Alkaloid and lignan constituents of Cinnamosma madagascariensis

A new lignan glycoside, 5-methoxy-9-β-xylopyranosyl-(-)- isolariciresinol and two indole alkaloids have been characterised from the bark of Cinnamosma madagascariensis.     

Biosynthetic relationship of citral-trans and citral-cis in cymbopogon flexuosus (lemongrass)

Use of [¹⁴C,³H]-labelled precursors revealed that leaf blades of Cymbopogon flexuosus converted geraniol (3,7-dimethylocta-trans-2,6-diene-1-ol) into citral-trans with loss of pro-(1S) hydrogen whereas nerol lost the pro-(1R) hydrogen while being converted into citral-cis. Secondly, the citral-trans is converted into citral-cis and vice versa and there is no separate route for the biosynthesis of either of the two aldehyde isomers.     

Biosynthetic relationship between tetrahydroanthracene and anthraquinone in Aloe saponaria

The incorporation of Me¹⁴COONa into aloesaponol I, laccaic acid D methyl ester and aloesaponarin I was demonstrated. The biosynthetic relation between aloesaponol I and aloesaponarin I was established, but incorporation of aloesaponol I into laccaic acid D methyl ester, or vice versa was not demonstrated and this result was confirmed by an investigation using labelled laccaic acid D methyl (¹⁴CH₃) ester. It was possible to show that aloesaponol I and laccaic acid D methyl ester were biosynthesized in parallel in Aloe saponaria.     

Bound forms of alkaloids in Papaver somniferum and P. Bracteatum

The polysaccharide fraction of the pericarp and seed of Papaver somniferum were shown to contain bound forms of morphine which were derived from radioactive morphine fed to living plants. Bound forms of codeine, thebaine and some unidentified alkaloid-like compounds were also detected in the pericarp and bound thebaine occurred in the pericarp of Papaver bracteatum. The complexity and molecular weight of the bound alkaloids seemed to increase during ripening, and it is suggested that these substances represent transitional forms in the metabolism and transiocation of morphine from latex to seed.     

Biosynthetic and metabolic activities of some organelles in Papaver somniferum latex

The biosynthesis of the five major alkaloids of the opium poppy (Papaver somniferum L. from radioactive dihydroxyphenylalanine has been studied in the 1000 g, 10 000 g, 100 000 g pellets and the 100 000 g supernatant fractions of the capsule latex. A normal poppy variety as well as one which produces only traces of alkaloids were used. Definite evidence of biosynthesis was obtained for both varieties but only in the 1 000 g pellet (as previously reported . None was found in the other fractions although electron microscopy showed that organelles, including vesicles, were present. The amounts of alkaloid biosynthesized however were very small relative to the amounts involved in the rapid changes already reported for the developing capsules. In contrast, all fractions of the latex were able to metabolize T-morphine in vitro, with the 100 000 g supernatant showing the highest activity and the amounts involved were also consistent with the changes found in the living plant.     

Morphinane alkaloids in cultured tissues and redifferentiated organs of Papaver somniferum

The capacity of alkaloid synthesis was examined in cultured tissues of Papaver somniferum. Callus, derived meristemoids, redifferentiated roots and     

Two cage-type lupin alkaloids from Sophora franchetiana

Two new cage-type lupin alkaloids, (?)-tsukushinamine-B and tsukushinamine-C, have been isolated from the fresh epigeal parts of Sophora franchetiana, along with (?)-cytisine, (?)-N-formylcytisine, (?)-rhombifoline, (?)-anagyrine, (?)-baptifoline and (±)-ammodendrine, as well as (?)-tsukushinamine-A. The structures of these novel tsukushinamine-type lupin alkaloids were determined by spectroscopic data and partly by a chemical reaction. Variations of the alkaloid contents in the seeds, seedlings and various parts of S. franchetiana were also examined.     

Biosynthesis of (2E,4E,6E)-5-acetoxymethyltetradeca-2,4,6-trienoic acid in Eremophila oppositifolia

Evidence is presented indicating that the triple conjugated branched chain fatty acid from Eremophila oppositifolia R.Br. arises by the acetate-malonate pathway with the side chain carbon atom originating from the S-methyl group of methionine.     

Biosynthesis of tropane ester alkaloids in Datura

Datura meteloides plants were fed via the roots with [1″,2′-¹⁴C]tigloyl hygroline and as a control, [2′-¹⁴C]hygrine. After a week the alkaloids were isolated and degraded. Despite hydrolysis of the putative precursor it was possible, by label ratio, to show that esterification occurs after, and not before, the tropane ring has been synthesized. Hygroline is proposed as a possible intermediate.     

Synthesis of [3-14C]-2′-methylreticuline and its incorporation into alkaloid fractions of Papaver somniferum

[3-¹⁴C]-2′-Methylreticuline has been synthesized by standard methods. This modified opium alkaloid precursor is efficiently incorporated by aberrant biosynthesis into alkaloid fractions of Papaver somniferum, particularly into a highly purified codeine fraction.     

Resolution and Synthesis of (S)-1-(2-Naphthyl)ethanol with Immobilized Pea Protein: As a New Biocatalyst

(S)-1-(2-Naphthyl)ethanol was yielded by immobilized pea (Pisum sativum L.) protein (IPP) from (R, S) 2-naphthyl ethanol (>99% ee, yield; about 50%), in which the (R)-enantiomer was selectively oxidized to 2-acetonaphthone. IPP could be reused consecutively at least three times without any decrease of yield and optical purity.     

