Comparative pharmacokinetics of baicalin in plasma after oral administration of Huang-Lian-Jie-Du-Tang or pure baicalin in MCAO and sham-operated rats

A sensitive and specific HPLC method was developed to analyze baicalin in rat plasma. The author had compared the pharmacokinetics of baicalin after oral administration of HLJDT decoction or pure baicalin in MCAO and sham-operated rats. All the rats were divided into two groups, MCAO and sham-operated rats. Each group contained two subgroups: HLJDT decoction and pure baicalin subgroup. The HLJDT subgroup oral administration of HLJDT decoction extract 10.00 g/kg according to body weight (containing baicalin 400.00 mg/kg according to body weight), the pure baicalin subgroup received a gavages at a dosage of baicalin 400.00 mg/kg according to body weight too. The pharmacokinetics parameters were analyzed by kinetica. The results indicated that the pharmacokinetics of baicalin in rat plasma was non-linear and there were significant differences between different groups. No matter in MCAO or sham-operated rats, pure baicalin had shown better absorption than HLJDT decoction. Whether administration of pure baicalin or HLJDT decoction, the MCAO rats show better, quicker absorption of baicalin than sham-operated rats. It was good for baicalin to exert pharmacological effects on healed cerebrovascular diseases. The method had been applied successfully to pharmacokinetics of baicalin in rat plasma after oral administration of pure baicalin or HLJDT decoction.     

Comparative pharmacokinetic study of paeoniflorin and albiflorin after oral administration of Radix Paeoniae Rubra in normal rats and the acute cholestasis hepatitis rats

A comparative study was designed and conducted to compare the pharmacokinetic difference of paeoniflorin and albiflorin after oral administration of Radix Paeoniae Rubra to normal rats and the acute cholestasis hepatitis rats induced by alpha-naphthylisothiocyanate (ANIT). UPLC-ESI-MS/MS method was employed to determine the level of paeoniflorin and albiflorin in rat plasma using geniposide as the internal standard (IS). Unpaired Student's t-test was used for the statistical comparison. The investigation showed that there were significant differences between the normal rats and the acute cholestasis hepatitis rat groups in calculated parameters, such as AUC(0-t), AUC(0-∞), T(max) and CLz/F. The results indicated that acute liver injury in rats could alter the pharmacokinetics of drug. Since patients are the final users of the drug, it is essential to investigate the pharmacokinetics of the drug in disease status. Therefore, we used normal rats and the acute cholestasis hepatitis rats to study pharmacokinetics of Radix Paeoniae Rubra with the purpose of examining the influence of disease on the metabolic course.     

Comparative pharmacokinetics of paclitaxel after oral administration of Taxus yunnanensis extract and pure paclitaxel to rats

Taxus yunnanensis (T. yunnanensis) is endemic to China and has been used in traditional medicine for the treatment of cancer, diabetic ailments and others. Paclitaxel is a representative antitumor compound in the Taxus species. The pharmacokinetic behavior of paclitaxel after oral administration of the crude extract of T. yunnanensis has not been investigated. This study attempts to compare the pharmacokinetics of paclitaxel after an oral administration of the crude extract of the twigs and leaves of T. yunnanensis and pure paclitaxel. A UPLC and a UPLC/MS/MS analysis method were developed for the determination of paclitaxel in T. yunnanensis extract and in the comparative pharmacokinetic study. Caco-2 cells were used to investigate the transport profile of paclitaxel in vitro. In the pharmacokinetic study, rats were randomly grouped and administered with T. yunnanensis extract or pure paclitaxel. The results showed that the AUC and C_max of paclitaxel in rats receiving the T. yunnanensis extract were significantly increased than those receiving the pure paclitaxel, and the in vitro Caco-2 cell monolayer transport study found that the coexisting constituents in the extract of T. yunnanensis could inhibit the efflux of paclitaxel. These findings suggested that the oral absorption and bioavailability of paclitaxel in T. yunnanensis extract were remarkably higher when compared with the pure paclitaxel, and the coexisting constituents in the T. yunnanensis extract might play an important role for the enhancement of the oral absorption and bioavailability of paclitaxel.     

