Evidence-Based Complementary and Alternative Medicine

Research Article

Rapid Screening of Potential Phosphodiesterase Inhibitors from the Roots of Ilex pubescens Hook. et Arn. Using a Combination of Ultrafiltration and LC–MS

Table 1

Characterization of constituents by LC–ESI–IT–TOF–MS from the roots of I. pubescens.


Number	(min)	Formula (theoretical m/z)	Experimental m/z (error, ppm)	Fragmentation	Identification

1	12.312	C₁₆ H₁₈ O₉ (353.0873)	353.0882 [M-H]⁻ (2.5)	353 (100%) → 191 ([M-H-Caffeoyl]⁻)	Chlorogenic

2	25.468	C₂₈H₃₆O₁₃ (579.2078)	579.2095 [M-H]⁻ (2.9)	579 (100%) → 417 ([M-H-Glc]⁻, 100%) → 402 ([M-H-Glc-CH₃]⁻), 181 ([Syringyl]⁻)	Tortoside A
			625.2131 [M+HCOO]⁻

3	25.630	C₂₅H₂₄O₁₂ (515.1190)	515.1230 [M-H]⁻ (7.8)	515 (100%) → 353 ([M-H-Caffeoyl]⁻, 100%) → 173 ([M-H-2Caffeoyl-H₂O]⁻), 179 ([Caffeic acid-H]⁻), 135 ([Caffeic acid-H-CO₂]⁻)	Isochlorogenic acid

4	27.838	C₂₅H₂₄O₁₂ (515.1190)	515.1190 [M-H]⁻ (0.0)	515 (100%) → 353 ([M-H-Caffeoyl]⁻, 100%), 191 ([Quinic acid-H]⁻) → 191 ([M-H-2Caffeoyl]⁻)	Isochlorogenic acid A

5	29.895	C₂₅H₂₄O₁₂ (515.1190)	515.1215 [M-H]⁻ (4.9)	515 (100%) → 353 ([M-H-Caffeoyl]⁻, 100%), 173 ([M-H-2Caffeoyl -H₂O]⁻) → 173 ([M-H-2Caffeoyl -H₂O]⁻)	Isochlorogenic acid

6	41.972	C₃₄H₃₀O₁₅ (677.1507)	677.1533 [M-H]⁻ (3.8)	677 (100%) → 515 ([M-H-Caffeoyl]⁻, 100%), 353 ([M-H-2Caffeoyl]⁻) → 353 ([M-H-2Caffeoyl]⁻, 100%), 335 ([M-H-2Caffeoyl- H₂O]⁻) → 173 ([Quinic acid-H- H₂O]⁻), 179 ([Caffeic acid-H]⁻), 191 ([Quinic acid-H]⁻), 135 ([Caffeic acid-H-CO₂]⁻)	3,4,5-Tricaffeoylquinic acid

7	45.220	C₄₇H₇₆O₁₈ (927.4953)	927.4996 [M-H]⁻ (4.6)	927 (100%) → 765 ([M-H-Glc]⁻, 100%) → 603 ([M-H-2Glc]⁻)	B₃
			973.5043 [M+HCOO]⁻

8	56.657	C₄₇H₇₆O₁₇ (911.5004)	911.5049 [M-H]⁻ (4.9)	911 (100%) → 765 ([M-H-Rha]⁻, 100%), 603 ([M-H-GlcRha]⁻) → 603 ([M-H-GlcRha]⁻, 100%) → 543 ([M-H-GlcRha-H₂O-CO₂]⁻), 585 ([M-H-GlcRha-H₂O]⁻)	I
			957.5107 [M+HCOO]⁻

9	57.873	C₃₆H₅₆O₁₁ (663.3744)	663.3766 [M-H]⁻ (3.3)	663 (100%) → 501 ([M-H-Glc]⁻, 100%) → 483 ([M-H-Glc-H₂O]⁻, 100%) → 439 ([M-H-Glc-H₂O-CO₂]⁻)
			709.3860 [M+HCOO]⁻

10	60.828	C₄₁H₆₆O₁₃ (765.4425)	765.4400 [M-H]⁻ (−3.3)	765 (100%) → 603 ([M-H-Glc]⁻, 100%) → 585 ([M-H-Glc-H₂O]⁻), 543 ([M-H-Glc-H₂O-CO₂]⁻)
			811.4497 [M+HCOO]⁻

11	75.675	C₃₀H₄₆O₆ (501.3216)	501.3239 [M-H]⁻ (4.6)	501 (100%) → 483 ([M-H-H₂O]⁻), 439 ([M-H-H₂O-CO₂]⁻)

compared with standard. Glc, glucosyl; Rha, rhamnosyl.