Biosynthesis of radiolabelled alkaloids from 14C-tyrosine in Erythrina crista-galli

Alkaloid biosynthesis has been demonstrated in the young expanding tissues of Erythrina crista-galli shoots, the stem part of which elaborated, from [2-^14C]-tyrosine, alkaloid of specific radioactivity 2μuCi mmol^?1, 10-fold greater than previously reported.     

Morphinan alkaloids in Papaver bracteatum: Biosynthesis and fate

The known metabolic pathway for hydrophenanthrene alkaloids in Papaver somniferum has been examined for occurrence in P. bracteatum, a species reported to contain thebaine but no codeine or morphine. 1,2-Dehydro-reticulinium-[3-¹⁴C] chloride and (±)-reticuline-[3-¹⁴C] were fed to P. bracteatum plants and both were incorporated, the former into reticuline and thebaine and the latter into thebaine, suggesting that thebaine biosynthesis is the same in the two species. Studies of the natural abundance of morphinan alkaloids in P. bracteatum and the results from feeding codeinone-[16-³H] and codeine-[16-³H] indicate that this species can reduce codeinone to codeine but can not perform either of the demethylations to produce codeinone or morphine. Fed thebaine-[16-³H] was substantially metabolized but not by pathways that involved demethylations to either oripavine or northebaine.     

The role of (25S)-5α-cholestan-3β, 26-diol and (25S)-5α-furostan-3β,26-diol in the biosynthesis of tomatidine and neotigogenin

(25S)-5α-Cholestan-3β,26-diol was incorporated into neotigogenin and tomatidine, and (25S)-5α-furostan-3β,26-diol only in neotigogenin,     

Leishsmania (Leishmania) amazonensis infection: Muscular involvement in BALB/c and C3H.HeN mice

Recent studies have provided some insights into Leishsmania (Leishmania) amazonensis muscular infection in dogs, although, muscular disease due to leishmaniasis has been poorly documented. The aim of our study was to evaluate involvement of Leishmania in muscular infection of two distinct mouse strains (BALB/c and C3H.He), with different genetic backgrounds. BALB/c mice, susceptible to Leishmania infection, showed, at the beginning of infection, a great number of infected macrophages among muscle fibers; however, in C3H.He resistant mice, muscle fibers were less damaged than in BALB/c mice, but some parasitized macrophages could be seen among them. A follow up of the infection showed an intense inflammatory infiltrate mainly composed of infected macrophages in BALB/c muscles and the presence of amastigotes within muscle fibers; while C3H.He mice exhibited a moderate inflammatory infiltrate among skeletal muscle fibers and an absence of amastigotes. Total destruction of muscles was observed in BALB/c mice in the late phase of infection (day 90) while C3H.He mice showed a process of muscle repair. We concluded that: (1) the muscles of BALB/c mice were more affected by leishmaniasis than those of C3/H.He mice; (2) Leishmania amastigotes are capable of infecting muscular fibers, as observed in BALB/c mice; (3) as inflammatory infiltrate is less intense in C3H.He mice these animals are capable of restoring muscular fibers.     

Alkaloidal,lignan and phenolic constituents of Ephedra alata

In addition to the known p-coumaric acid, the furanofuran lignan (±)-syringaresinol and the digalloylglucose, nilocitin, were obtained from the whole plant of Ephedra alata. A new natural alkaloid, ephedralone, was also isolated. The structures were determined mostly by mass, ¹H and ¹³CNMR spectroscopy.     

New alkaloids from Tabernaemontana divaricata

A re-investigation of the root bark of Tabernaemontana divaricata resulted in the isolation of 18 compounds, viz. α-amyrin acetate, lupeol acetate, α-amyrin, lupeol, cycloartenol, β-sitosterol, campesterol, benzoic acid, aurantiamide acetate, coronaridine, coronaridine hydroxyindolenine (1), ibogamine, 5-hydroxy-6-oxocoronaridine (6), 5-oxocoronaridine (9), 6-oxocoronaridine (10), (±)-19-hydroxycoronaridine (11), 3-oxocoronaridine (12) and voacamine. The alkaloids 6, 9, 10 and 11 are new compounds, whereas cycloartenol, campesterol, ibogamine, benzoic acid, aurantiamide acetate and coronaridine hydroxyindolenine are reported from this plant for the first time.     

Inhibition of benzo(a)pyrene-induced carcinogenesis by vitamin C alone and by vitamin C/vitamin E and selenium/glutathione

The reduction on peroxidation caused by benzopyrenes by some naturally occurring antineoplastic agents was studied in this experimental work. Inhibition/reduction of experimental carcinogenesis induced by benzo(a)pyrene by vitamin C alone and by vitamin C/vitamin E and selenium/glutathione was attempted in 224 female Wistar rats divided in four groups. Injected with 10.08 mL benzo(a)pyrene, the animals were treated with some naturally occurring substances like vitamin C alone and a combination of anticarcinogens. By calculating the carcinogenic potency of benzo(a)pyrene and the anticarcinogenic potency of substances used as well as histological examination of developed tumors and survival time of treated animals, it was found that vitamin C exerts a significant anticarcinogenic effect of 8.3 units and that the combination of the two anticarcinogens used produced a significant prolongation of the animals survival time with anticarcinogenic potency of 22.1 and 22.2 units, respectively. This is considered a potent anticarcinogenic effect. The question of an additional supportive administration of such agents complementary to the conventional cancer chemotherapy in humans is raised. Of course, further studies are needed.