Comparative pharmacokinetics of three triterpene acids in rat plasma after oral administration of Poria extract and its formulated herbal preparation: GuiZhi-FuLing capsule

A sensitive liquid chromatographic-mass spectrometric technique coupled with liquid-liquid extraction method was developed and validated for simultaneous determination of dehydro-tumulosic acid, tumulosic acid and polyporic acid C in rat plasma. The analytes were separated on a Kromasil C₁₈ column with a total running time of 12.5 min. Author had compared the pharmacokinetics of dehydro-tumulosic acid, tumulosic acid and polyporic acid C after oral administration of the extract of Poria and its formulated herbal preparation (GuiZhi-FuLing capsule). The improved pharmacokinetic profiles of the three compounds were found in the GuiZhi-FuLing capsule, indicating the more effective absorption and the slower elimination, compared with the Poria extract. Furthermore, this study revealed that as far as the Poria extract was concerned, it is very valuable to be used as a clinical instruction of GF capsule.     

Comparative pharmacokinetics of baicalin in normal and the type 2 diabetic rats after oral administration of the Radix scutellariae extract

Radix scutellariae was used alone or in combination with other medicinal herbs in the treatment of type 2 diabetes mellitus in China. At present, the pharmacokinetics of baicalin in type 2 diabetic rats following oral administration of Radix scutellariae extract was investigated. The results showed that the pharmacokinetics (especially AUC) of baicalin in type 2 diabetic rats after oral administration of Radix scutellariae extract was remarkably different from that in normal rats. Then the mechanism which resulted in the increased AUC of baicalin in diabetic rats was investigated from system clearance and presystemic metabolism. And it was found that the increased AUC of baicalin in diabetic rats at least partly resulted from higher production of baicalein in the intestinal tract of type 2 diabetic rats. Moreover, the activity of β-glucuronidase in intestinal mucosa of type 2 diabetic rats was demonstrated to be higher than that in normal rats, which confirmed the results above. In conclusion, the pharmacokinetic behavior of baicalin was significantly altered in type 2 diabetic rats after orally administrated Radix scutellariae extract, which may partly result from the increased activity of intestinal β-glucuronidase under the pathological state of type 2 diabetes mellitus.     

The studies of anti-inflammatory and analgesic activities and pharmacokinetics of Oxytropis falcate Bunge extraction after transdermal administration in rats

The aim of this study was to evaluate the activities of anti-inflammatory and analgesic of the total flavonoids extraction from Oxytropis falcate Bunge (FEO) after transdermal administration. The pharmacokinetics and absolute bioavailability of FEO in rat, furthermore, was studied. Firstly, the anti-inflammatory and analgesic effects of the FEO were studied by xylene-induced ear edema, adjuvant-induced joint inflammation law in rats, acetic acid-induced writhing and hot-plate tests in mice. Secondly, we developed a sensitive and specific HPLC method to analyze 2′, 4′-dihydroxychalcone (TFC, the mainly ingredient of FEO) in rat plasma to study the pharmacokinetic of TEC. The results showed FEO has anti-inflammatory and analgesic property in a dose-dependent manner, and that the high dose group (90.6 mg/kg) of FEO appeared more significantly effective than the positive drug. From the pharmacokinetic studies of TFC in rats, we got the main pharmacokinetic parameters of TFC, providing a basis for the future studies in clinic.     

Comparative pharmacokinetics and bioavailability studies of quercetin, kaempferol and isorhamnetin after oral administration of Ginkgo biloba extracts, Ginkgo biloba extract phospholipid complexes and Ginkgo biloba extract solid dispersions in rats

The aim of this study was to improve the oral bioavailability of Ginkgo biloba extract (GBE) through preparing G. biloba extract phospholipid complexes (GBP) and G. biloba extract solid dispersions (GBS). Firstly we prepared the GBP and GBS and studied their physicochemical properties by differential scanning calorimetry (DSC), powder X-ray diffraction (XRD) and dissolution. Then we studied the pharmacokinetic characteristics and bioavailability in rats. The results showed that the bioavailability of quercetin, kaempferol and isorhamnetin in rats was increased remarkably after oral administration of GBP and GBS comparing with GBE. The bioavailabilities of GBP increased more than that of GBS.     

Pharmacokinetics and tissue distribution of schizonepetin in rats

Schizonepetin, a natural monoterpene from Herba Schizonepetae, is a potential antiviral agent. In this paper, a simple, rapid and sensitive HPLC-UV method was first developed and validated for the determination of schizonepetin in rat plasma and tissue homogenates after oral and intravenous administration. The results showed that schizonepetin was absorbed and eliminated rapidly, and its oral absolute bioavailability in rats achieved about 75%. The drug distributed widely in various tissues of rats, and had no long-term accumulation in vivo. The research provides reliable scientific data for designing drug treatment regimens of schizonepetin.     

