Investigating the effectiveness of environmental and ecological factors on the amount of alkaloid compounds of the medicinal plant henbane (Hyoscyamus spp.)

Hyoscyamine and scopolamine alkaloids are valuable secondary metabolites that are mainly produced by plants of the Solanaceae family, especially the henbane genus. The production of these alkaloids in henbane is influenced by genetic processes, but environmental factors play a more prominent role in the economic synthesis of these alkaloids.
 
This research was carried out in 2020 to investigate the effect of environmental factors on the quantity and quality of hyoscyamine and scopolamine alkaloids on 10 henbane populations in northwest of Iran. The seeds of H.niger, H.reticulatus and H.pusillus species were collected from Ardabil and East Azarbaijan provinces and dried in shade. After extracting alkaloids from the populations, the amount of these alkaloids was measured by high performance liquid chromatography (HPLC). To study the physical and chemical properties of the soil, soil sampling was done from the root development depth of each plant (30 cm) in the studied habitats.
 
The results of variance analysis showed that the effect of above mean sea level factor on the amount of hyoscyamine and scopolamine alkaloids is significant at the 1% probability level. The results of variance analysis showed that soil nitrogen and phosphorus have a significant effect on the increase of hyoscyamine and nitrogen on the increase of scopolamine at the probability level of 1%. While the effect of potassium on the amount of hyoscyamine and the effect of phosphorus and potassium on the amount of scopolamine is not significant. The research results showed significant phytochemical diversity in terms of hyoscyamine and scopolamine among species, populations, and genotypes of henbane. Based on this, H.pusillus species in terms of scopolamine content and H.reticulatus species in terms of hyoscyamine content were at the top of the studied species, and Meshkinshahr population was at the top in terms of scopolamine and hyoscyamine, while Tabriz and Givi populations were at the bottom in this respect. The high amount of alkaloid in some of the studied ecotypes is affected by the high amount of nitrogen, phosphorus, organic carbon in the soil and due to the low potassium in the studied habitats.
 
Maximum similarity was observed between the populations of Ahar with Herris, Shabester with Azarshahr, Givi with Tabriz, and Shabester with Khalkhal in terms of the amount of hyoscyamine and scopolamine. In this case, in addition to genetic factors, the similarity of the ecological characteristics of the studied habitats can also be involved.