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Biomass accumulation and energy conversion efficiency in aromatic rice genotypes

Shahidullah SM, Hanafi MM, Ashrafuzzaman M, Razi Ismail M, Salam MA, Khair A

C. R. Biol., 2010 Jan;333(1):61-7.
PMID: 20176338 DOI: 10.1016/j.crvi.2009.10.002

A field experiment was conducted to evaluate photosynthetic efficiency along with different growth parameters of aromatic rice genotypes. Forty genotypes including three non-aromatic checks exhibited enormous variations for leaf area index (LAI), crop growth rate (CGR), relative growth rate (RGR), net assimilation rate (NAR), grain yield, total dry matter, harvest index and photosynthetic efficiency or energy use efficiency (Emu) at panicle initiation and heading stages. Minimum LAI-value was 0.52 in Khazar at PI stage and maximum was 4.91 in Sakkor khora at heading stage. The CGR-value was in the range of 4.80-24.11 g m(-2) per day. The best yielder BR39 produced grain of 4.21 t ha(-1) and the worst yielder Khazar gave 1.42 t ha(-1). Total dry matter (TDM) yield varied from 4.04 to 12.26 t ha(-1) where genotypes proved their energy use efficiency a range between 0.58 to 1.65%. Emu showed a significant positive relation with TDM (r=0.80(**)), CGR (r=0.72(**)) and grain yield (r=0.66(**)). A negative correlation was established between TDM and harvest index and LAI and RGR. Path analysis result showed that NAR at heading stage exerted highest positive direct effect (0.70) on Emu.

Matched MeSH terms: Plant Leaves/growth & development
Apigenin di- and trirhamnoside from Asplenium normale in Malaysia

Iwashina T, Matsumoto S, Kitajima J, Nakamura T, Kokubugata G, Suleiman M, et al.

Nat Prod Commun, 2010 Jan;5(1):39-42.
PMID: 20184017

Two new flavone rhamnosides, apigenin 7-O-alpha-L-rhamnopyranosyl-(1-->4)-O-alpha-L-rhamnopyranoside and apigenin 7-O-alpha-L-rhamnopyranosyl-(1-->4)-O-alpha-L-rhamnopyranoside-4'-O-alpha-L-rhamnopyranoside were isolated from the fronds of Asplenium normale D. Don, together with two known C-glycosylflavones, vicenin-2 and lucenin-2. The chemical structures of the isolated glycosides were established by UV, LC-MS, characterization of acid hydrolysates, and 1H and 13C NMR spectroscopy.

Matched MeSH terms: Plant Leaves/chemistry
Dunaliine A, a new amino diketone from Desmos dunalii (Annonaceae)

Awang K, Abdullah Z, Mukhtar MR, Litaudon M, Jaafar FM, Hadi AH, et al.

Nat Prod Res, 2009;23(7):652-8.
PMID: 19401920 DOI: 10.1080/14786410802323743

Dunaliine A (1), a new amino diketone, has been isolated from the leaves of Desmos dunalii together with four known dihydrochalcones: 2',4-dihydroxy-4',6'-dimethoxy-3',5'-dimethyldihydrochalcone (2), 2',4-dihydroxy-4',6'-dimethoxydihydrochalcone (3), 2',4-dihydroxy-4',5',6'-trimethoxydihydrochalcone (4) and 2',4-dihydroxy-5'-methyl-4',6'-dimethoxydihydrochalcone (5). The structures of these compounds were established notably by spectral analysis (1D- and 2D- (1)H, (13)C NMR), UV, IR and HRMS.

Matched MeSH terms: Plant Leaves/chemistry*
Leaf herbivory and decomposability in a Malaysian tropical rain forest

