Profiling hydroxycinnamic acid glycosides, iridoid glycosides, and phenylethanoid glycosides in baobab fruit pulp (Adansonia digitata).

The baobab (Adansonia digitata L.) is a magnificent tree revered throughout Africa and is becoming recognized for its high nutritional and medicinal values. Despite numerous reports on the pharmacological potential, little is known about its chemical compositions.

5-HT2A/C receptors mediate the antipsychotic-like effects of alstonine.

The purpose of this study was to determine the effects of alstonine, an indole alkaloid with putative antipsychotic effects, on working memory by using the step-down inhibitory avoidance paradigm and MK801-induced working memory deficits in mice. Additionally, the role of serotonin 5-HT2A/C receptors in the effects of alstonine on mouse models associated with positive (MK801-induced hyperlocomotion), negative (MK801-induced social interaction deficit), and cognitive (MK801-induced working memory deficit) schizophrenia symptoms was examined. Treatment with alstonine was able to prevent MK801-induced working memory deficit, indicating its potential benefit for cognitive deficits now seen as a core symptom in the disease.

Stability of cough linctus (streptol) formulated from named medicinal plant extracts.

Extracts of named medicinal herbs (Garcinia kola, Zingiber oificinale, Aframonum melequeta and Ocimum viride) were formulated into an antitussive preparation to alleviate cough. Some physical properties of the cough syrup formulation evaluated were: specific gravity, pH, viscosity, content uniformity, and shelf life. The specific gravity and viscosity of the formulations were stable on storage, with glycerin-based formulations having higher values.

Alstonine as an antipsychotic: effects on brain amines and metabolic changes.

Managing schizophrenia has never been a trivial matter. Furthermore, while classical antipsychotics induce extrapyramidal side effects and hyperprolactinaemia, atypical antipsychotics lead to diabetes, hyperlipidaemia, and weight gain. Moreover, even with newer drugs, a sizable proportion of patients do not show significant improvement.

The putative antipsychotic alstonine reverses social interaction withdrawal in mice.

Negative symptoms of schizophrenia are particularly problematic due to their deleterious impact on a patient's social life. The indol alkaloid alstonine, the major component of traditional remedies used for treating mental illnesses in Nigeria, presents a clear antipsychotic-like profile in mice, as well as anxiolytic properties. Considering that social interaction is the core of negative symptoms, and that anxiolytic drugs can improve social interaction behavior, the aim of this study was to evaluate the effects of alstonine in the social interaction and MK801-induced social withdrawal models in mice.

Antimicrobial principle from Aframomum longifolius.

Antimicrobial activity-directed fractionation of the seeds of Aframomum longifolius (Zingiberaceae) afforded two new labdane-type diterpenoids, 15-hydroxy-15-methoxylabda-8(17), 12( E)-dien-16-al (aframolin A) ( 1) and 8beta(17)-epoxy-15,15-dimethoxylabd-12( E)-en-16-al (aframolin B) ( 2), together with the known diterpenes labda-8(17),12( E)-diene-15,16-dial ( 3) and aframodial ( 4). Their structures were determined by spectroscopic methods. Compound 4 showed significant antimicrobial activity against Cryptococcus neoformans, Staphylococcus aureus and methicillin-resistant S.

Novel antimicrobial diterpenoids from Turraeanthus africanus.

The dichloromethane-methanol (1/1) extract of the stem bark of Turraeanthus africanus (Meliaceae) showed remarkable antimicrobial activity against Cryptococcus neoformans, Staphylococcus aureus and methicillin-resistant S. aureus. Phytochemical investigation of this extract afforded six new diterpenoid derivatives, (+)-16-acetoxy-12,15-epoxylabda-8(17),12,14-triene ( 3), [16( E),12 S,15 R]-16-acetoxy-12,15-epoxy-15-isopropoxy- ent-labda-8(17),13(16)-diene (turraeanin A, 4), [16( E),12 R,15 S]-16-acetoxy-12,15-epoxy-15-isopropoxy- ent-labda-8(17),13(16)-diene (turraeanin B, 5), [16( E),12 S,15 R]-16-acetoxy-12,15-epoxy-15-methoxy- ent-labda-8(17),13(16)-diene (turraeanin C, 6), [16( E),12 R,15 S]-16-acetoxy-12,15-epoxy-15-methoxy- ent-labda-8(17),13(16)-diene (turraeanin D, 7) and (12 S,13 S,15 R)-12,15-epoxy-15-methoxy- ent-labd-8(17)-en-16-al (turraeanin E, 9) together with the known compounds, 15,16-epoxy- ent-labda-8(17),13(16),14-triene ( 1), (+)-pumiloxide ( 2), ent-labda-8(17),12 ( E)-diene-15,16-dial ( 8) and 16-acetoxy-12( R),15-epoxy-15beta-hydroxylabda-8(17),13 (16)-diene ( 10).

