본 연구는 낙엽활엽수종인 이팝나무(Chionanthus retusa) 잎의 흡음 성능을 평가하고자 하였다. 잎을 주재료로 하여 재료의 크기와 두께 및 건조 조건을 달리해 흡음재를 제조하였다. 중간형 측정관(100㎐-3200㎐)을 적용한 관내법(Impedance tube method)을 이용하여 흡음율을 측정하였 다. 총 18개의 조건에서 측정된 흡음율을 분석하였다. 기건엽 조건(MC 13.92%)과 생엽 조건(MC 162.04%)의 흡음율은 두께가 증가함에 따라 크게 향상되었다. 흡음율은 밀도의 증가에 비례하는데, 부피당 밀도가 더 높은 생엽조건의 두께별 흡음율이 더 높게 나타났다. 생엽 조건군에서 크기 0.5 × 0.5㎠의 2.50㎝ 두께에서 평균 흡음율은 0.643으로 가장 높게 나타났으며, 각 시험처리 조건별 흡음재의 주파수 대역별 흡음율은 기건엽 조건의 두께 1.75㎝에서 가장 높게 나타났다. 이상의 연구결과로부터 전반적인 흡음율은 1000㎐ 이상의 대역에서 더 높은 성능을 보였다.

This study was designed to determine the biological activities of Chionanthus retusus flower extracts. Water and 90% ethanol extracts of C. retusus flower were prepared. The inhibitory activities of water and ethanol extracts with a phenolic content of 200 μg/mL against xanthine oxidase were 25.60% and 15.92%, respectively. Further, the water extract did not show any inhibitory activity against α-glucosidase whereas the ethanol extract showed 100.00% inhibition of α-glucosidase. The inhibitory activities of the extracts against tyrosinase were 17.27% (water extract) and 36.13% (ethanol extract), which suggest that the extracts may have a whitening effect. The water extract did not inhibit elastase activity but showed a collagenase-inhibitory activity of 20.21%. On the contrary, the ethanol extract showed 96.26% and 35.93% inhibition of collagenase and elastase, respectively. These findings suggest that the extracts may have an anti-wrinkle effect. Lastly, the extracts showed a hyaluronidase inhibitory activity of 36.96% (water extract) and 88.70% (ethanol extract), suggesting that they may have an anti-inflammatory effect. The results indicate that C. retusus flower extracts containing phenolic compounds can be used as functional resources because they have anti-gout, carbohydrate degradation-inhibitory, whitening, anti-wrinkle, and anti-inflammatory effects.