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.     

Furoquinoline alkaloids as photosensitizers in Chlamydomonas reinhardtii

Seven naturally occurring furoquinoline alkaloids were investigated for their photobiological activity using arg-1 cells of Chlamydomonas reinhardtii. UV-A-mediated toxicity of the compounds was calculated from the colony-forming ability of the treated cells. The UV-A-mediated mutagenicity was measured by counting the number of Arg+ revertants induced by the treatment. Dictamnine was found to be the strongest mutagen as well as the most toxic compound of the group. The mutagenic activities were measured as mutation frequencies at equal substance concentration and ranked in the following order: An increase in the number of substituents on the lateral aromatic nucleus greatly decreased the photomutagenicity. Except for evolitrine, a similar ranking order was found as reported for the dark mutagenicity of these compounds in Salmonella typhimurium strain TA98. Based on the result that furoquinolines are able to intercalate into DNA, we assume that the different mutagenic potencies may reflect differences in the geometry of the intercalation complex, which is important for the subsequent photochemical reaction.     

Dihydrochalcones, coumarins and alkaloids from Metrodorea nigra

Two novel dihydrochalcones, 2′,3,4′,6′-tetrahydroxy-4-methoxy-3′,5-di-(3,3-dimethylallyl)-dihydrochalcone and 2′,.3,6′-trihydroxy-4-methoxy-5-(3,3-dimethylallyl)-3′,4′-(2″,2″-dimethyldihydropyran)-dihydrochalcone, have been isolated from fresh fruits of Metrodorea nigra. Stems and leaves showed a similar composition and we have isolated common steroids, simple coumarins, several furocoumarins, furoquinoline alkaloids and a furofuran lignan. From stems, we have also isolated the pentacyclic 6-C-monoterpenyl-5,7-dioxycoumarin, deoxybruceol. Structures of the isolated compounds were elucidated on the basis of spectral data.     

Coumarins from Three Phebalium species

The twigs of Phebalium anceps yielded the common furocoumarins psoralen, bergapten and xanthotoxin whereas the leaves of P. coxii and P. ralstonii gare only 8-prenylated 7-methoxycoumarins. From R coxii murrangatin and murralongin were obtained whilst R ralstonii yielded both of these compounds and another coumarin, the novel 7-methoxy-8-(2-acetoxy-3-methyl-1oxobut-2-enyl)-coumarin. The chemotaxonomic implications of these results are discussed.     

Phytochemical and chemotaxonomic study on Dictamnus angustifolius G. Don ex Sweet (Rutaceae)

A phytochemical investigation of Dictamnus angustifolius led to the isolation of 14 compounds, including six furoquinoline alkaloids (1–6), two sesquiterpenoids (7, 8) and six flavonoids (9–14). The structures of these compounds were identified by spectroscopic methods and a comparison of their data with those reported in the literature. This is the first report of three furoquinoline alkaloids 1–3 and six flavonoids 9–14 from the genus Dictamnus and the first isolation of compounds 4–8 from D. angustifolius. The chemotaxonomic significance of furoquinoline alkaloids and sesquiterpenoids has also been summarized.     

Mesomeric form of quaternary indoloquinazoline alkaloid and other constituents from the Cameroonian Rutaceae Araliopsis soyauxii Engl.

A mesomeric form of quaternary indoloquinazoline alkaloid, soyauxinium chloride (1) was obtained through the chemical investigation of stem bark and roots of Araliopsis soyauxii Engl. [syn. Vepris soyauxii (Engl.) Mziray] (Rutaceae) together with fifteen known compounds, including three furoquinoline alkaloids, three 2-quinolones, two limonoids, two triterpenes, two steroids, a coumarin, an acridone alkaloid, and a flavonoid glycoside. Their structures were established by comprehensive spectroscopic and spectrometric analyses (1D and 2D NMR, ESI-HR-MS) and by comparison with previously reported data. ¹³C NMR data of araliopsinine are also reported here for the first time. The isolated compounds were screened in vitro for their effects on the viability of two different human cancer cell lines, namely prostate PC-3 adenocarcinoma cells and colorectal HT-29 adenocarcinoma cells. However, none of the tested compounds exhibited strong anti-proliferative or cytotoxic activities, to either prostate PC-3 cells or colon HT-29 cells. At 100 μM, the furoquinoline maculine showed a slightly increased anti-proliferative effect, however, exclusively on HT-29 cells. The chemotaxonomic significance of the isolated compounds has also been discussed.     

