Biodegradable antifungal films from nanocellulose-gellan gum incorporated with Anethum graveolens essential oil for bread packaging.

Biodegradable material incorporated with antifungal essential oil has become an alternative food preservation approach to reduce plastic waste. Essential oils of Amomum testaceum, Anethum graveolens, Piper longum, Kaempferia galanga, and Zanthoxylum limonella were tested for their antifungal activity against Aspergillus niger. A. graveolens essential oil demonstrated the highest inhibition zone diameter of 43.51 mm against A. niger after seven days comparing to those obtained from other essential oils ranging from 10.02 mm to 26.13 mm. The volatile compounds of A. graveolens essential oil were identified with major compounds such as carvone, trans-dihydrocarvone, limonene, and α-acorenol. The pineapple nanocellulose-gellan gum (PNC-GG) films incorporated with A. graveolens oil were formulated and tested for its physical and chemical properties. Addition of A. graveolens essential oil in PNC-GG films improved mechanical strength and decreased flexibility while solubility, water vapour permeability, and thermal stability slightly changed. PNC-GG films incorporated with A. graveolens essential oil were also tested as bread packaging inhibiting A. niger. The results indicated that no visible mycelial growth of A. niger was detected during 3-week storage. Therefore, the PNC-GG films incorporated with A. graveolens essential oil were recommended as biodegradable packaging material against A. niger in bread also extending its shelf life.

Characterisation of teaghrelin-like principles from Assam tea cultivated in Thailand.

Teaghrelins were identified as unique acylated flavonoid tetraglycosides and firstly reported in Chin-shin oolong tea. In the present study, two new teaghrelin-like compounds (1 and 2) were purified and characterised from Assam tea varieties collected in Thailand. Their chemical structures were constructed by the spectroscopic and spectrometric analysis. These two teaghrelin-like compounds were also not supposed to exhibit significant ghrelin receptor affinity according to the structural comparison with those teaghrelin-like compounds previously reported. In addition, compounds 1 and 2 did not display notable anti-inflammatory activity in human neutrophils assay.[Formula: see text].

UHPLC-ESI-QTOF-MS/MS-Based Molecular Networking Guided Isolation and Dereplication of Antibacterial and Antifungal Constituents of Ventilago denticulata.

Ventilago denticulata is an herbal medicine for the treatment of wound infection; therefore this plant may rich in antibacterial agents. UHPLC-ESI-QTOF-MS/MS-Based molecular networking guided isolation and dereplication led to the identification of antibacterial and antifungal agents in V. denticulata. Nine antimicrobial agents in V. denticulata were isolated and characterized; they are divided into four groups including (I) flavonoid glycosides, rhamnazin 3-rhamninoside (7), catharticin or rhamnocitrin 3-rhamninoside (8), xanthorhamnin B or rhamnetin 3-rhamninoside (9), kaempferol 3-rhamninoside (10) and flavovilloside or quercetin 3-rhamninoside (11), (II) benzisochromanquinone, ventilatones B (12) and A (15), (III) a naphthopyrone ventilatone C (16) and (IV) a triterpene lupeol (13). Among the isolated compounds, ventilatone C (16) was a new compound. Moreover, kaempferol, chrysoeriol, isopimpinellin, rhamnetin, luteolin, emodin, rhamnocitrin, ventilagodenin A, rhamnazin and mukurozidiol, were tentatively identified as antimicrobial compounds in extracts of V. denticulata by a dereplication method. MS fragmentation of rhamnose-containing compounds gave an oxonium ion, C6H9O3+ at m/z 129, while that of galactose-containing glycosides provided the fragment ion at m/z 163 of C6H11O5+. These fragment ions may be used to confirm the presence of rhamnose or galactose in mass spectrometry-based analysis of natural glycosides or oligosaccharide attached to biomolecules, that is, glycoproteins.

Antifungal activity of 8-methoxynaphthalen-1-ol isolated from the endophytic fungus Diatrype palmicola MFLUCC 17-0313 against the plant pathogenic fungus Athelia rolfsii on tomatoes.

