Showing papers in "Journal of Natural Products in 1986"
TL;DR: Vacuum liquid chromatography lvlc as mentioned in this paper was developed by Pelletier et al. for the separation of complex terpene and lipid mixtures derived from sofi corals.
Abstract: Vacuum liquid chromatography lvlc, a name coined by Targett et af. (l)] was developed because of the impatience of Australian chemists with classical column chromatography. We have applied the technique extensively and virtually exclusively to the separation of complex terpene and lipid mixtures derived from sofi corals (2-5). Pelletier et al. (6) have recently provided an excellent and detailed report on the application of the technique to the separation of alkaloids using aluminium oxide adsorbents. The technique is essentially a preparative layer chromatographic (plc) separation run as a column, the flow of which is activated by vacuum. It differs from flash chromatography (7), in that vlc involves step gradient elution, and the column is allowed to run dry after each fraction is collected. The similarity with plc then becomes obvious, because plc separation may be enhanced by repetitive running of plc plates dried between runs. Because Pelletier et af. (6) have so clearly described the details of the vlc experiment, it is not necessary to restate the same details that were given in our earliest papers (2-5). However, it is felt that some additional notes on the application of this technique to silica gel chromatography may be of assistance to potential users.
238 citations
TL;DR: The liquid chromatography (vlc) is an efficient, inexpensive chromatographic technique that can be used for the separation of complex alkaloid mixtures as discussed by the authors, which has proved useful for the extraction of mixtures of naturallyoccurring alkaloids as well as mixtures resulting from synthetic operations.
Abstract: hSTRfKT.-VaCUUII liquid chromatography (vlc) is an efficient, inexpensive chromatographic technique that can be used for the separation of complex alkaloid mixtures. Its application to the separation of eight mixtures of closely related diterpenoid alkaloids in both large and small samples is described. Comparison of vlc and preparative tlc for the separation of a 1.000 g commercial sample of Merck "aconitine" mixture demonstrates the superiority of the vlc method. Vlc has proved useful for the separation of mixtures of naturally-occurring alkaloids as well as mixtures resulting from synthetic operations.
188 citations
TL;DR: The bulbs of Pancratium littorale collected in Hawaii were found to contain a new phenanthridone biosynthetic product designated pancratistatin (4a) that proved to be effective against the murine P-388 lymphocytic leukemia.
Abstract: The bulbs of Pancratium littorale collected in Hawaii were found to contain a new phenanthridone biosynthetic product designated pancratistatin (4a) that proved to be effective (38-106% life extension at 0.75-12.5 mg/kg dose levels) against the murine P-388 lymphocytic leukemia. Pancratistatin also markedly inhibited (ED50, 0.01 microgram/ml) growth of the P-388 in vitro cell line and in vivo murine M-5076 ovary sarcoma (53-84% life extension at 0.38-3.0 mg/kg). An X-ray crystal structure determination of pancratistatin monomethyl ether (4c) and a detailed high resolution (400 MHz) nmr study of pancratistatin and its pentaacetate (4b) completed assignment of structure 4a. Companion antineoplastic constituents of P. littorale were found to be narciclasine (2c) and its 7-deoxy derivative (2a). The structure of 7-deoxynarciclasine (2c) was also confirmed by an X-ray crystallographic analysis.
163 citations
TL;DR: A pharmacological comparison between the enantiomers of shikonin and alkannin was made with regard to their inhibitory effects on the increased capillary permeability and thermal edema in rats, using phenylbutazone as a positive control in both models.
Abstract: A pharmacological comparison between the enantiomers, shikonin (R) and alkannin (S), was made with regard to their inhibitory effects on the increased capillary permeability and thermal edema in rats, using phenylbutazone as a positive control in both models. The results of experiments have shown that there is no significant difference in the anti-inflammatory activity between the two compounds.
159 citations
105 citations
90 citations
TL;DR: Two novel perylene oxide metabolites, altertoxins II and III, have been identified in extracts of A. alternata isolates that exhibit mutagenic responses in the Ames Salmonella typhimurium assay.
