ABSTRACTThe genus Erythrina, Fabaceae, is widely distributed in tropical and subtropical regions. Their flowers, fruits, seeds and bark are frequently used in folk medicine for its effects on the central nervous system such as anticonvulsant, antidepressant, analgesic, sedative, and hypnotic effects. Erythraline has been reported as one of the active compounds from Erythrina, but until now there are no pharmacokinetics data about this compound and only few results showing a putative metabolism were reported. To improve the information about erythraline metabolism, this article reports and discusses, for the first time, the in vitrometabolism biotransformation of erythraline by cytochrome P450 enzymes.

<p>The phytochemical investigation and evaluation of the phytotoxic effect of the extract and fractions obtained from the leaves of <italic>Annona nutans</italic>(R. E. Fr.) R. E. Fr. were performed. Phytotoxic activity was assessed on radicle and hypocotyl of <italic>Allium cepa</italic> and <italic>Lactuca sativa</italic>, where chloroform and ethyl acetate fractions proved active. Phytochemical investigation of the chloroform fraction was allowed identification of polyketides derivatives: triacontanal, 16-hentriacontane, octacosanol and triacontanol, using the ¹H NMR technique associated with data from GC/MS. Using ethyl acetate fraction, with low activity, flavonoids 3-<italic>O</italic>-β-D-galactopyranosyl-isorhamnetin, 3-<italic>O</italic>-β-D-galactopyranosyl-quercetin and 3-<italic>O</italic>-β-D-apiofuranosyl-(1→2)-galactopyranosyl-quercetin were identified, determined by spectrometric techniques one and two-dimensional NMR, combined with mass spectral data. All substances are being reported for the first time in <italic>Annona nutans</italic>. The phytotoxic activity of chloroform fraction may be related to the presence of triacontanol and similar substances. Triacontanol stimulates growth at very low concentrations, but can have an inhibitory effect at higher concentrations, such as those reported for auxin analogs. The toxicity assay using <italic>Artemia salina</italic> (BST) was also performed, with the chloroform fraction showing a negligible lethal dose, LD₅₀ = 500 mg mL^-1, while the other fractions and extracts showed no activity. Thus, the presence of acetogenins was ruled out.</p>

Erythrina verna is a medicinal plant used to calm agitation popularly known as mulungu. We purchased the barks of E. verna from a commercial producer and analyzed the alkaloid fraction of the bark by CG-MS and HRESI-MS. Five erythrinian alkaloids were identified: erysotrine, erythratidine, erythratidinone, epimer, and 11-hydroxieritratidinone. Here we report the compound 11-hydroxieritratidinone for the first time as a natural product.

A different methodology was used to isolate and purify oxoaporphine alkaloids, as they are difficult to separate by the usual workup when in mixture. Alkaloid extracts from Annonaceae species were obtained by base/acid extraction. The extracts were concentrated and submitted to partition in solutions of acids of different pKa values, followed by separation by preparative TLC using 1 mm thick silica gel impregnated with oxalic acid (11.2% w/w). Liriodenine, lisycamine, lanuginosine, and O-methylmoschatoline were obtained and tested against tumoral cells (line Hep2, ATCC-CCL 23, larynx carcinoma). Only O-methylmoschatoline (IC50 12.4 µM) was more active than cisplatin (18.0 µM).