Tatapudi Kiran Kumar, Bandi Siva, Kotta Ramulu, Kanivebagilu Shankaranarayana Vinayaka, Ramalingam Vaikundamoorthy, Babu Katragadda Suresh
Department of Natural Products & Medicinal Chemistry, CSIR-Indian Institute of Chemical Technology, Uppal Road, Tarnaka, Hyderabad 500 007, Telangana, India.
Academy of Scientific and Innovative Research (AcSIR), Sector 19, Kamala Nehru Nagar, Ghaziabad, Uttar Pradesh, 201002, India.
J AOAC Int. 2025 Mar 1;108(2):180-188. doi: 10.1093/jaoacint/qsae074.
The genus Usnea (Parmeliaceae; lichenized Ascomycetes) is pale grayish-green fruticose lichens, which grow as leafless mini-shrubs and comprise about 360 species. Most of the Usnea species are edible and are utilized in preparation of traditional foods as well as in medicines to combat a wide range of ailments.
This study aimed to quantify usnic acid (UA) in three Usnea spp. (Usnea ghattensis [UG], Usnea orientalis [UO], and Usnea undulata [UU]) using HPTLC-MS. Additionally, chemical profiling of acetone extracts using UPLC-QTof-MSE resulted in the identification of 16 compounds based on their MS/MS fragmentation patterns.
Hyphenated techniques, HPTLC-MS, and UPLC-QTof-MSE have been proposed to quantify UA and analyze metabolites in crude extracts qualitatively. This method allowed tentative characterization of metabolites from Usnea spp.
The quantification study showed excellent linearity for UA at 0.25-1 µg/band with a correlation coefficient r2 > 0.99, and the LOD and LOQ were found to be 51.7 and 156.6 ng/band, respectively. Furthermore, UPLC-QTof-MSE analysis of crude extracts led to identification of lichen secondary metabolites through their exact molecular masses and MS/MS fragmentation studies.
The present study summarizes an HPTLC method for quantification of UA in three different Usnea spp. Additionally, two herbal formulations containing Usnea spp. as an ingredient, the developed method was validated as per the ICH guidelines and further UPLC-QTof-MSE analysis facilitated tentative characterization of 16 different secondary metabolites based on their MS/MS fragmentation patterns.
A rapid HPTLC method for quantification of UA in three different Usnea spp., along with two herbal formulations, and metabolite profiling using UPLC-QTof-MSE.
松萝属（梅衣科；地衣化子囊菌）是浅灰绿色的枝状地衣，生长为无叶的小型灌木，约有360个物种。大多数松萝物种可食用，可用于制作传统食品以及治疗多种疾病的药物。
本研究旨在使用高效薄层色谱-质谱联用（HPTLC-MS）法对三种松萝属植物（加特松萝[UG]、东方松萝[UO]和波缘松萝[UU]）中的松萝酸（UA）进行定量。此外，使用超高效液相色谱-四极杆飞行时间质谱联用（UPLC-QTof-MSE）对丙酮提取物进行化学分析，根据其二级质谱（MS/MS）裂解模式鉴定出16种化合物。
已提出采用联用技术、HPTLC-MS和UPLC-QTof-MSE对UA进行定量，并对粗提物中的代谢产物进行定性分析。该方法可对松萝属植物的代谢产物进行初步表征。
定量研究表明，UA在0.25-1μg/条带范围内具有良好的线性，相关系数r2>0.99，检测限（LOD）和定量限（LOQ）分别为51.7和156.6 ng/条带。此外，通过对粗提物的UPLC-QTof-MSE分析，通过其精确分子量和MS/MS裂解研究鉴定出地衣次生代谢产物。
本研究总结了一种用于定量三种不同松萝属植物中UA的HPTLC方法。此外，对于两种含有松萝属植物作为成分的草药制剂，所开发的方法根据国际人用药品注册技术协调会（ICH）指南进行了验证，进一步的UPLC-QTof-MSE分析有助于根据其MS/MS裂解模式对16种不同的次生代谢产物进行初步表征。
一种用于定量三种不同松萝属植物中UA的快速HPTLC方法，以及两种草药制剂，并使用UPLC-QTof-MSE进行代谢产物分析。
