Therefore, we evaluated the seasonality of these aromatic compounds and the antioxidant potential of the extracts from L. macrophylla stem bark. We also determined the correlation between the extraction methods used and precipitation levels during each period for 1 year. The total flavonoid and phenolic content, DPPH-scavenging potential, percentage of phosphomolybdenum complex reduction, and iron-reducing power were quantified. The levels of phenolic compounds were the highest in June, whereas those of flavonoids were the highest in September and October; however, these differences were not significant. The extracts from April, November, and June showed the best results for DPPH scavenging, phosphomolybdenum reduction, and iron reduction power, respectively. Significant differences in the phenolic content and DPPH-scavenging activity were observed between the more- and less-rainy seasons. The total phenolic content was positively correlated with FRAP and DPPH, whereas flavonoid levels were negatively correlated.

【摘要】大叶李坎尼亚（Licania macrophylla）是一种源自亚马逊流域的药用植物，其主要使用形式为汤剂，且已有研究报道该植物含有多种酚类化合物。然而，季节性对该植物酚类组成与抗氧化潜能的影响尚未得到充分研究，尤其是在受雨季与旱季交替影响的亚马逊地区。为此，本研究针对L. macrophylla茎皮提取物中的酚类成分季节变化规律及其抗氧化潜能开展评估，并分析了1年内各采样时期的提取方法与降水量之间的相关性。本研究定量测定了总黄酮与总酚含量、DPPH自由基清除能力、磷钼络合物还原率以及铁还原能力。结果显示，酚类化合物含量于6月达到峰值，而黄酮类化合物含量则在9月和10月最高，但上述差异均无统计学显著性。4月、11月和6月的提取物分别在DPPH自由基清除、磷钼络合物还原及铁还原能力方面表现最优。雨季与旱季的酚类含量及DPPH自由基清除活性存在显著差异。总酚含量与铁还原抗氧化能力（FRAP）及DPPH自由基清除能力呈正相关，而黄酮类含量则呈负相关。