Determination of Scutellaria baicalensis and Forsythia suspensa in compound Houttuynia mixture

Wind-heat cold is caused by wind-heat evil appearance and lung Qi loss. Symptoms are severe fever, mild bad wind, head pain, sweat, sore throat, cough, phlegm or yellow, nasal congestion yellow nose, thirst and drinking, red tongue tip edge, thin white yellowish moss. Wind heat cold is more common in spring, caused by external wind heat. Traditional Chinese medicine believes that wind-heat cold is the superficial syndrome caused by the evil of feeling wind-heat.

Compound Houttuynia mixture was used for sore throat caused by exogenous wind heat. Acute pharyngitis, tonsillitis with wind-heat syndrome. Compound herba houttuyniae mixture is used heartleaf houttuynia herb medicine, TCM believes that its taste, sex cold, can qingrejiedu, swelling pain therapy sores, diuresis dehumidification, with solid heat, heat cure poison, the origin, heat disease with pulmonary abscess, ulcers swollen poison, hemorrhoids hematochezia, spleen and stomach, heating, etc., or combine of compatibility of compound, both internal and external use or the use of a variety of folk dietotherapy method curative effect.

This article refers to the method in the national consultation draft, and adopts high performance liquid chromatography to detect baicalin and forsythin in compound Houttuynia cordata mixture with Yuexu Ultimate® XB-C18. The specific methods are as follows:

Baicalin Chromatographic conditions:

Column: Ultisil® XB-C18(4.6×250mm, 5μm).

Mobile phase: 0.6% phosphoric acid solution/methanol=58/42;

Detection wavelength: 280nm;

Column temperature: 35℃;

Reference solution: take an appropriate amount of baicalin reference substance, add methanol to make a 20 μg/mL solution.

Test solution: take 2mL of this product, put it in a 50mL volumetric flask, add methanol to dilute to the mark, shake well, filter, and take the filtrate.

Spectra and Data

Baicalin reference substance

P/N	RT	Area	Height	Plate no(USP)	Tailing	Separation(USP)
1	20.716	3335	129	15301	0.904	–
2	22.217	794346	24648	10933	0.929	1.975
Total		797681	24777

Sample solution

P/N	RT	Area	Height	Plate no(USP)	Tailing	Separation(USP)
1	20.716	9800	364	15274	0.897	–
2	22.247	1889414	61707	12183	0.930	2.011
3	24.372	335869	12564	19070	0.941	2.810
Total		2234183	74635

Forsythin chromatographic conditions:

Column: Ultisil® XB-C18(4.6×250mm, 5μm).

Mobile phase: 0.1% phosphoric acid solution/acetonitrile=78/22;

Detection wavelength: 229nm;

Column temperature: 30℃;

Reference solution: take an appropriate amount of forsythin reference substance, add 50% methanol to make a 50μg/mL solution.

Test solution: take 15mL of this product, add water-saturated n-butanol, shake and extract 3 times, 25ml each time, combine the n-butanol solution, recover the solvent to dryness, add 70% ethanol 10mL to dissolve the residue, add neutral On an alumina column (100-200 mesh, 2 g, inner diameter 1.5 cm), eluted with 80 mL of 70% ethanol, collected the effluent and eluent, evaporated to dryness, the residue was dissolved in 50% methanol, and transferred to a 5 mL volumetric flask , add 50% methanol to dilute to the mark, shake well, filter, and take the continuous filtrate.

Forsythin reference substance

P/N	RT	Area	Height	Plate no(USP)	Tailing	Separation(USP)
1	29.025	1178588	35636	18173	0.893	–
Total		1178588	35636

Sample solution

P/N	RT	Area	Height	Plate no(USP)	Tailing	Separation(USP)
1	27.033	42346	1445	18510	0.968	–
2	29.080	1965640	58812	17969	0.901	2.463
3	31.234	12216	408	24364	0.85	2.582
Total		2020203	60664

Conclusion

Using Ultisil® XB-C18 (4.6×250mm, 5μm) chromatographic column meets the detection requirements of the content determination of the above two items.