Identification and screening of a tadalafil analogue found in adulterated herbal products

Ji Hyun Lee; Hyung Joo Kim; Eunyoung Noh; Jung Yeon Kim; So Hyun Cho; Jung-Ah Do; Chang-Yong Yoon; Sooyeul Cho; Woo Seong Kim

doi:10.1016/j.jpba.2014.11.006

Identification and screening of a tadalafil analogue found in adulterated herbal products

J Pharm Biomed Anal. 2015 Jan 25:103:80-4. doi: 10.1016/j.jpba.2014.11.006. Epub 2014 Nov 13.

Authors

Ji Hyun Lee¹, Hyung Joo Kim¹, Eunyoung Noh¹, Jung Yeon Kim¹, So Hyun Cho¹, Jung-Ah Do¹, Chang-Yong Yoon¹, Sooyeul Cho¹, Woo Seong Kim²

Affiliations

¹ Advanced Analysis Team, Toxicological Evaluation and Research Department, National Institute of Food and Drug Safety Evaluation, Ministry of Food and Drug Safety, Osong Health Technology Administration Complex, 187 Osongsaengmyeong2-ro, Yeonje-ri, Osong-eup, Heungdeok-gu, Cheongju-si, Chungcheongbuk-do 363-700, Republic of Korea.
² Advanced Analysis Team, Toxicological Evaluation and Research Department, National Institute of Food and Drug Safety Evaluation, Ministry of Food and Drug Safety, Osong Health Technology Administration Complex, 187 Osongsaengmyeong2-ro, Yeonje-ri, Osong-eup, Heungdeok-gu, Cheongju-si, Chungcheongbuk-do 363-700, Republic of Korea. Electronic address: kwsh964@korea.kr.

PMID: 25462124
DOI: 10.1016/j.jpba.2014.11.006

Abstract

A tadalafil analogue was detected in an herbal product by high performance liquid chromatography-diode array detector (HPLC-DAD) with a similar chromatographic retention time to tadalafil. The compounds were separated using semi-preparative HPLC. The structure of the detected tadalafil analogue was elucidated by LC-quadrupole time-of-flight mass spectrometry (LC-Q-TOF/MS) and nuclear magnetic resonance (NMR) spectroscopy. A positive ion at m/z 404.1644 was detected by LC-Q-TOF/MS, corresponding to a molecular formula of C23H22N3O4. This unknown compound was identified as an analogue of tadalafil containing an additional methylene group and named homotadalafil. Homotadalafil was detected in 10 of 91 herbal products at concentrations of 0.058mgg(-1) to 8.735mgg(-1).

Keywords: Homotadalafil; LC-Q-TOF/MS; NMR; Screening; Tadalafil analogue.

MeSH terms

Chromatography, High Pressure Liquid / methods
Herbal Medicine*
Magnetic Resonance Spectroscopy
Mass Spectrometry
Phosphodiesterase 5 Inhibitors / analysis*
Spectrophotometry, Ultraviolet
Tadalafil / analogs & derivatives*
Tadalafil / analysis

Substances

Phosphodiesterase 5 Inhibitors
Tadalafil