Labdane and Clerodane Diterpenoids from Colophospermum mopane.

Five labdane (1-5), an isolabdane (6), and five clerodane diterpenoids (7-11), were isolated from seeds, husks, and leaves of Colophospermum mopane. Compounds 1-3 and 6-9 are new, and their structures were elucidated by means of physical data analysis (1D and 2D NMR, HRESIMS). The absolute configurations of 1, 7, and 10 were determined by single-crystal X-ray diffraction with Cu Kα radiation. For compounds 2 and 6, the absolute configurations were established by the modified Mosher's method and corroborated by comparison of experimental and calculated electronic circular dichroism spectra of their 3-p-bromobenzoate derivatives. The crude extracts and compounds were evaluated for antimicrobial activity. The leaf extract was the most active against Staphylococcus aureus (125 µg/mL). Compound 11 showed the best inhibitory activity, with minimum inhibitory values of 15.6 µg/mL against Escherichia coli and Staphylococcus aureus and 31.3 µg/mL against Enterococcus faecalis.

7-substituted coumarins inhibit proliferation and migration of laryngeal cancer cells in vitro.

BACKGROUND: Coumarins are a large group of naturally-occurring compounds with a wide range of biological properties, including anticancer activity. 7-Substituted coumarins (umbelliferone, scoparone, and herniarin) were analyzed for their potential anticancer activity against laryngeal cancer cells (LCC). MATERIALS AND METHODS: High-performance counter-current chromatography was applied for successful separation of umbelliferone from fruits of Heracleum leskowii. A two-phase solvent system composed of n-heptane-methanol-ethyl acetate-water (1:2:1:2, v/v/v) was successfully used. Cell proliferation was assessed after 48-72 h by means of MTT test, and tumor cell motility by a wound assay model. Measurement of cell death was estimated using enzyme-linked immunosorbent assay (ELISA), and cell-cycle analysis was performed by flow cytometry. Extracellular signal-regulated kinases-1/2 (ERK1/2) and AKT kinase activation status were analyzed by western blotting. RESULTS: Umbelliferone, scoparone, and, to a lesser extent, herniarin reduced viability and migration of RK33 LCC in a dose-dependent manner. Scoparone and herniarin were found to induce apoptosis of LCC. None of the tested compounds influenced the ERK1/2 and AKT kinase activity, nor significantly affected cell-cycle progression in the LCC line studied. CONCLUSION: Our findings suggest the therapeutic potential of 7-substituted coumarins in the treatment of laryngeal cancer.

Antimicrobial activity of southern African medicinal plants with dermatological relevance: From an ethnopharmacological screening approach, to combination studies and the isolation of a bioactive compound.

ETHNOPHARMACOLOGICAL RELEVANCE: Ethnobotanical reports on more than 100 southern African medicinal plants with dermatological relevance have been highlighted, yet there is still limited scientific data to support claims for their antimicrobial effectiveness against skin pathogens. Guided by ethnobotanical data, this paper explores the antimicrobial efficacies of southern African medicinal plants used to treat skin ailments. AIM OF THE STUDY: To investigate the antimicrobial properties of southern African medicinal plants against dermatologically relevant pathogens. The study also aimed at providing a scientific rationale for the traditional use of plant combinations to treat skin diseases and the isolation of the bio-active compound from the most active species, Aristea ecklonii (Iridaceae). MATERIALS AND METHODS: Organic and aqueous extracts (132) were prepared from 47 plant species and screened for antimicrobial properties against dermatologically relevant pathogens using the micro-titre plate dilution method. Four different plant combinations were investigated for interactive properties and the sum of the fractional inhibitory concentration (Æ©FIC) calculated. Isobolograms were used to further investigate the antimicrobial interactive properties of Pentanisia prunelloides combined with Elephantorrhiza elephantina at varied ratios. A bioactivity-guided fractionation process was adopted to fractionate the organic leaf extract of Aristea ecklonii. RESULTS: Plants demonstrating notable broad-spectrum activities (MIC values ≤1.00mg/ml) against the tested pathogens included extracts from Aristea ecklonii, Chenopodium ambrosioides, Diospyros mespiliformis, Elephantorrhiza elephantina, Eucalyptus camaldulensis, Gunnera perpensa, Harpephyllum caffrum, Hypericum perforatum, Melianthus comosus, Terminalia sericea and Warburgia salutaris. The organic extract of Elephantorrhiza elephantina, a plant reportedly used to treat acne vulgaris, demonstrated noteworthy antimicrobial activity (MIC value of 0.05mg/ml) against Propionibacterium acnes. Similarly, Diospyros mespiliformis reported for its traditional use to treat ringworm, also displayed noteworthy antimicrobial activity against Trichophyton mentagrophytes (MIC 0.10mg/ml) and Microsporum canis (MIC 0.50mg/ml). The aqueous root extracts of Pentanisia prunelloides combined (1:1) with Elephantorrhiza elephantina displayed synergistic interactions (Æ©FIC values 0.31-0.38) against Staphylococcus aureus, gentamycin-methicillin resistant Staphylococcus aureus, Staphylococcus epidermidis and Candida albicans. Fractionation of Aristea ecklonii resulted in the isolation of the known bio-active compound, plumbagin, displaying noteworthy antimicrobial activity (MIC range between 2.00µg/ml and 16.00µg/ml). CONCLUSION: Most of the plant extracts demonstrated pathogen specific antimicrobial effects with a few exhibiting broad-spectrum activities. Positive antimicrobial effects noted for plants such as Elephantorrhiza elephantina and Diospyros mespiliformis used for acne vulgaris and ringworm infections, respectively, give some validation to their reported traditiona l uses. Synergistic interactions noted for Pentanisia prunelloides combined with Elephantorrhiza elephantina validate an enhanced antimicrobial effect when used in combination. Noteworthy antimicrobial activities (MIC range between 2.00µg/ml and 16.00µg/ml) were observed for plumbagin isolated from Aristea ecklonii.

