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A new nitrogen containing compound named xylactam B (2), along with a further eight known compounds, ceramide 2a, cerebroside B, cyc/o(prolyl, valyl), marmesin, 5-methoxycarbonylmellein, 5-methylmellein, polypropylene glycol and p-hydroxybenzoic acid, were isolated from an endophytic Xylaria sp. The structure elucidation of the new compound and the other isolates was carried out with the help of spectroscopic analyses and databases.

Coronilla scorpioides (L.) W.D.J. Koch is known for producing several compounds with pharmaceutical interest, such as the hydroxycoumarins umbelliferone, scopoletin and daphnoretin, the dihydrofuranocoumarin marmesin, and the furocoumarin psoralen. In vitro callus cultures of C. scorpioides were established from hypocotyl, leaf, stem internode and root explants in order to evaluate the possibility of in vitro production of these active secondary metabolites. Calli were obtained with high frequency from all the explant types both in B5 and MS medium. However, after the third subculture, B5 medium, giving the best results, was selected for subsequent transfers. Homogeneous calli were kept either in darkness or in light. Chemical analyses showed that scopoletin and the intermediate products of the biogenetic pathway of psoralen, umbelliferone and marmesin, were always present in the calli and excreted into the media, while daphnoretin was never detected. Light seems to be a prerequisite for psoralen biosynthesis. Root-derived calli produced a significantly higher amount of psoralen (137.5 μg g−1DW). Principal component analysis showed that umbelliferone, marmesin and psoralen contents are related to variables associated with different explant types.

A mixture of diastereomers of the coumarin glycoside 3′- O-β-D-glucopyranosyl-3′,4′-dihydroxanthyletin (1), along with six known pyranocoumarins, columbianoside (4), marmesin (5), 3′-hydroxy-3′,4′-dihydroxanthyletin (6), decursin (7), decursinol angelate (8), and isoimperatorin (9), were isolated from the roots of Angelica gigas Nakai. The racemic compound 1 was successfully separated by preparative HPLC to obtain a new isomer 3′( S)- O-β-D-glucopyranosyl-3′,4′-dihydroxanthyletin (2), and a known isomer 3′( R)- O-β-D-glucopyranosyl-3′,4′-dihydroxanthyletin (3). The absolute configuration of compounds 2 and 3 was determined by comparison of optical rotation and NMR data of their acid hydrolysis products.