Thirty-four endophytic fungal isolates were obtained from the leaves of the medicinal plant Polyscias fruticosa, and their antagonistic activities against the growth of the common tomatoes plant pathogenic fungus Athelia rolfsii were initially screened using a dual culture assay. The endophytic fungus MFLUCC 17-0313, which was later molecularly identified as Diatrype palmicola, displayed the highest inhibition percentage (49.98%) in comparison to the others. This fungus was then chosen for further evaluation. Its culture broth and mycelia from a 10 L scale were separated and extracted using ethyl acetate, methanol, and hexane. Each extract was tested for antifungal activity against the same pathogen using a disc diffusion assay. Only the crude hexane extract of fungal mycelium showed antifungal activity. The hexane extract was fractioned using sephadex gel filtration chromatography and each fraction was tested for antifungal activity until the one with the highest inhibition percentage was obtained. The bioactive compound was identified as 8-methoxynaphthalen-1-ol using nuclear magnetic resonance spectroscopy and mass spectrometry. The minimum inhibition concentration of 8-methoxynaphthalen-1-ol was demonstrated at 250 µg/mL against the selected pathogen. Using the leaf assay, the solution of 8-methoxynapthalen-1-ol was tested for phytotoxic activity against A. rolfsii and was found to have no phytotoxic effects. These results showed that 8-methoxynaphthalen-1-ol has the potential for controlling the growth of A. rolfsii, the cause of Southern blight disease on tomatoes. This study may provide the foundation for future use of this compound as a biofungicide.

Antibacterial and Antioxidant Metabolites of Diaporthe spp. Isolated from Flowers of Melodorum fruticosum.

Fifty-two strains of endophytic fungi were isolated from flowers of the medicinal plant Melodorum fruticosum. Seven genera were identified including Alternaria, Aspergillus, Colletotrichum, Diaporthe, Fusarium, Greeneria and Nigrospora. All strains were cultured for 30 days and further macerated in ethyl acetate solvent for 3 days. The obtained fungal extracts were examined for antibacterial activity using agar disc diffusion against nine pathogenic bacteria: Staphylococcus aureus, Bacillus subtilis, B. cereus, Klebsiella pneumoniae, Pseudomonas aeruginosa, Escherichia coli, Shigella flexneri, Vibrio cholerae and V. parahaemolyticus. Forty-three fungal extracts exhibited antibacterial activity against at least one tested pathogen. The antioxidant properties of all extracts were also investigated by DPPH scavenging assay. Sixteen extracts displayed high antioxidant capacity (IC50 ranging from 10 to 50 µg/mL) when compared to the gallic acid and trolox standards (IC50 of 12.46 and 2.55 µg/mL, respectively). The crude extracts of Diaporthe sp. MFLUCC16-0682 and Diaporthe sp. MFLUCC16-0693 exhibited notable antibacterial and antioxidant activities. Analysis of chemical composition using gas chromatography-mass spectrometry suggested that the observed antibacterial activity of the two Diaporthe spp. was possibly due to the presence of abienol, 4-methoxy stilbene, phenethyl cinnamate and 2Z,6Z-farnesal, while their potential antioxidant activity could be attributed to phenolic compounds, such as benzene acetaldehyde, benzyl benzoate, salicylaldehyde, benzoin and benzyl cinnamate. The results suggest that the genus Diaporthe is a potential source of metabolites that can be used in a variety of applications.

Fungal Endophytes: an Alternative Source for Production of Volatile Compounds from Agarwood Oil of Aquilaria subintegra.

