Allergen content of popular chemical hair relaxers: A product analysis.

BACKGROUND: Chemical hair relaxers are widely utilized by black women, yet little research exists on the allergens present in these products. OBJECTIVE: This study aims to investigate allergen prevalence in the most popular chemical hair relaxers. METHODS: We analysed 41 products from five major retailers, identifying allergens through ingredient lists and comparing them to the 2020 American Contact Dermatitis Group Core allergen series. RESULTS: The most common contact allergens in chemical relaxers include propylene glycol, cetyl steryl alcohol, fragrance, D/L-a-tocopherol, tea tree oil and cocamidopropyl betaine. CONCLUSION: Understanding allergen exposure in products used by individuals with textured hair is needed for managing contact dermatitis in diverse populations. This analysis underscores the presence of potential allergens in hair relaxers, emphasizing the importance of dermatologists' awareness and patient scrutiny of ingredient lists.

Adulteration of Essential Oils: A Multitask Issue for Quality Control. Three Case Studies: Lavandula angustifolia Mill., Citrus limon (L.) Osbeck and Melaleuca alternifolia (Maiden & Betche) Cheel.

The quality control of essential oils (EO) principally aims at revealing the presence of adulterations and at quantifying compounds that are limited by law by evaluating EO chemical compositions, usually in terms of the normalised relative abundance of selected markers, for comparison to reference values reported in pharmacopoeias and/or international norms. Common adulterations of EO consist of the addition of cheaper EO or synthetic materials. This adulteration can be detected by calculating the percent normalised areas of selected markers or the enantiomeric composition of chiral components. The dilution of the EO with vegetable oils is another type of adulteration. This adulteration is quite devious, as it modifies neither the qualitative composition of the resulting EO nor the marker's normalised percentage abundance, which is no longer diagnostic, and an absolute quantitative analysis is required. This study aims at verifying the application of the two above approaches (i.e., normalised relative abundance and absolute quantitation) to detect EO adulterations, with examples involving selected commercial EO (lavender, bergamot and tea tree) adulterated with synthetic components, EO of different origin and lower economical values and heavy vegetable oils. The results show that absolute quantitation is necessary to highlight adulteration with heavy vegetable oils, providing that a reference quantitative profile is available.

Analysis of biologically active oxyprenylated phenylpropanoids in Tea tree oil using selective solid-phase extraction with UHPLC-PDA detection.

An efficient analytical strategy based on different extraction methods of biologically active naturally occurring oxyprenylated umbelliferone and ferulic acid derivatives 7-isopentenyloxycoumarin, auraptene, umbelliprenin, boropinic acid, and 4'-geranyloxyferulic acid and quantification by UHPLC with spectrophotometric (UV/Vis) detection from Tea tree oil is reported. Absorption of the pure oil on Al2O3 (Brockmann activity II) prior washing the resulting solid with MeOH and treatment of this latter with CH2Cl2 resulted the best extraction methodology in terms of yields of oxyprenylated secondary metabolites. Among the five O-prenylphenylpropanoids herein under investigation auraptene and umbelliprenin were never detected while 4'-geranyloxyferulic acid was the most abundant compound resulting from all the three extraction methods employed. The UHPLC analytical methodology set up in the present study resulted to be an effective and versatile technique for the simultaneous characterization and quantification of prenyloxyphenylpropanoids in Tea tree oil and applicable to other complex matrices from the plant kingdom.

The Influence of Toothpaste Containing Australian Melaleuca alternifolia Oil and Ethanolic Extract of Polish Propolis on Oral Hygiene and Microbiome in Patients Requiring Conservative Procedures.

The study was based on the use of a toothpaste with antiphlogistic activity, containing Australian Melaleuca alternifolia oil (tea tree oil-TTO) and ethanolic extract of Polish propolis (EEP). Fifty-one patients with varying conditions of the gingiva were divided into two groups. The study group received the toothpaste with TTO and EEP, while the control group received the same toothpaste but without TTO and EEP. Approximal plaque index (API), simplified oral hygiene index (OHI-s) and modified sulcus bleeding index (mSBI) were assessed in three subsequent stages. During each examination, swabs were employed for microbiological inoculation. During the period of use of toothpastes with TTO and EEP, a significant reduction of the API was observed, as assessed upon the control visit after 7 days and after 28 days, compared to baseline. A statistically significant reduction of mSBI was observed after 7 and 28 days of using the toothpaste with TTO and EEP, as compared to the value upon the initial visit. Statistically significant differences in the OHI-s value were observed in the study group, which was using the active toothpaste. The use of a toothpaste containing TTO and EEP helps to maintain microbiome balance. The observed stabilisation of bacterial microflora confirms the beneficial activity of toothpaste containing EEP and TTO compared to the control group, where the lack of these substances contributed to the emergence of qualitative and quantitative changes in oral microbiome.

