Improved HPLC method for the determination of curcumin,demethoxycurcumin, and bisdemethoxycurcumin

Commercially available curcumin, a bright orange-yellow color pigment of turmeric, consists of a mixture of three curcuminoids, namely, curcumin, demethoxycurcumin, and bisdemethoxycurcumin. These were isolated by column chromatography and identified by spectroscopic studies. The purity of the curcuminoids was analyzed by an improved HPLC method. HPLC separation was performed on a C(18) column using three solvents, methanol, 2% AcOH, and acetonitrile, with detection at 425 nm. Four different commercially available varieties of turmeric, namely, Salem, Erode, Balasore, and local market samples, were analyzed to detect the percentage of these three curcuminoids. The percentages of curcumin, demethoxycurcumin, and bisdemethoxycurcumin as estimated using their calibration curves were found to be 1.06 +/- 0.061 to 5.65 +/- 0.040, 0.83 +/- 0.047 to 3.36 +/- 0.040, and 0.42 +/- 0.036 to 2.16 +/- 0.06, respectively, in four different samples. The total percentages of curcuminoids are 2.34 +/- 0.171 to 9.18 +/- 0.232%.     

Purification of curcumin, demethoxycurcumin, and bisdemethoxycurcumin by high-speed countercurrent chromatography

Curcuminoids are substances of great interest because of their important pharmacological activities, particularly anti-inflammatory, anticarcinogenic, and anti-Alzheimer's activities. In this study, we report the first procedure and effect of processing for the high, efficient, and useful purification of curcumin, demethoxycurcumin, and bisdemethoxycurcumin from turmeric powder. Purification involves high-speed countercurrent chromatographic (HSCCC) separation of these curcuminoids using a simple two-phase solvent system composed of n-hexane/chloroform/methanol/water (5/10/7.5/2.5, v/v). The HSCCC-fractionated effluent peaks indicated that the peak resolutions were 1.7 between curcumin and demethoxycurcumin and 2.1 between demethoxycurcumin and bisdemethoxycurcumin for 25 mg of loaded turmeric powder. These purified substances were analyzed by liquid chromatography-tandem mass spectrometry with scan and daughter scan negative modes, and the wide absorbance from 200 to 500 nm was monitored by photodiode array detection. The separation yielded 1.1 mg of curcumin, 0.6 mg of demethoxycurcumin, and 0.9 mg of bisdemethoxycurcumin (>98% purity). Moreover, the antioxidant effect of curcuminoids was measured by a 1,1-diphenyl-2-picrylhydrazil assay. The order of antioxidant activity was purified curcumin > purified demethoxycurcumin > purified bisdemethoxycurcumin > turmeric powder. Curcumin, demethoxycurcumin, and bisdemethoxycurcumin can be used for various evaluations of their pharmacological activities.     

Curcuminoids and sesquiterpenoids in turmeric (Curcuma longa L.) suppress an increase in blood glucose level in type 2 diabetic KK-Ay mice

Turmeric, the rhizome of Curcuma longa L., has a wide range of effects on human health. The chemistry includes curcuminoids and sesquiterpenoids as components, which are known to have antioxidative, anticarcinogenic, and antiinflammatory activities. In this study, we investigated the effects of three turmeric extracts on blood glucose levels in type 2 diabetic KK-A(y) mice (6 weeks old, n = 5/group). These turmeric extracts were obtained by ethanol extraction (E-ext) to yield both curcuminoids and sesquiterpenoids, hexane extraction (H-ext) to yield sesquiterpenoids, and ethanol extraction from hexane-extraction residue (HE-ext) to yield curcuminoids. The control group was fed a basal diet, while the other groups were fed a diet containing 0.1 or 0.5 g of H-ext or HE-ext/100 g of diet or 0.2 or 1.0 g of E-ext/100 g of diet for 4 weeks. Although blood glucose levels in the control group significantly increased (P < 0.01) after 4 weeks, feeding of 0.2 or 1.0 g of E-ext, 0.5 g of H-ext, and 0.5 g of HE-ext/100 g of diet suppressed the significant increase in blood glucose levels. Furthermore, E-ext stimulated human adipocyte differentiation, and these turmeric extracts had human peroxisome proliferator-activated receptor-gamma (PPAR-gamma) ligand-binding activity in a GAL4-PPAR-gamma chimera assay. Also, curcumin, demethoxycurcumin, bisdemethoxycurcumin, and ar-turmerone had PPAR-gamma ligand-binding activity. These results indicate that both curcuminoids and sesquiterpenoids in turmeric exhibit hypoglycemic effects via PPAR-gamma activation as one of the mechanisms, and suggest that E-ext including curcuminoids and sesquiterpenoids has the additive or synergistic effects of both components.     

