Showing papers in "Journal of Natural Products in 1979"
122 citations
TL;DR: The anticancer activity of the roots of Ervatamia heyneana (Apocynaceae) was found to be due principally to the known alkaloid, camptothecin, and the closely related, but less active, 9-methoxycamptethecin was obtained.
Abstract: The anticancer activity of the roots of Ervatamia heyneana (Apocynaceae) was found to be due principally to the known alkaloid, camptothecin (1). The closely related, but less active, 9-methoxycamptothecin (2) was also obtained. This is the first reported isolation of these biogenetically interesting alkaloids from the indole alkaloid rich Apocynaceae.
102 citations
TL;DR: Several hundred flavonoid derivatives, natural and synthetic, which have been tested in the screening program of the National Cancer Institute have been examined for indications of structure-activity relationships which might exist among these compounds.
Abstract: Several hundred flavonoid derivatives, natural and synthetic, which have been tested in the screening program of the National Cancer Institute, have been examined for indications of structure-activity relationships which might exist among these compounds. No such relationships are apparent. In spite of occasional activity these compounds do not warrant further detailed pursuit as anti-tumor agents.
83 citations
78 citations
TL;DR: Experiments with calf thymus DNA indicate that, unlike photoactive furanocoumarins, phenylheptatriyne does not form interstrand cross linkages with DNA in ultraviolet light.
Abstract: The tropical weed Bidens pilosa L. (Asteraceae) contains a number of polyacetylenes which are phototoxic to bacteria, fungi, and human fibroblast cells in the presence of sunlight, artificial sources of long-wave ultraviolet light, or cool-white fluorescent light. The principle photoactive compound in the leaf, phenylheptatriyne, is present in the cuticle as well as in the underlying cells. Experiments with calf thymus DNA indicate that, unlike photoactive furanocoumarins, phenylheptatriyne does not form interstrand cross linkages with DNA in ultraviolet light.
76 citations
TL;DR: (+)-Nortrachelogenin (I) showed effects on the central nervous system producing depression in rabbits, and was established as 8(R), 8'(R)-4,4',8'-trihydroxy-3,3'-dimethoxylignan-olid(9, 9') on the basis of spectroscopic evidence and comparison with its enantiomers.
Abstract: A new lignan, (+)-nortrachelogenin (I), and a known compound, daphnoretin were isolated from Wikstroemia indica C. A. Meyer (Thymelaeaceae). The structure of (+)-nortrachelogenin was established as 8(R), 8'(R)-4,4',8'-trihydroxy-3,3'-dimethoxylignan-olid(9, 9') on the basis of spectroscopic evidence and comparison with its enantiomer, (-)-nortrachelogenin. (+)-Nortrachelogenin (I) showed effects on the central nervous system producing depression in rabbits.
60 citations
59 citations
57 citations
TL;DR: Kinetics reaction of the reverse transciptase inhibition showed that the alkaloids stopped the DNA polymerase synthesis instantly, probably by interacting with the template primer.
Abstract: Benzophenanthridine alkaloids, fagaronine 4, O-methylfagaronine 5, nitidine 1, allonitidine 3 and methoxydihydronitidine 2 have been shown to posses inhibitory activity against reverse transcriptase of RNA tumor viruses. The enzyme inhibition (50%) by these alkaloids was found in the range of 6-60 microgram per milliliter of the reaction mixture when polynucleotide-oligodeoxynucleotide complexes were used as template primers. The results suggested that the benzophenanthridine alkaloids interacted with the template primers (particularly of the A:T base pairs) and not with the enzyme proteins. Kinetics reaction of the reverse transciptase inhibition showed that the alkaloids stopped the DNA polymerase synthesis instantly, probably by interacting with the template primer.
55 citations
53 citations
TL;DR: The known coumarins, micromelin and scopoletin, were crystallized from the active fractions and demonstrated to have antitumor activities and converted to the corresponding butenolide (deoxymicromelin) which was inactive in the 9KB assay.
Abstract: 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.
TL;DR: Three hundred and twenty-seven indigenous Iraqi plant species were screened for their antimicrobial activities and for the presence of alkaloids, finding five species were highly active, while another 90 species showed weak activity against one or more microorganisms.
Abstract: Three hundred and twenty-seven indigenous Iraqi plant species were screened for their antimicrobial activities and for the presence of alkaloids. The plants represent 221 genera and 49 families. Ethanolic extracts were tested for the presence of alkaloids with both Mayer's and Dragendorff's reagents. Of these, 146 species, belonging to 109 genera distributed among 32 families, showed positive alkaloid tests to both reagents. Of these, 26 genera have not been previously reported in the literature as containing alkaloid-bearing plants. The extracts were also tested for their in vitro antimicrobial activity by an agar dilution-streak method against six economically significant microbes. Five species were highly active, while another 90 species showed weak activity against one or more microorganisms.
TL;DR: DL-(214C) mevalonate was used to confirm the biosynthesis of sterols in both latex and callus cultures, and Euphol was present in large amounts in the latex, but tirucallol predominated in greater quantities in explants andCallus indicating synthesis and/or accumulation of tiruc allol by cells other than the laticifer cell.