Determination of Enantiomeric Distribution of Terpenes for Quality Assessment of Australian Tea Tree Oil.

A number of papers have appeared in recent years proposing the use of enantiomeric ratios of key monoterpenes in Australian tea tree oil (TTO) for detection of adulterated oils. There are however a range of reported values, even from exactly the same suite of authentic oils, and we address here probable reasons for these differences and stress the importance of establishing reference ratios within each laboratory based on oils of known provenance. Any biological variation in the ratio for the key terpene terpinen-4-ol has been demonstrated to be effectively unmeasurable, because the standard deviation on multiple measurements of the same oil is of the same order as that of multiple authentic oils.

Óleo de melaleuca (Melaleuca alternifolia Maiden & Betche, Cheel) no controle de cercosporiose em beterraba / Tea tree oil (Melaleuca alternifolia Maiden& Betche, Cheel) in control of Cercospora beticola Sacc. on Beet

RESUMO O óleo volátil da melaleuca (Melaleuca alternifolia Maiden & Betche, Cheel) possui atividade antimicrobiana podendo causar efeitos sobre as plantas. Avaliou-se a inibição do óleo em Cercospora beticolaSacc., e seu efeito no aumento da produção e qualidade de raízes de beterraba. As doses foram de 0,13; 0,67; 0,80 e 1,00% do óleo, além das testemunhas composta pelo meio de cultura Batata Dextrose Ágar (BDA) no experimento in vitro, e água no experimento in vivo. As plantas foram pulverizadas duas vezes por semana. O delineamento foi inteiramente casualizado, com 4 repetições, e as médias foram comparadas pelo teste Tukey a 5% de probabilidade. O índice de infecção das folhas foi determinado por escala diagramática além do peso e diâmetro das raízes. Os resultados de inibição do crescimento micelial para as doses do óleo foram 0; 56; 87; 83 e 99%, e os índices de infecção: 77,08; 35,62; 21,04; 19,37 e 20,00%, respectivamente, para a testemunha e as doses 0,13; 0,67; 0,80 e 1,00% do óleo. Somente na concentração de 0,80% o óleo proporcionou relação positiva entre o ganho de peso e o diâmetro das raízes. O óleo de Melaleuca foi eficaz no controle de C. beticola e, como consequência, houve produção de raízes de beterraba com melhor desenvolvimento.

ABSTRACT The volatile oil from Melaleuca (Melaleuca alternifolia Maiden & Betche Cheel.) has antimicrobial properties and can promote several effects on plant cultivation. The aim of this study was to evaluate the inhibition of the oil in Cercospora beticola Sacc. and if it favors the growth and development of beet root. The doses were 0.13, 0.67, 0.8 and 1% of oil, besides the control PDA (potato-dextrose-agar) in vitro (laboratory condition) and with water as treatment control in vivo (field conditions). The plants were sprayed twice a week. The treatments were completely randomized and the averages were compared using the Tukey test at 5%. The infection rate of leaves was measured by diagrammatic scale besides the weight and diameter of tubers. The inhibition results of the radial growth by oil treatments were 0; 56, 87, 83 and 99%, while the infection rate showed: 77.08, 35.62, 21.04, 19.37 and 20% respectively to the control and to the oil concentration of 0,13; 0,67; 0,80 e 1,00%. Only at concentration of 0.8% the tea tree oil showed a positive relationship between tuber´s weight and tuber´s diameter gains. It can be concluded that tea tree oil is effective to controlling C. beticola, and also promotes an increase on development in beet tubers.

Multiplexed dual first-dimension comprehensive two-dimensional gas chromatography-mass spectrometry with contra-directional thermal modulation.