Kurokawa H, Nakashizuka T

Ecology, 2008 Sep;89(9):2645-56.
PMID: 18831185

There is accumulating evidence that similar suites of plant traits may affect leaf palatability and leaf litter decomposability. However, the possible association between leaf herbivory and litter decomposition rates across species in species-diverse natural ecosystems such as tropical rain forests remains unexplored, despite its importance in estimating the herbivory effects on carbon and nutrient cycling of ecosystems. We found no strong association between leaf herbivory and litter decomposition rates across 40 tree species in a Malaysian tropical rain forest, even though the leaf and litter traits were tightly correlated. This is because the leaf and litter traits related to herbivory and decomposition rates in the field were inconsistent. Leaf toughness accounted for only a small part of the variation in the herbivory rate, whereas a number of litter traits (the leaf mass per area, lignin to nitrogen ratio, and condensed tannin concentration) accurately predicted the decomposition rate across species. These results suggest that herbivory rate across species may not be strongly related to single leaf traits, probably because plant-herbivore interactions in tropical rain forests are highly diverse; on the other hand, plant-decomposer interactions are less specific and can be governed by litter chemicals. We also investigated two factors, phylogeny and tree functional types, that could affect the relationship between herbivory and decomposition across species. Phylogenetic relatedness among the species did not affect the relationship between herbivory and decomposition. In contrast, when the plants were segregated according to their leaf emergence pattern, we found a significant positive relationship between herbivory and decomposition rates for continuous-leafing species. In these species, the condensed tannin to N ratios in leaves and litter were related to herbivory and decomposition rates, respectively. However, we did not observe a similar trend for synchronous-leafing species. These results suggest that the relationship between herbivory and decomposition may be more greatly affected by functional types than by phylogenetic relatedness among species. In conclusion, our results suggest that well-defended leaves are not necessarily less decomposable litter in a tropical rain forest community, implying that herbivory may not generate positive feedback for carbon and nutrient cycling in this type of ecosystem.

Matched MeSH terms: Plant Leaves/metabolism*
[The roots of Cha and Gambir]

Sugiyama S

Yakushigaku Zasshi, 2005;40(2):98-106.
PMID: 17152831

This article attempts to trace the origin of tea. The author believes the ancient Chinese tea, "chia", is either Jicha (water extract from the pith of Acacia catechu that grows naturally in the mountainous border between the Yunnan province of China and southern Asian countries) or Jicha-Kagikazura (water extract from the young branches and leaves of Uncaris gambir, originally found in India/Sri Lanka). Both were pulverized after being kiln-dried and then mixed with water to produce a thick suspension, or tea. Although the drink is bitter and has an astringent property, it has a particular flavor with a refreshing after-taste. Its components with medicinal properties include tannin, catechin, and various flavonoids, making us believe it was worthwhile for the people at the time to consume the drink regularly. Generally speaking, tea cultivation in China flourished south of the Yangzi Jiang River including the present Zhejiang and Anhui provinces. Depending on the regions, there were words for tea in various languages, including the names of places where particular teas were grown. In addition to the names that appear in the famous Chajing book, it is interesting to note Da Fang pronounced tea as "TAH". Because the area south of the Yangzi Jiang has traditionally been active in foreign trade since the ancient and middle ages. People in this region consumed various foreign originated teas as well. This included Gambir, which was introduced to southern Asia (including present Malaysia and Indonesia) and was consumed as an herbal tea under names such as Guo Luo or Ju Luo teas. Paan, from India, also uses Gambir paste and was a popular chewing refreshment to prevent diseases caused by miasma as well as to keep one's mouth clean. The name A-sen-yaku used in Japan was taken from the plant name Acasia, and Gambir was used to dye Buddhist monks' Ke-Ra bags to a blackish yellow color. The Daikanwa dictionary states the Ra in the name, which means thin silk, was later replaced with "A". The official name for Ji-cha [Er Cha] in modern China is "Gaiji-cha", [Hal-Er Cha], which comes from the name of a variety of tea made by the Ai-Ni tribal subgroup of the ethnic Ha-Ni in Yunnan province. The [see character in text] character is pronounced "ni", which is a homophony of [character in text]. Based on these facts, "Ai-Ni" should be considered the same as "Hai-Ni". Because the ethnic groups in Yunnan province used primitive and tough tea leaves, which were eaten instead of being infused in water, the leaves were first fermented by being buried in the ground. Even today, people of these ethnic groups prefer fungus-fermented black tea with a particular flavor. In contrast, the ethnic Hans used and still use improved and softer young shoots of tea leaves to prepare mainly green tea. It has recently been discovered that Acapsia, as well as Gambir, has anti-oxidant properties, and that consumption over time is effective against many lifestyle-related adult diseases. It may be well worthwhile to cast fresh light upon ancient tea drinking customs.

