Cullen corylifolium Fruit

Cullen corylifolium Fruit

Proposed For Comment Version 0.2

Cullen corylifolium Fruit





The article consists of the dried fruit of Cullen corylifolium (L.) Medik., formerly known as Psoralea corylifolia (Family Fabaceae). The fruit may be misidentified as seeds. It contains NLT 0.1% of coumarins as the sum of psoralen and bakuchicin, and NLT 2.0% of bakuchiol on the dried basis.



Cullen corylifolia (L.) Medik.

Cullen corylifolius (L.) Medik.

Lotodes corylifolia (L.) Kuntze

Psoralea corylifolia L.

Psoralea patersoniae Schonl.

Trifolium unifolium Forssk.



Senna tora (L.) Roxb.



Chinese: 补骨脂

English: Blackdot, psoralea, scurfy-pea

Hindi: Babchi, bavachi, bakuchi

Swedish: Skovärt



Coumarin: Psoralen, bakuchicin

Terpene: Bakuchiol



• A. Botanical Characteristics

Macroscopic: Fruit indehiscent, one seeded pod, ovoid, oblong to orbicular, somewhat flattened, occasionally kidney shaped, varying in size, 3–5 mm in length, 2.5–3.5 mm in breadth and 2–3 mm in thickness, glabrous, deeply wrinkled, forming fine reticulate and closely pitted surface, with or without calyx. Calyx gamosepalous, five lobed, unequal in size, membranous with longitudinal veins and circular glands, externally dark brown to yellowish brown, internally pale brown to whitish in colour; seed inseparable from pericarp. Odour indistinct, taste bitter, oily, unpleasant and acrid.

Microscopic: Detailed transverse structure of the fruit shows an outer layer of the epicarp composed of rectangular to tangentially elongated dark brown coloured cells covered with thin cuticle, 5–6 rows of irregularly arranged parechymatous cells of hypodermis filled with dark brown content, underneath of which lies a row of tangentially running big oleoresin canals; the remaning mesocarp tissue is narrow, composed of yellowish tangentially running parenchymatous cells containing vascular strands; beneath which lies a layer of endocarp. The spermoderm attached with the fruit wall shows an outermost layer of palisade like cells of an outer epidermis or malpighian layer, the cells of which are thick walled, longitudinally striped, squarish at the top with faint light line, ‘linea lucida’ extending across, broader at the base, thick-walled with a narrow lumen. A layer of sub-epidermis consisting of a row of spool shaped cells known as bearer cells lie under the palisade layer. The inner zone of the testa is composed of outer tangentially running parenchyma and inner collapsed parenchymatous tissue traversed by vascular strands, and a layer of endosperm lying underneath. The epidermal cells of the cotyledon are squarish to somewhat rectangular; cells of the mesophyll are radially arranged, with aleurone grains and oil globules.


B. HPTLC for Articles of Botanical Origin <203>

Standard solution A: 0.05 mg/mL of USP Psoralen RS in methanol

Standard solution B: 50 mg/mL of USP Cullen corylifolium Fruit Dry Extract RS in methanol. Sonicate for 10 min, centrifuge or filter, and use the supernatant or the filtrate.

Sample solution: Sonicate about 1 g of Cullen corylifolium Fruit, finely powdered, in 10 mL of methanol and reflux for 15 min, centrifuge or filter, and use the supernatant.

Chromatographic system

Adsorbent: Chromatographic silica gel F254 mixture with an average particle size of 5 µm.

Application volume: 5 µL of Standard solution A, 2 µL of Standard solution B, and 5 µL of the Sample solution, as 6-mm bands

Relative humidity: Condition the plate to a relative humidity of about 33% using a suitable device.

Developing solvent system: Toluene, ethyl acetate, and formic acid (80:18:2)

Developing distance: 6 cm


Samples: Standard solution A, Standard solution B, and Sample solution

  Apply the Samples as bands and dry in air. Develop in a saturated chamber (30 min with filter paper), remove the plate from the chamber, and dry in air. Examine under UV light at 254 and 365 nm.

System suitability: Under UV 254 nm, the chromatogram of Standard solution B exhibits one intense dark band and two dark bands in the upper half of the chromatogram, with the band with lowest RF corresponding in RF and color to the psoralen band in the chromatogram of Standard solution A. The most intense dark band is bakuchiol and the dark band right below the bakuchiol band is bakuchicin. About eight additional dark bands seen in the lower half of the chromatogram. One pale bluish band appears near RF 0.3. Under UV 365 nm, a blue fluorescent band in the upper half of the chromatogram similar in RF and color to the psoralen band in the chromatogram of Standard solution A. A dark band, faint blue band, and two orange bands, with increasing RF above the psoralen band appear in Standard solution B. A bright blue fluorescent band and a less bright fluorescent band appear below the psoralen band. Below the less fluorescent band, with decreasing RF, a dark intense dark band, an intense bright blue fluorescent band appears in Standard solution B.

Acceptance criteria: Under UV 254 nm, the chromatogram of the Sample solution exhibits three dark bands in the upper half of the chromatogram, with the lowest dark band corresponding in RF and color to the psoralen band in the chromatogram of Standard solution A. Two additional dark bands above the psoralen band, with an intense band in the upper RF corresponding with bakuchiol and the lower dark band corresponding with bakuchicin. About eight dark bands in the lower half of the chromatogram with one bluish dark band near RF 0.3. Under UV 365 nm, a blue band similar in RF and color to the psoralen band appears in the chromatogram of Standard solution A. Above the psoralen band, with increasing RF, a faint white or bluish band, and two orange bands appear. Below the psoralen band, with decreasing RF, two blue bands, a dark band, a bright blue band, and several blue bands appear.



