In the first phytochemical study of the Aureliana genus (Solanaceae), two new withanolides, 1 and 2, together with two known sterols, were isolated from the MeOH extract of the leaves of Aureliana fasciculata var. fasciculata. The structures were established as (4S,22R)-16a-acetoxy-5b,6b-epoxy-4b,17a-dihydroxy-1-oxowitha-2,24-dienolide (aurelianolide A) and (4S,22R)-16a-acetoxy-4b,17a-dihydroxy-1-oxowitha-2,5,24-trienolide (aurelianolide B). The new compounds possessed the unusual 16a,17a-dioxygenated group and were fully characterized by spectroscopic techniques, including 1 H-and Introduction. -The withasteroids comprise a group of naturally occurring C 28 -steroids characterized by an unaltered or a modified ergostane skeleton with a lactone or potential lactone ring in the C 9 side chain [1]. The most abundant type is designated usually as withanolide, and these compounds possess an a,b-unsaturated d-lactone ring in the side chain of the molecule. These steroid derivatives are frequently polyoxygenated, and biogenetic transformations can produce highly modified structures, both in the steroid nucleus and in the side chain, such as physalins, withaphysalins, acnistins, withanolides, ixocarpalactones, and perulactones [2]. To date, over 400 withasteroids have been reported which are restricted in distribution to the plant family Solanaceae occurring primarily in ca. 20 genera [1] [2]. However, the occurrence of steroidal lactones is not completely restricted to Solanaceae, whereas these compounds have also been found in soft coral from Minabea sp.

Solanum americanum is one of the most prominent species used to treat type 2 diabetes in Guatemala. In our ongoing efforts to find antidiabetic and antioxidative compounds from natural sources, an ethyl acetate extract of this medicinal herb was investigated using dual high-resolution α-glucosidase/radical scavenging inhibition profiling. The high-resolution biochromatograms obtained by this technique were used to target subsequent structural elucidation by HPLC-HRMS-SPE-NMR analysis towards the bioactive constituents. This led to identification of 4-hydroxybenzoic acid (1) and 3-indolecarboxylic acid (6) associated with radical scavenging activity, and the amide alkaloids N-trans-p-coumaroyloctopamine (3), N-trans-p-feruloyloctopamine (4), N-trans-p-coumaroyltyramine (8) and N-trans-p-feruloyltyramine (9) correlated with α-glucosidase inhibitory activity as well as radical scavenging activity. Further analysis revealed a new lactone, methyl 5-ethyl-4-hydroxy-5-methyl-2-oxotetrahydro-2H-pyran-4-carboxylate (7) and a new steroid with a rare F ring (11). Corchorifatty acid B (12) was reported for the first time in the Solanaceae family. Their structures were elucidated by extensive use of 1D and 2D NMR spectroscopy as well as HRMS analysis.

Athenaea (Solanaceae) is an endemic genus belonging to the Brazilian Atlantic Rainforest. Recently, botanical investigations suggested the re‐evaluation of the generic status of the genus Athenaea as a synonym of Aureliana. In this study, the first investigation of the Athenaea genus performed on Athenaea martiana by means of HPLC‐HR‐MS‐SPE‐NMR combined with high‐resolution radical scavenging profile led to identification of several phenolic acids as radical scavengers: protocatechuic acid (1), 4‐hydroxybenzoic acid (2), caffeic acid (3), vanillic acid (4), and ferulic acid (6). Additional analysis revealed a new steroidal lactone, named athenolide A (9). Their structures were elucidated by extensive use of NMR spectroscopy as well as HR‐MS. Chemotaxonomic considerations based on these results supported the chemical relationships between the Athenaea and Aureliana genera, in agreement with the recent botanical findings.