Two New Oxazoles from Amyris texana P. Wilson

From the roots of Amyris texana P. Wilson, two new oxazoles, texamine (1) and texaline (2) were isolated together with 0-isopentenylhalfordinol ( 3 ) .The structures of the new compounds were established by spectroscopic methods, including long-range HETCOR 2-D mnr.Oxazole alkaloids are rare naturally-occurring compounds, and those found in 2-4 flowefing plants such as the genera ~olium,' Amyris, ~eglopsis,~ ~e g l e , ~-' and Iialfordiagrg are structurally simple substances bearing substituents at the 2 and 5 positions of the ring.During our study of the chemical constituents of the roots of Pnnyris texana P.Wilson, we have isolated two new 2.5-diaryloxazoles, texamine (1) and texaline (2), together with 0-isopentenylhalfordinol ( 3 ) .Texanine (1) had mp 134-137OC , crystallized from ethyl acetate-hexane.Its elemental composition C16H11N03 was established by high-resolution mass measuremenr: M+, m/z 265.0748, &-1.0 m.Ir (KBr) , 1600, 1585, 1543, 1495, 1480, and 1445 (aromatic), 1240 and 928 (ether).The uv (%OH) spectrum gave maxima at 215, 253, and 324 nm (log E 4.53, 4.39, and 4.63, respectively), characteristic of a 2.5-diarylo~azole.~~The typical cleavages of 2.5-diaryloxaz~les~~ were also f i n a n c i a l s u p p o r t .REFERENCES 1