Furoquinoline alkaloids from Teclea nobilis

Five new furoquinoline alkaloids, namely tecleabine (1), tecleoxine (2), isotecleoxine (3), methylnkolbisine (4) and chlorodesnkolbisine (5) were isolated from the aerial parts of Teclea nobilis, together with seven known furoquinoline derivatives; one acridone alkaloid, and one known flavanone. The structures of the alkaloids 1-5 were established by 1D and 2D NMR spectral data, including COSY, HMQC and HMBC experiments, as well as HRMS.     

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.     

An azole, an amide and a limonoid from Vepris uguenensis (Rutaceae)

The limonoid derivative, methyl uguenenoate, the azole, uguenenazole, and the amide, uguenenonamide, together with the known furoquinoline alkaloids flindersiamine and maculosidine, and syringaldehyde have been isolated from the root of the East African Rutaceae Vepris uguenensis. While methyl uguenenoate and the furoquinoline alkaloids displayed mild antimalarial activity, the azole and amide were completely inactive.     

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.     

Isolation and Antimacrofouling Activity of Indole and Furoquinoline Alkaloids from ‘Guatambú’ Trees (Aspidosperma australe and Balfourodendron riedelianum)

In this work, the antifouling activity of five alkaloids, isolated from trees of the Atlantic rainforest, was studied. The tested alkaloids were olivacine ( 1 ), uleine ( 2 ) and N‐methyltetrahydroellipticine ( 3 ) from Aspidosperma australe (‘yellow guatambú’) and the furoquinoline alkaloids kokusaginine ( 4 ) and flindersiamine ( 5 ) from Balfourodendron riedelianum (‘white guatambú’). All these compounds can be isolated from their natural sources in high yields in a sustainable way. The five compounds were subjected to laboratory tests (attachment test of the mussel Mytilus edulis platensis) and field trials, by incorporation into soluble matrix paints, and 45 days of exposure of the painted panels in the sea. The results show that compound 3 is a very potent antifoulant, and that compounds 4 and 5 are also very active, while compounds 1 and 2 did not show any significant antifouling activity. These results open the way for the development of environmentally friendly antifouling agents, based on abundant and easy‐to‐purify compounds that can be obtained in a sustainable way.     

New furanopyridine alkaloids from the leaves of Glycosmis pentaphylla

Three new furanopyridine alkaloids, namely glypenfurans A–C (1–3), were isolated from the leaves of Glycosmis pentaphylla together with six known furoquinoline alkaloids. Their structures were determined by extensive spectral analysis (UV, IR, MS, 1D and 2D NMR).     

Alcaloïdes de Zanthoxylum tsihanimposa

From the bark of Zanthoxylum tsihanimposa (Rutaceae) 5 furoquinoline and benzophenanthridine alkaloids were isolated. Three are known compounds: γ-fagarine, skimmianine and dihydrochelerythrinylacetone. The other two, dihydrochelerythrinylacetaldehyde and O-methyldihydrochelerythrinyl-acetone, are probably artefacts.     

Alkaloids from Corals

Alkaloids, which are generally basic N‐containing compounds, have been found in a variety of natural sources. Recently, the interest in alkaloids from corals increased significantly due to their remarkable bioactivities. This review deals with the chemical structures and biological activities of alkaloids in corals. The literature has been covered up to June 2011, and a total of 102 alkaloids from the 51 publications are discussed and reviewed. Some of these compounds showed various biological properties, such as cytotoxic, antibacterial, insecticidal, antifouling, and other activities.     

