Identification of unprecedented purine-containing compounds, the zingerines, from ginger rhizomes (Zingiber officinale Roscoe) using a phase-trafficking approach

Abstract

Three unprecedented purine-containing compounds, named [6]-, [8]-, and [10]-zingerines as they are 5-(6-amino-9H-purin-9-yl) analogs of [6]-, [8]-, and [10]-gingerols, respectively, were isolated from a methanolic extract of ginger rhizomes using a phase trafficking-based method that utilizes solid phase reagents allowing for fast and selective simultaneous separation of basic, acidic, and neutral components of natural products extracts.

Fig. 1

Structure of compounds 1–3

Fig. 2

General catch-and-release protocol scheme

Fig. 3

HPLC trace (UV, 254 nm) of (A) methanolic extract, (B) acidic fraction, (C) basic fraction, and (D) neutral fraction.

Fig. 4

Proposed fragmentation of compounds 1–3

Fig. 5

Selected HMBC correlations of observed for compound 1

Fig. 6

Synthesis of compounds 1–3

Fig. 7

HPLC chiral resolution of [6]-zingerine (1) (A) isolated from ginger rhizome and (B) obtained by synthesis.