Fungal endophytes are microorganisms that are well-known for producing a diverse array of secondary metabolites. Recent studies have uncovered the bioprospecting potential of several plant endophytic fungi. Here, we demonstrate the presence of highly bioactive fungal endophytic species in Aquilaria subintegra, a fragrant wood plant collected from Thailand. Thirty-three fungal endophytic strains were isolated and further identified to genus level based on morphological characteristics. These genera included Colletotrichum, Pestalotiopsis, Fusarium, Russula, Arthrinium, Diaporthe and Cladosporium. All strains were cultured on potato dextrose broth for 30 days prior to partitioning with ethyl acetate. The volatile compounds of all extracts were investigated by gas chromatography-mass spectrometry (GC-MS). Four strains-Arthrinium sp. MFLUCC16-0042, Colletotrichum sp. MFLUCC16-0047, Colletotrichum sp. MFLUCC16-0048 and Diaporthe sp. MFLUCC16-0051-produced a broad spectrum of volatile compounds, including ß-agarofuran, α-agarofuran, δ-eudesmol, oxo-agarospirol, and ß-dihydro agarofuran. These compounds are especially important, because they greatly resemble those originating from the host-produced agarwood oil. Our findings demonstrate the potential of endophytic fungi to produce bioactive compounds with applications in perfumery and cosmetic industries. Antioxidant activity of all extracts was also evaluated by using 2,2-diphenyl-2-picrylhydrazyl radical scavenging assays. The ethyl acetate extract of Diaporthe sp. MFLUCC16-0051 demonstrated superior antioxidant capacity, which was comparable to that of the gallic acid standard. Our results indicate that the MFLUCC16-0051 strain is a resource of natural antioxidant with potential medicinal applications.

Antibacterial Activities of Endophytic Fungi Isolated from Mentha cordifolia Leaves and Their Volatile Constituents.

A total of 17 endophytic fungal isolates were obtained from the leaves of Mentha cordifolia Opiz (Lamiaceae). Seven isolates were identified to the level of genus by using taxonomically relevant morphological traits. Colletotrichum and Phoinopsis species were dominant among these strains. All strains were separated from M cordifolia leaf for the first time. The ethyl acetate extracts of all endophytic fungi were tested for antibacterial activity against Salmonella typhimurium TISTR 1166 and Pseudomonas aeruginosa TISTR781. Most endophytes exhibited antibacterial activity. Ustilago sp. MFLUCC15-1024 presented the highest inhibition zone diameter with a MIC of 31.25 µg/mL against the tesfed pathogens. The chemical composition of the ethyl acetate extract of this strain was investigated using gas chromatography-mass spectrometry. Twenty-one components were identified. 2-Phenylethanol (38.7%), E-ligustilide (12.4%), a-eudesmol (10.2%), ß-vetivone (4.6%), ß-ylangene (3.7%) and verbanol (3.4%) were the major components of the extract. The strong antibacterial activity of Ustilago sp. MFLUCC15-1024 ethyl acetate extract may be attributed to the presence of a high concentration of bioactive compounds including phenyl ethyl alcohol, E-ligustilide and a-eudesmol. The results indicate that there is high diversity of endophytic fungi in M cordifolia leaf, and that Ustilago sp. MFLUCC l5-1024 strain could be an excellent resource of natural antibacterial compounds.

Chemical composition and antibacterial activity of essential oil and extracts of Citharexylum spinosum flowers from Thailand.

The chemical composition and antibacterial and antioxidant activities of the essential oil and various solvent extracts of Citharexylum spinosum flowers are reported. The chemical compositions were determined by GC-MS with 151 volatile constituents identified. Methyl benzoate, piperitone, maltol, and maple furanone were the major constituents. All extracts were tested for their antibacterial activity against eight microorganisms. The flower oil had the greatest antibacterial activity against all bacterial strains (MIC values of 31.2 microg/mL), while the other solvent extracts had MIC values ranging from 31.2 to 1000 microg/mL. The essential oil had the highest antioxidant activity and total phenol content with IC50 values of 62.7 and 107.3 microg/mL, respectively.

Volatile constituents of Murraya koenigii fresh leaves using headspace solid phase microextraction--gas chromatography-mass spectrometry.