Curcuminoids, curcumin, and demethoxycurcumin reduce lead-induced memory deficits in male Wistar rats

This study investigated the neuroprotective effects of the curcuminoids against lead-induced neurotoxicity. The results show that lead significantly increases lipid peroxidation and reduces the viability of primary hippocampal neurons in culture. This lead-induced toxicity was significantly curtailed by the co-incubation of the neurons with the curcuminoids. In a whole animal experiment, rats were trained in a water maze and thereafter dosed with lead and/or curcumin (CURC), demethoxycurcumin (DMC), or bisdemethoxycurcumin (BDMC) for 5 days. Animals treated with curcumin and demethoxycurcumin but not bisdemethoxycurcumin had more glutathione and less oxidized proteins in the hippocampus than those treated with lead alone. These animals also had faster escape latencies when compared to the Pb-treated animals indicating that CURC- and DMC-treated animals retain the spatial reference memory. The findings of this study indicate that curcumin, a well-established dietary antioxidant, is capable of playing a major role against heavy metal-induced neurotoxicity and has neuroprotective properties.     

Curcuma longa L. constituents inhibit sortase A and Staphylococcus aureus cell adhesion to fibronectin

The inhibitory activity of Curcuma longa L. (turmeric) rhizome constituents against sortase A, a bacterial surface protein anchoring transpeptidase, from Staphylococcus aureus ATCC 6538p was evaluated. The activity of the isolated compounds (1-4) was compared to that of the positive control,p-hydroxymecuribenzoic acid (pHMB). The biologically active components of C. longa rhizome were characterized by spectroscopic analysis as the curcuminoids curcumin (1), demethoxycurcumin (2), and bisdemethoxycurcumin (3). Curcumin was a potent inhibitor of sortase A, with an IC50 value of 13.8 +/- 0.7 microg/mL. Bisdemethoxycurcumin (IC50 = 31.9 +/- 1.2 microg/mL) and demethoxycurcumin (IC50 = 23.8 +/- 0.6 microg/mL) were more effective than pHMB (IC50 = 40.6 +/- 1.2 microg/mL). The three isolated compounds (1-3) showed no growth inhibitory activity against S. aureus strain Newman, with minimum inhibitory concentrations (MICs) greater than 200 microg/mL. Curcumin also exhibited potent inhibitory activity against S. aureus cell adhesion to fibronectin. The suppression of fibronectin-binding activity by curcumin highlights its potential for the treatment of S. aureus infections via inhibition of sortase activity. These results indicate that curcumin is a possible candidate in the development of a bacterial sortase A inhibitor.     

