The economic importance of grasses has driven extensive research, mainly on their use as pasture, but alkaloids in grasses have been noted. Previous studies reported indole bases (gramine in barley, 5-methoxy-N-methyltryptamine in Phalaris arundinacea), perloline in Lolium perenne and other species (Festuca arundinacea, Setaria lutescens), and pyrrolizidine derivatives (loline, lolinine, lolinidine) in Lolium temulentum. This study extracted and isolated alkaloids from Thelepogon elegans: paper chromatography revealed at least five bases, with two (thelepogine, C₁₉H₂₇ON; thelepogidine, C₁₉H₂₇O₂N) purified. Thelepogine showed an hydroxyl group (IR 3300 cm⁻¹) and no UV absorption above 20000 cm⁻¹; thelepogidine had ether linkages (no hydroxyl or carbonyl IR absorption). Due to material shortage, a thelepogine methiodide derivative was prepared for X-ray diffraction, which revealed structure (I) and its relationship to manool and pyrrolizidine alkaloids. C-methyl analysis of thelepogine (1.2 C-methyl groups) suggested allylic oxidation of double bond-activated methyl groups may have affected the determination. The gross structure of Lirioresinol-B dimethyl ether was established by Dickey (1958) and independently by Jefferies, Knox, and White (1961), with evidence for cis-fused tetrahydrofuran rings. Dickey concluded its stereochemical arrangement matched (+)-pinoresinol via molecular rotation differences. To confirm this, X-ray diffraction was performed on its 2,2'-dibromodimethyl ether derivative. Crystals (orthorhombic, space group P2₁2₁2, cell dimensions a=16.7 Å, b=15.8 Å, c=4.70 Å) had a density indicating two molecules per unit cell (half in the asymmetric unit), requiring a twofold rotation axis of symmetry. This eliminated structure (II) and ruled out structure (III) (incompatible with cell dimension), confirming structure (IV) as the correct molecular configuration, consistent with Dickey's conclusion.