Matched MeSH terms: Plant Leaves*
Species diversity in the Palaeotropical leaf-litter genus Apelaunothrips (Thysanoptera, Phlaeothripinae)

Mound LA

Zootaxa, 2013;3741:181-93.
PMID: 25112982 DOI: 10.11646/zootaxa.3741.1.7

Species of Apelaunothrips are fungus-feeders on dead leaves, particularly in leaf-litter, and they are recorded across the Old World tropics from Africa to northern Australia and southern Japan. All species in this genus have the maxillary stylets 4-6 microns in diameter, considerably broader than the 2-3 micron diameter that is typical among Phlaeothripinae. The species are largely uniform in structure, but in four species the larger males have fore femora enlarged with a conspicuous tubercle on the inner margin at the base. In one of these species, the males are dimorphic, with no intermediates between large and small individuals, in contrast to the continuous variation in structure found in many polymorphic Phlaeothripidae. A key is provided to the 37 recognised species of Apelaunothrips, including the following: A. desleyae sp.n. from northern Australia; A. bogor sp.n. from Java; A. gombak sp.n. from Peninsular Malaysia.

Matched MeSH terms: Plant Leaves/parasitology
Chemotaxonomical markers in essential oil of Murraya koenigii

Nagappan T, Ramasamy P, Vairappan CS

Nat Prod Commun, 2012 Oct;7(10):1375-8.
PMID: 23157015

The composition of the essential oils of Murraya koenigii (L.) Spreng, cultivated at six locations in Peninsula Malaysia and Borneo are presented. The oils were obtained from fresh leaves by hydrodistillation and analyzed by gas chromatography-mass spectrometry (GC-MS); 61 compounds were identified, of which eleven were present in all the specimens analyzed. The two major volatile metabolites were identified as beta-caryophyllene (16.6-26.6%) and alpha-humulene (15.2-26.7%) along with nine minor compounds identified as beta-elemene (0.3-1.3%), aromadendrene (0.5-1.5%), beta-selinene (3.8-6.5%), spathulenol (0.6-2.7%), caryophyllene oxide (0.7-3.6%), viridiflorol (1.5-5.5%), 2-naphthalenemethanol (0.7-4.8%), trivertal (0.1-1.0%) and juniper camphor (2.6-8.3%). The results suggest that beta-caryophyllene and alpha-humulene could be used as chemotaxonomical markers for Malaysian M. koenigii, hence these specimens could be of the same stock and different from the ones in India, Thailand and China.

Matched MeSH terms: Plant Leaves/chemistry
Laboratory and field tests of the effectiveness of the lemon-eucalyptus extract, Citridiol, as a repellent against land leeches of the genus Haemadipsa (Haemadipsidae)

Kirton LG

Ann Trop Med Parasitol, 2005 Oct;99(7):695-714.
PMID: 16212803

Citridiol is an extract of the leaves of Corymbia citriodora (Myrtaceae), the lemon eucalyptus, and mostly consists of p-menthane-3,8-diol isomers. The effectiveness of this extract as a repellent against land leeches of the genus Haemadipsa (Haemadipsidae), primarily H. sylvestris, was tested in the laboratory and field, in Peninsular Malaysia. The formulation tested, Mosi-guard Natural spray, contained 40% (w/w) Citridiol in a base of ethanol, water and isopropanol. In the laboratory test, specimens of H. sylvestris that were placed within moist, untreated arenas enclosed by treated paper rings made numerous attempts to cross the rings but were prevented or delayed from crossing over, in a dose-dependent manner. Mortality was high among the leeches that attempted to cross over the paper rings that had been sprayed to saturation point but low among the leeches that attempted to cross over paper rings that had only been partially treated, with a droplet-spray. The field study was carried out using indices that were formulated to reflect the severity of leech attack and the degree of repellency. Heavy or moderate spraying of footwear and trouser legs (tucked into socks) not only gave complete protection against bites by H. sylvestris and H. picta but also provided high enough repellency to keep the treated footwear virtually free of leeches. Even a light spray greatly reduced the numbers of leeches on footwear and delayed their progression toward biting the test subjects, although it failed to prevent bites completely. There was no decline in the repellency of the Citridiol when hourly assessments were made over a 6-h test period in the field. The results of the study show that Citridiol is highly repellent as well as toxic to leeches, and can be effectively used to prevent leech bites in the field.

