School of Biology, Research Center for Biotechnology, Institute of Technology of Costa Rica, 159-7050, Cartago, Costa Rica.
National Center for Biotechnological Innovations of Costa Rica - CENIBiot, 1174-1200, San José, Costa Rica.
Phytochemistry. 2018 Jul;151:26-31. doi: 10.1016/j.phytochem.2018.03.008. Epub 2018 Apr 6.
Uncaria tomentosa (Willd.) D.C. (Rubiaceae), commonly known as "Uña de Gato" or "Cat's Claw", is a tropical vine from the rainforest used in traditional medicine and spread through Central and South America, including Costa Rica. There is an increasing demand for medicinal extracts with biological activity attributed mainly to oxindole alkaloids (OA), where the ratio between tetracyclic (TOA) and pentacyclic oxindole alkaloids (POA) determines its feasibility for medicinal applications. The ratio is affected by distinct factors including the dynamics of environmental conditions during seasons. The purpose of the study was to assess the seasonality effect in oxindole alkaloids content in relation to plant organs from U. tomentosa grown in the Caribbean region of Costa Rica. Young leaves followed by mature leaves presented the highest amount of total OA during seasons; for these, isoryncophylline, pteropodine and isomitraphylline, were the predominant OA. The POA/TOA ratio of both leaf materials was nearly 1:1 (3.2 mg g: 3.1 mg g). Bark and root material showed a pentacyclic chemotype in all seasons with a ratio of 6:1 (6.7 mg g: 1.3 mg g) with pteropodine and isomitraphylline as the predominant POA. The POA content presented seasonality with a significant increase from rainy to dry season in young leaves, bark and roots. In contrast, TOA amount remained virtually unchanged in all plant parts. Humidity and temperature between the studied seasons were constant except for precipitation, reflecting that differences of water content had an effect in the POA amounts. Further studies of abiotic factors, like water stress, could explain the variation of POA content due to seasonality.
钩藤（Willd.）D.C.（茜草科），俗称“猫爪”或“猫爪”，是一种来自热带雨林的热带藤本植物，用于传统医学，并在中美洲和南美洲传播，包括哥斯达黎加。对具有生物活性的药用提取物的需求不断增加，主要归因于吲哚生物碱（OA），四环（TOA）和五环吲哚生物碱（POA）的比例决定了其在药用方面的可行性。该比例受季节期间环境条件动态等不同因素的影响。本研究旨在评估与哥斯达黎加加勒比地区种植的钩藤植物器官有关的吲哚生物碱含量的季节性变化。嫩叶和成熟叶在季节中表现出最高的总 OA 含量；对于这些叶子，异鸡纳碱、吡咯烷和异米托菲林是主要的 OA。两种叶片材料的 POA/TOA 比例几乎为 1:1（3.2mg g：3.1mg g）。在所有季节中，树皮和根材料均表现出五环化学型，比例为 6:1（6.7mg g：1.3mg g），主要的 POA 为吡咯烷和异米托菲林。POA 含量具有季节性，嫩叶、树皮和根中的含量在雨季到旱季之间显著增加。相比之下，所有植物部分的 TOA 含量几乎保持不变。在所研究的季节之间，湿度和温度保持不变，除了降水外，这反映出水分含量的差异对 POA 含量有影响。对非生物因素（如水分胁迫）的进一步研究可以解释由于季节性变化导致的 POA 含量的变化。