芹菜根中一种具有抗癌活性的双氨基甲酸酯

研究芹菜根(Apium graveolens L.)乙醇提取物的化学成分及其体外抗肿瘤活性。利用多种色谱方法进行分离纯化,现代波谱技术对分离得到的化合物进行结构鉴定;采用MTT法对分离出的单体化合物进行抗肿瘤实验。从芹菜根的乙醇提取物中分离得到3个单体化合物,它们的结构分别为双氨基甲酸酯AG-01 (1)佛手柑内酯(2)芹菜素(3)。化合物1为一新化合物,MTT细胞毒活性显示其对人体胃癌细胞SGC-7901和肝癌细胞BEL-7402的IC50分别为29. 6μM和32. 4μM。     

Furoquinoline alkaloids from the southern African Rutaceae Teclea natalensis

The chloroform and ethyl acetate extracts of the leaves of Teclea natalensis have yielded two furoquinoline alkaloids, 6-[(2,3-epoxy-3-methylbutyl)oxy]-4,7-dimethoxyfuro[2,3-b]quinoline and 4,7-dimethoxy-6-[(3-methyl-2-butenyl)oxy]furo[2,3-b]quinoline, and the known alkaloids 4,7-dimethoxy-8-[(3-methyl-2-butenyl)oxy]furo[2,3-b]quinoline, flindersiamine and dictamnine.     

Pregnane alkaloids from Sarcococca ruscifolia and their cytotoxic activity

Six pregnane alkaloids were isolated from the root of Sarcococca ruscifolia. The structures of three new alkaloids, namely, sarcorucinine E–G (1–3), were elucidated using spectroscopic methods, while three known alkaloids, namely, epipachysamine D, pachysamine M, and sarcovagine D, were identified by comparing their spectral data with those of the compounds reported earlier. All compounds were evaluated for their inhibitory activities against multiple types of cancer cells.     

Chemical constituents of Sigmatanthus trifoliatus Huber ex Emmerich (Rutaceae)

The phytochemical investigation of Sigmatanthus trifoliatus Huber ex Emmerich (Rutaceae) allowed the isolation and identification of the coumarins seselin, osthol, coumurrayin and braylin, besides the furoquinoline alkaloids evolitrine, dictamnine, γ-fagarine and skimmianine. Their chemical structures were determined based on MS, NMR analyses, and supported by comparison with those reported in the literature. The essential oils composition of leaves, roots, and trunk were also analyzed, showing the compounds b-Caryophyllene (33.2%), germacrene-D (28.1%) and bornyl acetate (14.7%) as main components, respectively. The chemotaxonomic significance of the isolated compounds was discussed.     

Bioactive monoterpene indole alkaloids from Nauclea officinalis

Two new monoterpene indole alkaloids, naucleaoffines A (1) and B (2), together with six known alkaloids (3–8), were isolated from the stems and leaves of Nauclea officinalis. The structures of 1 and 2 were elucidated by extensive spectroscopic methods and the known compounds were identified by comparisons with the data reported in literature. All isolated compounds were evaluated for their anti-inflammatory activities and anti-HIV-1 activities. Compounds 1–8 exhibited significant inhibitory activities on nitric oxide (NO) production induced by lipopolysaccharide in mouse macrophage RAW 264.7 cells in vitro with IC₅₀ values comparable to that of hydrocortisone. In addition, compounds 1–8 showed significant anti-HIV-1 activities with EC₅₀ ranged from 0.06 to 2.08 µM. These findings suggest that the discoveries of these indole alkaloids with significant anti-inflammatory activities and anti-HIV-1 activities isolated from N. officinalis could be of great importance to the development of new anti-inflammatory and anti-HIV agents.     

In vitro and in vivo activities of Haplophyllum myrtifolium against Leishmania tropica

This study aimed to evaluate the in vitro and in vivo leishmanicidal activity of an endemic Turkish plant and compare its efficacy with a reference drug. In addition to the in vitro activities of the ethanol, acidified and alkaloid extracts and furoquinoline alkaloids skimmianine and gamma-fagarine, in vivo antileishmanial activitiy of the acidified extract of Haplophyllum myrtifolium Boiss. (Rutaceae) were investigated against Leishmania tropica (L. tropica), a causative agent of cutaneous leishmaniasis. All the extracts and pure compounds showed in vitro inhibitory activity against the promastigotes of. L. tropica. The in vitro 50% inhibitory concentrations of y-fagarine, acidified extract, ethanol extract, skimmianine and alkaloid extract against promastigotes were determined as 8.7, 9.4, 10.9, 25.7 and 25.8 microg/ml respectively. In vivo results of Haplophyllum myrtifolium acidified extract showed that this plant has a limited effect on decreasing the lesion size of experimental mice infected with Leishmania tropica. To the best of our knowledge, this is the first time both the in vitro and in vivo antileishmanial activity of Haplophyllum mrytifolium have been reported in the same research.