Abstract: The mold genus Alternaria is a widely distributed plant pathogen. Some of these species, e.g., A. alternata, are common decay organisms of fruits and vegetables. Two novel perylene oxide metabolites, altertoxins II and III, have been identified in extracts of A. alternata isolates that exhibit mutagenic responses in the Ames Salmonella typhimurium assay. These identifications were based on mass, optical rotational, and 1H- and 13C-nmr spectral studies. Previous reports of related perylene dione mycotoxins have been clarified.
88 citations
TL;DR: Three new lanostanoids--ganodermenonol (1), ganodermadiol (2), and ganodermatriol (3)--were isolated from the MeOH extract of Ganoderma lucidum, together with ergosterol and its peroxide.
Abstract: Three new lanostanoids--ganodermenonol (1), ganodermadiol (2), and ganodermatriol (3) [isolated as its triacetate derivative (3a)]--were isolated from the MeOH extract of Ganoderma lucidum, together with ergosterol and its peroxide. The new compounds were identified as 26-hydroxy-5 alpha-lanosta-7,9(11),24-trien-3-one (1), 5 alpha-lanosta-7,9(11),24-triene-3 beta, 26-diol (2), and 5 alpha-lanosta-7,9(11),24-triene-3 beta, 26,27-triol (3) by their respective spectral data.
87 citations
TL;DR: The profiles of alkaloids in the new northern populations of D. histrionicus are typical of the species in containing a set of about eight histrionicotoxins, in marked contrast to a related species, Dendrobates lehmanni, which does not contain histrionics.
Abstract: Forty alkaloids were detected and characterized from skin extracts of high- and low-elevation populations of the poison frog Dendrobates histrionicus from northwestern Colombia. Combined gc/ms with NH3 or ND3 in a chemical ionization mode detected protonated parent ions and determined the number of exchangeable NH and OH hydrogens. Six previously unknown dendrobatid alkaloids were characterized. Two were 2,5-disubstituted pyrrolidines, which included pyrrolidine 197B, a trans-2-butyl-5-pentylpyrrolidine, while a third was a 2,6-dipentylpiperidine. Indolizidines 239AB and 239CD had the same relative configuration as the parent alkaloid 223AB [(5E,9E)3-butyl-5-propylindolizidine] and contained, respectively, a omega-hydroxy group in the propyl or butyl side chain. The profiles of alkaloids in the new northern populations of D. histrionicus are typical of the species in containing a set of about eight histrionicotoxins, in marked contrast to a related species, Dendrobates lehmanni, which does not contain histrionicotoxins.
85 citations
80 citations
TL;DR: The isolation and structure of the first of these blood pigments tunichrome B-1 from the Ascidia nigra is reported.
Abstract: The tunicates, or sea squirts, are common marine organisms that selectively accumulate metals such as V, Fe, Mo, Nb, in their blood cells. Despite the more than 70 years of interest in the compounds responsible for this accumulation, their extreme lability has eluded attempts to isolate and characterize them. The isolation and structure of the first of these blood pigments tunichrome B-1 from the Ascidia nigra is reported.
TL;DR: Eleven sesterterpenes have been characterized from the biotoxic extracts of Hyrtios erecta, and they were accompanied by five previously described scalaranes, 1, 4, 5a, 6, and 8, along with hyrtial, a novel norsesterterpene.
Abstract: Eleven sesterterpenes have been characterized from the biotoxic extracts of Hyrtios erecta. Their structures and stereochemistry were established by spectral properties or results from chemical interconversions. Especially valuable for establishing stereochemical features were 13C-nmr methyl shift correlations and analysis of 1H-nmr couplings and chemical shifts. The new scalarane sesterterpenes included 2, 3, 7, 9, and 10a (but 9 and 10a might be artifacts), and they were accompanied by five previously described scalaranes, 1, 4, 5a, 6, and 8, along with hyrtial (11), a novel norsesterterpene. Many of these sesterterpenes exhibited interesting biological activity.
