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Melaleuca cajuputi (MC) is an aromatic herb that belongs to Myrtaceae family. MC leaves are widely used as traditional medicine, cooking flavour and freshening agent in cosmetics. In this study, the proximate analysis of MC leaves comprised of moisture (2.74%), ash (7.76 ± 0.04%), crude fat (4.83 ± 0.20%), calorie (4974 Cal/g), dietary fibre (9.49 ± 0.01%), protein (6.42 ± 0.06%) and carbohydrates (78.25 ± 1.02%). Besides that, in BSLA only MCME produced toxicity effect with LC50 value of 427 µg/mL while MCEO, MCAE and MCDE not showed any toxicity effect based on Meyer’s and Clarkson’s classification. Moreover, MCME produced the highest TPC and TFC value followed with MCAE, MCEO and MCDE which indicated highest free radical scavenging activity. Next, GCMS analysis revealed that 19 compounds are found in MCEO that possess antidepressant and anxiolytic effects. Furthermore, the concentrations of heavy metals in MCEO (lead, cadmium, arsenic and mercury) are within normal range concentrations based on British pharmacopoeia 2008.

Melaleuca cajuputi subsp. cajuputi is one of the Australian Melaleuca species commonly found in Pulau Buru (Maluku, Indonesia). Its oil, the M. cajuputi essential oil (MCEO), has been utilized as the main flavor of the Indonesian functional food, Cajuputs Candy. However, the availability of MCEO is becoming limited. On the other hand, Indonesia has many other potential MCEO sources which can be developed as flavor ingredient. Thus, it is noteworthy to explore these new MCEO sources by studying their sensory characteristics and metabolite profiles. This study was conducted to identify potential metabolites that are correlated to sensory attributes of MCEO by using the metabolomics approach. The metabolite profiles of thirteen MCEOs from different origins were analyzed by gas chromatography-mass spectrometry while sensory analyses on Cajuputs Candy were conducted by difference-from-control and rate-all-that-apply tests. Sixty metabolites from the MCEO were annotated that includes 1,8-cineole, α-terpineol, caryophyllene, α-pinene, and γ-terpinene. Sensory analysis revealed cooling aftertaste and sweet taste as favorable attributes. Further analysis using Orthogonal Partial Least Square indicated that 1,8-cineole and γ-terpinene were correlated with cooling aftertaste, while 1,8-cineole and caryophyllene were also correlated with sweet taste. In contrast, linalool and nerolidol were associated with the feature of the most characteristic manufacturer's products which have unfavorable attributes such as floral, iodophor-like, metallic, and soapy attributes. The identification of these metabolites will be useful for the selection of MCEOs that can potentially be used as flavor.

Melaleuca cajuputi essential oil (MCEO) from Pulau Buru (PBR), Indonesia, has been used as a functional flavor on Cajuputs Candy for years. Our recent study has explored thirteen other alternative MCEO sources to be developed as food flavor. However, not all of the MCEO had similarities to PBR MCEO both in their sensory and volatile profiles. This study aimed to identify the aroma-active compounds which would affect the overall aroma perception of the most- and the least-liked MCEO as a flavor ingredient based on the nasal impact frequency (NIF) method. Initial screening was performed to evaluate the overall liking of thirteen MCEO on Cajuputs Candy through a hedonic test, conducted by seventy-eight untrained panelists. The sample obtained from Mojokerto (MOJ) was the most-liked alternatives MCEO in a similar degree of liking to the currently used PBR, while Belu (BEL) was the least-liked. Further analysis using Gas chromatography–Mass spectrometry/Olfactometry (GC-MS/O) was carried out on the MCEO from PBR, MOJ, as well as BEL. The response of nine panelists showed that the overall aroma perception of PBR was contributed by 1,8 cineole (eucalyptus-like, mint, fresh), α-pinene (pine, green, fresh), and ylangene (spicy, fresh, woody) as the main aroma-active compounds. In addition to α-pinene and 1,8 cineole, the unique aroma of MOJ was dominantly contributed by caryophyllene, possessing a woody, sweet, and spicy aroma. The strong floral odor of linalool and nerolidol, the aroma-active compounds of BEL, generated distinct sensory characteristics in comparison to the reference, PBR.

Essential oil extracted from Melaleucagenus has been widely used worldwidefor many purposes. Most of the its has been reported as the source of phytochemical compound where mostly have anti-inflammatory, antiulcer, antioxidant, antimicrobial and insecticide properties. Thus, three objectives that have been highlighted in this study are (1) to extract essential oil (cajuput oil) from fresh leaves of MelaleucacajuputiPowell using simple steam distillation,(2) to determine the chemical components of MelaleucacajuputPowell essential oil using GCMS and (3) to compare the chemical compound and its percentage with the previous study.Results found that there were 41 chemical compounds that have been identified. The chemical compounds were monoterpenes such as α-terpinolene, α-pinene, sabinene, 4-terpineol and γ-terpinene. The highest chemical compounds found were caryophyllene (20.16%), α-terpinolene (17.0%),α-humulene (11.91%), β-elemene (7.62%) and γ-terpinene (5.62%). In previous research, 1,8-cineole chemical compound was foundhowever, in this study a different chemical compound found, it was caryophyllene, this is due to different geographic area.As a conclusion, most of the compounds found was aromatic, antibacterial andinsecticide properties.