Matched MeSH terms: Plant Leaves/chemistry
Coumarins from Malaysian Micromelum minutum

Rahmani M, Susidarti RA, Ismail HB, Sukari MA, Hin TY, Lian GE, et al.

Phytochemistry, 2003 Oct;64(4):873-7.
PMID: 14559284

In a continuation of our study of the Rutaceae, detailed chemical investigation on Micromelum minutum (Rutaceae) collected from Sepilok, Sabah, Malaysia gave four new coumarins. The structures of the coumarins have been fully characterised by spectroscopic methods as 3",4"-dihydrocapnolactone 1, 2',3'-epoxyisocapnolactone 2, 8-hydroxyisocapnolactone-2',3'-diol 3 and 8-hydroxy-3",4"-dihydrocapnolactone-2',3'-diol 4.

Matched MeSH terms: Plant Leaves/chemistry
Effect of pulping variables on the characteristics of oil-palm frond-fiber

Wan Rosli WD, Law KN, Zainuddin Z, Asro R

Bioresour Technol, 2004 Jul;93(3):233-40.
PMID: 15062817

Caustic pulping of oil-palm frond-fiber strands was conducted following a central composite design using a two-level factorial plan involving three pulping variables (temperature: 160-180 degrees C, time: 1-2 h, alkali charge: 20-30% NaOH). Responses of pulp properties to the process variables were analyzed using a statistical software (DESIGN-EXPERT). The results indicated that frond-fiber strands could be pulped with ease to about 35-45% yield. Statistically, the reaction time was not a significant factor while the influences of the treatment temperature and caustic charge were in general significantly relative to the properties of the resultant pulps.

Matched MeSH terms: Plant Leaves/chemistry*
Phoebegrandine C, a novel proaporphine-tryptamine dimer, from Phoebe grandis (Nees) Merr

Mukhtar MR, Hadi AH, Sévenet T, Martin MT, Awang K

Nat Prod Res, 2004 Apr;18(2):163-7.
PMID: 14984091

A novel proaporphine-tryptamine dimer alkaloid, named phoebegrandine C 1, was isolated from the leaves of Phoebe grandis (Nees) Merr. Its structural elucidation was carried out using spectroscopic techniques, notably 2D NMR.

Matched MeSH terms: Plant Leaves/chemistry
Proteomics of Sago Palm Towards Identifying Contributory Proteins in Stress-Tolerant Cultivar

Hussain H, Mustafa Kamal M, Al-Obaidi JR, Hamdin NE, Ngaini Z, Mohd-Yusuf Y

Protein J, 2020 02;39(1):62-72.
PMID: 31863255 DOI: 10.1007/s10930-019-09878-9

Metroxylon sagu Rottb. or locally known as sago palm is a tropical starch crop grown for starch production in commercial plantations in Malaysia, especially in Sarawak, East Malaysia. This plant species accumulate the highest amount of edible starch compared to other starch-producing crops. However, the non-trunking phenomenon has been observed to be one of the major issues restricting the yield of sago palm starch. In this study, proteomics approach was utilised to discover differences between trunking and non-trunking proteomes in sago palm leaf tissues. Total protein from 16 years old trunking and non-trunking sago palm leaves from deep peat area were extracted with PEG fractionation extraction method and subjected to two-dimensional gel electrophoresis (2D PAGE). Differential protein spots were subjected to MALDI-ToF/ToF MS/MS. Proteomic analysis has identified 34 differentially expressed proteins between trunking and non-trunking sago samples. From these protein spots, all 19 proteins representing different enzymes and proteins have significantly increased in abundance in non-trunking sago plant when subjected to mass spectrometry. The identified proteins mostly function in metabolic pathways including photosynthesis, tricarboxylic acid cycle, glycolysis, carbon utilization and oxidative stress. The current study indicated that the several proteins identified through differentially expressed proteome contributed to physical differences in trunking and non-trunking sago palm.