A multiplexed dual-primary column comprehensive two-dimensional gas chromatography-mass spectrometry approach (2GC×GC-MS) is introduced. The approach splits injected samples into two first-dimension columns with different stationary phases, and recombines the two streams into one second-dimension column that terminates at a single detector. The approach produces two two-dimensional chromatograms for each injection, and is made possible by using a dual-stage modulator operated in contra-directional modulation mode. The dual two-dimensional chromatograms produced by this single detector system provide complementary information due to selectivity differences between the three separation columns used in the column ensemble. An aged Australian tea tree (Melaleuca alternifolia) essential oil was analyzed to demonstrate the 2GC×GC-MS approach. The number of compounds separated by each of the GC×GC separations in the 2GC×GC experiment is comparable to conventional GC×GC experiments with matching column configurations. Robust peak assignment was possible for this sample based on the combination of MS library matches and multiple linear retention index searching. Forty-nine components (22 unique) were identified using a non-polar×mid-polar column combination and 34 components (7 unique) were positively identified using a polar×mid-polar column combination. Twenty-seven peak assignments were corroborated by positive identification in both of the multiplexed separations.

Vibrational spectroscopy as a rapid quality control method for Melaleuca alternifolia cheel (tea tree oil).

INTRODUCTION: Tea tree oil (TTO) is an important commercial oil which has found application in the flavour, fragrance and cosmetic industries. The quality is determined by the relative concentration of its major constituents: 1,8-cineole, terpinen-4-ol, α-terpineol, α-terpinene, terpinolene, γ-terpinene and limonene. Gas chromatography coupled to mass spectrometry (GC-MS) is traditionally used for qualitative and quantitative analyses but is expensive and time consuming. OBJECTIVE: To evaluate the use of vibrational spectroscopy in tandem with chemometric data analysis as a fast and low-cost alternative method for the quality control of TTO. METHODS: Spectral data were acquired in both the mid-infrared (MIR) and near infrared (NIR) wavelength regions and reference data obtained using GC-MS with flame ionisation detection (FID). Principal component analysis (PCA) was used to investigate the data by observing clustering and identifying outliers. Partial least squares (PLS) multivariate calibration models were constructed for the quantification of the seven major constituents. RESULTS: High correlation coefficients (R(2) ) of ≥ 0.75 were obtained for the seven major compounds and 1,8-cineole showed the best correlation coefficients for both MIR and NIR data (R(2) = 0.97 and 0.95, respectively). Low values were obtained for the root mean square error of estimation (RMSEE) and root mean square error of prediction (RMSEP) values thereby confirming accuracy. CONCLUSION: The accurate prediction of the external dataset after introduction into the models confirmed that both MIR and NIR spectroscopy are valuable methods for quantification of the major compounds of TTO when compared with the reference data obtained using GC-MS. Copyright © 2013 John Wiley & Sons, Ltd.

Tea tree oil.

Tea tree oil is an increasingly popular ingredient in a variety of household and cosmetic products, including shampoos, massage oils, skin and nail creams, and laundry detergents. Known for its potential antiseptic properties, it has been shown to be active against a variety of bacteria, fungi, viruses, and mites. The oil is extracted from the leaves of the tea tree via steam distillation. This essential oil possesses a sharp camphoraceous odor followed by a menthol-like cooling sensation. Most commonly an ingredient in topical products, it is used at a concentration of 5% to 10%. Even at this concentration, it has been reported to induce contact sensitization and allergic contact dermatitis reactions. In 1999, tea tree oil was added to the North American Contact Dermatitis Group screening panel. The latest prevalence rates suggest that 1.4% of patients referred for patch testing had a positive reaction to tea tree oil.

Análise da atividade antimicrobiana dos óleos de dopaíba (Copaifera officinalis) e da melaleuca (Melaleuca alternifolia) sobre Fusobacterium nucleatum e Porphyromonas gingivalis: determinação das concentrações inibitórias e bactericidas mínimas e efeito de concentrações subinibitórias sobre a agregação / Antimicrobial activity of copaiba (Copaifera officinalis) and melaleuca (Melaleuca alternifolia) oils on Porphyromonas gingivalis and Fusobacterium nucleatum: determination of minimum inhibitory and bactericidal concentrations and subinibitory effect on the aggregation