Antioxidant compounds from Algerian Convolvulus tricolor (Convolvulaceae) seed husks.

Seed husk extracts of Convolvulus tricolor L. (Convolvulaceae) afforded six compounds, identified for the first time from this plant: isorhamnetin 3-O-beta-D-galactopyranoside (1), isorhamnetin 3-O-beta-D-(6"-acetyl)-galactopyranoside (2), isorhamnetin 3-O-robinobioside (3), 3,4-di-O-caffeoylquinic acid (4), gentisic acid 5-O-glucoside (5), and scopoletin (6). Separation of compounds was carried out by CC and CPC. Structural elucidations were performed by HPLC-UV-DAD, HPLC-ESI/MS (negative mode) and NMR.

Anti-inflammatory, antioxidant and antifungal activity of Chuquiraga spinosa.

CONTEXT: Stem and leaves infusion of Chuquiraga spinosa (R&P) Don. (Asteraceae) is used in the Peruvian traditional medicine for its anti-inflammatory properties and for the treatment of vaginal infections. OBJECTIVE: This study evaluated the antioxidant, anti-inflammatory and antifungal activities of C. spinosa for the first time. MATERIALS AND METHODS: Extracts of methanol, 50% methanol and water were obtained from C. spinosa aerial parts. Antioxidant activity of the extracts was evaluated (DPPH˙, ABTS˙(+) and superoxide radical-scavenging activity). The correlation between these results and total polyphenolic content was determined by Pearson's Correlation Coefficient. Anti-inflammatory activity of 50% methanol extract was evaluated with the rat model of carrageenan-induced acute inflammation and mouse model of TPA-induced acute inflammation. The antifungal activity of the extracts against Cladosporium cucumerinum and Candida albicans was studied by direct bioautography, and antifungal activity against phytopathogenic fungi was performed by culture in potato dextrose agar plates. RESULTS: All the extracts showed high antioxidant activity, and there was correlation between the activity and total polyphenolic compounds. As 50% methanol extract was administered orally, the paw edema in rats was reduced significantly (52.5%). This extract, by topical administration, produced a reduction of 88.07% of the edema TPA-induced in ear of mice. The aqueous and 50% methanol extracts were active against C. albicans (minimum inhibitory concentration of 2.5 and 6.25 µg, respectively). The aqueous extract showed antifungal activity against C. cucumerinum (MIC: 2.5 µg). DISCUSSION AND CONCLUSION: Preliminary phytochemical screening and the analysis of the three extracts by high-performance liquid chromatography diode-array detection showed the majority compounds are flavonoids and phenolic acid derivatives. These compounds may be responsible of the radical-scavenging activity of these extracts as well as responsible of anti-inflammatory effect in vivo of 50% methanol extract. Several authors have demonstrated the antioxidant and anti-inflammatory properties of some flavonoids and phenolic acids. The antifungal activity of the extracts obtained from aerial parts of C. spinosa has been investigated here for the first time. Other studies are necessary to determine the mechanism of action and to identify the bioactive compounds of this plant.