Pharmacokinetics and tissue distribution study of scoparone in rats by ultraperformance liquid-chromatography with tandem high-definition mass spectrometry

Scoparone is an important constituent of Yinchenhao (Artemisia annua L.), a famous Chinese medicinal plant, and has several known bioactivities, and displayed bright prospects in prevention and therapy of jaundice and liver disorders. The aim of this study was to investigate the in vivo plasma pharmacokinetic and tissue distribution characteristics of scoparone after oral administration. The levels of scoparone in plasma, and tissues were measured by a rapid and sensitive UPLC-MS/MS method. The biosamples were prepared using methanolic precipitation and the separation of scoparone was achieved on a UPLC HSS T3 column by linear gradient elution using water (containing 0.1% formicacid) and acetonitrile (containing 0.1% formic acid) as the mobile phase at a flow rate of 0.5mL/min The total run time was only 3.9min. Our results successfully demonstrate that this method has excellent and satisfactory selectivity, sensitivity, linearity, precision, accuracy and recovery. The estimated pharmacokinetic parameters (i.e., C(max), AUC and CL), were C(max)=14.67mg/L, AUC=81.15mg*h/L, CL=1.23L/h for scoparone. The pharmacokinetic study found that scoparone was distributed and eliminated rapidly in rats. Tissue distribution showed the highest level was observed in liver, followed by the kidney and spleen; the lower level appeared in the muscle, thyroid, and adrenal. It was not detected in the brain which indicated that scoparone does not cross the blood-brain barrier after oral administration. Our developed method was suitable for the study on pharmacokinetics and tissue distribution of scoparone after oral administration.     

Comparative pharmacokinetic and bioavailability studies of three salvianolic acids after the administration of Salviae miltiorrhizae alone or with synthetical borneol in rats

Salviae miltiorrhizae is one of the most commonly used herbal plants in the treatment of numerous ailments including cardiovascular diseases for hundreds of years. According to the theory of traditional Chinese herbal medicine, S. miltiorrhizae is always used in combination with borneol to obtain better pharmacological effects. The purpose of this study was to investigate the effects of borneol on the pharmacokinetic and bioavailability of S. miltiorrhizae. The pharmacokinetics studying on rosmarinic acid, salvianolic acid A and salvianolic acid B which are the main active compounds of S. miltiorrhizae in rat plasma, was achieved using a optimal high-performance liquid chromatographic technique coupled with liquid-liquid extraction method. After administration of either single salvianolic acids or salvianolic acids in combination with borneol, plasma concentrations of rosmarinic acid, salvianolic acid A and salvianolic acid B of male Sprague-Dawley rats were determined at different time points (5, 10, 20, 30, 45, 60, 90, 120, 180, 240, 300, and 360 min). In comparison with salvianolic acid extract alone, there were statistically significant differences in pharmacokinetic parameters of rosmarinic acid, salvianolic acid B and salvianolic acid A, and the bioavailability of the three salvianolic acids increased by different degrees when the salvianolic acid extract and borneol were administered together. These results indicated that borneol could enhance the intestinal absorption, decrease the distribution and inhibit the metabolism of salvianolic acids.     

Permeability determination and pharmacokinetic study of nobiletin in rat plasma and brain by validated high-performance liquid chromatography method

In the present study, we are reporting permeability and pharmacokinetics of nobiletin in rat plasma and brain, using a validated reverse phase high performance liquid chromatographic method. Protein precipitation method was used for the extraction of nobiletin and coumarin (IS) from rat plasma and brain tissue. The system was run in isocratic mode with mobile phase consisting of potassium dihydrogen ortho-phosphate (pH 4.5; 0.04 mM) and acetonitrile in ratio of 50:50, v/v. The total chromatographic run time was 9.0 min. The method was proved to be accurate and precise at linearity range of 0.05–10 μg/mL with a correlation coefficient (r) of ≥ 0.994 in rat plasma and ≥ 0.995 in rat brain. The intra- and inter-day precision and accuracy values are found to be within the assay variability limits as per the FDA guidelines. Nobiletin was found stable in the battery of stability studies viz., bench-top, auto-sampler, freeze/thaw cycles and long term storage in a freezer at − 70 ± 10 °C. Maximum concentrations of nobiletin in both plasma and brain were observed at 1 h after single oral dosing (50 mg/kg). The maximum concentration in plasma and brain were 1.78 and 4.20 μg/mL, respectively. The AUC_0–t in plasma and brain were 7.49 and 20.66 μg·h/mL, respectively. The mean elimination half life (t_1/2) in plasma and brain were 1.80 and 11.42 h, respectively. The Parallel Artificial Membrane Permeability Assay (PAMPA) permeability of nobiletin was found to be high at both pH 4.0 and 7.0.     