The aim of this study was to evaluate the in vitro activity of Melaleuca cajuputi essential oil leaf extract against Aedes aegypti and Aedes albopictus. The essential oil of the M. cajuputi was obtained via steam hydro-distillation and analyzed by GC-MS for the chemical constituents. GC-MS analysis showed that the essential oil of M. cajuputi contained 13 compounds with two major chemical constituents, 2-propenoic acid (29.55%) and caryophyllene (20.04%). Adulticidal and larvicidal bioassay was evaluated following WHO guidelines. Larvicidal bioassays were conducted with the 10, 50, 80, 100, and 120 mg/L M. cajuputi essential oil against late 3rd instar of Ae. aegypti and Ae. albopictus which give LC50 120.99 mg/L and 222.58 mg/L, respectively. Adult mortality was observed after 24 h with the LC50 of 0.029 mg/cm2 for Ae. aegypti and 0.028 mg/cm2 for Ae. albopictus. In adulticidal bioassay, M. cajuputi essential oils showed effective results at 0.04 mg/cm2 concentrations, with values for KT50 of 77.71 min for Ae. aegypti and 69.49 min for Ae. albopictus. M. cajuputi essential oils exhibited moderate toxicity effects against the larva and adults of Aedes species and may be used as an alternative to chemical insecticide.

Background: Cajuput oil is a traditional and famous product of Thua Thien Hue, it is considered as a potential product, contributing to the economic development of Thua Thien Hue. Currently, there are many different products of cajuput oil in the market. However, the quality of cajuput oils in the production facilities has not been considered. The aim of the present study was to apply GC to the determination of the main components of commercial cajuput oils from M. cajuputi species in the Thua Thien Hue province. Materials and method: The chemical composition of 10 commercial cajuput oils extracted from leaves of Melaleuca cajuputi Powell collected in the Thua Thien Hue province was determined by gas chromatography. Results and conclusion: The major componentsofthe oils wereα-pinene, β-pinene, limonene, 1,8-cineoleand terpineol. The result obtained demonstrate that 1,8-cineole is the main component,present in 10 samples with values ranging from 15 to 59%. Key words: Cajuput oil, Melaleuca cajuputi, 1,8-cineole, α-pinene, β-pinene, limonene, terpineol

Due to food security issues and weeds problem in rice production, allelopathy is introduced as an alternative towards sustainable weeds management. One of Myrtacea plants known as Melaleuca cajuputi extract is studied to assess its herbicidal or allelopathic effect on notorious paddy weeds known as barnyard grass. The plant extract of Melaleuca cajuputi is extracted using supercritical carbon dioxide extraction and soxhlet extraction. The chemical composition of the extract is determined using gas chromatograph mass spectrometry analysis and it was reported that caryophyllene and humulene are detected as the two major sesquiterpenes present. The effectiveness of the inhibition of the weeds was also studied and compared with conventional herbicides and caryophyllene standards. It is determined that Melaleuca cajuputi extract of supercritical and soxhlet extraction induces visible injuries towards the weeds at bud stage of less than 0.75 cm. Thus, it is recommended to increase the concentration higher than 0.05 M to suppress the weeds that grown. Melaleuca cajuputi oil can be further studied to be a potential source for bio-herbicides.

Widiana A, Ukit, Thahirah A, Paijiah E. 2019. Diversity of endophytic fungi in cajuput leaf waste (Melaleuca cajuputi). Biodiversitas 20: 562-569. Cajuput Oil Factory at Jatimunggul, Indramayu of Forest Management Unit of Perum Perhutani (State Forest Enterprises) produces cajuput leaf waste during distillation process. This waste is difficult to decompose due to the presence of lignin in the secondary cell wall. Therefore, fungi are needed to produce some enzymes for speeding up the degrading process. This research was aimed at finding out the diversity of fungi growing in the cajuput (Melaleuca cajuputi Powell) leaf waste of zero, two and four months old. The result indicated that a total of 14 species of fungi belonging to four genera namely Aspergillus, Arthrinium, Rhizopus, and one unidentified genus are produced by cajuput leaf waste. Ten different types of endophytic fungi were isolated from two-month-old waste, seven Rhizopus and types of fungi were found in the zero-month-old waste, and only five types of isolates are found in the four-month-old waste. Three species of isolated fungi were also tested for their cellulase enzyme activity.

Waste of cajuput leaves (Melaleuca cajuputi Powell) has the potential to be used as an alternative cattle feed because it has a fairly high nutritional content. The nutritional content of cajuput leaf waste needs to be improved before being used as an alternative feed. The fermentation process can increase nutrient content in cajuput leaf waste and increase the digestibility of organic matter (OMD), dry matter digestibility (DMD), Ammonia (NH3), and Volatile Fatty Acid (VFA). This study aimed to determine the improvement of cajuput leaf waste nutrition with the help of yeast as well as the effect of fermented cajuput leaf waste along with a mixture of concentrates and field grass on digestibility, NH3, and VFA which were carried out in vitro test. The results showed the nutritional content of cajuput leaf waste fermented by yeast of Aspergillus chevalieri had the best value of protein 16.03%, fiber 16.92%, and fat 5.93%. The treatment R4 (50% cajuput leaf waste + 25% concentrate + 25% field grass) had the best digestibility (DMD=46.12%; DMO=32.08%), NH3 (8.37mM) and VFA (168.5mM) production.

Background: The main problem in nitrogen fertilization for crop cultivated is the very low efficiency due to the leaching process. The purpose of this study was to the determination of the optimum levels of biochar amendment made from Melaleuca cajuputi biochar (MCB) and urea fertilizer (UF) for nitrogen use efficiency in upland rice under M. cajuputi stands.Methods: The study was conducted during dry season within March to June 2019 in Menggoran Forest Resort, Playen Forest Section, Yogyakarta Forest Management District, Indonesia. The experimental design was laid out in a randomized complete block design factorial with three replications as the response surface methodology (RSM). The treatments consisted of MCB levels (0, 5, 10, 15 tons ha-1) and UF levels (0, 100, 200, 300 kg ha-1) as independent variables. The observation parameters were nitrate reductase activity (NRA), total chlorophyll (TC), leaf photosynthesis rate (LPR), nitrogen loss (NL), nitrogen use efficiency (NUE) and seed yield (SY). The data was analyzed using RSM approach and ridge regression.Result: The optimizing applications of 11.14 tons ha-1 of MCB and 281.13 kg ha-1 of UF resulted in NUE and SY by 2.14 kg grain kg Nfertilizer-1 and 5.83 tons ha-1 or increased by 19.07% and 13.02%, compared to a single application of UF by 300 kg ha-1.

