Centro de Ciências da Saúde, Instituto de Biologia, Departamento de Botânica, Universidade Federal do Rio de Janeiro, Cidade Universitária, Rio de Janeiro, Brazil.
Photochem Photobiol. 2013 Mar-Apr;89(2):391-9. doi: 10.1111/php.12006. Epub 2012 Nov 8.
Antioxidant compounds protect plants against oxidative stress caused by environmental conditions. Different light qualities, such as UV-A radiation and blue light, have shown positive effects on the production of phenols in plants. Kalanchoe pinnata (Lamarck) Persoon (Crassulaceae) is used for treating wounds and inflammations. Some of these beneficial effects are attributed to the antioxidant activity of plant components. We investigated the effects of blue light and UV-A radiation supplementation on the total phenol content, antioxidant activity and chromatographic profile of aqueous extracts from leaves of K. pinnata. Monoclonal plants were grown under white light, white plus blue light and white plus UV-A radiation. Supplemental blue light improved the antioxidant activity and changed the phenolic profile of the extracts. Analysis by HPLC of supplemental blue-light plant extracts revealed a higher proportion of the major flavonoid quercetin 3-O-α-L-arabinopyranosyl (1→2) α-L-rhamnopyranoside, as well as the presence of a wide variety of other phenolic substances. These findings may explain the higher antioxidant activity observed for this extract. Blue light is proposed as a supplemental light source in the cultivation of K. pinnata, to improve its antioxidant activity.
抗氧化化合物可保护植物免受环境条件引起的氧化应激。不同的光质，如 UV-A 辐射和蓝光，已显示出对植物中酚类物质生产的积极影响。长寿花（Kalanchoe pinnata）（景天科）用于治疗伤口和炎症。这些有益作用中的一些归因于植物成分的抗氧化活性。我们研究了蓝光和 UV-A 辐射补充对长寿花叶片水提物的总酚含量、抗氧化活性和色谱图谱的影响。单克隆植物在白光、白光加蓝光和白光加 UV-A 辐射下生长。补充蓝光可提高抗氧化活性并改变提取物的酚类图谱。对补充蓝光植物提取物的 HPLC 分析表明，主要类黄酮槲皮素 3-O-α-L-阿拉伯吡喃糖苷（1→2）α-L-鼠李吡喃糖苷的比例更高，并且存在多种其他酚类物质。这些发现可以解释该提取物观察到的更高抗氧化活性。蓝光被提议作为长寿花栽培中的补充光源，以提高其抗氧化活性。
