Iridoids content in aboveground plant organs of berry crops

Abstract

A study of iridoid content in fruits, leaves and sprouts of untraditional berry plants — Actinidia polygama, Actinidia macrosperma, Viburnum opulus and Lonicera caerulea is presented. The highest content of iridoids is observed in the fruits, buds and leaves of V. opulus. It was determined, that their content in the bark and the leaves of the plants during vegetation almost do not change and reach 2–3%. Meanwhile the content of iridoids in the fruits varies in more broad bounds and depends on the phase of growth of the plants. So, it reaches 6.85% at the end of July, but it was equals to 3.75% at the end of September. The highest content of iridoids was found in unripe fruits of Viburnum. The fruit, bark and leaves of bitter-fruited form V. opulus have the higher content of iridoids compared to sweet-fruited. There were not any iridoids in roots of both forms of V. opulus. The presence of iridoids in the fruit and leaves of A. polygama and A. macrosperma in the introduction of conditions in the forest-steppe of Ukraine was found. Given this, the leaves of these species, especially A. macrosperma, can be used as a medicinal plant. It was found, that A. polygama leaves, which change its color to silver, have higher contents of iridoids compared to green ones (silver leaves — 0.22%, green leaves — 0.18%). In fruits of honeysuckle, which do not have a bitter taste, iridoids are not found, while, forms and varieties of L. caerulea with bitter fruits accumulate the largest quantity of iridoids. So, when using fruits V. opulus and L. caerulea as medicinal plants, bitter-fruited forms should be preferred.