A cavidade bucal é um habitat microbiano complexo que apresenta mais de 500 espécies bacterianas como componentes da microbiota. A saúde periodontal está estabelecida quando há equilíbrio entre os microrganismos patogênicos e o hospedeiro. O digluconato de clorexidina é um dos antimicrobianos bucais mais utilizados, no entanto, essa substância tem sido associada a alguns efeitos colaterais indesejáveis. Os óleos de copaíba e de melaleuca tem sido estudados como importantes fitoterápicos, devido aos seus diversos efeitos, entre eles ação antibacteriana. Partindo-se do princípio de que o óleo copaíba e de melaleuca possuem atividade antimicrobiana e de que não há dados suficientes na literatura utilizando esses fitoterápicos sobre Porphyromonas gingivalis e Fusobacterium nucleatum, foram preparados testes de Concentração Inibitória Mínima (CIM) e Concentração Bactericida Mínima (CBM) das bactérias Fusobacterium nucleatum (ATCC 25586) e Porphyromonas gingivalis (ATCC 3327) frente ao digluconato de clorexidina e aos óleos provindos de Copaifera officinalis e de Melaleuca alternifólia. Realizaram-se ainda testes para determinação de Concentração Subinibitória (CS) e ensaios para determinar a capacidade de autoagregação e coagregação dessas bactérias expostas às concentrações subinibitórias das soluções testadas. Como controles foram utilizados apenas meio de cultura e meio de cultura acrescido de Tween 80. Todos os óleos utilizados tiveram sua composição analisada por cromatografia gasosa acoplada à espectrometria de massa. O óleo de melaleuca, após identificação de sua composição, apresentou, respectivamente, os seguintes constituintes em maiores concentrações: terpin-4-ol, -terpineno, -terpineno, terpinoleno e 1,8-cineol. O óleo de copaíba apresentou como principais constituintes, respectivamente, trans-cariofileno, germacreno B, -humuleno, germacreno D e -copaeno. Os resultados obtidos como CIM para F.nucleatum foram semelhantes à CBM em todas as...

The oral cavity is a complex microbial habitat that has more than 500 bacterial species as components of the microbiota. Periodontal health is established when there is equilibrium between pathogens and host. The chlorhexidine digluconate is one of the most commonly used oral antibiotics, however, this substance has been associated with some undesirable side effects. Copaiba and melaleuca oils have been studied as important herbal medicines because of their effects, including antibacterial action. Based on the principle that the copaiba oil and tea tree have an antimicrobial activity and that is no sufficient data in the literature using these herbal medicines against Porphyromonas gingivalis and Fusobacterium nucleatum, Minimum Inhibitory Concentration (MIC) and minimum bactericidal concentration (MBC) tests of Fusobacterium nucleatum (ATCC 25586) and Porphyromonas gingivalis (ATCC 3327) related to chlorhexidine digluconate and oils coming from Copaifera officinalis and Melaleuca alternifolia, were prepared. Assays were performed to determine the subinibitory concentration and the capacity of those bacteria to autoaggregation and coaggregation when exposed to subinibitory concentrations, previously tested. Medium and medium added Tween 80 were used as a control. All oils used had their composition analyzed by gas chromatography-mass spectrometry. The tea tree oil mainly chemical compounds were identified as terpin-4-ol, -terpinen, -terpinen, terpinolene and 1,8-cineole while copaiba oil presented as its main constituents trans-caryophyllene, germacrene B, -humulene, germacrene D and -copaene. The MIC results for F.nucleatum were similar to the CBM data in all solutions. For the bacterium P. gingivalis, all solutions tested inhibited bacterial growth, however, the results obtained during the determination of CBM showed that the copaiba oil was bacteriostatic. All solutions tested inhibited the autoaggregation process but only...

Curativo imediato com hidrogel à base de água, óleo de melaleuca alternifolia e emulsificantes após queimaduras / Burns immediate dressing with water, oil of melaleuca and emulsificants

Introdução: O Burnshield® (United Medical, Brasil) é uma opção de curativo imediato paraqueimaduras que visa à hidratação e ao resfriamento da ferida, sendo objetivo deste trabalhoavaliar sua eficácia. Método: Estudo experimental controlado cego, com 36 ratos Wistardivididos em 3 grupos de 12: (A) tratados com Burnshield®, (B) tratados com água correntepor 15 minutos e (C) não tratados. Metade dos animais de cada grupo foi sacrificada com 30minutos após queimadura, e a outra metade com 24 horas de evolução. O critério de avaliaçãofoi a maior profundidade de lesão encontrada em cada animal. Resultados: O grupo Capresentou as queimaduras mais profundas em relação aos demais, com 30 minutos e 24 horas.Não houve diferença entre os grupos A e B com 30 minutos, porém houve melhor resultadosignificativo no grupo A nas 24 horas de evolução. Conclusão: O Burnshield® mostroueficácia comparável à água corrente no tratamento inicial de queimaduras, com melhoresresultados depois de 24 horas de evolução. Apresenta como maior vantagem a praticidade,podendo ser usado enquanto o paciente é deslocado até o centro de tratamento especializado.

