Chemical and biological studies of propolis and its origin plants

蜂胶是蜜蜂从各种植物中收集的一种树脂状物质。本文研究了蜂胶的成分、生物活性及其来源植物。在日本，巴西蜂胶被广泛使用。为了直接确定巴西蜂胶的植物来源，我们对巴西米纳斯吉拉斯州的蜜蜂进行了观察，并对蜜蜂使用的植物进行了化学分析。我们鉴定了巴西蜂胶的植物来源为龙舌兰。进一步研究了日本不同地区蜂胶的抗氧化活性。采用光电二极管阵列（PDA）和质谱（MS）相结合的高效液相色谱法（HPLC）对蜂胶乙醇提取物（EEP）的主要成分进行了鉴定，并对各成分进行了定量分析。产自秋田（南秋田）和冲绳的EEP具有较强的抗氧化活性，且与总多酚含量相关。秋田产蜂胶含有大量的抗氧化化合物、咖啡酸和咖啡酸苯乙酯。冲绳蜂胶中含有其他地区蜂胶中没有的抗氧化剂。这些抗氧化剂经波谱法分离鉴定为新型烯酰化类黄酮。对韩国蜂胶的抗氧化活性进行了研究。进一步研究了各组分在蜂胶中的吸收代谢。我们给大鼠口服EEP，用高效液相色谱法（HPLC）、PDA和MS检测其血浆和尿液，并检测了EEP中几种黄酮类化合物的含量。另一方面，我们证明了蜜蜂根据季节使用不同的原产植物。

Propolis is a resinous substance collected by honeybees from various plant sources. We studied the constituents and biological activities of propolis and its origin plants. In Japan, Brazilian propolis is widely used. To identify the plant origin of Brazilian propolis directly, we observed of honeybees in Minas Gerais State of Brazil and analyzed chemically the plant used by honeybees. We identified that plant origin of Brazilian propolis is Baccharis dracunculifolia. Further we examined the antioxidant activity of propolis from various areas of Japan. We identified the major constituents in ethanol extracts of propolis (EEP) by HPLC analysis by a photodiode array (PDA) and mass spectrometric (MS) detection, and quantitatively analyzed each component. EEP from Akita (Minamiakita) and Okinawa had relatively strong antioxidant activity, and was correlated with total polyphenol contents. Propolis from Akita (Minakiakita) contained large amounts of the antioxidative compounds, caffeic acid and phenethyl caffeate. Propolis from Okinawa had antioxidants not seen in propolis from other areas. These antioxidants were isolated and identified by spectroscopic methods to be novel prenylated flavonoids. Also concerning with Korean propolis, we examined the antioxidant activity. Further we investigated the absorption and metabolism of the components in propolis. We administered EEP orally to rats and analyzed their plasma and urine by HPLC with PDA and MS detection, and detected several flavonoids in it. On the other hand, we proved that honeybees use different origin plants by seasons.