Natural products as a source of protein kinase activators and inhibitors.

Many of the protein kinase activators and inhibitors presently under investigation are natural products or are derivatives of natural products. Since over 500 kinases are encoded by the human genome, the task is to discover modulatory compounds which have high specificity for a single enzyme. Many different low molecular weight compounds have been studied for activity. These come from various sources, such as plants, marine organisms, microorganisms and cyanobacteria. The search for specific inhibitors is mainly performed in cell-based assays.

Effects of an n-butanol extract from the stem of Tinospora crispa on blood pressure and heart rate in anesthetized rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Tinospora crispa has been used in folkloric medicine for control of blood pressure, as an antipyretic, for cooling down the body temperature and for maintaining good health. AIM OF THE STUDY: To investigate the effects and mechanisms of action of an n-butanol extract from the stems of Tinospora crispa (T. crispa extract) on blood pressure and heart rate in anesthetized rats. MATERIALS AND METHODS: Air-dried stems of T. crispa were extracted with water, followed by partitioned extract with chloroform, ethyl acetate, and finally by n-butanol. The n-butanol soluble part was evaporated under reduced pressure and lyophilization to obtain a crude dried powder (T. crispa extract). The effects and mechanisms of the T. crispa extract on blood pressure and heart rate were studied in anesthetized normal and reserpinized rats in vivo in the presence of different antagonists. RESULTS: T. crispa extract (1-100 mg/kg, i.v.) caused a decrease in mean arterial blood pressure (MAP) and this effect was inhibited by propranolol, phentolamine, atenolol and/or the ß(2)-antagonist ICI-118,551, but not by atropine or hexamethonium. In reserpinized rats, the T. crispa extract had a dual effect: reduction in hypotensive activity, followed by a small increase in blood pressure. The decrease in MAP in reserpinized rat was slightly potentiated by phentolamine, but inhibited by propranolol or ICI-118,551 only if atenolol and phentolamine were also present. The increase in MAP was potentiated by propranolol and ICI-118,551, but was inhibited by phentolamine. The T. crispa extract had a dual effect on heart rate in the normal rat: a small transient decrease, followed by an increase in heart rate. The positive chronotropic effect of T. crispa extract was inhibited by propranolol, phentolamine and atenolol, but not by ICI-118,551, atropine or hexamethonium. Reserpine potentiated the positive chronotropic effect of the T. crispa extract and this effect was inhibited by propranolol, atenolol and ICI-118,551, but not by phentolamine. CONCLUSIONS: From these results we suggest that T. crispa extract possesses at least three different cardiovascular-active components that act directly via (1) ß(2)-adrenergic receptors to cause a decrease in blood pressure, and ß(1)- and ß(2)-adrenergic receptors to cause an increase in heart rate, (2) α-adrenergic receptors to cause an increase in blood pressure and heart rate, and (3) a non-adrenergic and non-cholinergic pathway to cause a decrease in MAP and heart rate. These findings provide scientific support for the tradition of using this plant to modify the actions of the human cardiovascular system.

Hypotensive activity of an n-butanol extract and their purified compounds from leaves of Phyllanthus acidus (L.) Skeels in rats.

We aimed to investigate the effects, identify the active substances and establish the mechanisms involved in the hypotensive activity of an n-butanol extract from leaves of Phyllanthus acidus (PA extract). PA extract caused a decrease in blood pressure of anesthetized rats that was not modified by atropine or propranolol. PA extract caused a persistent dilatation of thoracic aortic rings preconstricted with either phenylephrine or KCl, and these effects were not modified by LNA or removal of the vascular endothelium. For phenylephrine-preconstricted aortic rings, the dilatory activity of the PA extract was not modified by atropine, propranolol or indomethacin. TEA, glybenclamide or ODQ significantly inhibited the dilatory activity of the PA extract on endothelium-denuded aortic rings. Nifedipine or a Ca(2+)-free medium depressed the aortic rings constrictor response to phenylephrine, and that was further augmented by the PA extract. Adenosine, 4-hydroxybenzoic acid, caffeic acid, hypogallic acid, and kaempferol were isolated from the PA extract. Each caused a decrease in blood pressure and dilatation of the aortic rings. LNA or removal of the endothelium reduced this activity. ODQ and TEA attenuated the vasodilatory activity of adenosine whereas glybenclamide and ODQ attenuated the effect of hypogallic acid. These results suggest that the hypotensive activities of the PA extract is likely the result of the direct action of these five compounds on the blood vessels by stimulating release of nitric oxide from the vascular endothelium, in part through stimulation of soluble guanylate cyclase, and opening of K(ATP) and K(Ca) channels in the vascular smooth muscle.