Matched MeSH terms: Plant Leaves/metabolism*
Essential oil composition of Alseodaphne perakensis (Gamble) Kosterm from Malaysia

Anuar MZA, Salleh WMNHW, Khamis S, Nafiah MA, Mat Said Z

Nat Prod Res, 2021 Feb;35(3):508-511.
PMID: 31266357 DOI: 10.1080/14786419.2019.1636245

The chemical composition of the essential oil from the leaves of Alseodaphne perakensis (Gamble) Kosterm (Lauraceae) growing in Perak, Malaysia was investigated for the first time. The essential oil was obtained by hydrodistillation and fully characterized by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). A total of 37 components (90.9 ± 2.5%) were successfully identified in the essential oil which were characterized by high proportions of bicyclogermacrene (15.8 ± 0.5%), δ-cadinene (11.7 ± 0.2%), γ-cadinene (6.3 ± 0.4%), and aromadendrene (5.6 ± 0.5%).

Matched MeSH terms: Plant Leaves/chemistry
Distinctive phyllosphere bacterial communities in tropical trees

Kim M, Singh D, Lai-Hoe A, Go R, Abdul Rahim R, Ainuddin AN, et al.

Microb Ecol, 2012 Apr;63(3):674-81.
PMID: 21990015 DOI: 10.1007/s00248-011-9953-1

Recent work has suggested that in temperate and subtropical trees, leaf surface bacterial communities are distinctive to each individual tree species and dominated by Alpha- and Gammaproteobacteria. In order to understand how general this pattern is, we studied the phyllosphere bacterial community on leaves of six species of tropical trees at a rainforest arboretum in Malaysia. This represents the first detailed study of 'true' tropical lowland tree phyllosphere communities. Leaf surface DNA was extracted and pyrosequenced targeting the V1-V3 region of 16S rRNA gene. As was previously found in temperate and subtropical trees, each tree species had a distinctive bacterial community on its leaves, clustering separately from other tree species in an ordination analysis. Bacterial communities in the phyllosphere were unique to plant leaves in that very few operational taxonomic units (0.5%) co-occurred in the surrounding soil environment. A novel and distinctive aspect of tropical phyllosphere communities is that Acidobacteria were one of the most abundant phyla across all samples (on average, 17%), a pattern not previously recognized. Sequences belonging to Acidobacteria were classified into subgroups 1-6 among known 24 subdivisions, and subgroup 1 (84%) was the most abundant group, followed by subgroup 3 (15%). The high abundance of Acidobacteria on leaves of tropical trees indicates that there is a strong relationship between host plants and Acidobacteria in tropical rain forest, which needs to be investigated further. The similarity of phyllosphere bacterial communities amongst the tree species sampled shows a significant tendency to follow host plant phylogeny, with more similar communities on more closely related hosts.

Matched MeSH terms: Plant Leaves/microbiology*
Fulltext Functional characterization of a new terpene synthase from Plectranthus amboinicus

Ashaari NS, Ab Rahim MH, Sabri S, Lai KS, Song AA, Abdul Rahim R, et al.

PLoS One, 2020;15(7):e0235416.
PMID: 32614884 DOI: 10.1371/journal.pone.0235416

Plectranthus amboinicus (Lour.) Spreng is an aromatic medicinal herb known for its therapeutic and nutritional properties attributed by the presence of monoterpene and sesquiterpene compounds. Up until now, research on terpenoid biosynthesis has focused on a few mint species with economic importance such as thyme and oregano, yet the terpene synthases responsible for monoterpene production in P. amboinicus have not been described. Here we report the isolation, heterologous expression and functional characterization of a terpene synthase involved in P. amboinicus terpenoid biosynthesis. A putative monoterpene synthase gene (PamTps1) from P. amboinicus was isolated with an open reading frame of 1797 bp encoding a predicted protein of 598 amino acids with molecular weight of 69.6 kDa. PamTps1 shares 60-70% amino acid sequence similarity with other known terpene synthases of Lamiaceae. The in vitro enzymatic activity of PamTps1 demonstrated the conversion of geranyl pyrophosphate and farnesyl pyrophosphate exclusively into linalool and nerolidol, respectively, and thus PamTps1 was classified as a linalool/nerolidol synthase. In vivo activity of PamTps1 in a recombinant Escherichia coli strain revealed production of linalool and nerolidol which correlated with its in vitro activity. This outcome validated the multi-substrate usage of this enzyme in producing linalool and nerolidol both in in vivo and in vitro systems. The transcript level of PamTps1 was prominent in the leaf during daytime as compared to the stem. Gas chromatography-mass spectrometry (GC-MS) and quantitative real-time PCR analyses showed that maximal linalool level was released during the daytime and lower at night following a diurnal circadian pattern which correlated with the PamTps1 expression pattern. The PamTps1 cloned herein provides a molecular basis for the terpenoid biosynthesis in this local herb that could be exploited for valuable production using metabolic engineering in both microbial and plant systems.

