:
With the emergence of the novel severe acute respiratory syndrome coronavirus-2
(SARS-CoV-2), the whole world is suffering from atypical pneumonia, which resulted in more
than 559,047 deaths worldwide. In this time of crisis and urgency, the only hope comes from new
candidate vaccines and potential antivirals. However, formulating new vaccines and synthesizing
new antivirals are a laborious task. Therefore, considering the high infection rate and mortality due
to COVID-19, utilization of previous information, and repurposing of existing drugs against valid
viral targets have emerged as a novel drug discovery approach in this challenging time. The transmembrane
spike (S) glycoprotein of coronaviruses (CoVs), which facilitates the virus’s entry into
the host cells, exists in a homotrimeric form and is covered with N-linked glycans. S glycoprotein
is known as the main target of antibodies having neutralizing potency and is also considered as an
attractive target for therapeutic or vaccine development. Similarly, targeting of N-linked glycans of
S glycoprotein envelope of CoV via carbohydrate-binding agents (CBAs) could serve as an attractive
therapeutic approach for developing novel antivirals. CBAs from natural sources like lectins
from plants, marine algae and prokaryotes and lectin mimics like Pradimicin-A (PRM-A) have
shown antiviral activities against CoV and other enveloped viruses. However, the potential use of
CBAs specifically lectins was limited due to unfavorable responses like immunogenicity, mitogenicity,
hemagglutination, inflammatory activity, cellular toxicity, etc. Here, we reviewed the current
scenario of CBAs as antivirals against CoVs, presented strategies to improve the efficacy of
CBAs against CoVs; and studied the molecular interactions between CBAs (lectins and PRM-A)
with Man9 by molecular docking for potential repurposing against CoVs in general, and SARSCoV-
2, in particular.
Inhibition of infection and transmission of HIV-1 and lack of significant impact on the vaginal commensal lactobacilli by carbohydrate-binding agents
