A new monoterpenoid indole alkaloid from Rauvolfia yunnanensis

One new monoterpenoid indole alkaloid, 11-methoxyburnamine-17-O-3′,4′,5′-trimethoxybenzoate (1), was isolated from Rauvolfia yunnanensis Tsiang. Its structure was identified by spectroscopic evidences.     

A new type of monoterpenoid indole alkaloid precursor from Alstonia rostrata

Currently, all monoterpenoid indole alkaloids (MIAs) have been derived from strictosidine, which originates from the condensation of tryptophan with secologanin in a 1:1 ratio. However, our phytochemical research on Alstonia rostrata revealed a potential new precursor for these compounds. We isolated the alstrostines A and B, and it was determined that they were derived from tryptophan and secologanin in a 1:2 ratio, which supported the presence of a new type of MIA precursor.     

A cage-monoterpene indole alkaloid from Alstonia scholaris

An unprecedented cage-like alkaloid, scholarisine A was isolated from the leaves of Alstonia scholaris and its structure determined on the basis of 1D and 2D NMR, FTIR, UV, and high-resolution mass spectroscopic data. This alkaloid might be derived from picrinine via oxygenation, rearrangement, and lactonization.     

Calophyline A, a new rearranged monoterpenoid indole alkaloid from Winchia calophylla

Calophyline A (1), a novel unprecedented rearranged monoterpenoid indole alkaloid, along with a new natural product N-methyl aspidodasycarpine (2) and six known analogues, was isolated from the trunk barks of Winchia calophylla. The structure of compound 1 was elucidated on the basis of spectroscopic data and then confirmed by a single-crystal X-ray crystallographic analysis. A hypothetical biogenetic pathway for compound 1 was proposed. All isolated compounds were evaluated for their in vitro cytotoxicity against a small panel of human cancer cell lines.     

A new indole alkaloid with anti-inflammatory from the branches of Nauclea officinalis

Abstract

A new indole alkaloid, 17-oxo-19-(Z)-naucline, and six known alkaloids 2–7 were isolated from the branches of Nauclea officinalis. The structure of the new compound 1 was characterised mainly by analysing its physical data including IR, 1?D, 2?D NMR, and HR-ESI-MS. Other compounds were identified by comparisons their data with those reported in the literature. Compound1, 4, 5, 6, 7 showed in vitro anti-inflammatory activity decrease the LPS-stimulated production of nitric oxide in RAW264.7 cell, while all compounds exhibited weak cytotoxicity against human tumour cell lines (LOVO, A549 and HepG2).     

Kororamide A,a new tribrominated indole alkaloid from the Australian bryozoan Amathia tortuosa

A new tribrominated indole alkaloid, kororamide A together with the known alkaloid convolutamine F, were isolated through the application of mass directed purification from the bryozoan, Amathia tortuosa collected from northern New South Wales, Australia. The structure of kororamide A was deduced from the analysis of 1D/2D NMR and MS data. Kororamide A exists in solution as a mixture of interconverting cis–trans amide regioisomers in a ratio of 4:5. Bioactivity testing demonstrated that kororamide A was marginally active against chloroquine-sensitive and resistant strains of the malarial parasite Plasmodium falciparum, and was inactive against normal human cell lines.     

Kingamide A, a new indole alkaloid from the ascidian Leptoclinides kingi

Chemical investigation of the CH₂Cl₂/MeOH extract from the Australian ascidian Leptoclinideskingi led to the isolation of a new brominated indole alkaloid, kingamide A (1). The planar structure of kingamide A was elucidated following the interpretation of 1D/2D NMR and MS data, and the absolute configuration was determined using Marfey’s method. This is the first report of a natural product from L. kingi.     

