Heikki Vuorela

• PhD Pharm
• Professor at University of Helsinki

Mentha spp. are used in the food and pharmaceutical industry; the plants are characterized by natural interspecies hybridization. In this study, knowledge of the chemical composition of Mentha spp. was broadened by focusing on plants grown in a geographically small region of Estonia. The antibacterial activity of Mentha spp. essential oils and wate...

Mint flavorings are widely used in confections, beverages, and dairy products. For the first time, mint flavoring composition of mint candies and food supplements (n = 45), originating from 16 countries, as well as their antibacterial properties, was analyzed. The flavorings were isolated by Marcussonʼs type micro-apparatus and analyzed by GC-MS. T...

Ethnopharmacological relevance: Aqueous autolysate from the snake Eryx miliaris (SNA) has been used in traditional medicine of Uzbekistan as anti-inflammatory, hepatoprotective and immunomodulatory agent. However, little is known about the chemical composition and its mechanisms of activity. Aim of the study: This is our first attempt to analyse...

Microbial resistance to currently available antibiotics is a public health problem in the fight against infectious diseases. Most antibiotics are characterized by numerous side effects that may be harmful to normal body cells. To improve the efficacy of these antibiotics and to find an alternative way to minimize the adverse effects associated with...

Piper guineense is a food and medicinal plant commonly used to treat infectious diseases in West-African traditional medicine. In a bid to identify new antibacterial compounds due to bacterial resistance to antibiotics, twelve extracts of P. guineense fruits and leaves, obtained by sequential extraction, as well as the piperine and piperlongumine c...

Ethnobotanical relevance: Piper guineense occurs commonly in West Africa where it is used for fungal infections instead of the costly and not always accessible conventional antifungals. Fungal, yeast-based diseases are common in West-Africa especially among those living with HIV/AIDS, and thus this study was performed in Imo state, South-Eastern Ni...

In this study, a thin-layer chromatography (TLC) and a high performance liquid chromatographic (HPLC) methods were developed for the chemical profiling, qualitative and quantitative analysis of P. guineense extracts. To obtain a chromatogram with satisfactory resolution and favorable retention time, DryLab software was used to simulate and optimize...

This article reviews new discoveries related to the phytochemistry and biological activities of bioactive compounds from Piper species. It outlines the anticancer, anti-parasitic, and antimicrobial activities of Piper species in relation to drug discovery. The use of bioactive compounds from medicinal plants as therapeutic agents has been an import...

Desorption atmospheric pressure photoionization (DAPPI) is an ambient mass spectrometry (MS) technique that can be used for the analysis of polar and nonpolar compounds directly from surfaces. Here, the feasibility of DAPPI-MS in the screening of plant metabolites from dried Peucedanum palustre leaves and umbels was studied. DAPPI-MS requires no pr...

Article in print

The coumarin composition of Peucedanum palustre (L.) Moench populations growing in Finland was investigated. 132 flowering P. palustre specimens from 43 locations in southern and central Finland were collected, divided into root, stem, leaf and umbel samples, and analyzed by HPLC. HPLC coupled to high-resolution mass spectrometry was used to aid th...

Context: Identification of bioactive components from complex natural product extracts can be a tedious process that aggravates the use of natural products in drug discovery campaigns. Objective: This study presents a new approach for screening antimicrobial potential of natural product extracts by employing a bioreporter assay amenable to HPLC-b...

Rhazya stricta Decne. (Apocynaceae) contains a large number of terpenoid indole alkaloids (TIAs). This study focused on the composition of alkaloids obtained from transformed hairy root cultures of R. stricta employing ultra-performance liquid chromatography-mass spectrometry (UPLC-MS). In the UPLC-MS analyses, a total of 20 TIAs were identified fr...

The qualitative and quantitative composition of isolated mint flavour distillates in 45 commercially available mint flavoured candies, chocolates and food supplements were studied using GC-MS. The yields of flavour distillates varied from 11.2 to 847.2 mg/100 g. The most abundant flavour compounds were limonene, menthone, menthol, menthofuran, isom...

Combretum psidioides and C. fragrans are used as decoctions for diarrhea and wounds in African traditional medicine [1]. In Nigeria, C. fragrans is used for the treatment of Blackleg disease in cattle among Fulani pastoralists. There exists no research on antibacterial compounds of these species but some phytochemical investigations have been perfo...