Curcuminoids-cellular uptake by human primary colon cancer cells as quantitated by a sensitive HPLC assay and its relation with the inhibition of proliferation and apoptosis

Curcumin, which is a bright orange-yellow pigment of turmeric with antioxidant properties, has been shown to produce a potent preventative action against several types of cancers in recent studies. It has also been reported to protect the development of colon tumor in animals being fed with carcinogen. In the colon cancer cells, curcumin was illustrated to inhibit cell proliferation and induce apoptosis. As an antioxidant, it acts as an anti-inflammatory as well as an antitumor agent. Curcumin has been detected to exist in nature in the form of curcuminoids, a mixture of curcumin, the major component, with two of its related demethoxy compounds (demethoxycurcumin and bisdemethoxycurcumin). In the present study, we have investigated the antiproliferation and induced apoptosis effects of curcuminoids on colon cancer, using the primary cancer cells isolated from Taiwanese colon cancer patients as the model for colorectal cancer. Results showed that curcuminoids inhibited cell proliferation and induced apoptosis of these human primary colon cancer cells. The effects were observed in a dose-dependent manner as dose increased from 12.5 to 100 microM. With the aim of furthering the fundamental understanding of the mechanisms underlying the antiproliferation and induced apoptosis effects of curcuminoids on these human colon cancer cells, we developed a sensitive, rapid, and reproducible assay method based on high-performance liquid chromatography (HPLC). This HPLC technique developed was found to successfully determine, in a quantitative manner, the cellular uptake of curcuminoids. The uptake of these curcuminoids by the colon cancer cells was shown to increase as the dose of curcuminoids was increased. The observations of inhibited proliferation and increased apoptosis in the colon cancer cells appeared to be associated with the cellular uptake of curcuminoids.     

Curcumin bioavailability from enriched bread: the effect of microencapsulated ingredients

Human bioavailability of curcumin from breads enriched with 1 g/portion of free curcumin (FCB), encapsulated curcumin (ECB), or encapsulated curcumin plus other polyphenols (ECBB) was evaluated. Parental and metabolized curcuminoids and phenolic acids were quantified by HPLC/MS/MS in blood, urine, and feces collected over 24 h. The concentrations of serum curcuminoids were always below 4 nmol/L and those of glucuronides 10-fold less. Encapsulation delayed and increased curcuminoid absorption as compared to the free ingredient. Serum and urinary concentrations of ferulic and vanillic acid were between 2- and 1000-fold higher than those of curcuminoids, with ECBB eliciting the highest amounts. Fecal curcuminoids were 6-fold more abundant after ECB than FCB, while phenolic acids after ECBB quadruplicated those after ECB. Curcuminoid encapsulation increased their bioavailability from enriched bread, probably preventing their biotransformation, with combined compounds slightly reducing this effect. Phenolic acids are the major metabolites of curcuminoids and may contribute to their biological properties.     

Effects of naturally occurring compounds on fibril formation and oxidative stress of beta-amyloid

Beta-amyloid (betaA)-induced oxidative toxicity on neuronal cells is a principal route in Alzheimer's disease (AD), and its toxicity occurs after fibril formation. Inhibitory or promoting effects of naturally occurring compounds on betaA fibril formation were evaluated. Among 214 tested compounds, curcuminoids, flavone type flavonoids, and naphthoquinones were shown to be potent inhibitors of betaA fibrilization. The addition of the curcuminoids, curcumin, demethoxycurcumin, and bisdemethoxycurcumin strongly inhibited betaA fibril formation. Flavonoids such as quercetin, rhamnetin, and fisetin strongly inhibited betaA fibril formation. Limonoids, cinnamic acids, and catechins enhanced fibril formation in vitro. Anthothecol possessed the most enhancing activity on fibril formation of the compounds tested. On the other hand, it was found that curcuminoids showed cytotoxicity with the 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide assay and did not protect HT22 murine neuroblastoma cells from betaA(25-35) insult. Two flavone type flavonoids, morin and quercetin, exhibited no cytotoxicity and strongly protected HT22 murine neuroblastoma cells from betaA(25-35) oxidative attack. Conclusively, morin or quercetin could be a key molecule for the development of therapeutics for AD.     

