Linear furocoumarins and other constituents from thamnosma texana

Eight linear furocoumarins and three coumarins were isolated and identified from Thamnosma texana. They were xanthotoxin, imperatorin, bergapten, alloimperatorin methyl ether epoxide, heraclenin, isopimpinellin, psoralen, oxypeucedanin, and the coumarins herniarin, osthol and thamnosmin. The linear furocoumarins appear to be agents that account for the known photosensitizing properties of Thamnosma texana, and consequently its colloquial name, ‘blisterweed.’ This is the first report on the occurrence of imperatorin, heraclenin, oxypeucedanin, herniarin or osthol in any Thamnosma species.     

Substances antiappétantes pour insectes phytophages présentes dans Angelica silvestris et Heracleum sphondylium

Eleven furocoumarins from Angelica silvestris and Heracleum sphondylium were tested for their antifeedant activity gainst two insect larvae: Mythimna unipuncta and the Colorado beetle Leptinotarsa decemlineata. Angular furocoumarins show a smaller effect that the corresponding linear homologues. The following order of activity is observed for substituents:

4-Methoxybenzofuran, a synthetic analogue shows also medium activity. But the most active component is a sesquiterpene: the known bisabolangelone.     

Frameshift mutations in bacteria produced in the dark by several furocoumarins; Absence of activity of 4,5′,8-trimethylpsoralen

4 furocoumarins, namely psoralen (P), 8-methoxypsoralen (8-MOP), 4,5′,8-trimethylpsoralen (TMP) and angelicin (A) were tested for dark mutagenesis in E. coli lac⁻. Three compounds; P, 8-MOP and A were shown to be weak frameshift mutagens. TMP, surprisingly in view of its very active photosensitizing action, was found to be non-mutagenic. These results are discussed in relation to the photosensitizing action of the furocoumarins.     

Antihyperlipidaemic and antihypercholesterolaemic effects of Anethum graveolens leaves after the removal of furocoumarins.

Serum triacylglycerides and total cholesterol levels in rats, with hyperlipidaemia induced by diet, were determined after oral adminstration of a water extract of Anethum graveolens leaves before and after the extraction of the furocoumarin content of the leaves. Administration of the extracts consecutively for 14 days reduced the triacylglycerides and total cholesterol levels by almost 50 and 20%, respectively. Chloroform extraction of furocoumarins from the aqueous extracts did not reduce the antihyperlipidaemic potential of the extracts to a significant degree. Oral administration of the essential oil of A. graveolens seeds, at two different doses, also reduced the triacylglyceride levels by almost 42%. The total cholesterol level was not reduced by the same doses of the essential oil.     

Psoralen and other linear furocoumarins as phytoalexins in celery

A linear furocoumarin phytoalexin response was observed in stressed celery (Apium graveolens). Heretofore, linear furocoumarins found in diseased c     

Mutagenic compounds in an extract from Rutae Herba (Ruta graveolens L.). II. UV-A mediated mutagenicity in the green alga Chlamydomonas reinhardtii by furoquinoline alkaloids and furocoumarins present in a commercial tincture from Rutae Herba

A commercial tincture prepared from Rutae Herba (Ruta graveolens L.) exhibited a moderate photomutagenicity in an arginine-requiring mutant strain of Chlamydomonas reinhardtii. In the tincture some furocoumarins, e.g., bergapten, psoralen, imperatorin, and 3 furoquinoline alkaloids (dictamnine, gamma-fagarine, skimmianine) were detected. All compounds revealed photomutagenic properties but their activities were quite different. Bergapten was the most potent furocoumarin. Dictamnine, the furoquinoline with the strongest effect, reached only about 10% of the activity of bergapten. Based on the amount of these compounds in the tincture and their activities we conclude that bergapten is mainly responsible for the photomutagenicity of the tincture. The lower phototoxicity and photomutagenicity of the furoquinoline alkaloids may be due to the fact that furoquinolines form only monoadducts with DNA in the presence of UV-A in contrast to furocoumarins which also form biadducts.     

Mutagenic compounds in an extract from Rutae Herba (Ruta graveolens L.) II. UV-A mediated mutagenicity in the green alga Chlamydomonas reinhardtii by furoquinoline alkaloids and furocoumarins present in a commercial tincture from Rutae Herba

A commercial tincture prepared from Rutae Herba (Ruta graveolens L.) exhibited a moderate photomutagenicity in an arginine-requiring mutant strain of Chlamydomounas reinhardtii. In the tincture some furocoumarins, e.g., bergapten, psoralen, imperatorin, and 3 furoquinoline alkaloids (dictamnine, γ-fagarine, skimmianine) were detected. All compounds revealed photomutagenic properties but their activities were quite different. Bergapten was the most potent furocoumarin. Dictamnine, the furoquinoline with the strongest effect, reached only about 10% of the activity of bergapten. Based on the amount of these compounds in the tincture and their activities we conclude that bergapten is mainly responsible for the photomutagenicity of the tincture.The lower phototoxicity and photomutagenicity of the furoquinoline alkaloids may be due to the fact that furoquinolines form only monoadducts with DNA in the presence of UV-A in contrast to furocoumarins which also form biadducts.     