Piper guineense Schumach is a medicinal plant that contains piperine as its major bioactive compound. Piperine alkaloid has antidepressant like properties [1]. The analysis of piperine is usually performed by thin layer chromatography (TLC), a method widely used in the analysis of bioactive compounds for drug discovery. However, the TLC method used...

Anogeissus leiocarpus occurs in savannas in tropical and subtropical regions of Africa and is used among traditional medicinal practitioners for treatment of various diseases, among them bacterial infections [1]. Eight flavonoids [2], methyl ellagic acid, ellagic acid [4, 5] and the ellagitannins castalagin and flagallonic acid [6] have been report...

Terminalia laxiflora Engl & Diels. is used as decoctions against bacterial infections and their symptoms such as cough and diarrhea [1]. Stem wood fumigations are used against malaria parasite, venereal diseases and skin disorders [2,3,4]. Previous research demonstrated in vitro anti-acne properties of stem wood of T. laxiflora and agrees with the...

Key message: Transgenic hairy roots of R. stricta were developed for investigation of alkaloid accumulations. The contents of five identified alkaloids, including serpentine as a new compound, increased compared to non-transformed roots. Rhazya stricta Decne. is a rich source of pharmacologically active terpenoid indole alkaloids (TIAs). In order...

Use of DryLab for high-performance liquid chromatographic method optimization of a Piper guineense extract. Eunice Ego Mgbeahuruike, Heikki Vuorela and Teijo Yrjönen University of Helsinki, Faculty of Pharmacy, Division of Pharmaceutical Biosciences, P.O. Box 56, FI-00014 University of Helsinki, Finland. eunice.mgbeahuruike@helsinki.fi Piperine, a...

Rhazya stricta Decne. (Apocynaceae) is a medicinal plant rich in terpenoid indole alkaloids (TIAs), some of which possess important pharmacological properties. The study material including transgenic hairy root cultures have been developed and their potential for alkaloid production are being investigated. In this study, a comprehensive GC-MS metho...

The purpose of this study was to investigate the effect and selectivity of an extract of Schisandra chinensis berries against Chlamydia pneumoniae and C. trachomatis. Among the ethnopharmacological uses of the extract from Schisandrae fructus are cough and pneumonia. Therefore we focused on respiratory pathogens. The extract completely inhibited th...

Lignans from Schisandra chinensis berries show various pharmacological activities, of which their antioxidative and cytoprotective properties are among the most studied ones. Here, the first report on antibacterial properties of six dibenzocyclooctadiene lignans found in Schisandra spp. is presented. The activity was shown on two related intracellu...

Cytokines are messenger proteins that regulate the proliferation and differentiation of cells and control immune responses. Interferons, interleukins, and growth factors have applications in cancer, autoimmune, and viral disease treatment. The cytokines are susceptible to chemical and physical instability. This article reviews the structure and sta...

Naphthoquinones and anthraquinones are a well-studied class of molecules that play a role in preventing and treating various illnesses. A thorough literature search shows that these molecules are potent antifungal, anticancer, antidiabetes, and neuroprotective agents. In addition to their beneficial properties, naphtho- and anthraquinones have toxi...

Biodiversity in the seas is only partly explored, although marine organisms are excellent sources for many industrial products. Through close co-operation between industrial and academic partners, it is possible to successfully collect, isolate and classify marine organisms, such as bacteria, fungi, micro- and macroalgae, cyanobacteria, and marine...

Corn mint ( Mentha arvensis ) provides a good source of natural phenols such as flavone glycosides and caffeic acid derivatives, which may have prophylactic properties against inflammations. This study investigated whether corn mint extract would be beneficial against a universal respiratory tract pathogen, Chlamydia pneumoniae , infection. The ext...

Besides small molecules from medicinal chemistry, natural products are still major sources of innovative therapeutic agents for various conditions, including infectious diseases. Here we present the first attempt to design a combination treatment targeted against Chlamydia pneumoniae infection using coadministration of natural phenolics with calciu...

Unlabelled: Thymoquinone (TQ), an active component of Nigella sativa L., is known to have anti-cancer and anti-inflammatory effects; however, no studies on its analytical detection in serum and its protein binding have been published. Using high performance liquid chromatography analysis, we show that the average recovery of TQ from serum is 2.5%...

Quinones are a class of natural and synthetic compounds that have several beneficial effects. Quinones are electron carriers playing a role in photosynthesis. As vitamins, they represent a class of molecules preventing and treating several illnesses such as osteoporosis and cardiovascular diseases. Quinones, by their antioxidant activity, improve g...

