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At least 199 records · Page 11Linked to original sources
PubMed2004

Analysis of kavalactones from Piper methysticum (kava-kava).

The chemical analysis and quality control of both Piper methysticum G. Forster (kava-kava) and extracts obtained by aqueous acetone or aqueous methanol as well as supercritical fluid extraction are reviewed. In the last two decades various procedures concerning the separation and detection of kavalactones have been routinely carried out by gas chromatography (without previous derivatization of kavalactones) and high performance liquid chromatography but most of them are not validated or only partially validated. Recently, analyses by supercritical fluid chromatography and micellar electrokinetic chromatography have also been reported. Both gas chromatography and high performance liquid chromatography can be used for the analysis of kavalactones with some advantages and disadvantages for each method. Using gas chromatography analysis, methysticin and yangonin, which are two of the major components, are generally not separated. In addition, the high temperature of the injection port caused the decomposition of methysticin. Concerning high performance liquid chromatography analyses, the reversed-phase is generally better because highly reproducible with a very low detection limit for all compounds even if the quantitative analysis of the kavalactones by liquid chromatography needs to be carried out in the absence of light to prevent the cis/trans isomerisation of yangonin.

Chromatography↗
PubMed2005

HPLC analysis of flavokavins and kavapyrones from Piper methysticum Forst.

A simultaneous HPLC separation of the six major kavapyrones and the flavokavins A-C in an ethanolic extract of Piper methysticum was carried out on a Symmetry C18 column. For quantitative determinations of the flavokavins, calibration curves with correlation coefficients between 0.9986 and 0.9998 were established. Detection limit for each flavokavin of 0.5 ng per injection was measured at 355 nm. The precision of the HPLC analysis was verified by six determinations of the content of flavokavins in the kava extract. Flavokavins A-C contents of 0.62+/-0.01 mg/100 mg, 0.34+/-0.01 mg/100 mg and 0.14+/-0.003 mg/100 mg ethanolic kava extract was found, respectively. From the corresponding relative standard deviation of 1.53, 1.99 and 2.30% the confidential interval (P=95) of the mean value was calculated for each flavokavin. The accuracy of the method was proven by recoveries between 99.2+/-0.3% and 101.1+/-0.4% for the flavokavins A-C.

Chalcone↗
PubMed2006

Psychometric properties of the revised Piper Fatigue Scale in Dutch cancer patients were satisfactory.

OBJECTIVE: To examine the psychometric properties of the revised Piper Fatigue Scale (PFS) in Dutch cancer patients. STUDY DESIGN AND SETTING: Participants were 64 patients with lung (any stage, nonsurgery) and breast (any stage) cancer, selected for curative high-dose radiotherapy (> or =50 Gy). Prior to radiotherapy, patients completed the revised PFS (translated into Dutch), the Multidimensional Fatigue Inventory (MFI), and the Rotterdam Symptom Checklist (RSCL). Reliability and construct and criterion validity of the PFS were investigated. RESULTS: Overall, the structure of the Dutch revised PFS appeared appropriate, with corrected item-subscale correlations being higher than the correlations of the same item with the three other subscales; furthermore, internal consistency was excellent (Cronbach's alpha > or =0.90). Lung cancer patients were significantly more tired then breast cancer patients, supporting construct validity. Criterion validity was also satisfactory, with highest correlations of PFS total fatigue with the MFI subscale general fatigue (0.84) and RSCL overall quality of life score (0.74). Internal consistency was similar in Dutch and U.S. breast cancer patients; fatigue scores were lower on several PFS subscales in the Dutch study population. CONCLUSION: Psychometric properties of the Dutch version of the revised PFS, as tested in cancer patients prior to radiotherapy, were satisfactory.

Adult↗
PubMed2004

Pharmacokinetic and pharmacodynamic drug interactions with Kava (Piper methysticum Forst. f.).

