Marine Sesquiterpenes for Plant Protection: Discovery of Laurene Sesquiterpenes and Their Derivatives as Novel Antiviral and Antiphytopathogenic Fungal Agents

The unreasonable use or long-term use of a single variety of pesticide has led to drug resistance and made the pesticides ineffective. Therefore, the creation of new, efficient, and low-risk pesticides is imminent. Marine natural products play a vital role in serving as new lead compounds. In this work, we realized the efficient preparation of nine marine sesquiterpenes with the Stork-Danheiser reaction as the key step and designed and synthesized a series of their derivatives. The antiviral activity and antifungal activity research showed that these compounds exhibited good to excellent biological activities. Compounds 7b and 8e displayed significantly higher antiviral activities against tobacco mosaic virus (TMV) than ribavirin and could be used as new antiviral candidates. The antiviral mode of action research indicated that compound 8e inhibited the formation of the 20S protein disk by acting on the TMV coat protein and therefore inhibited the assembly of TMV particles. This work provides a new idea for the development of new pesticides based on marine sesquiterpenes.