Ultra-performance liquid-chromatography with tandem mass spectrometry performing pharmacokinetic and biodistribution studies of croomine,neotuberostemonine and tuberostemonine alkaloids absorbed in the rat plasma after oral administration of Stemonae Radix

Stemonae Radix (Stemona tuberosa Lour, Bai Bu) is an important traditional Chinese medicinal (TCM) plant known for its antitussive activity. Croomine, neotuberostemonine and tuberostemonine alkaloids of Stemonae Radix are major components responsible for antitussive action. In this work, plasma pharmacokinetic and biodistribution characteristics of the three alkaloids after oral administration of Stemonae Radix are investigated using a rapid and sensitive UPLC-Q-TOF–HDMS method. Mass spectrometry (MS) was performed on a Waters Micromass high-definition technology with an electrospray ionization source in positive ion mode, with excellent MS mass accuracy and enhanced MS data acquisition. Separation of main alkaloids was achieved on a Waters BEH C₁₈ column by linear gradient elution. Data were analyzed and estimated by compartmental methods and pharmacokinetic parameters calculated using WinNonlin Professional version 5.1. It was found that croomine, neotuberostemonine and tuberostemonine had faster absorbed into the bloodstream, maintain the high plasma concentration, and pose a large AUC value. The biodistribution of neotuberostemonine and tuberostemonine showed that the higher levels were in liver, and lung. Croomine was discovered in brain and showed that it could cross the blood–brain barrier, indicating that croomine plays an antitussive effect as acting on the central nervous system. Neotuberostemonine and tuberostemonine were not discovered in brain, demonstrating that they play an antitussive effect as peripheral antitussive. This work suggests that the pharmacokinetics and biodistribution based-UPLC-Q-TOF–HDMS can provide a reliable tools for screening bioactive components contributing to pharmacological effects of medicinal herbs.     

Hypoglicemic effect of Leandra lacunosa in normal and alloxan-induced diabetic rats

Leandra lacunosa, popularly known as "erva-do-jabuti", is used in Brazilian folkloric medicine for the treatment of diabetes mellitus. Based on this traditional indication, the aim of this work was to evaluate the hypoglycemic activity of the hydroalcoholic extract of L. lacunosa aerial parts (LLH) in normal and alloxan-induced diabetic rats. Chromatographic fractionation of LLH was also carried out by several techniques, affording isolation of the following major compounds: ursolic acid (1), kaempferol (2), luteolin (3), and quercetin (4). The oral administration of LLH (500 mg/kg) in normal rats caused a significant reduction of 24.7% (P<0.05) in the blood glucose levels after 2 h of treatment, while the administration of chlorpropamide (20 mg/kg, p.o.) led to a reduction of 40.2% (P<0.01). After oral administration of glucose (10 g/kg, p.o.), LLH (500 mg/kg, p.o.) significantly inhibited the increase in blood glucose levels compared with the negative control group. The oral treatment with LLH (500 mg/kg) in alloxan-induced diabetic rats significantly reduced the blood glucose levels in 47.8% after 4 h of treatment, while chlorpropamide resulted in a significant reduction of 71.7% in the 4th hour. Our results showed that LLH, displays hypoglycemic activity, which may be related to the effect of the major compounds identified in the crude extract. This study seems to provide biological evidence for the folkloric use of L. lacunosa in the treatment of diabetes mellitus.     

Long-term treatment with standardized Ginkgo biloba extract (EGb 761) attenuates cognitive deficits and hippocampal neuron loss in a gerbil model of vascular dementia

The standardized extract of Ginkgo biloba EGb 761 has been used to reduce cognitive dysfunction. The present study was designed to evaluate the effect of postischemic oral treatment with EGb 761 in a model of vascular dementia in gerbils. Daily oral posttreatment with EGb 761 led to a significant recovery of spatial memory assessed by the object location test, inhibited the decrease in plasma SOD activity and protected the hippocampal CA1 neurons, even when administered after the insult. These data provide further evidence for the therapeutic potential of EGb 761 in the treatment of vascular dementia.     

