Powdered Chaste Tree
DEFINITION
Powdered Chaste Tree is Chaste Tree reduced to a powder or a very fine powder. It contains NLT 0.05% of agnuside and NLT 0.08% of casticin, calculated on the dried basis.
IDENTIFICATION
•  A. Thin-Layer Chromatographic Identification Test
Standard solution:  100 mg of USP Powdered Chaste Tree Extract RS in 1 mL of methanol. Heat in a water bath at 60 for 10 min. Centrifuge, and use the clear supernatant.
Sample solution:  Transfer about 1 g of Powdered Chaste Tree to a screw-capped centrifuge tube. Add 10 mL of methanol, heat in a water bath at 60 for 10–15 min, cool, and filter.
Adsorbent:  Chromatographic silica gel with an average particle size of 10–15 µm (TLC plates)
Application volume:  90 µL, Standard solution; 60 µL, Sample solution; in bands that are 2 cm in length
Developing solvent system:  Ethyl acetate, methanol, and water (77:15:8)
Spray reagent:  10 mg/mL of p-dimethylaminobenzaldehyde in 1 N hydrochloric acid
Analysis 
Samples:  Standard solution and Sample solution
Develop to a length of NLT 12 cm, and dry the plate in a current of air. Spray the plate with Spray reagent, and heat for 10 min at 120.
Acceptance criteria:  The Sample solution shows the following: a blue zone (at an RF value of about 0.21) due to the presence of aucubin and that corresponds in color and RF value to a similar zone for the Standard solution; a blue zone (at an RF value of about 0.44) as a result of the presence of agnuside that corresponds in color and RF value to a similar zone for the Standard solution; and one broad zone, violet in the middle, near the solvent front and that corresponds in color and RF value to a similar zone for the Standard solution. Other colored zones of varying intensities may be observed for the Sample solution.
•  B. In the test for Content of Casticin, the chromatogram of the Sample solution shows a peak at the retention time corresponding to the casticin peak in the chromatogram of the Standard solution.
COMPOSITION
•  Content of Casticin
Standard solution:  About 0.05 mg/mL of USP Casticin RS in methanol, with sonication. Pass through a cellulose membrane filter of 0.45-µm or finer pore size.
Sample solution:  Place about 1000 mg of Powdered Chaste Tree in a container with a stopper. Extract twice with 40 mL of methanol, using a hand homogenizer at 19,000 rpm for 2 min. Filter each supernatant, and transfer to a 250-mL round-bottom flask. Rinse the residue with methanol, and filter the resulting solution into the flask. Evaporate the combined extract to dryness. Dissolve the residue in methanol, quantitatively transfer to a 20-mL volumetric flask, and dilute with methanol to volume. Pass through a cellulose membrane filter of 0.45-µm or finer pore size.
Solution A:  Methanol
Solution B:  5.88 g/L of phosphoric acid in water
Mobile phase:  See Table 1.
Table 1
Time
(min)
Solution A
(%)
Solution B
(%)
0 50 50
0 50 50
13 65 35
18 100 0
23 50 50
Chromatographic system 
Mode:  LC
Detector:  UV 348 nm
Column:  3.1-mm × 12.5-cm; 5-µm packing L1
Column temperature:  25
Flow rate:  1 mL/min
Injection size:  10 µL
System suitability 
Sample:  Standard solution
Suitability requirements 
Tailing factor:  NMT 2.0 for the casticin peak
Relative standard deviation:  NMT 2.0% for the casticin peak, in repeated injections
Analysis 
Samples:  Standard solution and Sample solution
Calculate the percentage of casticin in the portion of Powdered Chaste Tree taken:
Result = (rU/rS) × (CS/CU) × 100
rU== peak response of casticin from the Sample solution
rS== peak response of casticin from the Standard solution
CS== concentration of USP Casticin RS in the Standard solution (mg/mL)
CU== concentration of Powdered Chaste Tree in the Sample solution (mg/mL)
Acceptance criteria:  NLT 0.08% of casticin on the dried basis
•  Content of Agnuside
Solvent:  Methanol and water (1:19)
Standard solution:  Dissolve a quantity of USP Agnuside RS in Solvent, with sonication. Dilute with methanol to obtain a concentration of about 0.125 mg/mL. Pass through a cellulose membrane filter of 0.45-µm or finer pore size.