Thymoquinone (TQ), an active component of Nigella sativa L., is known to have anti-cancer and anti-inflammatory effects; however, no studies on its analytical detection in serum and its protein binding have been published. Using high performance liquid chromatography analysis, we show that the average recovery of TQ from serum is 2.5% at 10 μg/ml o...

Background and Aims: Much data is reported for the promising anticancer activity of Thymoquinone (TQ), an active component of Nigella sativa L. (Ranunculaceae). However, no analytical methods have been reported for its quantification from blood or serum. The aims of this study are: 1) to develop a method for the isolation and detection of TQ from s...

Sesquiterpene lactones (SLs) are plant-derived compounds often used in traditional medicine against inflammation and cancer. This review focuses on the chemical and biological properties of SLs that lead to enhanced anticancer and anti-inflammatory effects. The chemical properties comprise alkylating center reactivity, lipophilicity, and molecular...

Thymoquinone (TQ), a component of black seed essential oil, is known to induce apoptotic cell death and oxidative stress, however, the direct involvement of oxidants in TQ-induced cell death has not been established yet. Here, we show that TQ inhibited the proliferation of a panel of human colon cancer cells (Caco-2, HCT-116, LoVo, DLD-1 and HT-29)...

Thymoquinone (TQ), a component of black seed essential oil, is known to induce apoptotic cell death and oxidative stress, however, the direct involvement of oxidants in TQ-induced cell death has not been established yet. Here, we show that TQ inhibited the proliferation of a panel of human colon cancer cells (Caco-2, HCT-116, LoVo, DLD-1 and HT-29)...

Crystal morphology engineering of a macrolide antibiotic, erythromycin A dihydrate, was investigated as a tool for tailoring tabletting performance of pharmaceutical solids. Crystal habit modification was induced by using a common pharmaceutical excipient, hydroxypropyl cellulose, as an additive during crystallization from solution. Observed morpho...

Crystallization in the presence of pharmaceutically accepted excipients as additives was investigated as a tool for morphological crystal engineering of active pharmaceutical ingredients. Recrystallization of a model drug substance, erythromycin A dihydrate, was carried out by a precipitation technique in the presence of varying amount of hydroxypr...

Interactions between widely used anthranoid laxatives and other simultaneously administered drugs are not known. In this paper, the influence of rhein, danthron, sennidins A/B, sennosides A/B, and senna leaf infusion was investigated on the permeability of furosemide, ketoprofen, paracetamol, propranolol, verapamil, digoxin, and Rhodamine 123 acros...

A mathematical computer-aided model CELLOP was constructed in which the desirability functions in a three-dimensional experimental design can be used to find the optimal growing conditions for plant cells. CELLOP is intended for the optimisation of 3 to 6 physical, chemical, or biological variables in the cultivation conditions of plant cell cultur...

A comparison of the UV spectra of twenty seven pure coumarins was carried out using TLC-densitometer, spectrophotometer and high performance liquid chromatography (HPLC) with photodiode array detector (DAD). The data obtained from TLC-densitometer and HPLC in reference to those of the spectrophotometer showed that the dependencies were statisticall...

Methanolic extracts (25 microug/ml) of species belonging to the genera of Combretum, Terminalia and Pteleopsis, collected during a field expedition in Tanzania in 1999, were screened for their antiproliferative and cytotoxic effects against three human cancer cell lines (HeLa, cervical carcinoma; T 24, bladder carcinoma; and MCF 7, breast carcinoma...

Polymeric procyanidins, phenolic carboxylic acids and flavonoids of hawthorn (Crataegus laevigata) were fractionated prior to HPLC analysis using column chromatography and solid-phase extraction (SPE). The flavonoid fraction also contained (-)-epicatechin. The three groups of phenolics, each with clearly different UV spectra, were examined by means...

The computer-assisted simulation program DryLab has been used to simulate TLC separations. The simulations were based on data from preliminary TLC separations. For DryLab data entry R-F values from TLC were converted to retention times, the development distance on the plate was used as column length, and the plate thickness was used as the column d...

Chlamydial infections are very common worldwide. All chlamydial species have a tendency to cause persistent infections, which have been associated to several chronic diseases including blinding trachoma, infertility and coronary heart disease (CHD). At present, no efficient treatment for the eradication of chronic chlamydial infections exists and,...

Increasing evidence suggests that plant polyphenolic compounds may protect from cardiovascular diseases, which have been addressed to their antioxidative properties. In addition, these compounds have been shown to possess anti-inflammatory and anti-microbial potential. In the present study we tested the effects of two flavonoid compounds, quercetin...