Metabolism of curcuminoids in tissue slices and subcellular fractions from rat liver

Curcumin and its natural congeners are of current interest because of their putative anti-inflammatory and anticarcinogenic activities, but knowledge about their metabolic fate is scant. In the present study conducted with precision-cut liver slices from male and female Sprague-Dawley rats, five reductive but no oxidative metabolites of curcumin and its demethoxy and bis-demethoxy analogues were observed and identified by HPLC and GC-MS analysis, mostly by comparison with authentic reference compounds. The major reductive metabolites were the hexahydrocurcuminoids in both male and female rat liver slices, whereas male rats formed more octahydro than tetrahydro metabolites and female rats more tetrahydro- than octahydrocurcuminoids. Tetrahydro, hexahydro, and octahydro metabolites were predominantly present as glucuronides, but a significant proportion of sulfate conjugates was also observed. The lack of formation of oxidative metabolites of curcumin and the ready generation of reductive metabolites were confirmed using rat liver microsomes and cytosol, respectively. Results of enzymatic hydrolysis studies conducted under various conditions revealed that curcumin and demethoxycurcumin are chemically less stable than bis-demethoxycurcumin, whereas the reductive metabolites of all three curcuminoids are stable compounds. This is the first report on the metabolism of demethoxycurcumin and bis-demethoxycurcumin. In view of the chemical instability of the parent curcuminoids, it is proposed to use their major phase I metabolites, that is, the stable hexahydro products, as biomarkers for exposure in clinical studies.     

Extraction of essential oil and pigments from Curcuma longa [L] by steam distillation and extraction with volatile solvents

Curcuma longa [Linn] (turmeric), of the Zingiberaceae family, has a great importance in the food, textile, and pharmaceutical industries. The aim of this work was to identify the best processing conditions to maximize the yields of essential oil and pigments, as well as their content of ar-turmerone, (alpha and beta)-turmerone, and the curcuminoids, respectively. Autoclave pressure and distillation time were the variables studied for the steam distillation process. The highest yields of essential oil (0.46 wt %) and pigment (0.16 wt %)-expressed as curcumin, demethoxycurcumin, and bisdemethoxycurcumin-were obtained at a pressure of 1.0 x 10(5) Pa and a time of 2 h. On the other hand, with extraction by volatile solvents, the best yield of essential oil (5.49 wt %) was obtained when using 0.175, 0.124, 0.088 mm particles (Foust, A. S.; Wenzel, L. A.; Clump, C. W.; Maus, L.; Andersen, L. B. Princípios das Opera??es Unitárias; Editora Guanabara Dois S.A.: Rio de Janeiro, Brazil, 1982), at 40 degrees C, and 6 h of extraction. However, the best yield of pigment (7.98 wt %) was obtained under the same conditions, except for the temperature (30 degrees C).     

Effects of ingested turmeric oleoresin on glucose and lipid metabolisms in obese diabetic mice: a DNA microarray study

Turmeric, the rhizome of Curcuma longa L., has a wide range of effects on human health. Turmeric oleoresin, an extract of turmeric, is often used for flavoring and coloring. Curcuminoids and turmeric essential oil are both contained in turmeric oleoresin, and both of these fractions have hypoglycemic effects. In the present study, we comprehensively assessed the effect of turmeric oleoresin on hepatic gene expression in obese diabetic KK-Ay mice using DNA microarray analysis and quantitative real-time polymerase chain reaction (PCR). Female KK-Ay mice aged 6 weeks (n = 6/group) were fed a high-fat diet containing turmeric oleoresin, curcuminoids, and essential oil for 5 weeks. The same diet without any of these fractions was used as a control diet. Ingestion of turmeric oleoresin and essential oil inhibited the development of increased blood glucose and abdominal fat mass, while curcuminoids only inhibited the increase in blood glucose. DNA microarray analysis indicated that turmeric oleoresin ingestion up-regulated the expression of genes related to glycolysis, beta-oxidation, and cholesterol metabolism in the liver of KK-Ay mice, while expression of gluconeogenesis-related genes was down-regulated. Real-time PCR analysis was conducted to assess the contribution of the curcuminoids and essential oil in turmeric oleoresin to the changes in expression of representative genes selected by DNA microarray analysis. This analysis suggested that curcuminoids regulated turmeric oleoresin ingestion-induced expression of glycolysis-related genes and also that curcuminoids and turmeric essential oil acted synergistically to regulate the peroxisomal beta-oxidation-related gene expression induced by turmeric oleoresin ingestion. These changes in gene expression were considered to be the mechanism by which the turmeric oleoresin affected the control of both blood glucose levels and abdominal adipose tissue masses. All of these results suggest that the use of whole turmeric oleoresin is more effective than the use of either curcuminoids or the essential oil alone.     

