Chemical Studies of Casearia sylvestris Swartz

Casearia sylvestris is a popular herb used by Brazilian locally called “Chá de Bugre” [1] or “Guaçatonga” [2], which grows in South America. It has been used in Brazilian folk medicine as diuretic, appetite suppressant, weight loss products, and snakebites agent [1,3]. Some studies demonstrated that C. sylvestris possesses anti-snake venom, analgesic, anti-inflammatory, anti-ulcer and anticlastogenic activities. Many clerodane diterpenoids have been hitherto reported with regards to the phytochemical constituents of C. sylvestris and showed antitumoral, trypanocidal and DNA-modifying activities [4–7]. In the present report, the isolation and structure elucidation of two new highly oxygenated clerodane diterpenes casearins U and V (1 and 2) and two new ent -kauranoid diterpene glycosides sylvestriside A and B (3 and 4) were described from C. sylvestris (see Fig. 1), together with 3 known diterpenes, namely, (−)-hardwickic acid (5), (−)-patagonic acid (6) and ent-3β, 18-dihydroxykaur-16-ene (7), as well as 11 other known compounds, namely, spathulenol (8), 7, 8-dihydrovomifoliol (blumenol B 9), N-methyl-trans-4-hydroxy-L-proline (10), Cinnamic acid (11), Soyacerebroside I (12), methypheophorbides (13), pheophorbide a (14), chlorophyll (15), β-sitosterol (16), stigmastane-3, 6-diol (17), daucosterol (18), β-D-glucopyranoside, (3β)-stigmast-5-en-3-yl, 6-nonadecanoate (19). Their structures and relative configuration were established on the basis of 1D and 2D NMR spectroscopic analyses and comparison with literature data. References: [1] Cruz GL (1995), Dicionario Das Plantas Uteis Do Brasil, 5th ed., Bertrand. p.599. [2] Lorenzi H, Matos FJA (2002), Plantas medicinais do Brasil:nativas e exóticas. Instituto Plantarum, São Paulo, p220–221. [3] Borges MH, et al. (2001), Toxicon, Vol. 39: 1863–1869. [4] Ruppett BM, et al. (1991), Mem. Inst. Oswaldo Cruz, 87(2): 203–205. [5] Sertié JAA, et al. (2000), Pharmaceut. Biol. 38: 112–119. [6] Itokawa H, et al. (1988), Chem. Pharm. Bull. 36: 1585–1588. [7] Esteve I, et al. (2005), J. Ethnopharmacol. 101: 191–196.