Kava kava, a beverage or extract prepared from the rhizome of the kava plant (Piper methysticum Forst. f.), was used for many centuries as a traditional beverage in the Pacific Islands. During the past few decades, kava has also gained popularity in Western countries as well, due to its anxiolytic and sedative properties. However, in recent years, kava has been implicated in several liver failure cases which led to its ban in many countries and this has prompted wide discussion on its relative benefits and risks as a social beverage and a herbal remedy. Recently, it has been shown that several kavalactones, the assumed active principles of kava extracts, are potent inhibitors of several enzymes of the CYP 450 system (CYP1A2, 2C9, 2C19, 2D6, 3A4 and 4A9/11). This indicates that kava has a high potential for causing pharmacokinetic drug interactions with other herbal products or drugs, which are metabolised by the CYP 450 enzymes. In addition, several pharmacodynamic interactions have been postulated and indeed observed. Nevertheless, evidence of true pharmacokinetic and/or pharmacodynamic interactions remains unsubstantiated, and only few investigations of the potential of kava preparations to interact with specific drugs have been carried out. This review provides a critical overview of the existing data on interactions of kava with other drugs and concludes that there is an urgent need for further in vitro and in vivo investigations to fully understand clinically significant interactions with kava that have the potential to cause adverse effects or toxicity in kava users.

Anti-Anxiety Agents↗
PubMed2004

Analysis of plant extracts by NIRS: simultaneous determination of kavapyrones and water in dry extracts of Piper methysticum Forst.

A near-infrared reflection spectroscopy (NIRS) method was developed to determine the total content of kavapyrones, kavain and water in dry extracts of Piper methysticum Forst. (kava kava, Piperaceae). Based on the recorded spectra and the reference data, performed by HPLC and Karl Fischer titration, a chemometrical analysis was calculated using PLS 2 algorithm. In general, good calibration statistics are obtained for the prediction of the different contents presenting high correlation coefficients (r(2) > 0.9913) and low root mean square errors of prediction (RMSEP < 0.094%). Usually the main water bands are "cut out" of the spectra to improve the model, however this is associated with the loss of relevant spectroscopic information. Thus, the entire spectrum including the OH bands is used, as these are not only found in water but also in the kavapyrones. The use of this new strategy succeeds in overcoming the difficulties in NIRS and establishes NIRS as a valid alternative in the routine quality control of plant extracts.

Kava↗
PubMed2000

Potential of varietal resistance and Piper guineense seed oil to control infestation of stored millet seeds and processed products by Tribolium castaneum (Herbst).

Three grain forms (whole grains, broken grains and wholemeal flour) of three improved varieties (ICMV-N89305, GB8735 and Sosat) developed at ICRISAT (Patancheru, India), one cultivar which originated in Zimbabwe (Zimbabwean dwarf) and two local cultivars (Ex-borno and Gwagwa), of pearl millet were compared for their susceptibility to the rust-red flour beetle (Tribolium castaneum) under tropical storage conditions. The biological effects of Piper guineense seed oil were also investigated on T. castaneum confined on similar forms of millet (Ex-borno) contained in ventilated or unventilated devices. Mortality of adult flour beetles was significantly higher on whole grains of GB8735 (99.7%), Gwagwa (92.3%) and Ex-borno (77.7%) stored in unventilated glass jars than on whole grains of Zimbabwean dwarf (52.7%) stored in a similar device. The number of adult progeny was significantly higher in wholemeal flour than in broken grains; the number in broken grains was significantly higher than that in whole grains. Development of the beetle was significantly longer in GB8735 than in Zimbabwean dwarf and the overall susceptibility of Zimbabwean dwarf was significantly higher than that of ICMV-N89305. Susceptibility of the cultivars increased with decreasing grain particle size; susceptibility indices for the whole grains, broken grains and wholemeal flour were 2.52, 12.14 and 14.16, respectively. Significantly fewer beetles developed in grains/products treated with P. guineense seed oil than in untreated grains/products. The unventilated glass jar retained the biological efficacy of the two lower dosages (20 and 40 mg/10 g) of P. guineense seed oil significantly more than the ventilated clay pot or polypropylene sack.

Journal Article↗
PubMed2000

Phenylpropanoids and tetrahydrofuran lignans from Piper solmsianum.

A tetrahydrofuran lignan as well as the known tetrahydrofuran lignan, (-)-grandisin, and five phenylpropanoid derivatives were isolated from Piper solmsianum. Their structures were determined by means of spectral analyses, including 2D NMR techniques such as NOE-DIFF and HMBC 3J(C-H).

Anthracenes↗
PubMed2002

Kavalactones from Piper methysticum, and their 13C NMR spectroscopic analyses.

The kavalactone, 11-methoxy-5,6-dihydroyangonin, and eight previously reported analogs along with four other aromatic compounds were isolated from the root extracts of Piper methysticum (Kava Kava). Their structural elucidations were made by 1H and 13C NMR spectroscopic assignments using COSY, HMBC and HMQC experiments.

Carbon Isotopes↗
PubMed2003

Piperidine alkaloids from Piper methysticum.