Estimating Deoxynivalenol Content of Ground Oats Using VIS‐NIR Spectroscopy

The potential of VIS‐NIR spectroscopy as a rapid screening method for resistance of Fusarium‐inoculated oats to replace the costly chemical measurements of deoxynivalenol (DON) was investigated. Partial least squares (PLS) regression was conducted on second‐derivative spectra (400–2,350 nm) of 166 DON‐contaminated samples (0.05–28.1 ppm, mean = 13.06 ppm) with separate calibration and test set samples. The calibration set had 111 samples, and the test set had 55 samples. The best model developed had three PLS components and a root mean square error of prediction (RMSEP) of 3.16 ppm. The residual predictive deviation (RPD) value of the prediction model was 2.63, an acceptable value for the purpose of rough screening. Visual inspection and the VIS spectra of the samples revealed that high‐DON samples tended to be darker in color and coarser in texture compared with low‐DON samples. The second‐derivative spectra showed that low‐DON samples tended to have more water and fat content than high‐DON samples. With an RMSEP value of 3.16 and RPD of value of 2.63, it seems possible to use VIS‐NIR spectroscopy to semiquantitatively estimate DON content of oats and discard the worst genotypes during the early stages of screening.     

Extraction, processing, and storage effects on curcuminoids and oleoresin yields from Curcuma longa L. grown in Jamaica

Aromatic diarylheptanoid compounds from Curcuma longa Linn grown in Jamaica were quantified by UV-vis spectrophotometry and high-performance liquid chromatographic (HPLC) analyses. The oleoresin yields from ethanolic extracts were quantified and evaluated with regard to the effects of the type of postharvesting process and the type of extraction method conducted on the plant material. Fresh samples that were hot solvent extracted provided the highest oleoresin yields of 15.7% +/- 0.4 ( n = 3), and the lowest oleoresin yields of 7.8% +/- 0.2 ( n = 3) were from the dried milled samples that were cold solvent extracted. Data from the ASTA spectrophotometer assay confirmed that dried samples contained the highest curcuminoid content of 55.5% +/- 2.2 ( n = 6) at the fifth month of storage, and the fresh samples showed a curcuminoid content of 47.1% +/- 6.4 ( n = 6) at the third month of storage. A modified HPLC analysis was used to quantify curcumin content. Data from the HPLC analysis confirmed that the dried treated, hot extracted, room temperature stored samples had the highest curcumin content of 24.3%. A novel high-performance thin layer chromatography (HPTLC) method provided a chemical fingerprint of the C. longa with the use of a commercial curcumin standard.     

基于可见/近红外反射光谱的梨树叶片钾含量的快速测定研究

利用可见/近红外反射光谱定量分析技术对梨树鲜叶钾素含量进行快速测定研究。对150个梨树叶片样本进行光谱扫描,其中120个做建模集,30个做验证集。通过对样品的可见/近红外光谱进行多种预处理,并建立钾素预测模型,探讨了可见/近红外光谱数据预处理对预测精度的影响。结果表明,通过原始光谱与S-G(3)平滑相结合的预处理方法,用17个主成分建立的偏最小二乘法模型最好,其交叉验证集和预测集模型的决定系数(R2)分别为0.722 7和0.679 1,交叉验证均方根误差(RMSECV)为1.171,预测的平均相对误差为6.81%,能高效、快速地预测梨树叶片钾素含量,为梨树钾素快速测定提供了新的手段。     