Three new β-triketone flavanone hybrids, cajuputones A-C were obtained from Melaleuca cajuputi (the Australian 'tea tree'). The structures of cajuputones A-C were elucidated by 1D/2D NMR spectroscopy and HR-ESI-MS analyses; and their absolute configurations were established by electric circular dichroism (ECD) calculations using TDDFT method. Structurally, cajuputones A-C feature a rare 6/6/6/6 oxatetracyclic ring system fused between an acylphloroglucinol-derived β-triketone and a pinocembrin or strobopinin moiety via an angle-type pyran-like motif. DFT-based conformational optimization in chloroform explained the similarity of the 1D NMR data of cajuputones B and C (C-2 epimers).

GC-MS was applied to identify 24 main substances in Melaleuca cajuputi essential oil (TA) extracted from fresh cajeput leaves through steam distilling. The inhibitory capability of active compounds in the TA from Thua Thien Hue, Vietnam over the Angiotensin-Converting Enzyme 2 (ACE2) protein in human body - the host receptor for SARS-CoV-2 and the main protease (PDB6LU7) of the SARS-CoV-2 using docking simulation has been studied herein. The results indicate that the ACE2 and PDB6LU7 proteins were strongly inhibited by 10 out of 24 compounds accounting for 70.9% in the TA. The most powerful anticoronavirus activity is expressed in the order: Terpineol (TA2) ≈ Guaiol (TA5) ≈ Linalool (TA19) > Cineol (TA1) > β-Selinenol (TA3) > α-Eudesmol (TA4) > γ-Eudesmol (TA7). Interestingly, the synergistic interactions of these 10 substances of the TA exhibit excellent inhibition into the ACE2 and PDB6LU7 proteins. The docking results orient that the natural Melaleuca cajuputi essential oil is considered as a valuable resource for preventing SARS-CoV-2 invasion into human body.

Due to the rice production problem, control of paddy weeds with the use of allelopathy as active compounds serve as new alternative for sustainable weeds management. The volatile oil from Melaleuca cajuputi which has possible active allelopathy compound present is extracted and analyzed. Response Surface Methodology (RSM) with central composite rotatable design (CCRD) is used to design the experiment for optimization of supercritical carbon dioxide (SC-CO2) extraction of volatile oil from Melaleuca cajuputi leaves for maximum oil yield. Three factors which included carbon dioxide (CO2) flow rate (4–7 ml/min), temperature (40–55 ℃ ) and pressure (14–26 MPa) were investigated. The regression model shows a good prediction with coefficient of determination, R2 of 0.9607. The optimum condition of SC-CO2 extraction is determined to be at CO2 flow rate of 5.88 ml/min, temperature of 43.10 ℃ and pressure of 24.91 MPa with the prediction yield of 1.24 wt%. The optimum condition is validated with experimental runs which gives an average yield of 1.26 wt% which indicates good agreement between the measured and predicted value. The chemical composition of the volatile oil at optimized condition is analyzed using Gas Chromatography Mass Spectrometry (GC–MS) and Gas Chromatography with Flame Ionization Detector (GC-FID). Caryophyllene and humulene are the two major sesquiterpenes detected from the optimized condition. Thus, volatile oil extract from the foliage of Melaleuca cajuputi can be considered as potential source for bio-herbicides due to the presence of caryophyllene which has allelopathic effect. Kinetics studies are also studied with modified Reverchon-Sesti Osseo as the model fitting.

E ucalyptus (Melaleuca cajuputi), is a plant which often found on the coast of the city of Singkawang, West Kalimantan. This plant is potentially used to treat diarrhea. This study aimed to determine antibacterial activity of eucalyptus leaf from Singkawang city on bacteria Escherichia coli and Staphylococcus aureus. Isolation of the essential oils was using steam distillation, while the analysis of antibacterial activity with well diffusion method. The isolation resulted 0.55% yield. Analysis using GC-MS yielded 26 peak compounds with 2 main compounds namely 1.8 cineol at 71.96% and alpha-terpineol 11.44%. Furthermore, antibacterial activity test of eucalyptus leaf essential oil against E. coli and S. aureus bacteria belongs to the category of low. The diameter of the inhibition zone on bacteria E. coli at a concentration of 50 µg/µ l obtained 4.39 mm zone, while on S. aureus was 4.62 mm zone. Keywords: Eucalyptus leaf essential oil, Eschericia coli, Melaleuca cajuputi, Singkawang, Stapylococcus aureus ABSTRAK K ayu putih (Melaleuca cajuputi) merupakan t umbuhan yang banyak dijumpai di pesisir pantai Kota Singkawang. T umbuhan ini berpotensi digunakan untuk mengobati diare . Penelitian ini bertujuan untuk mengetahui aktivitas antibakteri daun kayu putih yang berasal dari Kota Singkawang terhadap bakteri uji Escherichia coli dan Staphylococcus aureus. Metode yang digunakan untuk isolasi minyak atsiri yaitu distilasi uap, sedangkan uji aktivitas antibakteri menggunakan metode difusi sumuran. Hasil isolasi minyak atsiri daun kayu putih menghasilkan rendemen sebesar 0,55%. Analisis GC-MS menghasilkan 26 puncak senyawa dengan 2 senyawa utama yaitu 1,8 sineol sebesar 71,96% dan alpha-terpineol sebesar 11,44%. Hasil uji aktivitas antibakteri minyak atsiri daun kayu putih terhadap bakteri E. coli dan S. aureus menghasilkan aktivitas yang tergolong lemah. Diameter zona hambat terhadap bakteri E. coli dengan konsentrasi 50µg/µ l menghasilkan zona sebesar 4,39 mm, sedangkan pada bakteri S. aureus yaitu sebesar 4,62 mm. Kata kunci: Escherichia coli, Melaleuca cajuputi, minyak atsiri daun kayu putih, Singkawang, Staphylococcus aureus