Pipermethystine (1), 3alpha,4alpha-epoxy-5beta-pipermethystine (2) and awaine (3) were isolated from the aerial parts of kava (Piper methysticum G. Forster, Piperaceae) and identified by HRMS and NMR spectroscopic analysis. 1 was concentrated in the stem peelings and leaves. 2 and 3 are new alkaloids with 2 found only in cv. Isa among the 11 cultivars examined, and 3 occurred primarily in young leaves of all cultivars. The stem peelings have been used in recent years as a source of kavalactones in kava dietary supplement industry. Quantitative aspects of these piperidine alkaloids in P. methysticum and their potential activities on human physiology are discussed.

Alkaloids↗
PubMed2003

Antifungal flavanones and prenylated hydroquinones from Piper crassinervium Kunth.

Bioactivity-guided fractionation of the EtOAc extract from leaves of Piper crassinervium yielded three prenylated hydroquinones together with two known flavanones naringenin and sakuranetin. Their structures were determined by means of spectroscopic analysis (NMR, IR, UV and MS) including two-dimensional NMR spectroscopy experiments (1H-1H COSY, HMQC, HMBC and NOESY). The antifungal activity was determined by direct bioautography against Cladosporium cladosporioides and C. sphaerospermum.

Antifungal Agents↗
PubMed1999

A chromene and prenylated benzoic acid from Piper aduncum.

In addition to nerolidol, 2',6'-dihydroxy-4'-methoxydihydrochalcone, methyl 2,2-dimethyl-8-(3'-methyl-2'-butenyl)-2H-1-chromene-6-carboxylate, methyl 2,2-dimethyl-2H-1-chromene-6-carboxylate and methyl 8-hydroxy-2,2-dimethyl-2H-1-chromene-6-carboxylate, two new natural products were isolated from the leaves of Piper aduncum, 2,2-dimethyl-2H-1-chromene-6-carboxylic acid and 3-(3',7'-dimethyl-2',6'-octadienyl)-4-methoxybenzoic acid. The structures of the isolates were established based on analysis of spectroscopic data, including ES-MS. The DNA-damaging activity of the isolated compounds was also investigated against mutant strains of Saccharomyces cerevisiae.

Benzoates↗
PubMed2000

Cenocladamide, a dihydropyridone alkaloid from Piper cenocladum.

A dihydropyridone alkaloid, cenocladamide, and a derivative of piplartine, 4'-desmethylpiplartine were isolated along with piplartine from the leaves of Piper cenocladum. The structures of the new compounds were determined by spectroscopic methods and by comparison to piplartine. Concentrations of these amides in plants with and without ant mutualists, are compared.

Gas Chromatography-Mass Spectrometry↗
PubMed2003

Hepatitis induced by Kava (Piper methysticum rhizoma).

BACKGROUND/AIMS: Botanical drugs are widely used and often contain highly active compounds. Kava root (Piper methysticum rhizoma), used frequently in Europe as a remedy against anxiety, contains kavapyrones with sedative effects. Seven case reports suggested the development of hepatitis after the intake of Kava. METHODS: We analyzed 29 novel cases of hepatitis along with Kava ingestion which occurred between 1990 and 2002 in addition to the seven already published case reports using a clinical diagnostic scale established for adverse hepatic drug reactions. RESULTS: Hepatic necrosis or cholestatic hepatitis were noticed with both alcoholic and acetonic Kava extracts. The majority of the 29 patients and the additional seven published reports were women (27 females, nine males). Both the cumulative dose and the latency to when the hepatotoxic reaction emerged were highly variable. Nine patients developed fulminant liver failure, of which eight patients underwent liver transplantation. Three patients died, two following unsuccessful liver transplantation and one without. In all other patients, a complete recovery was noticed after the withdrawal of Kava. Pathophysiologically, both immunoallergic and idiosyncratic factors may be responsible. CONCLUSIONS: The present report emphasizes the potentially severe hepatotoxicity of Kava which has recently led to the retraction of Kava-containing drugs by the pharmacovigilance authorities in Germany.

Acute Disease↗
PubMed1999

Contact leukomelanosis induced by the leaves of Piper betle L. (Piperaceae): a clinical and histopathologic survey.

