AChE (IC50 = 226 µM); μ Opioid Receptor/MOR
Corydaline targets multiple proteins. It acts as an acetylcholinesterase (AChE) inhibitor with an IC50 of 226 µM. It is a μ-opioid receptor agonist with a Ki of 1.23 µM. It also inhibits CYP2C19 and CYP2C9 and has anti-angiogenic activity. Its diverse targets contribute to its various pharmacological activities.

Corydaline treatment (12.5-50 μM; 24 hours) reduces COX-2 production and activation of JNK MAPK and P38 MAPK, but not ERK MAPK, which prevents EV71 replication [2].
In vitro, corydaline acts as an acetylcholinesterase inhibitor with an IC50 of 226 µM. It is a μ-opioid receptor agonist with a Ki of 1.23 µM. It inhibits the replication of enterovirus 71 with an IC50 of 25.23 µM and has anti-angiogenic activity. These activities have been demonstrated in various cell-based assays.

Corydanine (10 mg/kg; subcutaneous; once) therapy revealed analgesic effects by dramatically decreasing writhing behavior in mice [3].
In vivo, corydaline has demonstrated antiallergic, antinociceptive, and gastric emptying activities. It has shown potential in inhibiting the replication of certain viruses, making it a promising candidate for further antiviral research. However, specific details of in vivo efficacy studies are not extensively detailed in the available literature.

Enterovirus 71 (EV71) is a huge threat to the worldwide public health and there is no approved antiviral drug for EV71-induced disease therapy. Corydaline exists antiallergic and antinociceptive activities, but the anti-EV71 activity of corydaline is still not reported. In this study, corydaline could suppress the expression of viral structural and non-structural proteins. Furthermore, corydaline inhibits EV71 replication by suppressing the COX-2 expression and the phosphorylation of JNK MAPK and P38 MAPK but not ERK MAPK in vitro. Based on these findings, corydaline could be a potential lead or supplement for the development of new anti-EV71 agents in the future[2].

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Pain remains a key therapeutic area with intensive efforts directed toward finding effective and safer analgesics in light of the ongoing opioid crisis. Amongst the neurotransmitter systems involved in pain perception and modulation, the mu-opioid receptor (MOR), a G protein-coupled receptor, represents one of the most important targets for achieving effective pain relief. Most clinically used opioid analgesics are agonists to the MOR, but they can also cause severe side effects. Medicinal plants represent important sources of new drug candidates, with morphine and its semisynthetic analogues as well-known examples as analgesic drugs. In this study, combining in silico (pharmacophore-based virtual screening and docking) and pharmacological (in vitro binding and functional assays, and behavioral tests) approaches, we report on the discovery of two naturally occurring plant alkaloids, corydine and corydaline, as new MOR agonists that produce antinociceptive effects in mice after subcutaneous administration via a MOR-dependent mechanism. Furthermore, corydine and corydaline were identified as G protein-biased agonists to the MOR without inducing β-arrestin2 recruitment upon receptor activation. Thus, these new scaffolds represent valuable starting points for future chemical optimization towards the development of novel opioid analgesics, which may exhibit improved therapeutic profiles[3].
The in vitro enzyme assay for corydaline measures its ability to inhibit acetylcholinesterase (AChE) activity. These cell-free assays use purified AChE and a chromogenic substrate. The compound's inhibitory potency (IC50) is determined by measuring the reduction in enzyme activity. Its binding to μ-opioid receptors can be assessed using radioligand displacement assays.

Western Blot analysis [2]
Cell Types: Vero cells infected with EV71
Tested Concentrations: 12.5μM, 25μM, 50μM
Incubation Duration: 24 hrs (hours)
Experimental Results: The phosphorylation and expression of P38MAPK and JNKMAPK were diminished. COX-2.
In vitro cellular assays for corydaline assess its antiviral and anti-inflammatory effects. Cells infected with enterovirus 71 are treated with corydaline, and viral replication is measured. Its effects on opioid receptor signaling can be assessed in cells expressing μ-opioid receptors. These assays demonstrate the compound's functional activity in a relevant cellular context.

