The topic of this lead has been chosen toidentify with our friends in W. Europe suffering from an unprecedented heatwave that is causing human misery and bush fires.

Dictamnus is a genus of the Rutaceae family. The related species D. alba and D, dasycarpa, commonly called “burning bush”, inhabit woodlands across parts of Asia, Southern Europe and North Africa. Thecommon name, associated with the biblical story of Moses and the Burning Bush, is because these plants accumulate volatile oils that can spontaneously ignitein hot weather. One of these volatiles is #isoprene, discussed in Leaf 33 (http://t.ly/Qfne); others are limonoids that give the plants a lemony fragrance.

Dictamnus produces a large variety ofphytochemicals. The signature compounds are furoquinoline alkaloids exemplifiedby the dictamnine molecule in the cover illustration that.  shows basic furoquinoline structure, with the the O-containing furan ring (right) fused to a N-containing quinoline double ring. Furoquinolinesoccur almost exclusively within the Dictamnus genus.

Dictamnine has antifungal and antibioticactivities. It is cytotoxic and mutagenic in humans. Nevetheless, Dictamnusroot is important  in Traditional Chinese Medicine, where it goes by the name BaiXianPi (白鲜皮). Traditionally used to treat eczema, rubella, scabies, acute rheumatoid arthritis, skin inflammation, jaundice, cold, and headache, the beneficial bioactivities are attributed to the limonoids (e.g. obacunone)and furoquinolines, both mentioned previously.

We at @GREENMOUNTAINBIOTECH are interested in botanicals of potential use in dermatology. We already produce extract from another member of the Rutaceae, Phellodendron, and are particularly interested in its cousin Dictamnus (see Dharmananda, 2003). We are not sure if Dictamnusit can be used to treat sunburn, though the translation of the Chinese name may imply so (BaiXianPi / 白鲜皮means white fresh skin). However, it seems that for this week at least, Europeans are going to stay mostly out of the sun!

Further reading

Wikipedia 2022, “Dictamnus albus”, https://en.wikipedia.org/w/index.php?title=Dictamnus_albus&oldid=1079435961

Wikipedia 2022, “Furoquinoline alkaloid”, https://en.wikipedia.org/w/index.php?title=Furoquinoline_alkaloid&oldid=1094238378

Lv, Mengying et al. “Medicinal uses, phytochemistry and pharmacology of the genus Dictamnus (Rutaceae).” Journalof ethnopharmacology vol. 171 (2015): 247-63. https://doi.org/10.1016/j.jep.2015.05.053

Subhuti Dharmananda (2003), Safety Issues Affecting Chinese Herbs: The Case of Dictamnus and Herbs for Skin Diseases. Accessed July 22, 2022. http://www.itmonline.org/arts/dictamnus.htm

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