Antioxidant and enzyme inhibition activities and chemical profiles of Polygonum sachalinensis F.Schmidt ex Maxim (Polygonaceae).

Polygonum sachalinensis is a widespread invasive plant in Europe. Chemical profiles of its different organs were studied by HPLC-UV-ESI/MS. Seven major constituents quercetin-3-O-beta-D-galactopyranoside, quercetin-3-O-arabinopyranoside, lapathoside D, N-trans-feruloyltyramine, lapathoside C, hydropiperoside, and vanicoside B were isolated and identified. The free radical-scavenging, alpha/beta-glucosidase, and acetylcholinesterase inhibitory activities of crude MeOH extracts and isolated compounds were studied. The structure-activity relationships were discussed. The chemical profiles revealed flavonoids and phenylpropanoids are the major compounds of all the organs of this plant. Quercetin-3-O-arabinopyranoside, lapathoside D, N-trans-feruloyltyramine, lapathoside C and hydropiperoside were isolated from this species for the first time. In the alpha-glucosidase bioassay, quercetin-3-O-beta-D-galactopyranoside, lapathoside D and N-trans-feruloyltyramine demonstrated stronger activities than the positive reference acarbose. The trend in scavenging power showed no relation to enzyme inhibition in the test models.

Two new tropane alkaloids from the bark of Erythroxylum vacciniifolium Mart. (Erythroxylaceae).

Two new tropane alkaloid N-oxides substituted by a methylpyrrole moiety were isolated from the bark of Erythroxylum vacciniifolium Mart. (Erythroxylaceae), a Brazilian indigenous plant, locally known as catuaba and used in traditional medicine as an aphrodisiac. The alkaloid structures were determined by a combination of high resolution mass spectrometry and multi-dimensional NMR spectroscopy.

Ellagic acid derivatives from Syzygium cumini stem bark: investigation of their antiplasmodial activity.

Bioguided fractionation of Syzygium cumini (Myrtaceae) bark decoction for antiplasmodial activity was performed, leading to the isolation of three known ellagic acid derivatives (ellagic acid, ellagic acid 4-O-alpha-L-2"-acetylrhamnopyranoside, 3-O-methylellagic acid 3'-O-alpha-L-rhamnopyranoside), as well as the new derivative 3-O-methylellagic acid 3'-O-beta-D-glucopyranoside. Activity investigation was based on the reduction of P. falciparum (PfK1) parasitaemia in vitro and the inhibition of beta-hematin formation, a known mechanism of action of some antimalarial drugs. Among the investigated ellagic acid derivatives, only ellagic acid was able to reduce P. falciparum parasitaemia in vitro and inhibit beta-hematin formation, suggesting that free hydroxyl groups are necessary for activity within this class of compounds.

How can phytochemists benefit from invasive plants?

The phenomenon of invasive alien species has become one of the greatest threats to the biological diversity of the planet, placing major constraints on development. In order to provide the tools needed to address this pervasive issue, the current knowledge on invasive species must be further developed with a cross-sectoral and multi-disciplinary approach. Recent theories of invasion propose that exotic plants probably produce secondary metabolites which can be allelopathic, anti-herbivore, anti-microbial and which are either unique or underrepresented in the plants' new range. This review attempts to attract the attention of phytochemists to study either the mechanisms of plant invasion or to use this widespread plant resource for humans.

A TLC bioautographic method for the detection of alpha- and beta-glucosidase inhibitors in plant extracts.

