Small Molecule Inhibitors of White Spot Syndrome Virus: Promise in Shrimp Seedling Culture

Abstract

Rapid production of prawn (Litopenaeus vannamei) under artificial pressure can result in a series of obvious challenges and is vulnerable to serious losses related to aquatic environmental issues and the unrestrained outbreak of white spot syndrome (WSS). However, to date, there are no therapeutic strategies to contain the spread of the virus. Here, we synthesized 27 coumarin deriv-atives and evaluated their anti-white spot syndrome virus (WSSV) activity in L. vannamei larvae. We demonstrated that electron-withdrawing and electron-giving substituent groups play an im-portant role in reducing toxicity and WSSV replication, respectively. Two coumarin C2 (2-amino-5-oxo-4-(p-tolyl)-4H,5H-pyrano[3,2-c]chromene-3-carbonitrile) and C7 (2-amino-4-(4-chlorophenyl)-5-oxo-4H,5H-pyrano[3,2-c]chromene-3-carbonitrile) were regarded as the most promising anti-WSSV compounds with maximum antiviral response <5% and median effective concentration <10 mg/L. The mortality of WSSV-infected larvae decreased by more than 60% after exposure to C2 and C7. With continuous immersion of C2 and C7 exchange, the mortality further decreased to 40% at 120 h.Additionally, C2 and C7 are the relatively stable in aquacultural water, making these agents

The antiviral activity of currently used medicinal plants in aquaculture and structure–activity relationship of their active ingredients

“…Surprisingly, previous study found that paeoniflorin and esculin had anti‐WSSV effects in shrimp, which could be developed as lead compounds 96,128 . Interestingly, esculin belongs to the coumarin class of compounds and researchers have screened several coumarin derivatives with anti‐WSSV activity in previous studies 129–131 . Derivatives of coumarin were also selected for anti‐WSSV horizontal transmission experiments and were found to be effective in inhibiting WSSV horizontal transmission, providing a primer for their application 100 .…”

“…96,128 Interestingly, esculin belongs to the coumarin class of compounds and researchers have screened several coumarin derivatives with anti-WSSV activity in previous studies. [129][130][131] Derivatives of coumarin were also selected for anti-WSSV horizontal transmission experiments and were found to be effective in inhibiting WSSV horizontal transmission, providing a primer for their application. 100 Notably, previous study investigated the potential application of cuminaldehyde, a Chinese herbal medicine extract commonly found in cumin essential oil, in the prevention and treatment of WSSV.…”

“…40,41 Moreover, when the linked intermediate structure is a carbamide or thiourea structure, an electron-absorbing group on the benzene ring facilitates anti-WSSV activity, while an electron-donating group on the benzene ring enhances anti-WSSV activity when the intermediate structure is replaced by a nitrile group (Figure 5c). 130 Notably, the presence of the lactone ring is necessary for coumarins, regardless of their anti-SVCV, anti-IHNV, or anti-WSSV properties. 41,64,130 The lactone ring is a crucial component that contributes to the anti-SVCV and anti-IHNV activity of arctigenin derivatives.…”

Structural insights into proteins from white spot syndrome virus: Perspectives on structure‐based anti‐viral strategies

“…Currently, there is a lack of effective treatment strategies against the disease. In addition to the lack of efficacious treatments or preventative measures, complex infection transmission routes and its broad host range make its eradication from affected ponds difficult, 10 which further intensifies the potential damage 11 …”

“…In addition to the lack of efficacious treatments or preventative measures, complex infection transmission routes and its broad host range make its eradication from affected ponds difficult, 10 which further intensifies the potential damage. 11 The WSSV viral genome is a circular, double-stranded DNA ranging between 290 and 307 kb in different isolates. 12,13 Moreover, it has been classified as the only member of the genus Whispovirus belonging to the Nimaviridae family owing to its unique genetic and morphological characteristics.…”