Sample solution:  Place about 1000 mg of Powdered Chaste Tree in a container with a stopper. Extract twice with 40 mL of methanol, using a hand homogenizer at 19,000 rpm for 2 min. Centrifuge, and transfer each supernatant to a 250-mL round-bottom flask. Rinse the residue with methanol, and filter the resulting solution into the flask. Evaporate the combined extract to dryness, and dissolve the residue in 2 mL of Solvent. Quantitatively transfer the solution to a solid-phase extraction cartridge packed with neutral aluminum oxide previously conditioned with 5 mL of Solvent. Connect the cartridge to a vacuum pressure not exceeding 300 mbar, and collect the eluate. Rinse the round-bottom flask with 2 mL of Solvent, pass this solution through the cartridge, apply the vacuum, and collect the eluate. Rinse the cartridge with 4 mL of Solvent, and collect the eluate. Combine the eluates from the cartridge, transfer to a 10-mL volumetric flask, and dilute with Solvent to volume.
Solution A:  Acetonitrile
Solution B:  5.88 g/L of phosphoric acid in water
Mobile phase:  See Table 2.
Table 2
Time
(min)
Solution A
(%)
Solution B
(%)
0 7 93
0.6 10 90
5 10 90
7 14 86
13 15 85
13.1 100 0
18 100 0
18.1 7 93
23 7 93
Chromatographic system 
Mode:  LC
Detector:  UV 258 nm
Column:  3.1-mm × 12.5-cm; 5-µm packing L1
Column temperature:  25
Flow rate:  1.3 mL/min
Injection size:  10 µL
System suitability 
Sample:  Standard solution
Suitability requirements 
Tailing factor:  NMT 2.0 for the agnuside peak
Relative standard deviation:  NMT 2.0% for the agnuside peak, in repeated injections
Analysis 
Samples:  Standard solution and Sample solution
Calculate the percentage of agnuside in the portion of Powdered Chaste Tree taken:
Result = (rU/rS) × (CS/CU) × 100
rU== peak response of agnuside from the Sample solution
rS== peak response of agnuside from the Standard solution
CS== concentration of USP Agnuside RS in the Standard solution (mg/mL)
CU== concentration of Powdered Chaste Tree in the Sample solution (mg/mL)
Acceptance criteria:  NLT 0.05% of agnuside on the dried basis
CONTAMINANTS
•  Heavy Metals, Method III 231: NMT 20 ppm
•  Microbial Enumeration Tests 2021: It meets the requirements of the tests for absence of Salmonella species and Escherichia coli. The total aerobic microbial count does not exceed 106 cfu/g, the total combined molds and yeast count does not exceed 104 cfu/g, and the enterobacterial count does not exceed 1000 cfu.
SPECIFIC TESTS
•  Botanic Characteristics: Powdered Chaste Tree is dark brown, with a musty, slightly aromatic odor, and a taste resembling that of sage. The following characteristics are present: fragments of the calyx with covering and glandular trichomes on the outer side and rectangular, elongated cells with slightly wavy walls on the inner side; fragments of exocarp with trichomes and cells with large pits in the outer wall; thin-walled parenchymatous cells and globules of fixed oil; stone-pitted cells from the mesocarp; ovoid, lignified cells with bands of reticulate thickening from the testa; and endosperm and cotyledons with fixed oil.
•  Loss on Drying 731: Dry 1 g at 105 for 2 h: it loses NMT 10.0% of its weight.
ADDITIONAL REQUIREMENTS
•  Packaging and Storage: Preserve in well-closed containers, and store at controlled room temperature.
•  Labeling: The label states the Latin binomial and, following the official name, the part of the plant from which the article was derived.
•  USP Reference Standards 11
USP Agnuside RS
USP Casticin RS
USP Powdered Chaste Tree Extract RS
Auxiliary Information— Please check for your question in the FAQs before contacting USP.
Topic/Question Contact Expert Committee
Monograph Maged H. Sharaf, Ph.D.
Principal Scientific Liaison
1-301-816-8318
(DS2010) Monographs - Dietary Supplements
2021 Radhakrishna S Tirumalai, Ph.D.
Principal Scientific Liaison
1-301-816-8339
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USP35–NF30 Page 1241
Pharmacopeial Forum: Volume No. 29(4) Page 1268