Matched MeSH terms: Plant Leaves/enzymology
Essential oil composition of three Cryptocarya species from Malaysia

Azhar MAM, Salleh WMNHW, Khamis S

Z Naturforsch C J Biosci, 2020 Jul 28;75(7-8):297-301.
PMID: 32452825 DOI: 10.1515/znc-2020-0079

Cryptocarya species are mainly distributed in Africa, Asia, Australia and South America, widely used in traditional medicines for the treatment of skin infections and diarrhea. The present investigation reports on the extraction by hydrodistillation and the chemical composition of three Cryptocarya species (Cryptocarya impressa, Cryptocarya infectoria, and Cryptocarya rugulosa) essential oils from Malaysia. The chemical composition of these essential oils was fully characterized by gas chromatography (GC-FID) and gas chromatography-mass spectrometry (GC-MS). A total of 51 components were identified in C. impressa, C. infectoria, and C. rugulosa essential oils representing 91.6, 91.4, and 83.0% of the total oil, respectively. The high percentages of α-cadinol (40.7%) and 1,10-di-epi-cubenol (13.4%) were found in C. impressa oil. β-Caryophyllene (25.4%) and bicyclogermacrene (15.2%) were predominate in C. infectoria oil. While in C. rugulosa oil, bicyclogermacrene (15.6%), δ-cadinene (13.8%), and α-copaene (12.3%) were predominate. To the best of our knowledge, there is no report on the essential oil composition of these three species.

Matched MeSH terms: Plant Leaves/chemistry
Fulltext Daily feeding of fresh Neem leaves (Azadirachta indica) for worm control in sheep

Chandrawathani P, Chang KW, Nurulaini R, Waller PJ, Adnan M, Zaini CM, et al.

Trop Biomed, 2006 Jun;23(1):23-30.
PMID: 17041548 MyJurnal

This study was conducted to evaluate the anthelmintic effect of neem (Azadirachta indica) on nematode parasites of sheep. Twelve Santa Ines cross bred sheep from a government farm were randomly selected and equally divided into control (n = 6) and treated groups (n =6). Faecal egg counts (FEC) using the modified McMaster technique and the FAMACHA score for assessing clinical anaemia were carried out daily and recorded for 6 weeks. At the end of the study all the animals were slaughtered and the total worm count (TWC) was done. The results of FEC showed that there was no significant difference between the control and treated group (p = 0.081). However, worm burden estimations showed that the number of parasites was significantly higher in the control group compared to the treated group (p < 0.05). This result indicated that feeding Neem had an effect on worm numbers in sheep, but was not reflected in their faecal egg counts. Further work is needed to reconfirm the effect of Neem on helminth infections of sheep.

Matched MeSH terms: Plant Leaves*
Phenolic constituents and anticancer properties of Morus alba (white mulberry) leaves

Chan EWC, Wong SK, Tangah J, Inoue T, Chan HT

J Integr Med, 2020 May;18(3):189-195.
PMID: 32115383 DOI: 10.1016/j.joim.2020.02.006

Flavonoids are by far the most dominant class of phenolic compounds isolated from Morus alba leaves (MAL). Other classes of compounds are benzofurans, phenolic acids, alkaloids, coumarins, chalcones and stilbenes. Major flavonoids are kuwanons, moracinflavans, moragrols and morkotins. Other major compounds include moracins (benzofurans), caffeoylquinic acids (phenolic acids) and morachalcones (chalcones). Research on the anticancer properties of MAL entailed in vitro and in vivo cytotoxicity of extracts or isolated compounds. Flavonoids, benzofurans, chalcones and alkaloids are classes of compounds from MAL that have been found to be cytotoxic towards human cancer cell lines. Further studies on the phytochemistry and anticancer of MAL are suggested. Sources of information were PubMed, PubMed Central, ScienceDirect, Google, Google Scholar, J-Stage, PubChem and China National Knowledge Infrastructure.

