Variation in Rotenone and Deguelin Contents among Strains across Four Tephrosia Species and Their Activities against Aphids and Whiteflies

Abstract

Botanical pesticides have received increasing attention for sustainable control of insect pests. Plants from the genus Tephrosia are known to produce rotenone and deguelin. Rotenone is known to possess insecticidal activities against a wide range of pests, but deguelin’s activities remain largely inconclusive. On the other hand, the biosynthesis of rotenone and deguelin may vary in Tephrosia species. This study analyzed the rotenone and deguelin contents in 13 strains across 4 Tephrosia species over 4 growing seasons using HPLC. Our study shows that the species and even the strains within a species vary substantially in the biosynthesis of rotenone and deguelin, and their contents can be affected by the growing season. After identification of the LC50 values of chemical rotenone and deguelin against Aphis gossypii (Glover) and Bemisia tabaci (Gennadius), leaf extracts derived from the 13 strains were used to test their insecticidal activities against the 2 pests. The results showed that the extracts derived from 2 strains of T. vogelii had the highest insecticidal activity, resulting in 100% mortality of A. gossypii and greater than 90% mortality of B. tabaci. The higher mortalities were closely associated with the higher contents of rotenone and deguelin in the two strains, indicating that deguelin also possesses insecticidal activities. This is the first documentation of leaf extracts derived from 13 Tephrosia strains against 2 important pests of A. gossypii and B. tabaci. The strain variation and seasonal influence on the rotenone and deguelin contents call for careful attention in selecting appropriate strains and seasons to produce leaf extracts for the control of insect pests.

Biosynthesis and metabolic engineering of isoflavonoids in model plants and crops: a review

“…Additionally, rotenone exhibits anticancer activity in vitro but its application is limited due to neurotoxicity associated with its ability to cross the blood-brain barrier (Cannon et al, 2009;Deng et al, 2010). However, hydroxylated rotenoids are more hydrophilic and less likely to readily cross the blood-brain barrier, potentially acting as cellselective killers to inhibit the proliferation of cancer cells (Naguib et al, 2018;Zhang et al, 2022a). Indeed, the diversity and complexity of isoflavonoid compounds are largely due to chemical modifications such as methylation, glycosylation, and acylation.…”

Deguelin Restores Paclitaxel Sensitivity in Paclitaxel-Resistant Ovarian Cancer Cells via Inhibition of the EGFR Signaling Pathway

“…or Mundulea sericea (Leguminosae). 48 Rotenone, a highly toxic deguelin-analogue, has traditionally served as an insecticide and a herbicide for an extended period of time, 49 and has been studied as an inducer of Parkinson's disease. 50,51 Despite their structural similarities to rotenone, several studies have reported that deguelin exhibits distinct aspects of toxicity and molecular function compared to rotenone.…”

Inhibitory Effects of B-, C-, and E-Ring-Truncated Deguelin Derivatives Against A549, HCT116, and MCF-7 Cancer Cells

“…Deguelin (Figure 1) is a naturally occurring rotenoid 1 that was originally used as pesticide and fish poison. 2 It has emerged as a promising lead compound for therapeutic optimization and development due to its remarkable antiproliferative activity and unique mechanism of action. 3 Its favorable biological activity has been attributed to its role in regulating various tumor cell signaling transduction pathways.…”

“…Deguelin (Figure ) is a naturally occurring rotenoid that was originally used as pesticide and fish poison . It has emerged as a promising lead compound for therapeutic optimization and development due to its remarkable antiproliferative activity and unique mechanism of action .…”