Analytical and functional aspects on Saffron from Crocus sativus L.: development of quality control methods, species assortment and affinity to sigma-1 and NMDA receptors

Saffron from Crocus sativus L. (Iridaceae) is getting into focus of medicinal development because of antidepressant and anticancer activities. Within the present investigation a potential influence on central receptor systems of ethanolic saffron extract and the crocins was investigated. While the extract showed no affinity to NMDA receptor binding of the crocin was found with IC₅₀ 10µM. Using sigma-1 receptors a IC₅₀ of 30µM was determined for both, the extract and crocins. No affinity was found against sigma-2 receptors.

Using saffron for product development a strong need for validated control methods and use of reference standards is obvious. For that reason methods for isolation of reference material are described. Crocin-1,-2,-4, cis-crocin-1 and picrocrocin were isolated in good yields and high purity; identity was proven by NMR and MS. For determination of crocin distribution analytical RP-18 HPLC method with acetonitrile-TFA as mobile phase was developed. Using this method the different crocins can be quantified beside degradation products. Using an RP18 column picrocrocin was quantified from extracts effectively. Volatile compounds were analyzed by GC-MS, using isophoron, ketosiophoron and safranal for calibration. For investigation of drying conditions residual enzyme activity was investigated. All methods were validated. Short time stability was investigated using crocin-1, indicating sufficient stability of test solutions at RT; degradation was observed at higher temperatures. A broad investigation using 21 saffron samples indicated that products from certain proveniences (Spain, Iran, Greece, others) are not superior to others.