Fertilization of N, P, and K on soybean planted under Kayu Putih stands to serve to increase soil nutrients. Lithic Haplustert is a subgroup of Vertisol with a relatively low fertility and organic matter with a heavy clay texture. This research aims to determine the response of soybean to the application of N, P, and K fertilizers on the Lithic Haplustert in physiology and yield. This research was conducted from February to May 2015 in the Srikoyo hamlet, Menggoran village, Playen district, Gunungkidul regency, Yogyakarta. The experimental design is split-split plot with three levels of fertilization of N (0, 25, 50 kg urea ha-1), P (0, 150, 300 kg SP-36 ha-1), and K (0, 75, 150 kg KCl ha-1). The results showed that the application of 50 kg urea ha-1 and 300 kg SP-36 ha-1 can increase the leaf area and photosynthesis rate. Dosage 150 kg KCl ha-1 fertilizer increased the concentration of N, P, and K in the plant tissues significantly.

It was necessary to obtain optimum dose of nitrogen, phosphorus, and potassium obtained through fertilisation in order to improve productivity in the intercropping. Kayu putih tree was cultivated in Yogyakarta for oil production, and the inter-row was designed for intercropping plants, including soybean. The objective of present study was to obtain optimum dose of urea, SP-36, and KCl for soybean intercropped with kayu putih. The experiment was conducted in Menggoran Forest Resort (RPH Menggoran), Playen Forest Section (BDH Playen), Yogyakarta Forest Management District (KPH Yogyakarta) using split-split plot design. The main plot was urea, subplot was SP-36, and sub-subplot was KCl. Fertilisation consisted of three levels (0, 25, 50 kg ha-1 of urea), (0, 150, 300 kg ha-1 of SP-36) and (0, 75, 150 kg ha-1 of KCl). The results showed that application of 50 kg ha-1 urea, 300 kg. ha-1 SP-36, and 150 kg. ha-1 KCl increased N, P, K uptake per hectare as much as 16.23 kg N ha-1, 86.27 kg P ha-1, 40.02 kg K ha-1, respectively. There was positive interaction between urea and SP-36, SP-36 and KCl at leaf area, photosynthetic rate, number of seeds per plants, seed weight per plants, and seed weight per hectare. Under kayu putih intercropping, optimum dosage of urea, SP-36 and KCl were 0, 298.03 and 87.12 kg ha-1, respectively. These combination enabled to produce maximum seed weight of 2.01 tons. ha-1.

A new chromone, 5,7-dihydroxy-2 -(hydroxymethyl)-6,8-dimethyl-chromen-4-one, named melachromone, together with 12 known compounds, including chromones, anthraquinone, flavonoids, flavonoid glycosides, benzene derivatives, ellagic acids and terpenes, were isolated from the leaves of Melaleuca cajuputi Powell. Their structures were characterised by spectroscopic methods.

4 Abstract: Distillation process of M. cajuputi Powell leaves to produce cajuput oil, yields a large amount of solid residue as waste materials. In vitro testing was conducted to evaluate the potential of solid residue of M. cajuputi Powell leaves as cattle feed. The measured variables were NH3, volatile fatty acids (VFA), Dry Matter Digestibility (DMD), and Organic Matter Digestibility (DMO). Completely randomized design was made with 5 different treatments and 4 replications, in order to get 20 experimental units. Data was analyzed by analysis of variance (ANOVA), followed by Duncan's multiple range test with a significance level of 5%. The results showed that giving 100% of the solid residue of M. cajuputi Powell leaves produced VFA, DMD and DMO for about 102.25 mM, 59.75% and 42.28% respectively, but with lesser amount of NH3 (2.54mM). These results were significant (P < 0.05) and are higher than the results by using field grass. It can be concluded that the solid residue of M. cajuputi Powell leaves has the potential to be used as cattle feed.

Gelam putih (M. cajuputi Powell) in Central Kalimantan, has not been exploited well. In vitro test conducted to evaluate the potential of gelam leaves as cattle feed. The measured variables were NH3, volatile fatty acids (VFA), dry matter Digestibility (DMD) and organic matter Digestibility (DMO). Completely randomized design was made with 5 different treatments and 4 replications, in order to get 20 experimental units. Data were analyzed by analysis of Variance (ANOVA) Followed by Duncan's multiple range test with a significance level of 5%. The results showed that the giving 100% of gelam leaves produced NH3 dan VFA for about 4.01 and 151.25 mM, also DMD and DMO by 58.35 and 52.38%. These results were significant (p

Extracts of Melaleuca cajuputi were obtained by supercritical (carbon dioxide) extraction and solvent (hexane) extraction methods. This work is aimed at adapting the green technology of using supercritical CO2 (SC-CO2) as solvent in a batch process to extract Melaleuca cajuputi leaves. The plant leaves were collected from Trengganu, Malaysia. Cajuputi extract analyses were performed by GC and GC/MS. The maximum yields obtained were 4.2% and 6.0%, respectively, by supercritical fluid (SFE) and solvent extraction (SE). Several compounds were identified and significant qualitative and quantitative differences were observed under different conditions. The major components of Cajuputi oil consisted of sesquiterpenes (δ-elemene, β-elemene, β-caryophyllene, α-humulene, 9-epi-β-caryophyllene), their oxygenated derivatives (viridiflorol, platyphyllol, β-eudesmol, bulnesol, (Z,Z)-farnesol and (E,E)-farnesal) and polyphenolic ketones (isoeugenitine and three unknown compounds).

