Apparent Vitamin C in Certain Foodstuffs

The isolation and identification of a hydrojuglone glycoside occurring in the walnut

“…The Isolation and Identification of a Hydrojuglone Glycoside Occurring in the Walnut BY C. DAGLISH The Ovaltine Re8earch Laboratories, King'8 Langley, Herts (Received 7 February 1950) In a preliminary note (Daglish & Wokes, 1948) it was shown that the 'apparent vitamin C' of the walnut (Juglan8 regia) (Wokes, Organ, Duncan & Jacoby, 1943) was probably a hydrojuglone derivative. The evidence for this was based upon the findings that solutions of the substance separated by chromatography showed an ultraviolet absorption curve similar to those of reduced acetoxyjuglone and ahydrojuglone, and on hydrolysis yielded juglone.…”

The identification of the 'apparent vitamin C' of the walnut (Juglans regia) with hydrojuglone glucoside

“…The Identification of the 'Apparent Vitamin C' of the Walnut (Juglans regia) with Hydrojuglone Glucoside BY C. DAGLISH The Ovaltine Re8earch Laboratories, King'8 Langley, Herts (Received 5 April 1950) The provisional term 'apparent vitamin C' was applied (Wokes, Organ, Duncan & Jacoby, 1943) to compounds occurring in foodstuffs and natural products which interfered with the determination of ascorbic acid by the 2:6-dichlorophenol indophenol titration. It was applied to the non-specific dye reductant found in walnut extracts, and the occurrence of this was investigated by Wokes, Organ, James & Melville (1944) and more recently by Wokes & Melville (1949). As a-hydrojuglone glucoside, isolated from the walnut (Daglish, 1950a), shows marked reducing activity, it is possible that this compound is responsible for the so-called 'apparent vitamin C' activity.…”