Pharmacokinetic study of luteolin,apigenin, chrysoeriol and diosmetin after oral administration of Flos Chrysanthemi extract in rats

Flos Chrysanthemi (the flower of Chrysanthemum morifolium Ramat.) is widely used in China as a food and traditional Chinese medicine for many diseases. Luteolin and apigenin are two main bioactive components in Flos Chrysanthemi, and chrysoeriol and diosmetin are two methylated metabolites of luteolin in vivo by cathechol-O-methyltransferase (COMT). However, there was lack of pharmacokinetic information of chrysoeriol and diosmetin after oral administration of Flos Chrysanthemi extract (FCE). The present study aimed to develop an HPLC-UV method for simultaneous determination of rat plasma concentration of luteolin, apigenin, chrysoeriol and diosmetin and utilize it in pharmacokinetic study of the four compounds after orally giving FCE to rats. The method was successfully validated and applied to the pharmacokinetic study when oral administration of FCE to rats with or without co-giving a COMT inhibitor, entacapone. Chrysoeriol and diosmetin were detected in rat plasma after oral administration of FCE and their concentrations were significantly decreased after co-giving entacapone. Furthermore, AUC of luteolin was significantly increased by entacapone, while that of chrysoeriol was decreased by entacapone, which revealed COMT might play an important role in the disposition of luteolin in rats after dosing of FCE. In conclusion, a sensitive, accurate and reproducible HPLC-UV method for simultaneous determination of luteolin, apigenin, chrysoeriol and diosmetin in rat plasma were developed, pharmacokinetics of chrysoeriol and diosmetin combined with luteolin and apigenin were characterized after oral administration of FCE to rats, which gave us more information on pharmacokinetics and potential pharmacological effects of FCE in vivo.     

Comparative study on antioxidative system in normal and vitrified shoots of Populus suaveolens in tissue culture

To explore the physiological and biochemical mechanism of the occurrence of vitrified shoots of Populus suaveolens in tissue culture, the changes in water, chlorphyll, lignin, H₂O₂, phenylalanine ammonialyase (PAL), malonaldehyde (MDA), protective enzymatic systems, and some key enzymes involved in the ascorbate- glutathione cycle were comparatively studied in both normal and vitrified shoots of P. suaveolens. The results show that the lower activities of peroxidase (POD), catalase (CAT), ascorbate peroxidase (APX), dehydroascorbate reductase (DHAR), glutathione reductase (GR) and PAL, and the less contents of chlorphyll, lignin, ascorbate (ASA) and reduced glutathione (GSH) as well as the lower ratios of ASA / DHA and GSH / GSSG are observed in vitrified shoots than in normal ones during the whole culture period. While in comparison with normal shoots, the higher activity of superoxide dismutase (SOD) and the more concentrations of water, H₂O₂, MDA, dehydroascorbate (DHA) and oxidized glutathione (GSSG) are found in vitrified shoots. Statistical analysis indicates that the enhanced activity of SOD and the decreased activities of CAT and POD as well as some enzymes involved in the ascorbate-glutathione cycle might be closely correlated to the accumulation of H₂O₂. The less regeneration of ASA and GSH and the lower capacity of the ascorbate-glutathione cycle observed in vitrified shoots might be due to a significant decrease in APX, MDAR, DHAR and GR activities and a decline in redox status of ASA and GSH. The decreases in chlorphyll content might result in a decline in photosynthesis. The lower activities of POD and PAL could result in the decrease of lignin synthesis and cell wall ligination, which might be the key factor leading to the increase in water content. It is concluded that the deficiency of detoxification capacity caused by the lower capacity of the ascorbate-glutathione pathway and the decreased activity of protective enzymatic system might lead to the large accumulation of H₂O₂ and the enhancement of membrane lipid peroxidation, which might be the main cause leading to the occurrence of vitrifying shoots of P. suaveolens in tissue culture. [Supported by National Natural Science Foundation of China (Grant No. 30271093) and the Foundation of State-designated Base for Biology Researching and Teaching in Beijing Forestry University]     