Animal/Disease Models: Male CD1 mice (30-35 g, 7-8 weeks old) were injected with acetic acid [3].
Doses: 10 mg/kg.
Route of Administration: subcutaneousadministration; primary
Experimental Results:demonstrated anti-nociceptive effect on mice.
In vivo animal studies for corydaline have been conducted to evaluate its antinociceptive, antiallergic, and antiviral activities. However, specific details of these studies are not extensively detailed in the available literature. It is a research compound and is not approved for clinical use.

Specific pharmacokinetic data for corydaline are not extensively detailed in the available literature. As a natural alkaloid, its pharmacokinetic properties would be important for its in vivo efficacy. However, specific parameters such as half-life and bioavailability are not provided. It is intended for research use only.

Specific toxicity data for corydaline are not extensively detailed in the available literature. As a natural product, it is generally considered to have low toxicity. However, comprehensive toxicological studies would be required to establish its safety profile for therapeutic use. It is intended for research purposes only.

[1]. Acetylcholinesterase inhibitors from Corydalis yanhusuo. Nat Prod Res. 2011 Sep;25(15):1418-22.

[2]. Corydaline inhibits enterovirus 71 replication by regulating COX-2 expression. J Asian Nat Prod Res. 2017 Nov;19(11):1124-1133.

[3]. Identification and characterization of plant-derived alkaloids, corydine and corydaline, as novel mu opioid receptor agonists. Sci Rep. 2020 Aug 14;10(1):13804.

Corydaline is an isoquinoline alkaloid, belonging to the isoquinoline class of compounds. It has been reported to exist in Broomia spp., Corydalis yanhusuo, and other organisms with relevant data.
Corydaline (CAS 518-69-4) is an isoquinoline alkaloid from Corydalis tubers with acetylcholinesterase inhibitory (IC50 = 226 µM), μ-opioid receptor agonistic (Ki = 1.23 µM), and antiviral (IC50 = 25.23 µM against EV71) activities. It has antiallergic, antinociceptive, and gastric emptying activities. It has a molecular formula of C22H27NO4 and a molecular weight of 369.45. It is a research compound and is not approved for clinical use.

C22H27NO4

369.4541

369.194

C, 71.52; H, 7.37; N, 3.79; O, 17.32

518-69-4

101301

Typically exists as white to light yellow solids at room temperature

1.2±0.1 g/cm3

482.3±45.0 °C at 760 mmHg

135°

135.7±25.9 °C

0.0±1.2 mmHg at 25°C

1.600

4.19

0

5

4

27

503

2

O(C([H])([H])[H])C1=C(C([H])=C([H])C2=C1C([H])([H])N1C([H])([H])C([H])([H])C3=C([H])C(=C(C([H])=C3[C@@]1([H])[C@@]2([H])C([H])([H])[H])OC([H])([H])[H])OC([H])([H])[H])OC([H])([H])[H]

VRSRXLJTYQVOHC-YEJXKQKISA-N

InChI=1S/C22H27NO4/c1-13-15-6-7-18(24-2)22(27-5)17(15)12-23-9-8-14-10-19(25-3)20(26-4)11-16(14)21(13)23/h6-7,10-11,13,21H,8-9,12H2,1-5H3/t13-,21+/m0/s1

(13S,13aR)-2,3,9,10-tetramethoxy-13-methyl-5,8,13,13a-tetrahydro-6H-isoquinolino[3,2-a]isoquinoline

Corydalin; BRN 0096972; NSC 406036; BRN-0096972; NSC-406036; BRN0096972; NSC406036

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

DMSO : ~33.33 mg/mL (~90.22 mM)

Solubility in Formulation 1: ≥ 2.5 mg/mL (6.77 mM) (saturation unknown) in 10% DMSO + 40% PEG300 +5% Tween-80 + 45% Saline (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 400 μL PEG300 and mix evenly; then add 50 μL Tween-80 + to the above solution and mix evenly; then add 450 μL normal saline to adjust the volume to 1 mL.
Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH₂ O to obtain a clear solution.

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 (Please use freshly prepared in vivo formulations for optimal results.)