BACKGROUND: In April 1997, an unusual pigmentary disorder was noticed by dermatologists in Taiwan. All patients had a history of using facial dressings with steamed leaves of Piper betle L. (Piperaceae). OBJECTIVE: Our purpose was to clarify the evolution and the origin of this unique leukomelanosis. METHODS: Fifteen patients with an unusual pigmentary disorder, who visited our clinic in September and October 1997, were asked to complete a questionnaire designed to elicit the history related to the disorder. Eight of these 15 patients underwent skin biopsies: 6 on the mottled hyperpigmented area (group A) and 2 on the hypopigmented area (group B). All 8 specimens were prepared with hematoxylin-eosin, Masson-Fontana, and S-100 stains. RESULTS: The results of the questionnaire revealed that these patients had all experienced a temporary erythematous reaction in the first few days of the use of the facial dressing, and 9 of them also complained of an accompanying stinging sensation. A bleaching effect became noticeable approximately 1 week to 1 month later. Eight patients reported that the hyperpigmentation and confetti-like hypopigmentation occurred after overexposure to the sun. In both groups, histopathologic examination revealed some melanophages in the dermis. Masson-Fontana staining of specimens from group A showed local interspersed depigmentation and hyperpigmentation in the basal epidermis and pigmentary incontinence in the dermis. This picture was different from the homogeneous depigmentation within basal epidermis in specimens from group B. In both groups, S-100 staining was negative for melanocytes in the depigmented area. CONCLUSION: The clinical course and histopathologic findings suggest that the evolution of this pigmentary disorder can be divided into 3 stages. The first stage is the immediate bleaching stage, when an irritant reaction is usually conspicuous. The second stage consists of prominent hyperpigmentation visible both grossly and microscopically. The final stage is characterized by confetti-like depigmentation. It may be induced by chemicals in the betel leaves such as phenol, catechol, and benzene derivatives, perhaps through inhibition of melanin synthesis or melanocytotoxicity.

Adult↗
PubMed2001

Composition and chemical polymorphism of the essential oils from Piper lanceaefolium.

Essential oils obtained by hydrodistillation from leaves and spikes of Piper lanceaefolium H.B.K. of Costa Rica were analysed by GC-FID, GC-MS and 13C-NMR methods. Main constituents found in the oil from leaves were sesquiterpene hydrocarbons - especially beta-caryophyllene and germacrene D - and phenylpropanoids, of which elemicin and parsley apiol were the major ones. The volatile oil from spikes showed monoterpene hydrocarbons, namely alpha- and beta-pinene, and the same phenylpropanoids as in the oil from leaves as the major constituents. Results obtained in the analysis by GC-FID and GC-MS of the essential oils from individual plants of different geographic origin were submitted to chemometric cluster analysis and principal component analysis, showing the presence of three different types of oils (i) parsley apiol/elemicin, (ii) elemicin/parsley apiol/dill apiol, and (iii) parsley apiol/dill apiol.

Journal Article↗
PubMed2001

Two amides from Piper tuberculatum fruits.

The fruits of Piper tuberculatum yielded pellitorine, N-isobutyl-2E,4E-decadienamide (1), and piperidide-2E,4E-decadienamide (2). Their complete NMR analysis, based on one- and two-dimensional experiments, is reported.

Fatty Acids, Unsaturated↗
PubMed2001

Chemical composition of the essential oil from the leaves of Piper fulvescens, a plant traditionally used in Paraguay.

The essential oil from the leaves of the aromatic aniseed smelling plant Piper fulvescens, obtained by hydrodistillation, was investigated by GC and GC-MS, as well as by 13C-NMR after fractionation of the oil by column chromatography. A total of 37 constituents, representing 78.2% of the oil were identified. The main compounds were trans-anethole (26.4%) and ishwarane (12.1%), an unusual sesquiterpene hydrocarbon.

Gas Chromatography-Mass Spectrometry↗
PubMed1998

Piscicidal properties of piperovatine from Piper piscatorum (Piperaceae).

Extraction of the roots of the Amazonian medicinal plant, Piper piscatorum Trelease and Yuncker, with MeOH and subsequent bioassay guided fractionation using the guppy, Girardina guppii yielded the active amide, N-isobutyl-6-(p-methoxyphenyl) 2E, 4E-hexadieneamide (piperovatine) and a second inactive amide, N-isobutyl-(E)-7-(3,4-methylenedioxyphenyl)hept-2-enamide (pipercallosidine). The former displayed an LC50 of 115 ng/ml in toxicity tests and proved to be the constituent responsible for the dual ethnobotanical uses of this plant: that of fish stupefacient (barbasco) and oral local anesthetic.

Animals↗