Die verteilung von inhaltsstoffen in drei Pimpinella-arten

The roots of Pimpinella major Huds., P. saxifraga L. and P. peregrina L. do not contain any of the furocoumarins, indicated in previous literature. The main components of roots and fruits of P. major and P. saxifraga are isoeugenol epoxy tiglic ester, isoeugenol epoxy-2-methyl butanoic ester and 4-(1′,2′-epoxypropyl)-phenyl tiglic ester. The fruit and roots of P. peregrina do not contain these components. Only the fruit of P. major contains β-bisabolene and larger amounts of bisabolangelone.     

Alkaloids,limonoids and furocoumarins from three Mexican Esenbeckia species

The chemical constituents of three Mexican Esenbeckia species have been determined. Rutaevin was the main limonoid present in the seeds of all three species, E. litoralis, E. flava and E. berlandieri. The husks, leaves, wood and bark contained a wide array of known furocoumarins and furoquinoline alkaloids. In addition, 1-hydroxy-3-methoxy-N-methylacridone was obtained from E. litoralis bark and a new natural 2-quinolone alkaloid, formulated as 3,3-diisopropyl-N-methyl-2,4-quinoldione, was obtained from E. flava wood. The structure was assigned from spectroscopic considerations and conversion to N-methylhaplofoline.     

Phloroglucinol-type Furocoumarins,a Group of Potent Naturally-Occurring Insect Antifeedants

Phloroglucinol-type furocoumarins were found to have strong antifeeding activity against Spodoptera litura (tobacco cutworm), but the other furocoumarins belonging to pyrogallolor resorcinol-type had only weak activity. Antifeeding activity of these compounds against the other insects was also reported.     

Coumarin constituents of Selinum tenuifolium

Three furocoumarins, bergapten, heraclenin and heraclenol have been isolated from the roots of Selinum tenuifolium (Umbelliferae). Another coumarin, m.p. 85–86°, isolated from the same source and provisionally designated as ST-1, has been proved to be mixture of imperatorin, and 8-geranyloxypsolaren by analyses of various reaction products and separation by preparative TLC on silica gel G impregnated with silver nitrate.     

13 C NMR Chemical shifts and carbon-proton coupling constants of some furocoumarins and furochromones

The ¹³C NMR spectra of a variety of furocoumarins, dihydrofurocoumarins and furochromones are reported. The signals were assigned using carbon-proton coupling constants, ring annullation shifts, nuclear Overhauser effect considerations and shift effects caused by monothioester formation. Substituent effects on ¹³C chemical shifts and carbon-proton coupling constants are discussed. Methoxyl induced shifts of 5- and 8-substituted furocoumarins are additive, but their effects cannot be transferred to the furochromone system.     

Acute exposure of rhesus monkeys to DDT: Effect on carbohydrate metabolism

Four furocoumarins, two having a linear molecule, psoralen and 8-methylpsoralen and two having an angular molecule, angelicin and 4,5′-dimethylangelicin were tested for mutagenesis in Escherichia coli B wild type and in various strains deficient in known repair systems. The results indicate that both monoadducts and crosslinks are mutagenic. The mutagenic efficiency of the furocourmarins ranks in the following order 8-methylpsoralen > psoralen > angelicin > 4,5′-dimethylangelicin.     

The fungitoxicities of plant furocoumarins

A mixture of the furocoumarins pimpinellin, isopimpinellin, isobergapten and sphondin isolated from Heracleum sphondylium root was toxic to Gloeosporium limetticola, Botryis cinerea, Sclerotinia fructigena and Stereum purpureum at 200 p.p.m. or less in nutrient medium. The extractive of the leaves of plants that contain furocoumarins suppressed in vivo growth of G. limetticola and B. cinerea at concentrations lower than the contents of the extractive in the leaves. Furocoumarins may form an important class of natural defensive agents against fungi; this possibility is discussed.     

In vitro synergic efficacy of the combination of Nystatin with the essential oils of Origanum vulgare and Pelargonium graveolens against some Candida species

In this study we investigated a synergistic effect between the essential oils Origanum vulgare, Pelargonium graveolens and Melaleuca alternifolia and the antifungal compound Nystatin. Nystatin is considered a drug of choice in the treatment of fungal infections, but it can cause some considerable problems through its side effects, such as renal damage. Finding a new product that can reduce the Nystatin dose via combination is very important. Our findings showed an experimental occurrence of a synergistic interaction between two of these essential oils and Nystatin. The essential oil O. vulgare appeared to be the most effective, inhibiting all the Candida species evaluated in this study. Some combinations of Nystatin and P. graveolens essential oil did not have any synergistic interactions for some of the strains considered. Associations of Nystatin with M. alternifolia essential oil had only an additive effect.     

