Alkaloids as Potential Phytochemicals against SARS-CoV-2: Approaches to the Associated Pivotal Mechanisms

Table 1

In vitro studies of alkaloids with potential anti-SARS-CoV-2 activity.

Alkaloid	Chemical structure	Mechanisms of action	Type of study	EC50	Ref.
7-Methoxycryptopleurine		Blocking the S and N proteins, 3CL^pro inhibitor	In vitro	58 nM	[71]
Berbamine		Blocking the E proteins and the calcium transition	In vitro	14.5 μM, 2.3 mM	[73, 88]
Berbamine derivative (BE33)		Blocking the E proteins	In vitro	0.94 μM	[73]
Cepharanthine		Blocking the expression of S and N proteins, RdRp inhibitor	In vitro	0.83 μM	[46, 47]
Conessine		Mpro inhibitor	In vitro	2.34 μM, 10.75 μM	[35]
Emetine		Mpro inhibitor	In vitro	2.55 μM	[11, 55]
Fangchinoline		Blocking the expression of S and N proteins	In vitro	1.01 μM	[46]
Harmine		Mpro inhibitor	In vitro	1.9 μM, 13.46 μM	[35]
Hernandezine		Blocking the calcium transition	In vitro	10 μM	[89]
Homoharringtonine		Blocking S proteins	In vitro	0.46 μM	[11, 55, 57]
Lycorine		Mpro inhibitor	In vitro	15 nM, 0.15 μM 0.47 μM	[34, 35]
Neferine		Decreasing the levels of relative viral RNA	In vitro	10 μM	[89]
Oxysophoridine		Nucleotide biosynthesis inhibitor	In vitro	0.31 μM	[51]
Quinine		Mpro and S proteins inhibitor (in silico study)	In vitro	10.7 μM	[91, 93]
Tetrandrine		Blocking the expression of S and N proteins, Mpro inhibitor	In vitro	0.33 μM, 0.29 μM, 2.05 μM	[35, 46]
Tylophorine		Blocking the S and N proteins, 3CL^pro inhibitor	In vitro	20 nM	[53]

3CL^pro: 3-chymotrypsin-like protease, ACE2: angiotensin-converting enzyme 2, E proteins: envelope proteins, Mpro: main proteases, NI: not identified, N proteins: nucleocapsid proteins, Nsp15: nonstructural proteins, RdRp: RNA-dependent RNA polymerase, S proteins: spike proteins, TMPRSS2: transmembrane protease serine 2.