A future rise in sea level will expand areas of salt-affected acid sulfate soil, calling for studies on plant tolerance to combined aluminum (Al) and salt (NaCl) stress. We investigated random amplified polymorphic DNA (RAPD) profiles and tolerance to Al and NaCl alone and in combination in 14 Melaleuca cajuputi Powell provenances. Two-month-old seedlings were grown with or without 10 mM Al and/or 50 mM NaCl at pH 3.8 for 3 months. Plant growth was reduced mostly by combined Al and NaCl stress and then by NaCl and least by Al. Moreover, Al enhanced the effect of NaCl on growth and vice versa. There were significant differences in plant growth among provenances under all treatments; however, positive relationships were found among Al tolerance, NaCl tolerance, and combined Al and NaCl tolerance. Provenance variation in stress tolerance increases with the increasing levels of stress effect. Furthermore, NaCl tolerance tended to have a positive relationship with osmotic potential. Leaf sap K concentration was decreased by NaCl and increased by Al; however, provenances that were more tolerant to NaCl tended to have lower K concentrations. RAPD analysis also revealed genetic variation among provenances. These results suggest that the low tolerance to combined Al and NaCl stress in M. cajuputi is largely due to low tolerance to NaCl and the effect of interaction between Al and NaCl. Provenance variation in stress tolerance was significant and could be partly explained by the variation in genetic material and the ability of plants to reduce ion excess stress in their shoots.

To elucidate the mechanism of the high aluminum (Al) resistance of a Myrtaceae tree, Melaleuca cajuputi Powell, we investigated the responses of root tips to Al and compared them with those of an Al-sensitive species, M. bracteata F. Muell. Roots of seedlings of both species were treated with a calcium solution (pH 4.0) containing 0 or 1 mM AlCl3. After 3 h of Al treatment, inhibition of root elongation and deposition of callose and lignin in root tips, typical signs of Al injury, were induced in M. bracteata but not in M. cajuputi, yet Al accumulation in root tips was similar in both species. These results indicate that internal Al tolerance mechanisms, not Al exclusion mechanisms, are responsible for the Al resistance of M. cajuputi. After 3 h of Al treatment, amount of Al tightly bound to root tips, Al remaining after washing with a desorbing solution, was less in M. cajuputi than in M. bracteata. In M. bracteata, 6 h of Al treatment triggered the accumulation of hydrogen peroxide (H2O2) in root tips despite the upregulation of antioxidant mechanisms, activity of peroxidase and concentration of reduced glutathione. In M. cajuputi, 6 h of Al treatment did not affect the concentration of H2O2, but decreased activity of peroxidase, and increased concentration of reduced glutathione in root tips. These results suggest that the less Al tightly bound to root tips is involved in the suppressing the H2O2 accumulation and the internal Al tolerance in M. cajuputi, and that the H2O2 accumulation or changes in cellular environment that bring about H2O2 accumulation despite the upregulation of antioxidant mechanisms results in Al-induced inhibition of root elongation in M. bracteata.

We investigated the roles of Al-binding ligands in Al exclusion from roots and in internal Al detoxification in roots as Al resistance mechanisms in two Al-resistant Myrtaceae trees, Eucalyptus camaldulensis Dehnh. and Melaleuca cajuputi Powell. The amounts of ligands secreted from roots and contained in root tips of these species were compared with those of an Al-sensitive species, Melaleuca bracteata F. Muell., after the roots were exposed to 0 or 1 mM AlCl3 solution. Secretion of well-known ligands (citrate, oxalate, and malate) from roots under Al treatment was low in all species. However, in E. camaldulensis, the Al-binding capacity of root exudates under Al treatment was considerable and was higher than that in M. bracteata. Gel filtration chromatography revealed that a low-molecular-weight Al-binding ligand was secreted from roots in response to Al only in E. camaldulensis. On the other hand, the Al-binding capacity of cell sap in root tips under Al treatment was similar for the resistant and sensitive species. These results suggest that Al exclusion by secretion of the unknown low-molecular-weight Al-binding ligand from roots contributes to the Al resistance of E. camaldulensis, whereas M. cajuputi has developed Al-resistance mechanisms other than secretion of ligands from roots or concentration of internal ligands in root tips.

Distribution of aluminum (Al) within plant components and Al-induced changes in cell wall polysaccharides in root tips of Eucalyptus camaldulensis Dehnh. seedlings were compared with those of Melaleuca cajuputi Powell. In E. camaldulensis, 0.5 mM Al (pH 4.2 for 40 d) reduced plant dry weight by 50%, increased callose concentration in the root tips and induced leaf necrosis. In comparison with M. cajuputi, Al concentrations were higher in roots and leaves of E. camaldulensis on both a fresh weight basis and in the cell sap, but were lower in the cell wall. Al increased pectin, hemicellulose and cellulose concentration in the cell walls of E. camaldulensis root tips. Al-induced leaf necrosis and growth reduction in E. camaldulensis is discussed in the context of potentially toxic concentrations of Al in plant tissue and changes in polysaccharide content which could reduce water and nutrient uptake and cell wall extensibility in roots.