Analysis: Proceed as directed in the test for Content of Coumarins and Bakuchiol.

Acceptance criteria: The chromatogram of the Sample solution exhibits peaks at retention times corresponding to the peaks due to psoralen, bakuchicin, and bakuchiol in Standard solution B.



• Content of Coumarins and Bakuchiol

Solution A: 0.1% trifluoroacetic acid in water

Solution B: 0.1% trifluoroacetic acid in acetonitrile

Mobile phase: See Table 1.


Table 1


Solution A

Solution B





























Standard solution A: 0.025 mg/mL of USP Psoralen RS in methanol

Standard solution B: 1 mg/mL of USP Cullen corylifolium Fruit Dry Extract RS in methanol. Sonicate, and pass through a membrane filter of 0.45-µm or finer pore size.

Sample solution: Transfer 500 mg of Cullen corylifolium Fruit, finely powdered and accurately weighed, to a 250-mL flask and add 70 mL of methanol. Reflux at 80° for 15 min and transfer the extract into a 100-mL volumetric flask. Rince the flask twice with 10 mL of methanol and transfer the solution into the same volumetric flask. Dilute with methanol to volume. Pass through a membrane filter of 0.45-µm pore size.

Chromatographic system

(See Chromatography <621>, System Suitability.)

Detector: UV 290 nm

Column: 4.6-mm × 10-cm; 2.7-µm packing L1

Column temperature: 40°

Flow rate: 1.0 mL/min

Injection volume: 10 µL

System suitability

Samples: Standard solution A and Standard solution B

Suitability requirements

Chromatogram similarity: The chromatogram of Standard solution B is similar to the reference chromatogram provided with the lot of USP Cullen corylifolium Fruit Dry Extract RS being used.

Resolution: NLT 2.0 between the psoralen peak and the peak after, Standard solution B

Tailing factor: NMT 2.0 for the psoralen peak, Standard solution A

Relative standard deviation: NMT 2.0% for the psoralen peak in repeated injections, Standard solution A


Samples: Standard solution A, Standard solution B, and Sample solution

Using the chromatograms of Standard solution A, Standard solution B, and the reference chromatogram provided with the lot of USP Cullen corylifolium Fruit Dry Extract RS being used, identify the retention times of the peaks corresponding to psoralen, bakuchicin, and bakuchiol in the Sample solution. The approximate relative retention times of psoralen, bakuchicin, and bakuchiol are 1.00, 1.03, and 2.23, respectively.

Calculate the percentages of coumarins as the sum of psoralen and bakuchicin, and bakuchiol in the portion of Cullen corylifolium Fruit taken:


Result = (rU/rS) × CS × (V/W) × × 100


rU   = peak area of the relevant analyte from the Sample solution

rS   = peak area of psoralen from Standard solution A

CS  = concentration of USP Psoralen RS in Standard solution A (mg/mL)

V    = volume of the Sample solution (mL)

W   = weight of Cullen corylifolium Fruit taken to prepare the Sample solution (mg)

F    = conversion factor for analytes: 1.00 for psoralen, 1.05 for bakuchicin, and 2.99 for bakuchiol


Acceptance criteria

Coumarins: NLT 0.1% on the dried basis

Bakuchiol: NLT 2.0% on the dried basis



• Elemental Impurities—Procedures <233>

Acceptance criteria

Arsenic: NMT 2.0 µg/g

Cadmium: NMT 0.5 µg/g

Lead: NMT 5.0 µg/g

Mercury: NMT 0.2 µg/g

• Articles of Botanical Origin <561>, Pesticide Residue Analysis: Meets the requirements

• Microbial Enumeration Tests <61>: The total aerobic bacterial count does not exceed 105 cfu/g, the total combined molds and yeasts count does not exceed 103 cfu/g, and the bile-tolerant Gram-negative bacteria does not exceed 103 cfu/g.

• Tests for Specified Microorganisms <62>: Meets the requirements of the tests for the absence of Salmonella species and Escherichia coli



• Articles of Botanical Origin <561>, Methods of Analysis, Foreign Organic Matter: NMT 2.0%

• Articles of Botanical Origin <561>, Methods of Analysis, Alcohol-Soluble Extractives, Method 1: NLT 10.0%

• Articles of Botanical Origin <561>, Methods of Analysis, Water-Soluble Extractives, Method 2: NLT 12.0%

• Loss on Drying <731>

Sample: 2 g of Cullen corylifolium Fruit, finely powdered

Analysis: Dry the Sample at 105° for 5 h.

Acceptance criteria: NMT 10%

• Articles of Botanical Origin <561>, Methods of Analysis, Total Ash: NMT 8.0%

• Articles of Botanical Origin <561>, Methods of Analysis, Acid-Insoluble Ash: NMT 1.0%



• Packaging and Storage: Preserve in well-closed containers, protected from light and moisture, and store at room temperature.

• Labeling: The label states the Latin binomial and the part(s) of the plant contained in the article.

• USP Reference Standards <11>

USP Cullen corylifolium Fruit Dry Extract RS

USP Psoralen RS

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Key Information

Comment End Date:
August 5, 2018

Other Versions

Proposed For Development Version 0.1