During long-term storage, Scots pine ( Pinus sylvestris L.) seeds are susceptible to ageing, leading to declined vigour and poor germinability. To characterize biochemical changes associated with this ageing, vitamin E and fatty acid compositions of Scots pine seeds stored for 3–31 years were analysed. The seeds contained seven homologues of the vi...

Rapeseed, raspberry, and pine bark are promising bioactive sources of plant phenolics selected from among ca. 100 previously screened plant materials for in vitro preclinical evaluation of health related effects. Phenolic extracts and isolated fractions of the selected materials were investigated for antioxidant, antimicrobial, antiinflammatory, an...

The potential of microcristaline cellulose as sorbent in the separation of eight compounds: (+)-catechin (C), (-)-epicatechin (EC), (-)-gallocatechin (GC), (-)-epigallocatechin (EGC), (-)-epicatechin gallate (ECg), (-)-epigallocatechin gallate (EGCg), procyanidin B1 and procyanidin B2 was studied. Cellulose HPTLC plates prewashed in water (not nece...

An efficient off‐line procedure for primary screening of the bioactivity of a complex mixture was developed. The procedure includes HPLC separation, micro‐fractionation, and a bioactivity assay followed by scale up of preparative isolation of active substances. Test compounds were used to develop and validate a chemical assay based on a stable free...

Extracts made from berries, herbs, and various plant materials, which might possess a range of activities, are used as health promoting products. Because little is known about their effects on the absorption of co-administered drugs, the effects of some food supplements, Finnish berries, and herbs were studied on the permeability of some commonly u...

High performance liquid chromatography (HPLC) micro-fractionation was successfully coupled to an automated 45Ca2+ uptake assay using GH4C1 cells for the separation of natural product extracts and for the primary detection of their calcium antagonistic components. The reliability of the procedure was first established with a reference solution consi...

Thirty-five crude extracts of 5 species of Terminalia, 10 species of Combretum (Loefl.) and Pteleopsis myrtifolia (Laws.) Engl. & Diels. collected in Tanzania were investigated for their antifungal activity against 5 species of Candida and Cryptococcus neoformans. An agar diffusion method was used for the antifungal screening, and species of Termin...

Natural derived or originated compounds still play a major role as drugs, and as lead structures for the development of synthetic molecules. About 50% of the drugs introduced to the market during the last 20 years are derived directly or indirectly from small biogenic molecules. In the future, natural products will continue to play a major role as...

Biomembrane interactions of flavonoids and alkyl gallates were investigated using transport studies on Caco-2 cells and membrane affinity experiments in phospholipid vesicles. Flavone was rapidly absorbed across the cell monolayer (P(app),380 x 10(-6) cm/s), whereas efficient uptake but no apical to basolateral transport was observed with the flavo...

A reversed-phase HPLC method with atmospheric pressure chemical ionisation MS detection has been developed for the separation and identification of coumarins in plants of Peucedanum palustre L. (Moench) and Angelica archangelica (L.) var. archangelica. The Turbo Method Development program was utilised to optimise the mobile phase with two organic s...

The multifunctional ExtraChrom instrument was used in the extraction of antimicrobial and radical scavenging components from oak (Quercus robur L.) bark. Milled and sieved oak bark was extracted with 80% (v/v) methanol solution in water on the ExtraChrom instrument using step-gradient in the preparative separation. Extracts were tested using agar d...

A near infrared (NIR) quantitative analysis method was developed for determining the thickness of PVC-based plastic sheets used as pharmaceutical packs. Samples that can be analyzed are transparent films made of polyvinyl chloride (PVC), PVC coated with polyvinylidene dichloride (PVDC) or PVC coated with Thermoelast (TE) and PVDC. The method, based...

The effect of three operating variables on the extraction efficiency of medium pressure solid–liquid extraction (MPSLE) was studied using a factorial experimental design with three levels. The operating variables tested were medium particle size of the plant material, volume of extractant, and the equilibrium time between consecutive extractions of...

The purpose of this research was to study the effect of two process parameters (temperature and moisture content) on dehydration behavior of different materials using a novel multichamber microscale fluid bed dryer with a process air control unit and in-line near-infrared (NIR) spectroscopy. The materials studied were disodium hydrogen phosphates w...

