Coix lacryma-jobi Seed
Coix lacryma-jobi Seed
Proposed For Development Version 0.1
Coix lacryma-jobi Seed
The article consists of the dried ripe caryopsis, freed from the shell, of Coix lacryma-jobi var. ma-yuen (Rom.Caill.) Stapf (Family Poaceae, alt. Gramineae), collected in the fall. It contains NLT 3.5% of triglycerides calculated as the sum of trilinolein (C57H98O6), 1,2-dilinoleoyl-3-palmitin (C55H98O6), 1,2-dilinoleoyl-3-olein (C57H100O6), 1-palmitoyl-2-oleoyl-3-linolein (C55H100O6), 1,2-dioleoyl-3-linolein (C57H102O6), 1,2-dioleoyl-3-palmitin (C55H102O6), and triolein (C57H104O6), on the dried basis.
Coix chinensis Tod. ex Balansa
Coix chinensis Tod
Coix ma-yuen Rom.Caill.
POTENTIAL CONFOUNDING MATERIALS
Coix lacryma-jobi L.
Coix puellarum Balansa
Coix lacryma-jobi var. stenocarpa (Oliver) Stapf
Sorghum bicolor (L) Moench
Hordeum vulgare L
SELECTED COMMON NAMES
Chinese: 薏苡仁, 薏米
English: Coix seed, Job's Tears, adlay
French: Larmes de Job
Russian: Coix семян
Spanish: Lágrimas de Job
CONSTITUENTS OF INTEREST
Triglycerides: Trilinolein, 1,2-dilinoleoyl-3-palmitin, 1,2-dilinoleoyl-3-olein, 1-palmitoyl-2-oleoyl-3-linolein, 1,2-dioleoyl-3-linolein, 1,2-dioleoyl-3-palmitin, and triolein
Fatty acid: Oleic acid
• A. Botanical Characteristics
Macroscopic: Broad ovoid or elongated-elliptical, 4–8 mm long, 3–6 mm wide. Externally milky-white, smooth, occasionally with yellowish-brown testa. One end obtusely rounded, the other end relatively broad and slightly dented with one pale brown dotted hilum. Dorsal surface rounded and protruding; ventral surface with one relatively broad and deep longitudinal furrow. Texture hard, fracture white and starchy.
Transvers section: Irregular, cylindrical cells in the middle layer of pericarp, polygonal cells in endosperm, thin and numerous starch grains in the cells.
• B. Thin-Layer Chromatography
Standard solution A: 2 mg/mL of USP Oleic Acid RS in methanol
Standard solution B: 40 mg/mL (about 50 μL/mL) of USP Coix lacryma-jobi Seed Oil Extract RS in hexanes
Sample solution: Sonicate 1.0 g of Coix lacryma-jobi Seed, finely powdered, in 10 mL of hexanes for 15 min. Centrifuge and use the supernatant.
(See Chromatography <621>, Thin-Layer Chromatography.)
Adsorbent: Use a suitable chromatographic material with an average particle size of 5 µm (HPTLC plates, Si 60 RP-18 F254).
Application volume: 2 µL, as 8-mm bands
Relative humidity: Condition the plate to a relative humidity of about 33% using a suitable device.
Developing solvent system: Methylene chloride, acetone, and glacial acetic acid (20:50:40)
Developing distance: 7 cm
Derivatization reagent: 5 g of Phosphomolybdic acid in 200 mL of ethanol
Samples: Standard solution A, Standard solution B, and Sample solution
Apply the Samples as bands to a suitable HPTLC plate and dry in air. Develop the chromatograms in a saturated chamber, remove the plate from the chamber, and dry in a hood. Dip the plate (time 0, speed 5), heat at 120° for 5 min, and examine in daylight.
System suitability: In the upper half, the chromatogram of Standard solution B exhibits a band corresponding in Rf and color to the band for oleic acid in Standard solution A, and a band right above oleic acid with the same color as it. In the lower half, the chromatogram of Standard solution B exhibits a cluster of four blue bands.
Acceptance criteria: In the upper half, the chromatogram of Sample solution exhibits a band corresponding in Rf and color to the band for oleic acid in Standard solution A. The Sample solution exhibits additional bands corresponding to similar bands in chromatogram of Standard solution B; these include one band right above oleic acid with the same color as it, a cluster of four blue bands in the lower half, and some faint bands in the middle-third.
• C. HPLC
Analysis: Proceed as directed in the Assay for Content of Triglycerides.
Acceptance criteria: The chromatogram of the Sample solution exhibits a peak with a retention time corresponding to triolein in the chromatogram of Standard solution A; the peaks due to trilinolein, 1,2-dilinoleoyl-3-palmitin,1,2-dilinoleoyl-3-olein, 1-palmitoyl-2-oleoyl-3-linolein, 1,2-dioleoyl-3-linolein, and 1,2-dioleoyl-3-palmitin are at retention times corresponding to the same triglycerides in Standard solution B and the reference chromatogram provided with the lot of USP Coix lacryma-jobi Seed Oil Extract RS being used. 1,2-Dilinoleoyl-3-olein and 1,2-dioleoyl-3-linolein have the most intense peaks; 1-palmitoyl-2-oleoyl-3-linolein and triolein have medium intensity peaks; and trilinolein, 1,2-dilinoleoyl-3-palmitin, and 1,2-dioleoyl-3-palmitin have weak intense peaks (distinguished from Sorghum bicolor (L) Moench, which has similar triglycerides peaks but all of them are in weak intense; and Hordeum vulgare L., which has four triglycerides peaks and all of them are in weak intense). The content ratios for each triglyceride versus triolein are listed in Table 1.