Chemical constituents from the roots of Peucedanum praeruptorum Dunn and their chemotaxonomic significance

Chemical investigation on the roots of Peucedanum praeruptorum Dunn afforded 15 compounds, including five linear furocoumarins (1–5), six angular pyranocoumarins (6–11), two simple coumarins (12 and 13), a benzaldehyde derivative (14), and a phenylpropanoid glycoside (15). The structures of these compounds were established via spectroscopic analysis and comparison of their NMR data with the literature. Compound 1 was a new linear furocoumarin glycoside, while compounds 10–12, 14 and 15 were isolated from P. praeruptorum for the first time. The chemotaxonomic significance of these isolated compounds was summarized herein.     

Isolation and Characterization of pso Mutants Sensitive to Photo-Addition of Psoralen Derivatives in SACCHAROMYCES CEREVISIAE

We have isolated mutants sensitive to photo-addition of bi-functional and mono-functional derivatives of psoralen in Saccharomyces cerevisiae. Three of these pso mutants were analyzed in detail. They segregate in meiosis like Mendelian genes and complement each other, as well as existing radiation-sensitive (rad and rev) mutants. The study of heterozygous diploid strains (PSO⁺/pso) indicates that the three pso genes are recessive. The mutant pso1–1 demonstrates a cross-sensitivity to UV and γ-rays, whereas mutants pso2–1 and pso3–1 are specifically sensitive to photo-addition of psoralen derivatives. The comparison of exponentially growing cells to stationary-phase cells demonstrates that for the three mutants the defect in repair capacity of DNA cross-links and monoadducts concerns G1 and early S-phase cells. The pso2–1 mutant is, however, also defective in G2 repair and loses diploid resistance when it is in the homozygous state.—The block in repair capacity in these novel mutants is discussed in relation to the three other repair pathways known to be involved in the repair of furocoumarins photo-induced lesions in yeast DNA.     

Repair of interstrand cross-links in DNA of Saccharomyces cerevisiae requires two systems for DNA repair: The RAD3 system and the RAD51 system

Summary We have studied the role of the excision-repair system and the recombination-repair system in the removal of cross-links and monoadducts caused by furocoumarins plus 360 nm radiation in yeast DNA by neutral and alkaline sucrose gradients and by a fluorometric procedure which detects cross-linked DNA molecules. We found that the excision-repair system, represented by the rad3 mutations, is required both for the removal of monoadducts, causing single-strand break formation, and for the removal of cross-links, causing double-strand break formation. The recombination-repair system, represented by the rad51 mutation, is necessary for double-strand break repair following cross-link removal, but it has no role in the repair of monoadducts.It can be concluded that at least some of the same enzymes are used in yeast for both the excision of pyrimidine dimers and the excision of cross-links or monoadducts caused by furocoumarins plus light. The RAD3 and RAD51 repair systems, which act independently in the repair of UV-induced lesions, are part of a single system for the repair of cross-links.     

Post-irradiation dark recovery of photodamage to DNA induced by furocoumarins

Summary Photosensitization processes provoked by furocoumarins on various biological systems seem to be in connection with the photoreactions that these substances give bothin vitro andin vivo with pyrimidine bases of nucleic acids; in particular linear furocoumarins (psoralen) photoreact with native DNA giving both monofunctional and bifunctional additions (forming in this last case inter-strand cross-linkings) while angular furocoumarin (angelicin) can give only monofunctional additions. Previous studies on the possible recovery of this damage to DNA provoked both by linear and angular furocoumarins demonstrated that no repair underwent either by means of photosplitting experiments or through photoreactivation processes.In this paper are reported direct results indicating that the photodamage to DNA is repairable through post-irradiation dark recovery both operating on microbial cultures and on guinea-pig skin. In both biological systems monofunctional additions appear much more easily repairable than bifunctional additions; in any case bifunctional additions (which produce inter-strand cross-linkings) clearly appear to be repairable.     

Ability of plant callus cultures to synthesize and accumulate lower terpenoids

Callus cultures derived from seven oil-producing plants have been maintained under different regimes of media, temperature and illumination, and have been assayed for ability both to synthesize and to accumulate mono- and sesqui-terpenes. Callus of Pinus radiata (the sole gymnosperm) accumulated (α- and β-pinenes at levels comparable with those in the parent stem and needles; and that of Jasminum officinale accumulated traces of several monoterpenes (< 0.1 % the amount in petals) but cultures of Rosmarinus officinalis, Lavandula angustifolia, Anethum graveolens, Ocimum basilicum and Tanacetum vulgare did not detectably accumulate the lower terpenoids or secrete them into the medium. However, all seven culture lines yielded cell-free extracts containing prenyltransferase and an isomerizing system (as assayed by conversion of IPP into GPP, NPP and FPP) with activities some fold greater than those extracted from the parent mature plants, or up to 90-fold the levels extractable from young seedlings of the various species. Callus of five of the species (A. graveolens and O. basilicum were not assayed) also contained MVA-kinase, MVAP-kinase, MVAPP-decarboxylase and IPP-DMAPP isomerase at levels comparable with those in the parent tissue. Hence the angiosperms yielded cultures that presumably contained the crucial enzyniic machinery necessary for the synthesis of the lower terpenoids, although accumulation of those compounds did not occur. Reasons for this unexpected situation are discussed. These results imply that callus cultures may be a convenient source of biomass for studies on the enzymes of terpenoid biosynthesis.