Sophora tonkinensis is the dry root and the rhizome of Sophora tonkinensis Gagnep, a Leguminosae sprawling dwarf shrub plant that mainly originated from Guangxi and Guizhou, two provinces of China. It was first recorded in a Chinese medical book called “Kai Bao Ben Cao”. Its medicinal properties are bitter cold and toxic. The meridian tropism is in the lungs and stomach. The effects are heat-clearing and detoxicating, reducing swelling, and relieving sore throat. In modern clinical medicine, it is commonly used to treat diseases like swollen sore throat, jaundice with damp-heat, and arrhythmia. Here we will walk you through the recent studies on the chemical constituents of Sophora tonkinensis.
1. Alkaloids
Alkaloids separated from Sophora tonkinensis are divided into matrine-type, cytisine-type, sparteine-type, and lupinine-type, which is the most common. The main effective constituents are matrine and oxymatrine, as well as sophocarpine, sophoridine, sophoramine, sophoranol, cytisine, N-caulophylline, anagyrine, and oxysophocarpine. A research extracted 5α-hydroxysophocarpine, (+)-14α-hydroxymatrine, (-)-14β-hydroxymatrine, (+)-5α, 9α-dyhydroxymatrine and 9-hydroxymatrine from Sophora tonkinensis. With the continuous deepening of research, (-)-14β-carbethoxymatrine, (+)-14α-carbethoxymatrine, 13, 14-dehydrosophoranol and (-)-14β-hydroxyoxymatrine were separated successively.
2. Flavonoids
Flavonoids in Sophora tonkinensis are divided into sophoranone, sophoridine, sophorado-chromene and new flavone glycosides I-VII. Later on, sophora flavone A, sophora flavone B, baying, sophoranone, sophoradin, sophoranochromene, sophoradochromene, genistein, pterocarpin, maackian, sitosterol, lupeol, glabrol, genistein, maackiain, trifolirhizin, quercetin, rutin, isorhamnetin-3-rutoside, formononetin, 8-methylretusin, (-)-trifolirhizin. Six new flavone glycosides compounds were separated, including tonkinochromane A. A Chinese investigator named Long Jinqiao firstly separated glycyrrhizin and 7, 4-dyhydroxyflavone from Guangxi Sophora tonkinensis.
3. Polysaccharide
In a study, 8 polysaccharides were successively extracted with hot water, 1mol. L-1 NaOH, 2.5mol. L-1 NaOH after degreasing Sophora tonkinensis: SSa-1, SSa-2, SSa-3, SSa-4 and SSb-1 FA, SSb-2, SSb-3, SSc-1. Researchers used DEAE-cellulose ion-exchange chromatography and Sephadex G-100 gel chromatography to separate and purify and obtain water-soluble polysaccharide SSP1.
4. Triterpenoid
Triterpene and triterpenoid saponin that Sophora tonkinensis contains mainly belong to oleanene-type and some individuals belong to lupinane-type. Sophora tonkinensis contains abrisapogenol C, D, E, H, I, cantoniensistriol, kudzusapogenol A, melilotigenin, wistariasapogenol A, lupeol, kaikasaponin II, III, subprogenin A-D, soyasapogenol A and B, abrisapogenin I, dehydrosoyasaponin I, subpmside I-VII, sophoradiol, soyasaponin A, B, A3, 3-O-[α-L-rhamnosyl (1-2) -D-galactoside-(1-2)-β-D-glucosyl] soyasapogenolmethylester.
5. Other constituents
There are also other constituents of phenolic compounds, coumarin, anthraquinone, sterol, caffeic acid, fatty acid, protein, and amino acid existing in Sophora tonkinensis like piscidicacidmonoethylester, maltol, vanillic acid, p-hydroxybenzoic acid, dodecyl caffeinate, rheum emodin, physcion and β-sitosterol. The microelements of iron, copper, zinc and manganese in Sophora tonkinensis are all very abundant. Meanwhile, there are infinitesimal harmful elements of cadmium and lead existing in Sophora tonkinensis.
Sophora tonkinensis has rich chemical constituents and wide pharmacological activities as well as potential value in use. However, researches on pharmacological effects at present mainly focuses on alkaloids and polysaccharide, while there are few reports about the pharmacological effects of flavonoids, triterpenes, and other constituents, which have yet to be further studied.