Tabouensinium chloride, a novel quaternary pyranoquinoline alkaloid from Araliopsis tabouensis.

A novel pyranoquinoline alkaloid 3,4-dihydro-3-hydroxy-5-methoxy-2,2,10-trimethylpyrano [2,3-b]quinoline named tabouensinium chloride (1), was isolated from the stem bark of Araliopsis tabouensis along with twelve known quinoline alkaloids. In addition, the known flindisol, lupeol and beta-sitosterol glucoside were also identified. Their structures were deduced from spectral data.

Lack of pro-convulsant activity of the antipsychotic alkaloid alstonine.

Psychiatry co-morbidity with epilepsy is common and often requires the combined use of psychotropic and antiepileptic drugs (AEDs). For schizophrenic patients, the occurrence of seizures with atypical agents is highest among antipsychotics, although these agents are more effective in alleviating symptoms (including negative symptoms) and are associated with fewer extrapiramidal effects. The indol alkaloid alstonine is the major component of plants used by traditional Nigerian psychiatrists as anti-dementia drugs.

Antiplasmodial agents from the leaves of Glossocalyx brevipes.

A phytochemical study of the methylene chloride/methanol (1/1) extract of the leaves of Glossocalyx brevipes Benth. (Monimiaceae) afforded three new derivatives of homogentisic acid, methyl 2-(1'beta-geranyl-5'beta-hydroxy-2'-oxocyclohex-3'-enyl)acetate (1), 2-(1'beta-geranyl-5'beta-hydroxy-2'-oxocyclohex-3'-enyl)acetic acid (2), methyl 2-(1'beta-geranyl-5'beta-hydroxy-4'beta-methoxy-2'-oxocyclohexyl)acetate (3), and two known alkaloids, aristololactam BII and liriodenine. Compounds 1 and 2 and liriodenine showed modest in vitro activity against Plasmodium falciparum.

Anxiolytic properties of the antipsychotic alkaloid alstonine.

Anxiolytic properties may be a crucial feature of newer antipsychotics associated with the improvement of negative symptoms in schizophrenic patients. The indole alkaloid alstonine acts as an atypical antipsychotic in behavioral models, but differs in its dopamine and serotonin binding profile. The purpose of this study was to verify if alstonine possesses anxiolytic properties in mice.

Constituents of Peucedanum zenkeri seeds and their antimicrobial effects.

The methanol extract of Peucedanum zenkeri L. seeds showed antimicrobial activity which is concentrated in the n-hexane fraction. Bioactivity-guided chromatographic fractionation of the seeds of P.

Trypanocidal diarylheptanoids from Aframomum letestuianum.

Three new diarylheptanoids, (4Z,6E)-5-hydroxy-1-(4-hydroxy-3-methoxyphenyl)-7-(4-hydroxyphenyl)hepta-4,6-dien-3-one, letestuianin A (1), (4Z,6E)-5-hydroxy-1,7-bis(4-hydroxy-3-methoxyphenyl)hepta-4,6-dien-3-one, letestuianin B (2), and 1,7-bis(4-hydroxyphenyl)heptan-3,5-dione, letestuianin C (3), as well as the known (4Z,6E)-5-hydroxy-1,7-bis(4-hydroxyphenyl)hepta-4,6-dien-3-one (5) were isolated from Aframomum letestuianum. The known flavonoids 3-acetoxy-5,7,4'-trihydroxyflavanone, 3-acetoxy-7-methoxy-5,4'-dihydroxyflavanone, 7-methoxy-3,5,4'-trihydroxyflavone, and 3,3',4',5,7-pentahydroxyflavan were also obtained from this plant. Their structures were determined using a combination of 1D and 2D NMR techniques.

Capillary electrophoresis determination of biflavanones from Garcinia kola in three traditional African medicinal formulations.

A rapid capillary electrophoresis (CE) method for the quantification of four biologically active biflavanones present in three different traditional African medicinal preparations from the seeds of Garcinia kola was developed. The four biflavanones of interest (GB1, GB2 and GB1-glycoside and kolaflavanone) were quantified in a traditional tea preparation, and two commercially available ethanolic formulations. The optimum separation conditions consisted of a 100 mM borate, pH 9.

Novel antihyperglycemic terpenoid-quinones from Pycnanthus angolensis.

Two new compounds, pycnanthuquinone A (1) and pycnanthuquinone B (2), were isolated from leaves and stems of the African plant, Pycnanthus angolensis (Welw.) Warb (Myristicaceae), by bioassay-guided fractionation of an ethanolic extract using a diabetic mouse model. Pycnanthuquinones A and B are the first representatives of a novel terpenoid-type quinone skeleton, and both compounds possess significant antihyperglycemic activity.