TL;DR: Two cytotoxic sapogenols, the new hippocaesculin and the known barringtogenol-C 21-angelate, were isolated from the acid hydrolysis product of a crude saponin fraction that was obtained from the fruits of Aesculus hippocastanum.
Abstract: Two cytotoxic sapogenols, the new hippocaesculin (1) and the known barringtogenol-C 21-angelate (2), were isolated from the acid hydrolysis product of a crude saponin fraction that was obtained from the fruits of Aesculus hippocastanum. The structures of 1 and 2 were determined from their chemical transformations and spectral data. Compound 1 is either 21-O-angeloyl, 22-O-tigloyl R1-barrigenol, or 21-O-tigloyl, 22-O-angeloyl R1-barrigenol.
TL;DR: Extracts of root cultures of Linum flavum contained high cytotoxic activity due to the presence of 1% beta-peltatin-A methyl ether of the dry mass and coniferin was identified as the major uv-absorbing but noncytotoxic constituent.
Abstract: Extracts of root cultures of Linum flavum contained high cytotoxic activity due to the presence of 1% beta-peltatin-A methyl ether of the dry mass. During chromatographic analysis of the cell extracts, coniferin was identified as the major uv-absorbing but noncytotoxic constituent with levels of up to 3% of the dry mass. Growth, culture appearance, and product accumulation varied greatly with the 2,4-D concentration in the medium.
TL;DR: An assessment of a potential carcinogenic risk involved in mass production and handling of the plant should point to the very weak tumor-promoting activity and the chemical instability demonstrated for the diterpene constituents in the latex and hence in all plant parts.
Abstract: The latex of Euphorbia tirucalli originating from Madagascar contains as irritant constituents ingenane- and tigliane-type diterpene esters derived from the parent alcohols ingenol and phorbol. The main irritant constituents are isomeric 12,13-acetates, acylates of phorbol as well as 3-acylates of ingenol. As acyl groups, they carry homologous, highly unsaturated aliphatic acids of the general structure CH3-(CH2)m-(CH = CH)n-COOH (m = 2,4; n = 2,3,4,5; total number N of C-atoms = 2n + m + 2). The lack of 4-deoxyphorbol esters in this latex as compared to latex of South African origin is probably indicative of the existence of chemical races of E. tirucalli. In the acyl moiety of phorbol esters investigated in detail, an increasing number of C-atoms or an increasing number of double bonds at a fixed number of C-atoms leads to an increase of irritant activity. As compared to their saturated analogs, corresponding unsaturated phorbol esters exhibit similar irritant activities. On the other hand, by an increasing number of conjugated double bonds in the acyl moieties of phorbol esters, the promoting activity is decreased, thus indicating that irritant activity is a necessary, but insufficient, requirement for promoting activity of phorbol esters. An assessment of a potential carcinogenic risk involved in mass production and handling of the plant should point to the very weak tumor-promoting activity and the chemical instability demonstrated for the diterpene constituents in the latex and hence in all plant parts.
TL;DR: Intraperitoneal injection of an aqueous extract of the crude drug "shigoka" (Siberian ginseng), Eleutherococcus senticosus roots, remarkably diminished plasma-sugar level in mice, with marked hypoglycemic effects in normal and alloxan-induced hyperglycemic mice.
Abstract: Intraperitoneal injection of an aqueous extract of the crude drug "shigoka" (Siberian ginseng), Eleutherococcus senticosus roots, remarkably diminished plasma-sugar level in mice. Fractionation of the extract by monitoring the activity yielded seven glycans, eleutherans A, B, C, D, E, F, and G, which exerted marked hypoglycemic effects in normal and alloxan-induced hyperglycemic mice.
TL;DR: The isolation and structure determination of the alkaloid ent-norsecurinine (4) from Phyllanthus niruri L. is described and the structure and absolute stereochemistry have been confirmed by an X-ray analysis of ent-Norsecur inine hydrochloride.
Abstract: The isolation and structure determination of the alkaloid ent-norsecurinine (4) from Phyllanthus niruri L. is described. The structure and absolute stereochemistry have been confirmed by an X-ray analysis of ent-norsecurinine hydrochloride.