Mucuna pruriens Seed

Mucuna pruriens Seed

Proposed For Development Version 0.1

Mucuna pruriens Seed

 


 

DEFINITION

The article consists of the dried seeds of Mucuna pruriens (L.) DC. (Family Fabaceae). It contains NLT 3.0% of levodopa on the dried basis.

 

SYNONYMS

Carpogon capitatus Roxb.

Carpogon niveus Roxb.

Carpopogon pruriens (L.) Roxb.

Dolichos pruriens L.

Marcanthus cochinchinense Lour.

Mucuna axillaris Baker

Mucuna bernieriana Bail.

Mucuna cochinchinense (Lour.) A. Chev.

Mucuna esquirolii H. Lev.

Mucuna luzoniensis Merr.

Mucuna lyonii Merr.

Mucuna minima Haines

Mucuna nivea (Roxb.) DC.

Mucuna prurita Wight

Mucuna sericophylla Perkins

Mucuna velutina Hassk.

Negretia mitis Blanco

Stizolobium capitatum (Roxb.) Kuntze

Stizolobium cochinchinense (Lour.) Burk

Stizolobium niveum (Roxb.) Kuntze

Stizolobium pruritum (Wight) Piper

Stixolobium velutinum (Hassk.) Piper & Tracy

 

POTENTIAL CONFOUNDING MATERIALS

None known

 

SELECTED COMMON NAMES

Bengali: Akolchi

English: Velvet bean, Mucuna, Sea bean, Nescafe

Hindi: Kiwachi

Malayalam: Naicorna

Marathi: खाज कुइरी Khaj-kuiri

 

 

CONSTITUENTS OF INTEREST

Amino acid: Levodopa

Alkaloids: Mucunine, mucunadine, pruriendine, and prurieninine

 

IDENTIFICATION

• A. Botanical Characteristics

Macroscopic: Ovoid, slightly compressed, with a persistent oblong, funicular hilum, dark brown with spots; usually 1.2–1.8 cm long, 0.8–1.2 cm wide, hard, smooth to touch, not easily breakable

Microscopic: Thin seed coat and two hard colyledons; outer testa consists of single-layered palisade-like cells; inner testa composed of 2 or 3 layers, outer layer of tangentially elongated, ovoid, thin-walled cells, inner 1 or 2 layers of dumb-bell or beaker-shaped, thick-walled cells; tegmen composed of a wide zone of oval to elliptical, somewhat compressed, thin-walled, parenchymatous cells; some cells contain starch grains; cotyledons composed of polygonal, angular, thin-walled, compactly arranged parenchymatous cells, containing aleurone and starch grains; starch grains small; simple, rounded to oval measuring 6–41 µm in diameter, but not over 45 µm in diameter; a few vascular bundles with vessels showing reticulate thickening or pitted present

• B. Thin-Layer Chromatography

Standard solution A: 0.5 mg/mL of USP Levodopa RS in 30% phosphoric acid

Standard solution B: Sonicate 500 mg of USP Mucuna pruriens Seed Dry Extract RS with 10 mL of 30% phosphoric acid for 5 min. Transfer the solution to a 50-mL volumetric flask and add methanol to volume. Centrifuge or filter, and use the supernatant or the filtrate.

Sample solution: Deposit 1 g of Mucuna pruriens Seed, finely powdered, into a suitable beaker, and add 10 mL of 30% phosphoric acid. Sonicate for 5 min, and transfer to a 50-mL volumetric flask. Rinse the beaker with methanol and empty the rinsate into the same flask. Dilute with methanol to volume. Centrifuge or filter, and use the supernatant or the filtrate.

Chromatographic system

(See Chromatography <621>, Thin-Layer Chromatography.)

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

Application volume: 10 µL each of Standard solution A, Standard solution B, and Sample solution; as 8-mm bands

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

Developing solvent system: Butanol, alcohol, acetic acid, and water (60:32:12:8)

Developing distance: 8 cm

Derivatization reagent: Use a suitable reagent, if applicable.

Analysis

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

Apply the Samples as bands and dry in air. Develop in a saturated chamber (20 min with filter paper), remove the plate from the chamber, and dry in air. Treat the plate with the Derivatization reagent, heat at 100° for 5 min, and examine under white light.