We exposed the roots of nine Myrtaceae species (Melaleuca bracteata F. Muell., Melaleuca cajuputi Powell, Melaleuca glomerata F. Muell., Melaleuca leucadendra [L.] L., Melaleuca quinquenervia [Cav.] S.T. Blake, Melaleuca viridiflora Sol. ex Gaertner, Eucalyptus camaldulensis Dehnh., Eucalyptus deglupta Bl., and Eucalyptus grandis W. Hill ex Maiden) to 1 mM Al in a nutrient solution for either 24 h or 20 days to evaluate their sensitivity to excess Al and to determine whether callose and lignin formation can be used as interspecific indicators of Al sensitivity. Inhibition of root elongation by Al varied among the species. Melaleuca leucadendra, M. cajuputi, E. grandis, M. quinquenervia, and E. deglupta were tolerant to 1 mM Al, whereas M. viridiflora, E. camaldulensis, M. glomerata, and M. bracteata were sensitive to 1 mM Al. We found that Al induced callose formation in the root tips of each species, but lignin was formed only in the root tips of the most sensitive species, M. bracteata. Root elongation at 1 mM Al was negatively correlated with Al-induced callose formation but not with the Al-induced lignin formation in the root tips. These results suggest that Al-induced callose formation, rather than lignin formation, can be used as an interspecific indicator of Al sensitivity.

Responses of Melaleuca leucadendra (L.) L., Melaleuca cajuputi Powell, Acacia auriculiformis A. Cunn. ex Benth. and Eucalyptus camaldulensis Dehnh. to aluminum (Al) toxicity at low pH are poorly understood. We investigated effects of low pH and exudation of ligands by roots on Al tolerance of these species. Seedlings were grown hydroponically in nutrient solutions at pH 4.2 or 3.5 containing AlCl3 at concentrations ranging from 0 to 4 mM Al. The presence of 4 mM Al at pH 3.5 depressed growth in all species. Growth depression was greatest in E. camaldulensis, least in A. auriculiformis. In the low Al treatment (0.5 mM Al), roots of M. cajuputi tended to have the highest Al concentration among species, whereas in the 4 mM Al treatment, the highest Al concentration was found in roots of E. camaldulensis. Aluminum application enhanced root exudation of citrate in all species, with the enhancement in M. cajuputi, M. leucadendra and A. auriculiformis being similar and much greater than in E. camaldulensis. Exudation of oxalate and phenolic compounds was greater in E. camaldulensis than in the other species. The presence of Al enhanced phosphate exudation in all species, particularly in A. auriculiformis. Acacia auriculiformis was tolerant to low pH, probably because the presence of an unknown substance increased the pH. Application of 0.38 mM Al alleviated the toxicity of the pH 3.5 treatment in E. camaldulensis and M. cajuputi, whereas low pH alleviated Al toxicity in A. auriculiformis. We conclude that exudation of ligands such as citrate and phosphate only partly accounts for interspecific differences in Al tolerance among the tropical woody plants studied, whereas the reciprocal alleviation of Al toxicity and low pH differed considerably among the species.

The composition and antitermite activities of nine essential oils from two Melaleuca species, gelam and cajuputi, were compared using gas chromatography–mass spectrometry analysis and bioassays. Gelam oils were rich in compounds whose boiling points were high, and they were separated into the elemene-rich type and the γ-terpinene- and terpinolene-rich type. Cajuputi oils in this experiment were categorized into three chemotypes according to their 1,8-cineole content: high, low, none. In the termiticidal activity test, gelam oils were stronger than most cajuputi oils in the contact condition. The elemene-rich gelam lost its activity in the noncontact condition, whereas another type of gelam kept its termiticidal activity. The authentic sample of elemene showed the same result as the elemene-rich gelam, indicating that the termiticidal activity of gelam was caused by at least two types of compound: elemene and “others.” 1,8-Cineole exhibited the same tendency as elemene, but it was weak. Hence the 1,8-cineole content of cajuputi was irrelevant to termiticidal activity of samples that exhibited strong activity under both conditions despite their high content. The appearances of gelam and cajuputi leaves are easily confused, a problem that has not yet been solved. Other scientific methods, such as genetic analysis, are required to identify gelam. The difference in the compositions and antitermite activities, however, were charified in this experiment.

The identification of Melaleuca cajuputi leaf samples (trees) that demonstrate enhanced oil characteristics using near infrared (NIR) spectroscopy is described. Leaf samples from an unthinned M. cajuputi seedling seed orchard in Indonesia were collected and air-dried, and their 1,8-cineole content and oil concentrations were determined. NIR spectra of the leaves were obtained, and calibrations for 1,8-cineole content and oil concentration were developed using spectra that had been selected using spectral features; that is, no knowledge of 1,8-cineole content or oil concentration was used to select the calibration samples. The calibrations were used to predict the 1,8-cineole content and oil concentration of the remaining samples. It was demonstrated that NIR spectroscopy could be used to identify leaf samples that had high 1,8-cineole contents and oil concentrations. The technique has the potential to greatly reduce the time involved in ranking large numbers of samples for these attributes, as is a requirement in tree breeding programs to enhance oil production.