Abstract: Latex from E. Tirucalli, a potential rubber source, contains steroidal alcohols that are high in energy and thus of value in biomass conversion to fuels. Euphol was present in large amounts in the latex, but tirucallol predominated in greater quantities in explants and callus indicating synthesis and/or accumulation of tirucallol by cells other than the laticifer cell. Sterol production was significantly enhanced by certain nutrient media, as well as indole-3-acetic acid, and depressed by benzyladenine. Precursor stimulation of product synthesis was successful only with squalene, which promoted sterol production at 1.0 mg/liter but inhibited cell growth at higher concentrations. DL-mevalonic acid and lanosterol promoted neither growth nor sterol production. DL-(214C) mevalonate was used to confirm the biosynthesis of sterols in both latex and callus cultures.
TL;DR: The twigs, leaves, and flowers of Hyptis tomentosa were found to owe their major cytotoxic activity to the presence of desoxypodophyllotoxin, but the two weakly cytot toxic flavones also contributed to the total cytotoxicity of the crude extracts.
Abstract: The twigs, leaves, and flowers of Hyptis tomentosa were found to owe their major cytotoxic activity to the presence of desoxypodophyllotoxin (4), but the two weakly cytotoxic flavones 5-hydroxy-4',6,7,8-tetramethoxy flavone (3) and 5-hydroxy-4',3,6,7,8-pentamethoxy flavone (2) also contributed to the total cytotoxicity of the crude extracts The flavones eupatorin (6) and 5-hydroxy-3',4',6,7-tetramethoxy flavone (5) were isolated as inactive constituents, together with the lignan sesamin (1)
TL;DR: Montanin and spruceanol, two quite different diterpenes, were found to be responsible for the cytotoxic and antitumor activity of the root and root bark of Cunuria spruceana.
Abstract: Montanin (1) and spruceanol (2), two quite different diterpenes, were found to be responsible for the cytotoxic and antitumor activity of the root and root bark of Cunuria spruceana (Euphorbiaceae). The structure of spruceanol (2) was deduced from spectral interpretation and chemical correlation with 12-methoxycleistanth-8,11,13-trien-3-one (4).
TL;DR: Latex of Euphorbia tirucalli, collected in Colombia, yielded 12-O-2Z-4E-octadienoyl-4-deoxyphorbol-13-acetate, which exhibited an irritant potency equivalent to that of the standard irritant, phorbol, in a mouse ear test system.
Abstract: Latex of Euphorbia tirucalli, collected in Colombia, yielded 12-O-2Z-4E-octadienoyl-4-deoxyphorbol-13-acetate (1), which exhibited an irritant potency equivalent to that of the standard irritant, phorbol-12-tetradecanoate-13-acetate, in a mouse ear test system. The unsaturated 4-deoxyphorbol diesters recently reported in E. tirucalli grown in South Africa were not observed in the present study.
TL;DR: Dephinium cashmirianum Royle (Ranunculaceae) has yielded the new base cashmiradelphine (12), together with the known alkaloids anthranoyllycoctonine (9), lycaconitine (15), avadharidine (17), lappaconitines (4), and N-deacetyllappaconine (4) - the new aldehyde lycoctonal.
Abstract: Dephinium cashmirianum Royle (Ranunculaceae) has yielded the new base cashmiradelphine (12), together with the known alkaloids anthranoyllycoctonine (9), lycaconitine (15), avadharidine (17), lappaconitine (4), and N-deacetyllappaconitine (7). Pyridinium chlorochromate oxidation of lycoctonine furnished the new aldehyde lycoctonal (11). The arrhythmogenic and heart rate effects of several of these diterpenoidal alkaloids have been measured on the isolated guinea atria. Lappaconitine was arrhythmogenic at 10(-4)M concentrations. But in contrast to the reference drug aconitine, lappaconitine did not increase the heart rate. In anesthetized rabbits injected with lappaconitine, N-deacetyllappaconitine, and lappaconine up to 1 mg/kg, cardiac arrhythmia was quickly observed. Even up to 5 mg/kg, the other substances were non-arrhythmogenic.
TL;DR: 7-con-O-methylnogarol (7) is a highly active antitumor agent that has been converted to a series of analogs by removal of the carbomethoxy group at C-10 and replacement of the neutral sugar atC-7 by other groups.
Abstract: Nogalamycin, an antitumor antibiotic, has been converted to a series of analogs by removal of the carbomethoxy group at C-10 and replacement of the neutral sugar at C-7 by other groups. Removal of the carbomethoxy group to give disnogamycin (6) followed by acidic alcoholysis gave pairs of isomeric 7-alkoxy compounds differing in configuration at C-7. Treatment of 6 with trifluoroacetic acid followed by nucleophiles gave a series of analogs having substituents at C-7 with a configuration at C-7 opposite to that of nogalamycin. Among the analogs prepared, 7-con-O-methylnogarol (7) is a highly active antitumor agent.