The technique of mass-analyzed ion kinetic energy (MIKE) spectrometry is briefly reviewed. The direct analysis, without need of prior extraction or chromatographic purification, of cocaine and cinnamoylcocaine in coca plant tissues has been accomplished with this new technique. Detection limits of below 1 ng, with a quantitative accuracy of +/- 30% at the nanogram level, have been demonstrated.

Alkaloids↗

PubMedDate not supplied

Allyl isothiocyanate and allyl cyanide production in cell-free cabbage leaf extracts, shredded cabbage, and cole slaw.

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Brassica↗

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An investigation of the antitumor activity of Micromelum integerrimum (Rutaceae).

Extracts of Micromelum integerrimum (Buch.-Ham. ex Coleb.) M. Roem. were fractionated based on in vivo activity in mice in the P-388 lymphocytic leukemia system. Activity in ethanol extracts was concentrated in the chloroform partition fraction, which was further resolved by chromatography on silica gel. The known coumarins, micromelin and scopoletin, were crystallized from the active fractions and demonstrated to have antitumor activities. Micromelin was converted to the corresponding butenolide (deoxymicromelin) which was inactive in the 9KB assay.

Animals↗

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19-Hydroxybaccatin III, 10-deacetylcephalomannine, and 10-deacetyltaxol: new antitumor taxanes from Taxus wallichiana.

Activity-guided, chromatographic fractionation for a polar extract of Taxus wallichiana Zucc. (originally identified as Cephalotaxus mannii Hook.) resulted in the isolation of three new KB cytotoxic taxane derivatives. Nmr and ms spectral analyses permitted their characterization as 19-hydroxybaccatin III (3), 10-deacetylcephalomannine (4), and 10-deacetyltaxol (5). The latter two compounds, which are also active against PS leukemia in vivo, were observed to be especially labile, each forming equilibrium mixtures with their cytotoxic C-7 epimers (9, 10).

Alkaloids↗

PubMedDate not supplied

Potential antitumor agents. XVII. physalin B and 25,26-epidihydrophysalin C from Witheringia coccoloboides.

An investigation of Witheringia coccoloboides (Dammer) A. T. Hunziker [Capsicum fuscoviolaceum (Cufodontis) Mort. And Standl.] roots has resulted in the isolation of two cytotoxic compounds: physalin B (1) and a novel physalin, which was characterized by spectral analysis as 25,26-epidihydrophysalin C (2). Both compounds have demonstrated cytotoxic activity in 9KB and 9PS tumor cells (in vitro). Physalin B (1) has demonstrated moderate activity against the 3PS mouse leukemia (in vivo).

Animals↗

PubMedDate not supplied

Modification and evaluation of the potato disc assay and antitumor screening of euphorbiaceae seeds.

Galsky et al. (10, 11) have reported that the inhibition and growth of crown gall tumors, initiated on potato discs by Agrobacterium tumefaciens, apparently has good agreement with 3PS in vivo antileukemic activity in mice. We have now modified and evaluated this assay for its potential use as a prescreen and fractionation monitor of plant extracts for 3PS activity. The modified assay was performed on a series of natural compounds and plant extracts (known to have 3PS activity) and on extracts of seeds of 41 Euphorbiaceae species. The results suggest that the potato disc assay is a safe, simple, rapid, in-house, low cost, prescreen for 3PS antitumor activity; it detects some false positives, but few false negatives; it is statistically much more predictive (p = 0.002) of 3PS activity than either the 9KB (p = 0.140) or the 9PS (p = 0.114) cytotoxicity assays. Its extended use could easily obviate the expense and extensive need for animals in the initial stages of antitumor screening and plant fractionation.

Animals↗

PubMedDate not supplied

Use of potato disc and brine shrimp bioassays to detect activity and isolate piceatannol as the antileukemic principle from the seeds of Euphorbia lagascae.

EtOH extracts of the seeds of Euphorbia lagascae inhibited crown gall tumors on potato discs, were active against 3PS (in vivo) and 9PS (in vitro) mouse leukemia, and were toxic to brine shrimp. Using the potato disc and brine shrimp bioassays to monitor fractionation, piceatannol (3,4,3',5'- tetrahydroxystilbene ) was isolated as the 3PS active principle. Aesculetin (6,7-dihydroxycoumarin) was isolated in large quantity, was weakly cytotoxic in 9KB , but was inactive in the other bioassay systems. Sucrose was also isolated. A combination of the simple crown gall and brine shrimp bioassays can thus be used both to detect and to isolate plant antitumor substances, minimizing the need for extensive antitumor testing in vivo.

Animals↗

PubMedDate not supplied

Identification of new cactus alkaloids in Backebergia militaris by tandem mass spectrometry.

Tandem mass spectrometry, applied to simple extracts of Backebergia militaris, indicated the presence of a number of new alkaloids, including fully aromatic oxygenated isoquinolines, their di- and tetra-hydro analogs, and beta-phenethylamines. These conclusions were supported by separation using radial tlc and comparison with authentic compounds. Traces of seven alkaloids new to this cactus species were identified; four (3,4,8,11) were known previously from other cacti. Three novel cactus alkaloids were identified and confirmed by synthesis as 7,8-dimethoxy-3,4-dihydroisoquinoline (12, dehydrolemaireocereine), 6,7-dimethoxyisoquinoline (13, backebergine), and 7,8-dimethoxyisoquinoline (14, isobackebergine). The last two compounds are the first simple, fully aromatic, isoquinoline alkaloids to be reported from the Cactaceae. The sensitivity of this approach to new alkaloid discovery is emphasized; the entire project consumed only 10 g of dried plant material.

Alkaloids↗

PubMedDate not supplied