ABSTRACT In this paper we report the absolute configuration which has been determined from the refinement of the Flack parameter, x = 0.05(5), which indicate that the correct configuration had been assigned against 1353 (99%) CuKα Bijvoet pairs. On this basis the absolute configuration was assigned as C5R, C8S, C9R and C10S. The structure of 18-acetoxy-cis-cleroda-3,13E-dien-15-oic acid consists of a clerodane skeleton and the corresponding methyl groups are α-oriented (C8, C9) while C5 is β-oriented. The acidic lateral chain is β-oriented and the double bond between C13 and C14 has E isomeric. The ciclohexene, cyclohexane rings are cis fused, and in an sofa and chair conformation respectively. In the crystal the molecules are linked by one intermolecular O—H…O hydrogen bond forming 1D-dimensional chain with distance donor-acceptor of 2.060(6)Å with graph-set notation C 1 1(15).

ABSTRACT High-resolution mass spectrometry is currently used to determine the mass of biologically active compounds in plants and UHPLC-Orbitrap is a relatively new technology that allows fast fingerprinting and metabolomics analysis. In this work, several phenolic compounds including eleven phenolic acids, two fatty acids, two chromones and fourteen flavones were rapidly identified in the methanolic extracts of aerial parts and flowers of the unique Chilean species Ophryosporus triangularis Meyen, Asteraceae, growing in the Atacama Desert by means of ultrahigh resolution liquid chromatography orbitrap MS analysis (UHPLC-PDA-OT-MS) for the first time. The UHPLC-MS fingerprint generated can be used for the authentication of this endemic species. The methanolic extracts of the aerial parts and flowers showed also antioxidant capacities (65.34 ± 1.32 and 52.41 ± 1.87 µg/ml in the DPPH assay, 184.88 ± 13.22 and 196.80 ± 13.28 µmol TE/g dry weight in the ferric reducing power assay and 56.17 ± 3.03 and 65.41 ± 1.96% in the superoxide anion scavenging assay, respectively).

The crystal structure of the aromatic compound 3,4-dihydroxy-5-geranyl-benzoic acid (5) is reported for the first time. This compound was isolated from the resinous exudate of Manto Negro (Heliotropium taltalense I. M. Johnst), an endemic species growing in The Atacama Desert using a combination of High speed counter current chromatography (HSCCC) and permeation through Sephadex LH-20. The structure was elucidated by spectroscopic means and confirmed by X-ray crystal-structure analysis. All OH groups are involved in hydrogen bonding with the average H···O distance of 2.760(3) Å and O-H···O angles in the range 125-159°, so in the crystal packing the molecules are associated by three strong intermolecular hydrogen bonds forming ring with graph-set motif R2²(14) R2²(6).

The bioactive compound 5-hydroxy-7-methoxy-2-phenylchroman-4-one (pinostrobin, I), was isolated from aerial parts of Nolana ramossisima I.M. Johnst., a Chilean endemic species, using a combination of medium pressure column chromatography and high speed countercurrent liquid-liquid chromatography (HSCCC). The compound crystallized as a non-centrosymmetric polymorph in the orthorhombic chiral space group P2(1)2(1)2(1). Its structure had been previously reported by Shoja (Acta Cryst. C45, 828, 1989) and Yamovoi et al. (Khim. Prir. Soedin (5), 361, 2001) in the centrosymmetric space groups Pbca and P21/c, respectively.