A further quinazoline alkaloid from Adhatoda vasica

A new quinazoline alkaloid isolated from the leaves of Adhatoda vasica has been identified as 1,2,3,9-tetrahydro-5-methoxypyrrolo[2,1-b]quinazoline-3-ol.     

A chalcone glycoside from the flowers of Adhatoda vasica

2′,4-Dihydroxychalcone 4-glucoside has been identified in the flowers of Adhatoda vasica.     

Vasicol,a new alkaloid from Adhatoda vasica

A novel alkaloid isolated from the roots of Adhatoda vasica has been characterized as 1,2,3,4,9,11 hexahydro pyrrolo (2,1-b) quinazolin-3,11 diol by chemical and spectroscopic methods. Vasicinone has also been isolated from the roots of this plant.     

HPTLC determination of vasicine and vasicinone in Adhatoda vasica

A simple high-performance thin-layer chromatographic (HPTLC) method has been developed for the simultaneous determination of the pharmacologically important quinazoline alkaloids vasicine and vasicinone in Adhatoda vasica. The assay combines the separation and quantification of the analytes on silica gel 60 GF254 HPTLC plates with visualisation under UV and scanning at 270 and 281 nm. Using this technique, the alkaloidal content of different parts of the title plant have been determined.     

Screening of microalgae for species excreting norharmane, a manifold biologically active indole alkaloid

A screening of microalgae strains is described, with the objective to discover more species besides the known cyanobacterium Nodularia harveyana which excrete the manifold biologically active and co-mutagenic indole alkaloid norharmane (9H-pyrido(3,4-b)indole) into their environment. Seven more cyanobacterial species, Anabaena cylindrica, Anabaena inaequalis, Anabaenopsis siamensis, Chroococcus minutus, Nostoc carneum, Nostoc commune and Phormidium foveolarum, were newly discovered. The norharmane concentrations detected for cyanobacterial culture media varied in a species-dependent manner from less than 1 up to 525 μg l⁻¹. The risk for humans and livestock, resulting from the natural appearance of norharmane as an extracellular metabolite of various cyanobacteria, is discussed.     

Antifeedant and toxic activity of Adhatoda vasica leaf extract against Spodoptera littoralis (Lep., Noctuidae)

Abstract: The effect of crude methanolic extracts of Adhatoda vasica leaves on the feeding and performance of Spodoptera littoralis larvae was investigated in the laboratory. Feeding on fresh leaves resulted in 100% mortality of larvae after 26 days of unsubstantial growth. The extract exhibited strong antifeedant and toxic activity against the larvae when applied either on leaf discs or incorporated into artificial diet. Under choice conditions the antifeedant index calculated over 72 h for neonate larvae increased significantly (from 71.5 ± 3.2 to 92.1 ± 4.2) as the concentration of extract in the treated diet increased from 200 to 1000 ppm. Consumption by the sixth instar larvae of leaf discs dipped in 0.01, 0.1 and 0.2% extract solutions was significantly lower than consumption of control discs in both choice and no-choice tests. The latter two concentrations deterred feeding by 63.4 and 90.4%, respectively, under choice conditions, while only the 0.2% extract solution deterred feeding by 56.8% in the no-choice test. Toxicity of the extracts was manifested by a high mortality, reduced growth rates, and low weight gain by larvae fed on diets containing 200–2000 ppm of the extract. No larvae survived to pupation under the latter concentration. The time to pupation increased from 15.8 ± 0.4 to 37.9 ± 4.1 days as the extract concentration in diet increased from 0 to 1000 ppm. When fed to the fifth instar larvae, the crude extract significantly reduced consumption, growth, utilization of ingested and digested food, and approximate digestibility. The consumption-dependent growth efficiency of animals fed on extract-free diet was significantly higher than the growth efficiency of animals fed on extract-containing diets, suggesting both antifeedant and toxic activities of the extract.     

Dehydroheliamine,a trace alkaloid from the saguaro,Carnegiea gigantea (cactaceae)

Extraction of Carnegiea gigantea yielded a new 3,4-dihydroisoquinoline alkaloid, dehydroheliamine; the structure was confirmed by synthesis.     

Detoxification of aflatoxin B1 by an aqueous extract from leaves of Adhatoda vasica Nees

The effectiveness of aqueous extracts of various medicinal plants in detoxification of aflatoxin B1 (AFB1) was tested in vitro by thin-layer chromatography and enzyme-linked immunosorbent assay (ELISA). Among the different plant extracts, the leaf extract of Vasaka (Adhatoda vasica Nees) showed the maximum degradation of AFB1 (≥98%) after incubation for 24 h at 37 °C. The aflatoxin detoxifying activity of the A. vasica leaf extract was significantly reduced by heating to 100 °C for 10 min or autoclaving at 121 °C for 20 min. Dialysis had no effect on aflatoxin detoxifying ability of A. vasica extract and the dialyzed extract showed similar level of detoxification of AFB1 as that of the untreated extract. A time course study of aflatoxin detoxification by A. vasica extract showed that 69% of the toxin was degraded within 6 h and ≥95% degradation was observed after 24 h of incubation. Detoxification of AFB1 by A. vasica extract was further confirmed by liquid chromatography–mass spectrometry (LC–MS) analysis. Phytochemical analysis revealed the presence of alkaloids in methanolic extract of A. vasica leaves. A partially purified alkaloid from A. vasica leaves by preparative TLC exhibited strong AFB1 detoxification activity.     

