An anti-influenza virus compound, Gibberellin B

 Isatis Radix, also known as the big blue heel, is the dried root of the plant woad or big blue-green, which can be used clinically for influenza, mumps, chickenpox, and measles. 

The liver is the leading site of drug metabolism, and applying the liver microsomal model allows for metabolite analysis studies of drugs. Drug metabolite analysis has evolved rapidly to become an essential part of pharmacokinetic studies.

According to a study reported on the internet, it was found that based on the systematic screening of the active antiviral ingredients of radix isatidis, straight heliotropin B was the most abundant compound among the 31 compounds isolated from the aqueous extract of radix isatidis, and compound activity testing studies showed that it had significant antiviral and antioxidant activities.

Therefore, the lignan compound Gibberellin B contained in Isatidis Radix no toginseng is one of the critical active substance bases of Isatidis Radix no toginseng against viruses.

Larcholin-4,4'-di-O-β-D-diglucoside was the most abundant lignan-like compound isolated from the active antiviral site of Isatidis Radix no toginseng, accounting for about 2% of the active site and 0.04% of the raw drug amount. 

In vitro anti-HSV viral activity showed some inhibitory effect on HSV-1 and HSV-2 type viruses. Moreover, it has been reported in the literature that Clemastanin B has antioxidant and free radical scavenging activity, has a superoxide dismutase-like effect and has a significant protective effect on cells. In vitro metabolism studies of nematocysts B in human liver microsomes have been carried out, providing an essential basis for the preclinical evaluation of the efficacy of this compound. Because of the chemical stability of Clemastanin B, the study can be directly used to determine the content of Clemastanin B in Isatidis Radixquinquefolium by HPLC showed that the determination of Clemastanin B content can be used as a quality control method for Isatidis Radixquinquefolium granules.

1. Study on the metabolism of straight heliotrope in B in human-derived liver microsomal incubation system

Compared with traditional liquid chromatography techniques, LC-MS/MS has the advantages of high sensitivity, high throughput, and high accuracy and is widely used in drug metabolite analysis studies. Our Pharmacokinetics Lab has passed the  GLP certification by  NMPA. Following the guiding principles of  ICH, NMPA  and  FDA. The lab offers in vivo and in vitro pharmacokinetic tests according to the needs of our clients and provides them with complete sets of pharmacokinetic evaluation and optimization services.

One investigator has applied a human-derived liver microsomal incubation system to investigate the in vitro metabolism of Clemastanin B. The method involves co-incubating Clemastanin B with human liver microsomes, processing the samples by protein precipitation, and qualitative and quantitative analysis of the metabolites by LC-MS/MS. Chromatographic conditions: PhenomenexLunaC18 column (100 mm×2.0 mm, five μm); mobile phase: acetonitrile (containing 0.1% formic acid)-water (containing 0.1% formic acid), gradient elution; flow rate 400 μL-min-1; injection volume 10 μL. Mass spectrometry conditions: electrospray ionization source, negative ion mode detection.

The results revealed that straight heliotrope in B (compound 1) could be metabolized to larixenol-4-O-β-D-glucoside (compound 2) and larixenol-4′-O-β-D-glucoside (compound 3) in the human liver particulate incubation system.

 Therefore, it was found that in the incubation system of human liver particles, Clemastanin B could be partially metabolized to compound 2 with more vigorous anti-influenza activity, suggesting that the anti-influenza efficacy may be exerted in vivo through both the prototype and the active metabolite, providing an essential basis for the evaluation of the effectiveness of this compound.

2, The determination of straight iron Clemastanin B content can be used as a method for quality control of Isolariciresinol

The two compounds, Clemastanin B and Isorubicin, are lignan compounds isolated in relatively large amounts from the active antiviral parts of Isatidis Radix no toginseng, and some researchers have used high-performance liquid chromatography to determine their contents, which provides a basis for the quality evaluation of Isatidis Radix no toginseng.

To establish a method for determining the content of the active antiviral components of Isatidis Radixquinquefolium granules, Gibberellin B, and Isorubicin, the researchers used high-performance liquid chromatography[2]. The results showed good linearity with peak areas in the ranges of 0.1472 μg~1.7664 μg and 0.0608 μg~0.3648 μg for Clemastanin B and idarubicin, respectively, with r of 0.9999 and 0.9991, and the average recoveries of 95.76% and 97.94% with RSD of 2.76% and 1.69%, respectively. The method is simple, sensitive, and reliable in terms of results. It can be used as a quantitative method for the quality control of Isolariciresinol by analyzing the components of straight heliotropic B and idarubicin in different batches of Isolariciresinol from other manufacturers.

Isatidis Radix no toginseng has high clinical application value and is mainly used for the treatment of viral infectious diseases and has sound preventive and therapeutic effects on influenza. In addition, it is effective in treating acute pharyngitis, chronic pharyngitis, epidemic BSE, and chickenpox. The study of the components of Isatidis Radix no toginseng that exert their medicinal effects and the analysis of the content of the active therapeutic ingredients laid the foundation for the quality of Isatidis Radix no toginseng and its modern application.

[1] In vitro metabolism study of Clemastanin B in human liver microsomes [J].

[2] Determination of Gibberellin B and Isorubicin in Isolariciresinol by HPLC [J].