Prediction of nutritive values,morphology and agronomic characteristics in forage maize using two applications of NIRS spectrometry

This study evaluates nutritive, morphological and agronomic characteristics of forage maize predicted by using a high-quality near-infrared (NIR) spectrometer and an NIR hyperspectral-imaging technique using partial least squares (PLS) regression models. The study includes 132 samples of dried milled whole-plant homogenates of forage maize with variation in maturity, representing two growing seasons, three locations in Sweden and three commercial maize hybrids. The samples were measured by a classical sample cup NIR spectrometer and by a pushbroom hyperspectral-imaging instrument. The spectra and a number of variables (crude protein, CP, neutral detergent fibre, starch, water soluble carbohydrates (WSC) and organic matter digestibility), morphological variables (leaves, stems & ears) and crop yield were used to make PLS calibration models. Using PLS modelling allowed the determination of how well maize variables can be predicted from NIR spectra and a comparison of the two types of instruments. Most examined variables could be determined equally well, by both instruments, but the pushbroom technique gave slightly better predictions and had higher analytical capacity. Predictions of CP, starch, WSC and the proportions of ears in the maize gave robust. The findings open new possibilities to further utilise the technology in plant breeding, crop management, modelling and forage evaluation.     

Environmental Effects on Developing Wheat as Sensed by Near‐Infrared Reflectance of Mature Grains

For 30 years, near‐infrared (NIR) spectroscopy has routinely been applied to the cereal grains for the purpose of rapidly measuring concentrations of constituents such as protein and moisture. The research described herein examined the ability of NIR reflectance spectroscopy on harvested wheat to determine weather‐related, quality‐determining properties that occurred during plant development. Twenty commercial cultivars or advanced breeding lines of hard red winter and hard white wheat (Triticum aestivum L.) were grown in 10 geographical locations under prevailing natural conditions of the U.S. Great Plains. Diffuse reflectance spectra (1,100–2,498 nm) of ground wheat from these samples were modeled by partial least squares one (PLS1) and multiple linear regression algorithms for the following properties: SDS sedimentation volume, amount of time during grain fill in which the temperature or relative humidity exceeded or was less than a threshold level (i.e., >30, >32, >35, <24°C; >80%, <40% rh). Rainfall values associated with four pre‐ and post‐planting stages also were examined heuristically by PLS2 analysis. Partial correlation analysis was used to statistically remove the contribution of protein content from the quantitative NIR models. PLS1 models of 9–11 factors on scatter‐corrected and (second order) derivatized spectra produced models whose dimensionless error (RPD, ratio of standard deviation of the property in a test set to the model standard error for that property) ranged from 2.0 to 3.3. Multiple linear regression models, involving the sum of four second‐derivative terms with coefficients, produced models of slightly higher error compared with PLS models. For both modeling approaches, partial correlation analysis demonstrated that model success extends beyond an intercorrelation between property and protein content, a constituent that is well‐modeled by NIR spectroscopy. With refinement, these types of NIR models may have the potential to provide grain handlers, millers, and bakers a tool for identifying the cultural environment under which the purchased grain was produced.     

Organic Carbon and Total Iron Effect on Soil Vis-SWNIR Spectraand Quantification of Their Contents Using PLS R Models