A highly selective alkaloid uptake system in vacuoles of higher plants

Vacuoles were isolated from different plant cell cultures and the transport mechanism for alkaloid uptake at the tonoplast membrane, as well as the compartmentation of enzymes and products inside the cells were investigated. While serpentine, the major alkaloid of Catharanthus roseus cells, is definitely located inside the vacuole, two key enzymes of the indole-alkaloid pathway, strictosidine synthase and a specific glucosidase, are located in the cytosol. Transport of alkaloids across the tonoplast into the vacuolar space has been characterized as an active, engergy-requiring mechanism, which is sensitive to the temperature and pH of the surrounding medium, stimulated by K⁺ and Mg²⁺, and inhibited by N,N-dicyclohexylcarbodiimid and Cu²⁺. The alkaloids accumulate inside the vacuoles against a concentration gradient, and the uptake system is specific for alkaloids indigenous to the plant from which the vacuoles have been isolated.Abbreviation DCCD N,N-dicyclohexylcarbodiimid Dedicated to Professor Dr. Hubert Ziegler on the occasion of his 60th birthday     

Nupharopumiline,a new quinolizine alkaloid from Nuphar pumila

A new quinolizine alkaloid, (+)-nupharopumiline, has been isolated from the rhizomes of Nuphar pumila. It has been shown by spectroscopic and chemi     

Protopine-N-oxide,an alkaloid from Bocconia cordata

The structure of a minor alkaloid of Bocconia cordata has been deduced as protopine-N-oxide by spectroscopic methods and confirmed by synthesis.     

Na-formylechitamidine,an alkaloid from Alstonia boonei

A known alkaloid, echitamidine, and a new alkaloid, N_a-formylechitamidine, have been isolated from the stem bark of Alstonia boonei. The structure of this new alkaloid was assigned on the basis of chemical and spectroscopic data.     

(+)-5α,9α-dihydroxymatrine,a new lupin alkaloid from Euchresta horsfeldii

A new lupin alkaloid (+)-5α,9α-dihydroxymatrine has been isolated from the leaves of Euchresta horsfeldii (E. formosana cv riukiuensis) together with matrine, matrine N-oxide, sophoranol, sophoranol N-oxide, anagyrine, N-methylcytisine, N-formylcytisine and cytisine.     

Two simple tetrahydroisoquinoline alkaloid N-oxides from cacti

Tehuanine N-oxide was isolated from Pachycereus pringlei, and deglucopterocereine N-oxide was isolated from Pterocereus gaumeri. These     

Scholarine: An indole alkaloid of Alstonia scholaris

A new alkaloid designated scholarine was isolated from the leaves of Alstonia scholaris. It was (±) 12-methoxyechitamidine as determined by chemical and spectroscopic investigations.     

Isolation and identification of a humanTRPV1 activating compound from soy sauce

Transient receptor potential vanilloid 1 (TRPV1) was identified as a receptor of capsaicin, which is a pungent ingredient in hot red peppers. Due to its relevance for nociception, a physiological and pharmacological study of TRPV1 has also been developed. Therefore, it is important to enrich scientific knowledge regarding the TRPV1 activating or inhibiting compounds. In this study, we fractionated soy sauce based on the human TRPV1 (hTRPV1) activity using column chromatography and purified 5-(9H-pyrido[3,4-b]indol-1-yl)-2-furanmethanol (perlolyrine) as an hTRPV1-activating compound. Additionally, perlolyrine activates the human transient receptor potential ankyrin 1 (hTRPA1). The EC₅₀ of hTRPV1 and hTRPA1 were 2.87 and 1.67 μmol L^?1, respectively. HPLC quantification of soy sauces showed that they contain 2.22–12.13 μmol L^?1 of perlolyrine. The sensory evaluation revealed that perlolyrine has taste modification effect. The results of this study, for the first time, suggest that perlolyrine induces the activation of hTRPV1 and hTRPA1.     

3-Hydroxydiaboline,a tertiary alkaloid from Strychnos castelnaeana

A new alkaloid, 3-hydroxydiaboline, together with diaboline, was isolated from the upper stem bark of Strychnos castelnaeana. The structure of 3-hy