Acid sulfate, peat, sandy podzolic, and saline soils are widely distributed in the lowlands of Thailand and Malaysia. The nutrient concentrations in the leaves of plants grown in these type of soils were studied with the aim of developing a nutritional strategy for adapting to such problem soils. In sago and oil palms that were well-adapted to peat soil, the N, P, and K concentrations were the same in the mature leaves, while the Ca, Mg, Na, and Fe concentrations were higher in the mature leaves of the oil palm than of the sago palm. Melastoma malabathricum and Melaleuca cajuputi plants that were well-adapted to low pH soils, peat. and acid sulfate soils were also studied. It was observed that a high amount of Al accumulated in the M. marabathricum leaves, while Al did not accumulate in M. cajuputi leaves. M. cajuputi plants accumulated large amounts of Na in their leaves or stems regardless of the exchangeable Na concentration in the soil, while M. malabathricum that was growing in saline-affected soils excluded Na. Positive relationships between macronutrients were recognized between P and N, between K and N, and between P and K. Al showed antagonistic relationships with P, K, Ca, Mg, Fe, Zn, Cu, and Na. Na also showed antagonistic relationships with P, K, Zn, Mn, Cu, and Al. Fe showed weak antagonistic relationships with Zn, Mn, Cu, and Al.

We investigated the role of glycolysis and sucrolysis in the difference in tolerance to root hypoxia between two Myrtaceae tree species, Melaleuca cajuputi (which shows superior tolerance to root hypoxia) and Eucalyptus camaldulensis (which does not). Analysis of the adenylate energy charge (AEC) in roots subjected to a 4-day hypoxic treatment (HT) in hydroponic culture revealed that the interspecies difference in tolerance corresponds to the ability to maintain energy status under root hypoxia: AEC was reduced by HT in E. camaldulensis, but not in M. cajuputi. The energy status in HT roots of E. camaldulensis was restored by feeding of glucose (Glc) but not sucrose (Suc). These data provide evidence that low substrate availability for glycolysis resulting from an impairment of sucrolysis suppresses ATP production under hypoxic conditions in this species. Measurements of the rates of O2 consumption and CO2 production in roots indicated that E. camaldulensis, but not M. cajuputi, failed to activate fermentation in HT roots. These results cannot be attributed to enzymatic dysfunction, because no inhibition of main glycolytic and fermentative enzymes was observed in both species, and Glc feeding had a beneficial effect on AEC of HT roots of E. camaldulensis. The impairment of sucrolysis was demonstrated by inhibited soluble acid invertase activity in HT roots of E. camaldulensis. In contrast, there was no inhibition in all sucrolytic enzymes tested in HT roots of M. cajuputi, suggesting that steady Suc degradation is essential for maintaining high energy status under root hypoxia. We conclude that root sucrolysis is one of the essential factors that determines the extent of tolerance to root hypoxia.

The effects of N-source and Al on the growth of seedlings of Melastoma malabathricum, Acacia mangium, and Melaleuca cajuputi, which are tropical woody plants and are very tolerant to Al, and barley (Hordeum vulgare), which is a typical Al-sensitive plant, were investigated. The Al and N treatments consisted of the application of either 0 or 0.5 mM Al, and 2 mM NH4 + or N03 -, respectively. Growth of the tropical plants was enhanced by Al and NH4 application. In all the plant species, the pH of the culture solution decreased and the concentrations of soluble Al and P increased with the + NH4 treatment, which positively affected the growth of the tropical plant species. Excised roots of M. malabathricum dissolved insoluble Al with NH4 application and absorbed Al mainly from root tips. Al did not affect the leaf N concentration except in the case of barley. Roots of M. cajuputi exuded a large amount of citrate, which slightly increased by the + Al treatment. In A. mangium, the reactivity of soluble ...

Acid sulfate soils, peat soils, sandy podzolic, and saline soils are widely distributed in Peninsular Thailand. Native plants adapted to such problem soils have grown well, and showed no symptom of mineral deficiency or toxicity. Dominant plants growing in low pH soils (acid sulfate and peat) were Melastoma marabathricum and Melaleuca cajuputi. Since M. marabathricum accumulated a huge amount of aluminum (Al) in leaves, especially in new growing leaves, it can be designated an Al accumulator plant. While M. cajuputi did not accumulate Al in shoot, it can be designated an Al excluder plant. Both plant species adapted well to low pH soils, though a different strategy was used for Al. On the other hand, in acid sulfate and peat soils, M. cajuputi, Panicum repens, Cyperus haspan, and Ischaemum aristatum accumulated large amounts of Na in the leaves (or shoots), even in soil with low exchangeable Na concentration. Thus, when growing in the presence of high Al and Na concentration in soils, plant species have developed two opposite strategies: (1) Al or Na accumulation in the leaf and (2) Al or Na exclusion from the leaf. Al concentration in leaves had a negative relationship with the other mineral nutrients except for N and Mn, and Na concentration in leaves also had a negative relationship with P, Zn, Mn, Cu, and Al. Consequently, Al and Na accumulator plants are characterized by their exclusion of other minerals from their leaves.

Reference strains of Staphylococcus aureus ATCC 9144 (NCTC 6571), Escherichia coli ATCC 10536 (NCTC 10418) and Pseudomonas aeruginosa ATCC 25668 (NCTC 10662) as well as bacteria isolated from patient's clinical material were tested for their resistance to different cajuput oil fractions. The antimicrobial effect of (−)-linalool, (−)-terpinen-4-ol, (±)-α-terpineol and 1,8-cineole as isolated constituents of cajuput oil have been demonstrated.

A detailed analysis of cajuput essential oil—an industrial product from Vietnam—has been carried out by combining column chromatography, gas chromatography, GC–MS, IR and NMR spectroscopy. It contains 61 components of which 48 have been identified. The taxonomy of the material used was discussed and the antibacterial properties of the essential oil are mentioned.