ABSTRACT

Many factors could influence simultaneously soil spectra. We aimed to study the single effect of organic carbon and total iron in soil visible and short-wave near-infrared spectra and to quantify their contents. Two datasets of soil mixture samples were prepared by mixing, in various fractions, an organic carbon-rich material with a total iron-rich material and then with a total iron-poor material. For these two datasets, contents in organic carbon are quite similar but contents in total iron are significantly different. Results show that samples of the same dataset have the same overall spectral shape. Organic carbon has a decreasing effect that affects the whole spectral range without showing any specific absorption peaks. By contrast, total iron has specific absorption peaks. Spectra of the second dataset characterized by soil mixtures with higher total iron contents were more compact within the spectral bands 400–440 and 920–950 nm. Besides, continuum removal enables to exaggerate absorption peaks of wavelengths linked to total iron content. Partial Least Squares Regression (PLS R) models of both total organic carbon and total iron assign high coefficients to the wavelengths that are considered relevant and conversely low coefficients to those that are considered irrelevant. Both organic carbon content and total iron content were well predicted. For these models, coefficients of determination were superior to 0.9 and RMSE was closed to zero. The global models calibrated on all the samples demonstrated that PLS R was able to integrate sample heterogeneity.     

Near-infrared analysis of soluble and insoluble dietary fiber fractions of cereal food products

The use of near-infrared (NIR) reflectance spectroscopy for the rapid and accurate measurement of soluble and insoluble dietary fiber was explored in a diverse group of cereal products. Ground samples were analyzed for soluble and insoluble dietary fiber (AOAC Method 991.43) and scanned (NIRSystems 6500 monochromator) to obtain NIR spectra. Modified PLS models were developed to predict insoluble and soluble dietary fiber using data sets expanded to include products with high fat and high sugar contents. The models predicted insoluble dietary fiber accurately with an SECV of 1.54% and an R(2) of 0.98 (AOAC determined range of 0-48.77%) and soluble dietary fiber less accurately with an SECV of 1.15% and an R(2) of 0.82 (AOAC determined range of 0-13.84%). Prediction of independent validation samples by the soluble fiber model resulted in a bias that may be related to the way the reference method treats samples with different soluble fiber constituents. The insoluble fiber model can be used to rapidly monitor insoluble dietary fiber in cereal products for nutrition labeling.     

Application of near infrared reflectance (NIR) and fluorescence spectroscopy to analysis of microbiological and chemical properties of arctic soil

Applicability of near infrared reflectance (NIR) and fluorescence spectroscopic techniques was tested on highly organic arctic soil. Soil samples were obtained at a long-term climate change manipulation experiment at a subarctic fell heath in Abisko, northern Sweden. The ecosystem had been exposed to treatments simulating increasing temperature (open-top greenhouses), higher nutrient availability (NPK fertilization) and increasing cloudiness (shading cloths) for 15 years prior to the sampling. For each of the 72 samples from the 0 to 5 cm soil depth and 36 samples from the 5 to 10 cm depth, the wavelength range of 400-2500 nm (visible and near infrared spectrum) was scanned with a NIR spectrophotometer and fluorescence excitation-emission matrices (EEMs) were recorded with a spectrofluorometer.Principal component analyses of the visible, NIR and fluorescence spectra clearly separated the treatments, which indicates that the chemical composition of the soil and its spectral properties had changed during the climate change simulation. Similarly to the results from the conventional analyses of soil chemical and microbiological properties, fertilization treatment posed strongest effects on the spectra. Partial least-squares (PLS) regression methods with cross-validation were used to analyse relationships between the spectroscopic data and the chemical and microbiological data derived from the conventional analyses. The fluorescence EEMs of the dried solid soil samples were moderately related to soil ergosterol content (correlation coefficient r=0.84), bacterial activity analysed by leucine incorporation technique (r=0.78) and total phospholipid fatty acid (PLFA) content (r=0.74), but in general fluorescence provided inferior predictions of the chemical and microbiological variables to NIR. NIR was highly related to soil organic matter content (r>0.9) and showed promising predictions of soil ergosterol content (r>0.9), microbial biomass C, microbial biomass P, and total PLFA contents (r=0.78-0.79).These results suggest that especially NIR could be used to predict soil organic matter and fungal biomass. Since it is rapid and inexpensive, and requires little sample mass, it could be used as a ‘quick and dirty’ technique to estimate progression of the treatment responses in long-term ecosystem experiments, where extensive soil sampling is to be avoided.