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A new cyclic guanidine alkaloid, cimipronidine (1), together with the known compound fukinolic acid (2), was isolated from the n-BuOH-soluble fraction of Cimicifuga racemosa roots that showed 5-HT7 receptor binding activity. Structure elucidation of 1, a minor constituent, presented unique challenges based on its polarity, but was accomplished with the use of a combination of one- and two-dimensional NMR as well as MS analyses. The relative configuration was established by analyzing the H,H-coupling constants and the results of the 2-D gradient NOESY spectrum. The previously reported serotonergic (5-HT7), highly polar, n-BuOH-soluble fraction was characterized by HPLC-ELSD and was shown to be a mixture containing the following compounds: cimicifugic acids A, B, and F, fukinolic acid, ferulic acid, isoferulic acid, and compound 1, potentially significant as a marker compound of C. racemosa.

Four novel steroidal alkaloids, (+)-(20S)-20-(dimethylamino)-3-(3'alpha-isopropyl)-lactam-5alpha-+ ++preg n-2-en-4-one (1), (+)-(20S)-20-(dimethylamino)-16alpha-hydroxy-3-(3'alpha-isopropyl) -la ctam-5alpha-pregn-2-en-4-one (2), (+)-(20S)-3-(benzoylamino)-20-(dimethylamino)-5alpha-pregn-2-en-++ +4beta -yl acetate (3), and (+)-(20S)-2alpha-hydroxy-20-(dimethylamino)-3beta-phthalimido-5 alpha- pregnan-4beta-yl acetate (4), as well as five known compounds, (-)-pachyaximine A (5), (+)-spiropachysine (6), (+)-axillaridine A (7), (+)-epipachysamine D (8), and (+)-pachysamine B (9), were isolated from Pachysandra procumbens, using a bioassay-guided fractionation based on inhibition of 3H-tamoxifen binding at the antiestrogen binding site (AEBS). Compounds 1-7 and 9 demonstrated significant activity as AEBS-inhibitory agents, and compounds 3, 5 and 9 were found to potentiate significantly the antiestrogenic effect mediated by tamoxifen in cultured Ishikawa cells. The structure elucidation of compounds 1-4 was carried out by spectral data interpretation.

Starting with an extract derived from the stem of Macleaya cordata (Papaveraceae) that was active in the process of inhibiting phorbol 12,13-dibutyrate binding to partially purified protein kinase C (PKC), the benzophenanthridine alkaloid angoline was isolated and identified. This discovery appeared in context, as a related benzophenanthridine alkaloid, chelerythrine, has been reported to mediate a variety of biological activities, including potent and selective inhibition of protein kinase C (PKC). However, in our studies, angoline was not observed to function as a potent inhibitor of PKC. Moreover, we were unable to confirm the reported inhibitory activity of chelerythrine. In a comprehensive series of studies performed with various PKC isozymes derived from a variety of mammalian species, neither chelerythrine nor angoline inhibited activity with high potency. To the contrary, chelerythrine stimulated PKC activity in the cytosolic fractions of rat and mouse brain in concentrations up to 100 microM. In addition, chelerythrine and angoline did not inhibit [3H]phorbol 12,13-dibutyrate binding to the regulatory domain of PKC at concentrations up to 40 microg/ml, and no significant alteration of PKC-alpha, -beta, or -gamma translocation was observed with human leukemia (HL-60) cells in culture. Further, chelerythrine did not inhibit 12-O-tetradecanoylphorbol 13-acetate-induced ornithine decarboxylase activity with cultured mouse 308 cells, but angoline was active in this capacity with an IC50 value of 1.0 microg/ml. A relatively large number of biological responses have been reported in studies conducted with chelerythrine, and alteration of PKC activity has been considered as a potential mechanism of action. In light of the current report, mechanisms independent of PKC inhibition should be considered as responsible for these effects.

Rutaecarpine (1) and dehydroevodiamine (2) were isolated from the unripe fruit of Evodia rutaecarpa. In vitro uterotonic assay on rat uterus showed both alkaloids to be active. Dehydroevodiamine was further shown to be active in the in vivo uterotonic assay using rats as the animal model. Reference evodiamine hydrochloride (3) was also evaluated and found to be devoid of uterontonic activity at the doses administered.

A phytochemical investigation of the leaves and twigs of Helietta parvifolia (Rutaceae) resulted in the isolation of heliparvifoline, a new furoquinoline alkaloid, in addition to the known bases flindersiamine and isoflindersiamine.

From the turpentine broom, Thamnosma montana, four alkaloids and three coumarins were isolated and characterized. Skimmianine (5), N-methyl-acridone (4) and 5-(3'-methyl-2',3'-dihydroxybutanyl)-8-methoxypsoralen (1) were obtained previously from T. montana. Robustine (2) is reported from a Thamnosma species for the first time and acridone (6), thamnosmonin (9), and thamontanin (14) are reported from a natural source for the first time. Evidence for the structures of the new isolates is presented.