The volatile compound profiles of 11 Scots pine (Pinus sylvestris L.) seed lots were determined by solid phase microextraction combined with GC–MS analysis. Typical monoterpene constituents of pine volatile oils were identified, and total monoterpene content of these seeds was measured semi-quantitatively as peak area. Considerable variation in monot...

The versatile novel instrument for rotation planar extraction and rotation planar chromatography was exploited for the investigation of oak bark (Quercus robur L.). The same instrument enabled extraction of the bark, analytical proof of (+)-catechin directly in the crude extract and also its fractionation. Additionally, epimeric flavan-3-ols, (+)-c...

A spontaneously embryogenic cell line of the coumarin producing angelica [Angelica archangelica (L.) subsp. archangelica] was established via callus formation from seedlings grown from sterilized seeds on semi-solid, hormone-free modified B5 medium. The cell line has retained its embryogenic capacity for 5 years. The highest coumarin production for...

A near-infrared spectroscopic method was developed and validated for determining the caffeine concentration of single and intact tablets in a Finnish pharmaceutical product containing 58.82% (m/m) caffeine.The spectral region of interest contained a total of 474 data points. The second derivative of Savitsky-Golay, a standard normal variate, and me...

Extraction of onion (Allium cepa L.) with 80:20 (nu/nu) methanol-water in water by rotation planar extraction (RPE) and medium-pressure solid-liquid extraction (MPSLE) has been studied systematically. Rotation planar extraction was studied by use of an ExtraChrom separation instrument prototype. Only rotation planar extraction performed by use of t...

A method was developed to measure the radicalscavenging activity of compounds separated by reversed-phase TLC (RP-TLC) using phenolic acids as model analytes. TLC separation was followed by dipping the plate in a 0.04% (wt/vol) solution of 1,1-diphenyl-2-picrylhydrazyl (DPPH) in methanol. The compounds possessing radical-scavenging activity were de...

The separation of (+)-catechin and (-)-epicatechin on cellulose TLC plates with 1-butanol-water-acetic acid, 4 + 2 + 1 (v/v), has been studied under different development conditions on prewashed and untreated TLC plates. Plates were developed in horizontal chambers (tank and sandwich configuration) and in twin trough (unsaturated and saturated) dev...

A method for the separation of parasorboside and gerberin from the ornamental plant Gerbera hybrida (Asteraceae) has been developed. The two closely related glucosides were extracted using an Extrachrom instrument, a prototype multi-functional separation tool equipped with an extraction chamber. The rotation planar extraction procedure was compared...

An HPLC method using UV diode array detection was developed for analysing procyanidins qualitatively and quantitatively up to the hexameric level in hawthorn samples. The analysed compounds included procyanidin dimers B-2, B-4 and B-5, procyanidin trimers C-1, epicatechin-(4beta-->8)-epicatechin-(4beta-->6)-epicatechin and epicatechin-(4beta-->6)-e...

Oligomeric procyanidins were isolated from the leaves and flowers of hawthorn (Crataegus laevigata). A trimer, epicatechin-(4 beta-->8)-epicatechin-(4 beta-->6)-epicatechin, and a pentamer consisting of (-)-epicatechin units linked through C-4 beta/C-8 bonds have been isolated from hawthorn for the first time, in addition to known procyanidins incl...

A reversed-phase HPLC method was developed using a computer simulation program for the identification of dried roots of Echinacea purpurea, E. angustifolia, E. pallida and Parthenium integrifolium. Hydrophilic and lipophilic compounds were analysed simultaneously leading to a two-fold decrease in analysis time compared to traditional HPLC methods.

Near-infrared (NIR) reflectance spectroscopy was used to develop a fast identification method for Echinacea purpurea dried milled roots. Method development was carried out using a PLS (partial least-squares) algorithm and pretreatment options. The aim of this qualitative analysis was to confirm the identity of E. purpurea and to detect the presence...

The flavonoids comprise a large group of polyphenolic compounds that are ubiquitous in vegetables, berries, and fruits, and they have been shown to possess antioxidative activity. The interactions between flavonoids and membranes composed of dipalmitoylphosphatidylcholine (DPPC) have been studied by means of noncovalent immobilized artificial membr...

An ethnobotanical investigation on the medicinal uses of some species of Terminalia and Combretum (Combretaceae) was carried out in Mbeya, Tanzania during a 5-weeks field expedition. Of the sixteen species collected, Combretum fragrans F. Hoffm., Combretum molle G. Don., Combretum psidioides Welw., Combretum zeyheri Sond., Terminalia kaiserana F. H...