Introduction: Burnshield® (United Medical, Brazil) is an option of immediate dressing forburns aimed at hydrating and cooling the wound. Purpose: Investigate, histopathologically,the efficacy of Burnshield® as initial treatment for thermal burns. Method: Blind controlledexperimental study, with 36 Wistar rats divided into 3 groups of 12 rats: (A) treated withBurnshield®, (B) treated with running water for 15 minutes and (C) not treated. Half of theanimals of each group were sacrificed 30 minutes after the burn and the other half, within 24of evolution. The assessment criterion was the extension of lesion found in each animal.Results: Group C showed the deepest burns compared to the others, within 30 minutes and24 hours. There was no difference between groups A and B within 30 minutes; however, groupA showed better and significant results within 24 hours of evolution. Conclusion:Burnshield® showed efficacy comparable to running water at the initial treatment of burns,with better results after 24 hours of evolution. Its main advantage is its practicality, once itcan be used while the patient is carried up to the center of specialized treatment.

Tea tree oil.

Tea tree oil is a popular ingredient in many over-the-counter healthcare and cosmetic products. With the explosion of the natural and alternative medicine industry, more and more people are using products containing tea tree oil. This article reviews basic information about tea tree oil and contact allergy, including sources of tea tree oil, chemical composition, potential cross reactions, reported cases of allergic contact dermatitis, allergenic compounds in tea tree oil, practical patch testing information, and preventive measures.

Method development and validation for the GC-FID assay of p-cymene in tea tree oil formulation.

This paper describes the development and validation of an isothermal gas chromatography-flame ionisation detection (GC-FID) method for the assay of pure tea tree oil. The chromatographic conditions of the method employ a 5% carbowax packed column (20 m x 0.25 mm), isothermal elution with hydrogen at a column flow of 36 ml/min, injector and detector temperature at 220 degrees C and oven temperature at 100 degrees C, and a 1.5 microl injection volume. Samples and standard were diluted in hexane. The calibration curve for p-cymene was linear (r2=0.9995) from 20 to 120% range of the analytical concentration of 100 microg/ml. The precision of this method was calculated as the relative standard deviation (R.S.D.) was 0.66% (n=6). The R.S.D. for intermediate precision study was 0.13 and recovery of the p-cymene ranged between 93.39 and 97.86%. The limits of detection and quantitation were determined to be 2.08 and 10.39 ng/ml, respectively.

A validated HPTLC method for determination of tea tree oil from cosmeceutical formulations.

A HPTLC method has been developed and validated for the determination of tea tree oil from cosmeceutical formulations. Tea tree oil concentration was estimated by analyzing the terpinen-4-ol content. The method employed TLC aluminium plates precoated with silica gel 60F-254. The solvent system consisted of toluene and ethyl acetate in the ratio 85:15. The calibration curve of terpinen-4-ol was linear in the range of 100-900 ng. The polynomial regression data for the calibration plots showed a good linear relationship with r(2)=0.9949. The Rf value of terpinen-4-ol was found to be 0.62+/-0.05. The method was validated for precision and accuracy. The minimum detectable amount was found to be 60 ng. The limit of quantitation was found to be 100 ng. The drug content was within the limits (+/-5% of the labeled content of the formulations). The recovery of tea tree oil was greater than 99%. The method was found to be simple, sensitive, precise, accurate and specific for estimation of tea tree oil from formulations.

Preferred age for assessment of qualitative and quantitative characteristics of the essential oil of tea tree (Melaleuca alternifolia) seedlings prior to plantation establishment.

