Abstract

Juglans regia L. is a monoecious, heterodichogamous, deciduous tree species valued for its high-quality timber as well as its nuts. It belongs to the family Juglandaceae. Though, it is native to Central Asia, India, Nepal China and some part of Europe, it is being grown commercially in the USA, France, Italy and Spain for nut production. The nuts and plant parts of J. regia contain the aromatic secondary metabolite juglone (C₁₀H₆O₃) (1, 4 – naptha quinone, 5 hydroxy – 8CI). Juglone is a well-known allelopathic agent and being used in commercial hair dye and also has therapeutic properties. Juglone is commercially extracted from the husks of walnuts, but fresh leaves of J. regia contain significant amounts of juglone (up to 0.5 / 100 g dry weight) to be a good source of the chemical. Juglone is understudy for anti-carcinogenic effects. In human intestinal neoplasia juglone checked multiplicity of tumour cells and is also a strong inhibitor of peptidyl-prolyl isomerase Pin1 which is overexpressed in several types of cancer affected cells. Juglone increases efficacy of anti cancer drugs as well.

Key words: Phytochemical, medicinal, anticarcinogenic, antitumor, allelopathic.