A new indole alkaloid,antioxidant and antibacterial activities of crude extracts from Saccocalyx satureioides

Abstract

The new acylated indole alkaloid glucoside indole-3-carboxylic acid-(6'-O-caffeoyl)-β-D-glucoside 1 has been isolated from the ethyl acetate (EtOAC) extract of Saccocalyx satureioides Coss. & Dur. (Lamiaceae) together with eight known secondary metabolites 2-9. Two indoles 2 and 3, five methylated flavone aglycones 4-8 and one monoterpene glucoside 9 were reported for the first time in the genus Saccocalyx. The structural elucidation of these compounds was accomplished by spectroscopic methods including 1?D (¹H and ¹³C) and 2?D (COSY, HSQC and HMBC) NMR techniques, and mass spectrometry, and by comparison with literature data. Light petroleum, EtOAc, chloroform and n-butanol (n-BuOH) extracts of S. Satureioides were screened for their antioxidant activity using DPPH radical scavenging and β-carotene bleaching methods. The antibacterial activity of these extracts indicates that n-BuOH and EtOAc extracts possess the strongest activity.     

Naucline, a new indole alkaloid from the bark of Nauclea officinalis

A new indole alkaloid, naucline (1) together with four known alkaloids, angustine (2), angustidine (3), nauclefine (4) and naucletine (5), were isolated from the bark of Nauclea officinalis. The structures of all isolated compounds were elucidated with various spectroscopic methods such as 1D- and 2D- NMR, IR, UV and LCMS-IT-TOF. In addition to that of alkaloid 1, the complete 13C-NMR data of naucletine (5) were also reported. Naucline (1) showed a moderate vasorelaxant activity (90% relaxation at 1 × 10(-5) M) whereas, angustine (2), nauclefine (4), and naucletine (5) showed potent vasorelaxant activity (more than 90% relaxation at 1 × 10(-5) M) on an isolated rat aorta.     

Catharoseumine,a new monoterpenoid indole alkaloid possessing a peroxy bridge from Catharanthus roseus

Catharoseumine (1), a new monoterpenoid indole alkaloid possessing a unique peroxy bridge moiety, was isolated from the whole plants of Catharanthus roseus. Its structure was elucidated on the basis of NMR, IR, UV, and high-resolution mass spectrometric data, and its absolute configuration was determined by ECD and chemical methods. Catharoseumine (1) exhibited cytotoxicity against HL-60 cell line with IC₅₀ value of 6.28 μM and potential inhibition against Plasmodium falciparum falcipain-2 (IC₅₀ = 4.06 μM). A plausible biogenetic pathway of 1 was also proposed.     

A new alkaloid from Lysimachia patungensis

A new pyridine alkaloid and six known compounds were isolated from the whole plant of Lysimachia patungensis Hand.-Mazz. The structure of the new alkaloid, named patungensin, was characterized as (17R, E)-2-hydroxy-4,6-dimethoxy-17-acetoxy-cyclopentadeca-1, 3-diene[1,2-b]pyridine, and the six known compounds were identified as octacosanoic acid (1), palmic acid (2), stigmasterol (3), ardisiacrispin A (5), isorhamnetin 3-β-D-galactopyranoside (6), and isorhamnetin 3-robinobioside (7), respectively. Published in Khimiya Prirodnykh Soedinenii, No. 2, pp. 141–142, March–April, 2007.     

A new alkaloid from Lycoris aurea

A new alkaloid was isolated from the bulbs of Lycoris aurea(L'Herit.) Herb.Its structure was established as 3-o-ethyltazettinol through chemical and spectroscopic studies including 2D NMR.     

A new bisbenzylisoquinoline alkaloid from Plumulanelumbinis

One new bisbenzylisoquinoline alkaloid, neferine N-oxide(1), along with three known compounds,neferine(2), liensinine(3), and isoliensinine(4), were isolated from Plumulanelumbinis – the embryo of the seed of Nelumbonucifera. Their structures were elucidated by extensive spectroscopic analysis(MS,UV, IR, NMR), and the absolute configurations were determined by experimental circulardichroism(CD)spectra. Compound 1 is a new naturally occurring bisbenzylisoquinoline alkaloid with an N-oxide functionality, and the CD spectrum of(1R, 1'R) neferine is first reported. The antioxidant activities of compounds 1–4 were evaluated using the ORAC assay, which illustrated that all these compounds showed the different levels of oxygen radical absorbance capacity.     

A new alkaloid from Stemona sessilifolia

A new alkaloid, named sessilistemonamine D, was isolated from the roots of Stemona sessilifolia and the structure and relative configuration were determined on the basis of NMR and MS spectrometric data analysis.