An analytical method for determining the quality and hence the chemical variety status of tea tree transplants is described. The key to the procedure was found to be the leaf age of the test material. Investigation at very early development stages was seen to give misleading results due to the sequential onset of different monoterpenoid biogenetic pathways. For example, in the first few leaves, the high concentration of terpinolene in the terpinen-4-ol variety suggests that the terpinolene variety is under investigation. However, 1,8-cineole percent concentrations in plantation tree leaf were approximately 1.6 times lower than those measured for seedlings prior to transplant. Consequently, the use of a plantation cineole indicator is proposed for estimating plantation cineole from seedling leaf analyses. Although recent investigations enable the chemotype status to be predicted with some certainty, it is now proposed that analysis of leaf set 10 at the age of 6 weeks (seedling age approximately 17 weeks) provides an unambiguous analysis and correlates seedling quality with mature plantation quality. In addition, the oil yield of mature tea tree leaf was found, by steam distillation, to be approximately 5 times higher than that of seedling leaf.

[Quality evaluation of essential oils].

Essential oils on the market were analyzed using GC-MS and the main ingredients of each essential oil were quantified. Analysis of the essential oil of Lavandula officinalis (lavender oil) showed that each sample had a different ratio of the contents of main ingredients, such as linalool, linalyl acetate, and camphor. In addition, some commercial lavender oils were analyzed by GC-MS for comparison with the Lavandula flagrans (lavandin oil) and the reference standard. As a result of this analysis, although the components of almost all commercial lavender oils were approximately the same as those of the reference standard, there were a few products that contained more than 0.5% of the amount of camphor in lavandin oil. This suggests that some lavender oil samples are mixed with lavandin oil to lower the price. Commercial essential oils of Melaleuca alternifolia (teatree oil) and Mentha piperita (peppermint oil) were also analyzed by GC-MS. Each of the peppermint oil samples had a different ratio in the content of its main ingredient. With respect to teatree oils, the amount of terpinens in each sample differed. These results led to concern about the efficacy of essential oils. For achieve the expected efficacy of essential oils, correct information on their ingredients should be available and quality control using instrumental analysis should be introduced.

In vitro evaluation of the antibacterial activity of beta-triketones admixed to Melaleuca oils.

The in vitro antibacterial properties of mixtures of Australian tea tree oil and niaouli oil after adding the beta-triketone complex isolated from manuka oil were tested. MIC and MBC values for four different bacteria were determined applying the broth dilution method. Both Melaleuca oil mixtures showed good antimicrobial effects against Staphylococcus aureus and Moraxella catarrhalis, exceeding the effectiveness of myrtol, which is well established in the treatment of acute and chronic bronchitis and sinusitis. The death kinetics of S. aureus were determined to draw subtle comparisons between the mixtures. The kill rate data indicated that both Melaleuca oil mixtures achieved a complete kill within 240 min.

[Allergic contact dermatitis to cosmetics containing Melaleuca alternifolia (tea tree oil)]. / Dermatite de contact allergique aux cosmétiques à base de Melaleuca alternifolia (tea tree oil).

INTRODUCTION: Melaleuca alternifolia is a coniferous tree found in tropical regions, the needles contain an essential oil that is used in medical and cosmetic products. The essential oil contains turpentines (limonene, alpha-pinene, phellandrene) that are potentially allergenic. PATIENTS AND METHODS: In 1997, 1216 patients were patch tested in our dermatoligic unit. Fourteen of them tested because of eczema used products containing tea tree oil. The patients used creams, hair products and essential oils containing Melaleuca alternifolia for cosmetic reasons and to treat skin affections. They were patch tested for a standard panel of allergens, topical emulgators, perfumes, plants, topical medications, metal, gloves, topical disinfectants and preservatives, dental products and rubber derivatives. Products containing Melaleuca alternifolia were tested concentrated or diluted. RESULTS: We report on 7 cases of patients with an allergic contact dermatitis due to tea tree oil. Two of them also exhibited from a delayed type IV hypersensitivity towards fragrance-mix or colophony suggesting the possibility of cross reaction or an allergic group reaction caused by contamination of the colophony with the volatile fraction of turpentines. DISCUSSION: The allergic potential of low concentrations of Melaleuca alternifolia is presumed to be low on healthy skin. Photoaged Melaleuca alternifolia must be considered to be a stronger sensitizer.

Flavonoids of Melaleuca quinquenervia.

From the leaves of Melaleuca quinquenervia (Clav.) S. T. Blake, the new flavonoid 5,7,3',4'-tetrahydroxyflavone 2'-O-beta-D-glucopyranuronide, as well as eight known flavonol glycosides have been isolated and characterized. The structures were established by chromatography, chemical degradation and UV spectroscopy and confirmed by ESI-MS and NMR spectroscopy. This is the first report on the isolation and identification of these flavonoids in the genus Melaleuca.