Summary We compared the photosynthetic and photoassimilate transport responses of Melaleuca cajuputi Powell seedlings to root hypoxia with those of Eucalyptus camaldulensis Dehnh. Control and hypoxia treated roots were maintained in a nutrient solution through which air or nitrogen was bubbled. Under root hypoxic conditions, seedlings of M. cajuputi, a flood-tolerant species, maintained height growth, whereas seedlings of E. camaldulensis, a moderately flood-tolerant species, showed markedly decreased height growth compared with control seedlings. Root hypoxia caused decreases in whole-plant biomass, photosynthetic rate and stomatal conductance in E. camaldulensis, but not in M. cajuputi. Photoassimilate transport to roots decreased significantly in E. camaldulensis seedlings 4 days after treatment and starch accumulated in mature leaves. Photoassimilate supply to hypoxic roots of E. camaldulensisseedlings was, thus, limited by reduced photoassimilate transport rather than by reduced photosynthesis. In contrast, M. cajuputi seedlings showed sustained photoassimilate transport to hypoxic roots and persis tent photosynthesis, which together provided a substantial photoassimilate supply to the roots. Sucrose accumulated in hypoxic E. camaldulensisroots, but not in hypoxic M. cajuputi roots. A stable, low sucrose concentration in hypoxic roots would let M. cajuputiseedlings prolong photoassimilate transport to the roots. Photoassimilate partitioning among the water-soluble carbohydrates, starch and structural carbohydrates within the roots was unaffected by root hypoxia in E. camaldulensis, but in M. cajuputi, partitioning was shifted somewhat from structural carbohydrates to water-soluble carbohydrates. This suggests that M. cajuputi seedlings are able to increase photoassimilate utilization in metabolism and sustain energy production under root hypoxic conditions.

The negative charge on the plasma membrane (PM) is mainly derived from the phosphate group of phospholipids. One of the mechanisms of aluminum (Al) toxicity is to increase the PM permeability of root cells by binding to the negative sites on the PM. Thus, PM with a higher proportion of phospholipids could be more susceptible to Al toxicity. In our previous study, we showed that tolerance to Al and low-calcium in rice was enhanced by decreasing the proportion of phospholipids in root cells. Both Melastoma malabathricum L. and Melaleuca cajuputi Powell are dominant woody species that grow in tropical acid sulfate soils, and have been reported to be more tolerant to Al than rice. Surprisingly, the proportion of PM phospholipids in root cells of M. malabathricum and M. cajuputi was considerably low. Our present findings suggest that PM lipid composition plays an important role in Al tolerance mechanisms in various plant species.

Aluminum (Al) toxicity of crop plants is a serious problem in low pH soils throughout the world. However, since native plants adapted to low pH soils grow well even in such problem soils, the investigation of the nutritional characteristics of these plants is important. Plants were cultivated in nutrient solution, of which soluble Al and P were equilibrated, with three soluble Al levels (0, 0.11, and 0.56 mM Al) at pH 4.0. The growth of most plants adapted to low pH soils was stimulated by the Al application, while that of barley (Hordeum vulgare L.) was inhibited. Nevertheless, since the growth of most plants adapted to low pH soils was scarcely affected by the low pH itself (pH 3.5–4.5 in the absence of Al), the growth stimulation by the Al application could not be explained by the Al alleviation to H+ toxicity. Among plants of which growth was stimulated by Al application, melastoma (Melastoma malabathricum L.) and melaleuca (Melaleuca cajuputi Powell) had the greatest ability to decrease rhizosphere pH. However, melastoma accumulated more than 10000 mg Al kg-1 in leaves in the hydroponic condition, but less than 200 mg Al kg-1 in leaves of melaleuca.

Background The threat posed by drug-resistant pathogens has resulted in the increasing momentum in research and development for effective alternative medications. The antioxidant and antibacterial properties of phytochemical extracts makes them attractive alternative complementary medicines. Therefore, this study evaluated the phytochemical constituents of Melaleuca cajuputi flower and leaf (GF and GL, respectively) extracts and their antioxidant and antibacterial activities. Methods Radical scavenging capacity of the extracts was estimated using 2,2-diphenyl-2-picrylhydrazyl and Fe2+-chelating activity. Total antioxidant activity was determined using ferric reducing antioxidant power assay. Well diffusion, minimum inhibitory concentration, and minimum bactericidal concentration assays were used to determine antibacterial activity against eight pathogens, namely Staphylococcus aureus, Escherichia coli, Bacillus cereus, Staphylococcus epidermidis, Salmonella typhimurium, Klebsiella pneumonia, Streptococcus pneumoniae, and Pasteurella multocida. We identified and quantified the phytochemical constituents in methanol extracts using liquid chromatography/mass spectrometry (LC/MS) and gas chromatography (GC)/MS. Results This study reports the antioxidant and radical scavenging activity of M. cajuputi methanolic extracts. The GF extract showed better efficacy than that of the GL extract. The total phenolic contents were higher in the flower extract than they were in the leaf extract (0.55 ± 0.05 and 0.37 ± 0.05 gallic acid equivalent per mg extract dry weight, respectively). As expected, the percentage radical inhibition by GF was higher than that by the GL extract (81 and 75 %, respectively). A similar trend was observed in Fe2+-chelating activity and β-carotene bleaching tests. The antibacterial assay of the extracts revealed no inhibition zones with the Gram-negative bacteria tested. However, the extracts demonstrated activity against B. cereus, S. aureus, and S. epidermidis. Conclusions In this study, we found that M. cajuputi extracts possess antioxidant and antibacterial activities. The results revealed that both extracts had significant antioxidant and free radical-scavenging activity. Both extracts had antibacterial activity against S. aureus, S. epidermidis, and B. cereus. The antioxidant and antimicrobial activities could be attributed to high flavonoid and phenolic contents identified using GC/MS and LC/MS. Therefore, M. cajuputi could be an excellent source for natural antioxidant and antibacterial agents for medical and nutraceutical applications.