Anti-plasmodial sesquiterpenoids from the African Reneilmia cincinnata.

A new isodaucane sesquiterpenoid, 6,7,10-trihydoxyisodaucane, was isolated from the fruits of Reneilmia cincinnata, together with the known sesquiterpenoids oplodiol, oplopanone, 5E,10(14)-germacradien-1 beta, 4 beta-diol, 1(10)E,5E-germacradien-4 alpha-ol and eudesman-1,4,7-triol. A large amount of 5-hydroxy-3,7,4'-trimethoxyflavone was also isolated. Their structures were established by NMR techniques using 1D and 2D experiments.

Antipsychotic profile of alstonine: ethnopharmacology of a traditional Nigerian botanical remedy.

Although recently developed drugs have brought significant improvement, the treatment of psychotic disorders still presents serious drawbacks. Since inherent complexity and lack of satisfactory understanding of the underlying pathophysiology impose limits for rational drug design, resourceful approaches in the search for antipsychotics are pertinent. This paper reports pharmacological properties of alstonine, a heteroyohimbine type alkaloid, which exhibited an antipsychotic-like profile, inhibiting amphetamine-induced lethality, apomorphine-induced stereotypy and potentiating barbiturate-induced sleeping time.

Biodiversity prospecting in Nigeria: seeking equity and reciprocity in intellectual property rights through partnership arrangements and capacity building.

The regulation of genetic materials in Nigeria for the isolation of biologically active compounds and/or their exportation from the country fall under the purview of several government departments and parastatals. In principle, biological resources are considered similar to any other natural resource with different levels of stake holders. Specific restrictions, however, apply to the export of food crops.

Biological activity of saponins from two Dracaena species.

Many species of the west African "soap tree" Dracaena are used in traditional medicine for the treatment of a variety of diseases. In continuation of our search for anti-infective agents from plants implicated in traditional medicine, we evaluated the biological activities of saponins from extracts of Dracaena mannii and Dracaena arborea by using a battery of test systems such as radiorespirometry, Cytosensor bioautography, and agar dilution methods and molluscicidal tests. Bioassay-directed fractionation of the methanol extracts of seed pulp using a combination of chromatographic techniques, gel filtration, droplet countercurrent chromatography (DCCC), and low-pressure liquid chromatography (Lobar), led to the isolation and characterization of spiroconazole A, a pennogenin triglycoside [3 beta-O-[(alpha-L-rhamnopyranosyl(1-->2), alpha-L-rhamnopyranosyl(1-->3)-beta-D-glucopyranosyl]-17 alpha-hydroxyl-spirost-5-ene] (Fig.

Natural product drug discovery and development: new perspectives on international collaboration.

Until recently, the prevailing attitude in developed nations regarded the world's genetic resources, which are mainly concentrated in the developing world, as a common resource of humankind, to be exploited freely irrespective of national origin. With the devastation being wreaked in the tropical rainforests and the resurgence in interest in recent years in the discovery of novel drugs from natural sources, particularly plants and marine organisms, the international scientific community has realized that the conservation of these global genetic resources and the indigenous knowledge associated with their use are of primary importance if their potential is to be fully explored. With this realization has come a recognition that these goals must be achieved through collaboration with, and fair and equitable compensation of, the scientists and communities of the genetically rich source countries.

Medicinal plants in the fight against leishmaniasis.

Despite the tremendous progress mode in the understanding o f the molecular biology of Leishmania and the clinical possibilities presented by some experimental chemotherapeutic agents, no new drugs have been developed for the treatment of leishmaniasis since the introduction of the pentovalent antimoniols more than 50 years ago. As reviewed here by Maurice M. Iwu, Joan E.

African medicinal plants in the search for new drugs based on ethnobotanical leads.

In the African world view the natural environment is a living entity whose components are intrinsically bound to mankind. Dietary plants, spices and common herbs dominate the materia medica, in contrast with modern orthodox medicine which uses many regulated poisons. Drug development based on ethnobotanical leads has followed two paths: the classical approach of identification of single plant species with biologically active compounds and the characterization and standardization of traditional recipes for reformulation as medicines.

Evaluation of plant extracts for antileishmanial activity using a mechanism-based radiorespirometric microtechnique (RAM).

Extracts of eleven plants used in Nigerian traditional medicine have been evaluated for possible antileishmanial activity using a radiorespirometric microtest technique based on in vitro inhibition of catabolism of 14CO2 from a battery of 14C-substrates by promastigotes. Of 13 methanol extracts tested, 5 from Gongronema latifolia, Dorstenia multiradiata, Picralima nitida, Cola attiensis, and Desmodium gangeticum, were active at concentrations of 50 micrograms/ml or less against a visceral Leishmania isolate.