Betuloside or rhododendrin is an arylbutanoid glycoside and phenylpropanoid. This means the sugar group is linked to a phenol. There is also a methylated variant called methyl betuloside.

It was first known about in 1939 when it was isolated from European White Birch (Betula alba L.) (Sosa, 1939).

It is found in the leaves of the pine, Abies webbiana Lindl. (Sarkar et al., 1986), Taxus baccata L. (Parmar et al., 1991), Rhododendron aureum (Kim et al., 2011), Cistus salviifolius (Danne et al., 1994) and in birch sap.

The glycoside is produced in response to damage through grazing by hares and bark-boring insects as a protective chemical.

This sugar has analgesic, anti-inflammatory and diuretic benefits (Kim et al., 2011; Zhang et al., 2007).

The IUPAC name is:- (2R,3S,4S,5R,6R)-2-(Hydroxymethyl)-6-[(2R)-4-(4-hydroxyphenyl)butan-2-yl]oxyoxane-3, 4,5-triol. Its CAS number is 497-78-9.

References

Danne, A., Petereit, F., Nahrstedt, A. (1994). Flavan-3-ols, prodelphinidins and further polyphenols from Cistus salvifolius. Phytochemistry 37 (2) pp. 533–538. PMID 7765630. doi:10.1016/0031-9422(94)85094-1
Kim, M. H., Nugroho, A., Choi, J., Park, J. H., Park, H. J. (2011). Rhododendrin, an analgesic/anti-inflammatory arylbutanoid glycoside, from the leaves of Rhododendron aureum. Archives of Pharmacol. Research. 34 (6) pp. 971–978. PMID: 21725818. doi:10.1007/s12272-011-0614-1
Parmar, V. S., Vardhan, A., Taneja, P., Sinha, R., Patnaik, G. K., Tripathi, S. C., … & Larsen, S. (1991). Absolute configuration of epi-rhododendrin and (–)-rhododendrol [=(–)-betuligenol] and X-ray crystal and molecular structure of rhododendrin [= betuloside], a hepatoprotective constituent of Taxus baccata. Journal of the Chemical Society, Perkin Transactions 1, (11), pp. 2687-2690
Sarkar, S. K., Poddar, G., & Mahato, S. B. (1987). Glucosides from Abies webbiana. Planta Medica, 53(02), pp. 219-220.
Sosa, A. (1939). Recherches sur le” Betula Alba” L. et le Betuloside Carbinols et Cétones de la série p-Méthoxy-Phényl-Butylique. Masson et Cie..
Vinod, M., Singh, M., Pradhan, M., Iyer, S. K., & Tripathi, D. K. (2012). Phytochemical constituents and pharmacological activities of Betula alba Linn. A review. Int. J. of Pharm. Tech. Res, 4(2), pp. 643-647.
Zhang, B., Li, J.B., Zhang, D.M., Ding, Y., Du, G.H. (2007). Analgesic and anti- inflammatory activities of a fraction rich in gaultherin isolated from Gaultheria yunnanensis (Franch.)”. Rehder. Biol. Pharm. Bull. 30 (10) pp. 465–469. doi:10.4103/0973-7847.91102