The volatile components of Murraya koenigii fresh leaves, collected from Surat Thani province, Thailand were studied by using headspace (HS) solid-phase microextraction (SPME) coupled with gas chromatography-mass spectrometry (GC-MS). The four fibers employed to extract the volatiles were polydimethylsiloxane (PDMS), polydimethylsiloxane-divinylbenzene (PDMS-DVB), carboxane-polydimethylsiloxane (CAR-PDMS) and polydimethylsiloxane-divinylbenzene-carboxane (PDMS-DVB-CAR). The volatile constituents of M. koenigii fresh leaves were also extracted by hydrodistillation and analyzed by GC-MS. Fifty-one compounds were identified by these fibers. Five major compounds, γ-terpinene, ß-caryophyllene, ß-phellandrene, a-selinene and a-pinene, were detected in all fibers. The PDMS-DVB-CAR fiber was considered as the best for trapping key volatiles of M. koenigii fresh leaves.

Constituents, antibacterial and antioxidant activities of essential oils from Trachelospermum jasminoides flowers.

The present work reports the chemical compositions, antibacterial and antioxidant activities of essential oils from T jasminoides flowers collected from two different geographical areas, Chiang Rai and Chiang Mai, Thailand. The essential oil of T. jasminoides from the Chiang Rai area had 99 compounds representing 97.9% of the total oil composition, with E-nerolidol and α-phellandrene as the major constituents. In contrast, the essential oil of T. jasminoides collected from the Chiang Mai area contained 93 components representing 94.8% of the total oil, with trans-linalool oxide and citronellol as the major compounds. Flower oils of T. jasminoides exhibited greater antibacterial activities against Gram-negative bacteria than Gram-positive bacteria. Both oils displayed antioxidant activities.

Chemical compositions, antifungal and antioxidant activities of essential oil and various extracts of Melodorum fruticosum L. flowers.

This research presents the chemical composition antifungal and antioxidant activities of essential oils and various extracts from Melodorum fruticosum flowers. The essential oil composition of M. fruticosum flowers were investigated by GC-MS with 88 identified volatile constituents. Phenyl butanone, linalool, benzyl alcohol, alpha-cadinol, globulol and viridiflorol were found to be the major components, respectively. The dichloromethane extract played a major role as a remarkable fungicide according to their inhibition action against all tested pathogens followed by hexane extract, essential oil and methanol extract, respectively, along with their respective MIC values ranging from 125 to 1000 microg/ml. The dichloromethane extracts were also evaluated to be superior to all extracts tested with an IC(50) value of 87.6 microg/ml whereas other extracts showed their IC(50) values ranging from 100.13 to 194.50 microg/ml.

Comprehensive two-dimensional gas chromatography-mass spectrometry analysis of volatile constituents in Thai vetiver root oils obtained by using different extraction methods.

INTRODUCTION: Vetiver root oil is known as one of the finest fixatives used in perfumery. This highly complex oil contains more than 200 components, which are mainly sesquiterpene hydrocarbons and their oxygenated derivatives. Since conventional GC-MS has limitation in terms of separation efficiency, the comprehensive two-dimensional GC-MS (GC x GC-MS) was proposed in this study as an alternative technique for the analysis of vetiver oil constituents. OBJECTIVE: To evaluate efficiency of the hyphenated GC x GC-MS technique in terms of separation power and sensitivity prior to identification and quantitation of the volatile constituents in a variety of vetiver root oil samples. METHODOLOGY. Dried roots of Vetiveria zizanioides were subjected to extraction using various conditions of four different methods; simultaneous steam distillation, supercritical fluid, microwave-assisted, and Soxhlet extraction. Volatile components in all vetiver root oil samples were separated and identified by GC-MS and GC x GC-MS. The relative contents of volatile constituents in each vetiver oil sample were calculated using the peak volume normalization method. RESULTS: Different techniques of extraction had diverse effects on yield, physical and chemical properties of the vetiver root oils obtained. Overall, 64 volatile constituents were identified by GC-MS. Among the 245 well-resolved individual components obtained by GC x GC-MS, the additional identification of 43 more volatiles was achieved. CONCLUSION: In comparison with GC-MS, GC x GC-MS showed greater ability to differentiate the quality of essential oils obtained from diverse extraction conditions in terms of their volatile compositions and contents.