Matched MeSH terms: Plant Leaves/chemistry
Fulltext Comparative Chemical Profiles of the Essential Oils from Different Varieties of Psidium guajava L

Hassan EM, El Gendy AEG, Abd-ElGawad AM, Elshamy AI, Farag MA, Alamery SF, et al.

Molecules, 2020 Dec 29;26(1).
PMID: 33383905 DOI: 10.3390/molecules26010119

Guava (Psidium guajava) leaves are commonly used in the treatment of diseases. They are considered a waste product resulting from guava cultivation. The leaves are very rich in essential oils (EOs) and volatiles. This work represents the detailed comparative chemical profiles of EOs derived from the leaves of six guava varieties cultivated in Egypt, including Red Malaysian (RM), El-Qanater (EQ), White Indian (WI), Early (E), El-Sabahya El-Gedida (ESEG), and Red Indian (RI), cultivated on the same farm in Egypt. The EOs from the leaves of guava varieties were extracted by hydro-distillation and analyzed with GC-MS. The EOs were categorized in a holistic manner using chemometric tools. The hydro-distillation of the samples yielded 0.11-0.48% of the EO (v/w). The GC-MS analysis of the extracted EOs showed the presence of 38 identified compounds from the six varieties. The sesquiterpene compounds were recorded as main compounds of E, EQ, ESEG, RI, and WI varieties, while the RM variety attained the highest content of monoterpenes (56.87%). The sesquiterpenes, β-caryophyllene (11.21-43.20%), and globulol (76.17-26.42%) were detected as the major compounds of all studied guava varieties, while trans-nerolidol (0.53-10.14) was reported as a plentiful compound in all of the varieties except for the RM variety. A high concentration of D-limonene was detected in the EOs of the RM (33.96%), WI (27.04%), and ESEG (9.10%) varieties. These major compounds were consistent with those reported for other genotypes from different countries. Overall, the EOs' composition and the chemometric analysis revealed substantial variations among the studied varieties that might be ascribed to genetic variability, considering the stability of the cultivation and climate conditions. Therefore, this chemical polymorphism of the studied varieties supports that these varieties could be considered as genotypes of P. guajava. It is worth mentioning here that the EOs, derived from leaves considered to be agricultural waste, of the studied varieties showed that they are rich in biologically active compounds, particularly β-caryophyllene, trans-nerolidol, globulol, and D-limonene. These could be considered as added value for pharmacological and industrial applications. Further study is recommended to confirm the chemical variations of the studied varieties at a molecular level, as well as their possible medicinal and industrial uses.

Matched MeSH terms: Plant Leaves/chemistry
Identification of the compositional changes in Orthosiphon stamineus leaves triggered by different drying techniques using 1 H NMR metabolomics

Pariyani R, Ismail IS, Ahmad Azam A, Abas F, Shaari K

J Sci Food Agric, 2017 Sep;97(12):4169-4179.
PMID: 28233369 DOI: 10.1002/jsfa.8288

BACKGROUND: Java tea is a well-known herbal infusion prepared from the leaves of Orthosiphon stamineus (OS). The biological properties of tea are in direct correlation with the primary and secondary metabolite composition, which in turn largely depends on the choice of drying method. Herein, the impact of three commonly used drying methods, i.e. shade, microwave and freeze drying, on the metabolite composition and antioxidant activity of OS leaves was investigated using proton nuclear magnetic resonance (1 H NMR) spectroscopy combined with multivariate classification and regression analysis tools.
RESULTS: A total of 31 constituents comprising primary and secondary metabolites belonging to the chemical classes of fatty acids, amino acids, sugars, terpenoids and phenolic compounds were identified. Shade-dried leaves were identified to possess the highest concentrations of bioactive secondary metabolites such as chlorogenic acid, caffeic acid, luteolin, orthosiphol and apigenin, followed by microwave-dried samples. Freeze-dried leaves had higher concentrations of choline, amino acids leucine, alanine and glutamine and sugars such as fructose and α-glucose, but contained the lowest levels of secondary metabolites.
CONCLUSION: Metabolite profiling coupled with multivariate analysis identified shade drying as the best method to prepare OS leaves as Java tea or to include in traditional medicine preparation. © 2017 Society of Chemical Industry.

Matched MeSH terms: Plant Leaves/chemistry*

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