System suitability: Under white light, the chromatogram of Standard solution B exhibits the most intense dark gray or black band with similar RF and color as the levodopa band in the chromatogram of Standard solution A. Three to four dark pink bands appear below the levodopa band and one strong and two weak dark pink bands appear above the levodopa band.

Acceptance criteria: Under white light, the chromatogram of the Sample solution exhibits the most intense dark gray or black band  in the middle of the chromatogram, corresponding in RF to the levodopa band in Standard solution A. The Sample solution exhibits additional bands corresponding to similar bands in Standard solution B, in particular, two weak pink bands: one above and one below the levodopa band.

• C. HPLC

Analysis: Proceed as directed in the test for Content of Levodopa.

Acceptance criteria: The Sample solution exhibits the most intense peak at a retention time corresponding to the peak due to levodopa in Standard solution A and Standard solution B.

 

ASSAY

• Content of Levodopa

Solution A: 1.36 g of monobasic potassium phosphate in 900 mL of water and adjust with phosphoric acid to a pH of 2.5.

Solution B: Methanol

Mobile phase: A mixture of Solution A and Solution B (92:8)

Standard solution A: Dissolve 20 mg of USP Levodopa RS with 5 mL of 30% phosphoric acid and 5 mL of water in a 100-mL volumetric flask. Dilute with water to volume.

Standard solution B: Weigh accurately a sample quantity equivalent to 20 mg of levodopa to a 100-mL volumetric flask. Add 5 mL of 30% phosphoric acid and 5 mL of water, sonicate for 6 min, make up to volume, and centrifuge. Before injection, pass through a membrane filter of 0.45-µm or finer pore size.

Sample solution: Transfer about 2.5 g of Mucuna pruriens Seed, finely powdered and accurately weighed, into a 100-mL centrifuge tube, and add 25 mL of 9% phosphoric acid. Sonicate for 5 min, centrifuge at 3000 rpm for 5 min, and transfer the supernatant to a 100-mL volumetric flask. Repeat the extraction three more times by adding 20 mL of 9% phosphoric acid, and transferring the supernatant to the same 100-mL volumetric flask; dilute with 9% phosphoric acid to volume, and mix. Before injection, pass through a polyethersulfone membrane filter of 0.45-µm or finer pore size and discard the first portion of the filtrate.

Chromatographic system

(See Chromatography <621>, System Suitability.)

Detector: LC

Column: 4.6-mm × 25-cm; 5-µm packing L1

Column temperature: 30°

Flow rate: 1.0 mL/min

Injection volume: 20 µL

System suitability

Samples: Standard solution A and Standard solution B

Suitability requirements

Resolution: NLT 1.5 between levodopa and the peak before it, Standard solution B

Tailing factor: NMT 1.5 for the levodopa peak, Standard solution A

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

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

Analysis

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 Mucuna pruriens Seed Dry Extract RS being used, identify the retention times of the peaks corresponding to the peaks due to levodopa in the Sample solution.

Calculate the percentage of levodopa in the portion of Mucuna pruriens Seed taken:

 

Result = (rU/rS) × CS × (V/W) × 100

 

rU   = peak area of levodopa from the Sample solution

rS   = peak area of levodopa from Standard solution A

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

V   = volume of the Sample solution (mL)

W   = weight of Mucuna pruriens Seed taken to prepare the Sample solution (mg)

Acceptance criteria: NLT 3.0% of levodopa on the dried basis

 

CONTAMINANTS

• Elemental Impurities—Procedures <233>

Acceptance criteria

Arsenic: NMT 2.0 µg/g

Cadmium: NMT 0.5 µg/g

Lead: NMT 5 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

 

SPECIFIC TESTS

• Articles of Botanical Origin <561>, Methods of Analysis, Foreign Organic Matter: NMT 1.0%

• Articles of Botanical Origin <561>,  Methods of Analysis, Alcohol-Soluble Extractives, Method 1: NLT 3.0%

• Articles of Botanical Origin <561>,  Methods of Analysis, Water-Soluble Extractives, Method 2: NLT 23.0%

• Water Determination <921>, Method II: NMT 8.0%

• Articles of Botanical Origin <561>,  Methods of Analysis, Total Ash: NMT 5.0%

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

 

ADDITIONAL REQUIREMENTS

• 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 Levodopa RS

USP Mucuna pruriens Seed Dry Extract RS

 

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