INTRODUCTION: Bioautographic assays using TLC play an important role in the search for active compounds from plants. A TLC assay has previously been established for the detection of beta-glucosidase inhibitors but not for alpha-glucosidase. Nonetheless, alpha-glucosidase inhibition is an important target for therapeutic agents against of type 2 diabetes and anti-viral infections. OBJECTIVE: To develop a TLC bioautographic method to detect alpha- and beta-glucosidase inhibitors in plant extracts. METHODOLOGY: The enzymes alpha- and beta-d-glucosidase were dissolved in sodium acetate buffer. After migration of the samples, the TLC plate was sprayed with enzyme solution and incubated at room temperature for 60 min in the case of alpha-d-glucosidase, and 37 degrees C for 20 min in the case of beta-d-glucosidase. For detection of the active enzyme, solutions of 2-naphthyl-alpha-D-glucopyranoside or 2-naphthyl-beta-D-glucopyranoside and Fast Blue Salt were mixed at a ratio of 1 : 1 (for alpha-d-glucosidase) or 1 : 4 (for beta-d-glucosidase) and sprayed onto the plate to give a purple background colouration after 2-5 min. RESULTS: Enzyme inhibitors were visualised as white spots on the TLC plates. Conduritol B epoxide inhibited alpha-d-glucosidase and beta-d-glucosidase down to 0.1 microg. Methanol extracts of Tussilago farfara and Urtica dioica after migration on TLC gave enzymatic inhibition when applied in amounts of 100 microg for alpha-glucosidase and 50 microg for beta-glucosidase. CONCLUSION: The screening test was able to detect inhibition of alpha- and beta-glucosidases by pure reference substances and by compounds present in complex matrices, such as plant extracts.

Rapid separation of three glucosylated resveratrol analogues from the invasive plant Polygonum cuspidatum by high-speed countercurrent chromatography.

Three glucosylated resveratrol analogues (piceid, piceatannol glucoside, resveratroloside) were successfully isolated from the crude MeOH extract of the invasive plant species Polygonum cuspidatum by semi-preparative high-speed countercurrent chromatography with a two-phase solvent system composed of cyclohexane-ethyl acetate-methanol-water (1:5:1:5, v/v/v/v). Piceid (23 mg), resveratroloside (17 mg), piceatannol glucoside (15 mg) of purities over 80% were isolated from 500 mg crude MeOH extract in one step. Subsequent passage over a SPE column was used to quickly bring their purities to over 90%. The purities were determined by HPLC analysis and their structures were elucidated by proton nuclear magnetic resonance ((1)H-NMR), HMBC, ESI-MS and HR-MS.

Natural product analysis over the last decades.

Progress in natural product chemistry has always been strongly linked to innovations in analytical technology. The characterisation of metabolites in complex mixtures requires sophisticated techniques, which should provide good sensitivity and selectivity as well as structural information on the constituents of interest. This review outlines the most important chromatographic and spectral techniques which have been introduced in the field of natural products. Although there has been a very rapid evolution of methods over the last 50 years, the introduction of high-throughput screening programmes require even more efficient and sensitive methodologies which yield adequate on-line information for metabolite structure determination.

Ultra-performance liquid chromatography/time-of-flight mass spectrometry as a chemotaxonomic tool for the analysis of Gentianaceae species.

INTRODUCTION: The segregation between the genera Gentiana and Gentianella among the Gentianaceae family is poorly defined. In order to clarify the classification of these genera, some researchers have tried to incorporate data about the chemical constitution, but this has not yet been achieved in a comprehensive way. OBJECTIVE: To develop a fast and reproducible analytical method for the observation of characteristic fingerprints of secondary metabolites of each genus. METHODOLOGY: Seven species were investigated, three Gentianella and four Gentiana selected for their close taxonomic links within each genus. Ten xanthones previously isolated from one of these species were used as chemotaxonomic markers. A UPLC/ESI-TOF-MS method was developed to analyse the methanolic extracts. RESULTS: The UPLC/TOF-MS provided clear metabolic fingerprints and elemental composition of the compounds. The profiles of the three Gentianella species were strikingly similar. On the contrary, metabolic profiles of Gentiana species were very different from the Gentianella chromatograms and also from each other. Several compounds were unique to each genus and therefore could be used as biomarkers. CONCLUSION: UPLC/TOF-MS can be applied as a chemotaxonomic tool for the rapid screening of Gentianaceae species and for the distinction between closely related taxa from the Gentianaceae family.

Monoamine oxidase inhibition by Rhodiola rosea L. roots.

