Two further guaianolides were isolated from the aerial parts of Arctotis grandis. In addition to widespread polyacetylenes [1], the genus Arctotis (Compositae, tribe Arctoteae) has afforded several sesquiterpene lactones, especially guaianolides [2-6]. For example, three guaianolides have been isolated from Arctotis grandis Thunb [2,3,5]. We have re-investigated the polar fractions of the aerial parts of this plant. In addition to the lactones isolated previously two new ones were obtained. The more polar compound, C15H22O4, showed IR bands at 3600 and 1770 cm⁻¹ indicating the presence of a γ-lactone with hydroxy groups. Acetylation afforded a diacetate as followed from the molecular formula and from the ¹H NMR spectral data (Table 1) which further showed that a saturated lactone was present. Accordingly, two methyl doublets were visible. Spin decoupling allowed the assignment of all signals although a few signals were overlapping multiplets both in the spectrum of the diol and the corresponding diacetate. In the spectrum of the diol, five low field signals were visible. Two broadened singlets were due to the protons of an exomethylene group. A three-fold doublet at δ4.26, which was shifted to 5.03 in the spectrum of the diacetate, could be assigned to H-3 since irradiation at 2.57 in the spectrum of the diacetate collapsed one of the methyl doublets (0.94) to a singlet, the double doublet at 2.23 to a doublet and the low field signal at 5.03 to a double doublet. Further spin decoupling led to the sequence A which, after addition of the missing exomethylene group, led to structure 1. The stereochemistry clearly followed from the couplings observed if a model was considered. The corresponding 3-keto derivative has been isolated previously from the same species [5]. The less polar lactone was also a dihydroxy lactone; this followed from the mass spectrum. The molecular formula was C15H18O4, while a two-fold elimination of water (m/z 244 and 216) indicated the presence of a diol. The ¹H NMR spectrum (Table 1) displayed the typical signals of a methylene lactone (δ6.21 d and 5.48 d) which were coupled with a broadened double doublet at 3.05. Irradiation of the latter signal collapsed a three-fold doublet at δ4.45 to a double doublet, the double doublet at 1.80 to a singlet and sharpened the broadened doublet at 2.11. The latter two signals obviously were those of H-6 while that at 4.45 had to be assigned to H-8. The absence of additional couplings of H-6, except the geminal one, showed that one of the hydroxyl groups was at C-5, while the second one had to be placed at C-3. Accordingly, the corresponding H-3 signal was a broadened triplet whose chemical shift indicated an allylic position. This was established by decoupling. Irradiation at δ4.73 collapsed the doublets at 5.33 and 5.25 to singlets. Further decoupling allowed the assignment of all signals while the stereochemistry followed from the couplings observed. The α-position of the hydroxyl at C-5 was indicated by the chemical shift of H-6α (1.80 dd). A β-hydroxy group should have a deshielding effect leading to a downfield shift of H-6 double doublet. The ¹H NMR spectral data were close to those of the corresponding acetate, 4, which was isolated previously from the same species [3]. A new furan diterpenic acid was isolated from Stevia lucida. On the basis of IR, ¹H NMR and mass spectra, as well as chemical evidence, the acid was assigned the structure 5α,9βH,10α-17-labda-7,13(16),14-trien-15,16-epoxy-19-oic acid.