Ecological effects of lawn greens with pure and mixed stands in an urban setting

We studied the ecological benefits of four types of urban green spaces (lawn, a Robinia pseudoacacia stand, a Pinus tabulaeformis stand and a mixed stand of both species) in Yuan Dynasty Wall Relics Park, Beijing. Each of the eight sampling sites was about 0.1 hm². The experiment was carried out in June, 2006 over a period of eight consecutive days, during which we continuously measured air temperature, relative humidity (RH) and wind speed at the four green spaces in both horizontal and vertical directions. The results were as follows: in the horizontal direction, the all-day average temperature at the pine stand was the lowest and itsRHwas the highest under three different climate conditions. During the daytime high temperature period, the temperature of the lawn was the highest and its RH the lowest. The temperature was lowest for the mixed stand, and the RH was highest for the pine stand. The highest average daily temperature occurred in the locust stand. The temperature and RH of the four green spaces were statistically different at the 0.05 level of significance. In the vertical direction, the average daily temperature of the four green spaces increased with height. The average daily RH of the four green spaces decreased slightly with increased height. During the high temperature period of the day, the average temperature of the lawn and the P. tabulaeformis stand declined with the increased height, but the temperature at the R. pseudoacacia stand and the mixed P. tabulaeformis-R. pseudoacacia stand fluctuated greatly. With regard to the effect of lowering the wind speed, the mixed stand was better than the other green spaces. Based on these results, it can be concluded that the mixed Chinese pine and locust stand was the best choice for the establishment of urban green spaces. __________ Translated from Acta Ecologica Sinica, 2007, 27(2): 674–683 [译自: 生态学报]     

Pharmacokinetic properties of isorhamnetin, kaempferol and quercetin after oral gavage of total flavones of Hippophae rhamnoides L. in rats using a UPLC-MS method

An ultra performance liquid chromatography-mass spectrometric (UPLC-MS) method was developed to investigate the pharmacokinetic properties of isorhamnetin, kaempferol and quercetin from a total flavone extract of Hippophae rhamnoides L. (TFH) after single dose oral administration. Rat plasma samples were pretreated using liquid-liquid extraction, and chromatographic separation was performed on a C₁₈ column using a linear gradient of methanol and formic acid (0.1%). The pharmacokinetic parameters of isorhamnetin, kaempferol and quercetin from TFH in rats were quantitatively determined by UPLC with photodiode array detection (PDA). The qualitative detection of the three flavones was accomplished by selected ion monitoring in negative ion mode ESI-MS. Results of the pharmacokinetic study indicate that the three flavones in TFH were absorbed by passive diffusion in rats, and no “double-peak” phenomenon was observed in C-t curves of the three flavones from TFH except for quercetin. Results of this study indicate that the pharmacokinetic behaviors of isorhamnetin, kaempferol and quercetin when administered together in a complex herbal extract might be different than the individual behaviors of the same compounds administered in their pure forms. Results of this study also demonstrate that UPLC-MS is a rapid and practical method to determine the pharmacokinetic parameters of flavones present in an herbal extract.     

Differences in chemical constituents between vascular bundles and nonvascular bundles of cacao (<Emphasis Type="Italic">Theobroma cacao</Emphasis> L.) hull

 Cacao (Theobroma cacao L.) hulls were physically separated into vascular bundles (VBs) and nonvascular bundles (NVBs) to investigate their chemical compositions and the structural features of abundant polyphenolic compounds. Glucose content was determined to be 21.4% for VBs and 17.5% for NVBs, together with xylose content as 13.1% for VBs and 2.8% for NVBs. In addition, uronic acid in NVBs (12.9%) was much higher than that in VBs (5.2%). The content of total (poly)phenolic compounds (35.9%–39.1%) quantified as Klason residues (KRs) and acid-soluble phenolic compounds (ASPs) were similar in both cell types, although there were great differences in the structural characteris-tics of polyphenolic compounds. The pyrogram of VBs clearly showed high intensities of guaiacol and 4-vinylguaiacol together with low intensities of catechol and 4-methylcatechol. On the other hand, that of the NVBs showed opposite trends. These results were confirmed by alkaline nitrobenzene oxidation based on total yields of vanillin and syringaldehyde. Therefore, the accumulation of various polyphenolic compounds in cacao hulls relies strongly on the cell type and is correlated with the development of a secondary wall. Received: October 9, 2001 / Accepted: April 15, 2002 Present address: Institute of Biological Chemistry, Washington State University, Pullman, WA 99164-6340, USA Acknowledgments This project was partially supported financially by a Grant-in-Aid from the Ministry of Education, Culture, Sports, Science and Technology (no. 13375007). We thank Dr. Hadi S. Arifin, Faculty of Agriculture, Bogor Agricultural University, Indonesia, for collecting cacao fruits at the Rajamandala Cacao Plantation at Rajamandala in West Java. Correspondence to:K. Iiyama