AIM OF THE STUDY: Rhodiola rosea L. (Crassulaceae) is traditionally used in Eastern Europe and Asia to stimulate the nervous system, enhance physical and mental performance, treat fatigue, psychological stress and depression. In order to investigate the influence of Rhodiola rosea L. roots on mood disorders, three extracts were tested against monoamine oxidases (MAOs A and B) in a microtitre plate bioassay. MATERIALS AND METHODS: Methanol and water extracts gave the highest inhibitory activity against MAOs. Twelve compounds were then isolated by bioassay-guided fractionation using chromatographic methods. The structures were determined by 1H, 13C NMR and HR-MS. RESULTS: The methanol and water extracts exhibited respectively inhibitions of 92.5% and 84.3% on MAO A and 81.8% and 88.9% on MAO B, at a concentration of 100 microg/ml. The most active compound (rosiridin) presented an inhibition over 80% on MAO B at a concentration of 10(-5) M (pIC50=5.38+/-0.05). CONCLUSIONS: The present investigation demonstrates that Rhodiola rosea L. roots have potent anti-depressant activity by inhibiting MAO A and may also find application in the control of senile dementia by their inhibition of MAO B.

Preparative isolation of closely-related xanthones from Gentianella amarella ssp. acuta by High-speed countercurrent chromatography.

INTRODUCTION: A methanolic extract from Gentianella amarella ssp. acuta was shown to contain several xanthones exhibiting acetylcholinesterase inhibitory activity. These xanthones were difficult to separate by conventional LC techniques, which prevented the isolation of pure compounds in sufficient amounts to perform in-depth biological testing. OBJECTIVE: To develop a suitable preparative method for the separation of closely related xanthones. METHODOLOGY: The methanolic extract was first partitioned with solvents of increasing polarity, in order to separate glycosides from xanthone aglycones. High-speed countercurrent chromatography (HSCCC) methods were then optimised for the fractionation of both polar and non-polar extracts. RESULTS: The use of HSCCC enabled the separation of xanthones which co-eluted by HPLC. Ten closely related xanthones--three of which were isomeric--were successfully isolated by developing suitable solvent systems. All compounds were obtained in sufficient amounts to allow further biological assays (e.g. up to 250 mg), including even minor compounds that were not detectable by analytical HPLC. CONCLUSION: The orthogonality of HSCCC with HPLC and the absence of solid-phase supports enabled the detection, separation and preparative isolation of closely related compounds which were difficult to resolve by other techniques.

In vitro screening assays to identify natural or synthetic acetylcholinesterase inhibitors: thin layer chromatography versus microplate methods.

Acetylcholinesterase inhibitors (AChEI) are currently still the best available pharmacotherapy for Alzheimer patients. Successful screening for new AChEI relies on effective and fast assays. Two colorimetric screening assays frequently used to search for new AChEI, namely a thin layer chromatography (TLC) assay with Fast Blue B salt as reagent and a 96-well plate assay based on Ellman's method, were compared. For the majority (83%) of the 138 test compounds of natural and synthetic origin, the results obtained with the two assays converged and both screening assays were considered suitable for the generation of new hits. Fifteen percent of investigated compounds were classified as active with the microplate assay but were shown to be inactive by TLC and about 2% were measured active by TLC but showed to be inactive with the microplate assay. These divergences were not due to the main differences between the experimental protocols of the two screening assays, namely the different colorimetric methods and pre-incubation of test compounds with acetylcholinesterase (AChE). They might be explained by the interaction of either AChE or test compounds with the silica of the TLC plates, resulting in an altered affinity of the enzyme for the compounds.

Role of advances in chromatographic techniques in phytochemistry.

Chromatography is the lynchpin of phytochemistry and is the key to obtaining pure compounds for structure elucidation, for pharmacological testing or for development into therapeuticals. It also plays a fundamental role as an analytical technique for quality control and standardisation of phytotherapeuticals. Although liquid chromatography is barely 100 years old, an extraordinary variety of instrumental and ancillary equipment is available, notably in the domain of high-performance liquid chromatography. It is impossible to touch all areas of chromatography in such a review but certain areas are worthy of mention: HPLC, HPTLC, UPLC and countercurrent chromatography. Another important addition has been the development of hyphenated techniques involving HPLC: LC/UV, LC/MS, LC/MS(n) and LC/NMR. These are indispensable nowadays for the early detection and identification of compounds in crude plant extracts.