• Content of Triglycerides
Mobile phase: Methanol
Standard solution A: 0.20 mg/mL of USP Triolein RS in methanol, sonicate to dissolve.
Standard solutions: Dilute Standard solution A with methanol to obtain solutions of 0.0125, 0.025, 0.05, 0.10, and 0.20 mg/mL of USP Triolein RS. Pass each through a filter of 0.45-μm or finer pore size.
Standard solution B: 0.5 mg/mL of USP Coix lacryma-jobi Seed Oil Extract RS in methanol
Sample solution: Accurately transfer about 500 mg of Coix lacryma-jobi Seed, finely powdered, into a suitable flask and accurately add 35 mL of methanol. Sonicate for 30 min and filter with the aid of vacuum into a vacuum flask. Rinse the flask and the residue left in the flask with 5 mL of methanol, and wash the residue and paper on the filter using the rinsings. Repeat the rinse and wash procedure one more time. Transfer the filtrate into a 50-mL volumetric flask. Wash the vacuum flask with methanol, combine the washings into the volumetric flask, dilute to volume with methanol, and mix. Before injection, pass through a membrane filter of 0.45-μm or finer pore size, and discard the first portion of the filtrate. [Note—The filter and vacuum flask should be dry.]
(See Chromatography <621>, System Suitability.)
Detector: Evaporative light-scattering. [Note—The parameters of the detector are adjusted to achieve the best signal-to-noise ratio, according to manufacturer recommendations.]
Column: 3.0-mm × 10-cm; 2.7-μm packing L7 (Similar to AMT HALO™ C8 90 Å or Agilent poroshell 120 EC C8)
Column temperature: 20 ± 1°
Flow rate: 0.3 mL/min
Injection volume: 5 µL
Samples: Standard solution A, Standard solutions, and Standard solution B
Chromatogram similarity: The chromatogram of Standard solution B is similar to the reference chromatogram provided with the lot of USP Coix lacryma-jobi Seed Oil Extract RS being used.
Resolution: NLT 1.0 between the peak of 1,2-dilinoleoyl-3-olein and the peak following it, Standard solution B
Tailing factor: NMT 1.5 for triolein peak, Standard solution A
Relative standard deviation: NMT 5.0% for the triolein peak, Standard solution A
Signal-to-noise ratio: NLT 15 for the triolein peak, Standard solutions of 0.0125 mg/mL
Correlation coefficient: NLT 0.995 for the regression line as determined in Analysis, Standard solutions
Samples: Standard solutions, Standard solution B, and Sample solution
Using the chromatograms of Standard solutions, Standard solution B, and the reference chromatogram provided with the lot of USP Coix lacryma-jobi Seed Oil Extract RS being used, identify the retention times of the peaks corresponding to trilinolein, 1,2-dilinoleoyl-3-palmitin, 1,2-dilinoleoyl-3-olein, 1-palmitoyl-2-oleoyl-3-linolein, 1,2-dioleoyl-3-linolein, 1,2-dioleoyl-3-palmitin, and triolein in the Sample solution. [Note—The approximate relative retention times of the analytes are provided in Table 1.]
Plot the logarithms of peak responses versus the logarithms of concentrations, in mg/mL, of triolein from the Standard solutions, and determine the regression line using a least-squares analysis; or, establish a linear regression equation using a least-squares analysis according to the logarithms of the peak responses versus logarithms of concentrations, in mg/mL, of triolein from the Standard solutions.
Determine the concentration, C, in mg/mL, of the relevant analyte in the Sample solution by regression line or linear regression equation. Separately calculate the percentages of trilinolein, 1,2-dilinoleoyl-3-palmitin, 1,2-dilinoleoyl-3-olein, 1-palmitoyl-2-oleoyl-3-linolein, 1,2-dioleoyl-3-linolein, 1,2-dioleoyl-3- palmitin, and triolein in the portion of Coix lacryma-jobi Seed taken:
Result = C × (V/W) × 100
C = concentration of the relevant analyte in the Sample solution (mg/mL)
V = volume of the Sample solution (mL)
W = weight of Coix lacryma-jobi Seed taken to prepare the Sample solution (mg)
Add the percentages of trilinolein, 1,2-dilinoleoyl-3-palmitin, 1,2-dilinoleoyl-3-olein, 1-palmitoyl-2-oleoyl-3-linolein, 1,2-dioleoyl-3-linolein, 1,2-dioleoyl-3-palmitin, and triolein.
Acceptance criteria: NLT 3.5% on the dried basis
Arsenic: NMT 2.0 µg/g
Cadmium: NMT 0.3 µg/g
Lead: NMT 5.0 µg/g
Mercury: NMT 0.2 µg/g
• 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
Sample: 2.0 g of Coix lacryma-jobi Seed, finely powdered
Analysis: Dry the Sample at 105° for 5 h.
Acceptance criteria: NMT 15.0%
Analysis: 2 g of Coix lacryma-jobi Seed, finely powdered
Acceptance criteria: NMT 3.0%
• Packaging and Storage: Preserve in well-closed containers, protected from light and moisture, and store at 4°–10°.
• Labeling: The label states the Latin binomial and the part(s) of the plant contained in the article.
USP Coix lacryma-jobi Seed Oil Extract RS
USP Aflatoxins RS
USP Oleic Acid RS
USP Triolein RS
The commenting period for this monograph has expired.