Natural Product Research最新文献

This study investigated the extraction of capsaicin from Capsicum chinense cv Bhut Jolokia using rice bran oil (RBO) as a 'green solvent' via microwave- and ultrasound-mediated techniques (MME and UME) as an alternative to hazardous organic solvents. Extraction conditions were optimised using MME at 180 and 300 W for 2 and 8 min and UME at 300 and 400 W for 10 and 30 min. The maximum capsaicin yield obtained was 12.47 mg/mL, with a corresponding gamma oryzanol content of 8.46 mg/mL. The peroxide value of the extract (capsaicin-infused RBO) was found to be within permissible limits as per Codex Alimentarius specifications. Results strongly suggest the potential of RBO as a novel solvent for extraction of capsaicin. The capsaicin-enriched oil can be used as a functional food ingredient due to its health-promoting properties.

Phytochemical investigation of EtOH extract of Pittosporum heterophyllum led to one new esterified thujane monoterpenoid glycoside, pitheteroside A (1), together with one eudesmane sesquiterpenoid (2) and twelve lignans (3－14). Their structures were elucidated by extensive spectroscopic analysis, including 1D and 2D NMR, ECD calculation and HRESIMS spectra. Pitheteroside A is an unreported and highly esterified monoterpenoid glycoside. All isolates were evaluated for their nitric oxide production inhibition against LPS-induced BV-2 microglial cells. Among them, compounds 1, 6 and 8 showed significant activities with IC₅₀ values less than 10 μM. The results indicated the metabolisms from P. heterophyllum possess potential anti-inflammatory effects.

The volatile compositions and antimicrobial activity of aerial parts of Popowia pisocarpa from Vietnam were reported for the first time. From the GC/MS spectral, spathulenol (35.9%), bicyclogermacrene (5.7%) and muurola-4,10(14)-dien-1β-ol (4.2%) among the sesquiterpenoids, along with 4,4-dimethyl-3-(3-methylbut-3-enylidene)-2-methylenebicyclo[4,1,0]heptane (17.7%), an unsaturated cyclic compound, were the main constituents of the essential oil. Monoterpenoids were not identified in the essential oil. The essential oil displayed antimicrobial activity against the Gram-negative Escherichia coli ATCC 25922 with MIC value of 16.0 µg/mL and IC₅₀ value of 8.52 µg/mL. In addition, the essential oil also exhibited activity towards the Gram-positive bacteria of Staphylococcus aureus ATCC 13709, Bacillus subtilis ATCC 6633, and Lactobacillus fermentum N4 with MIC value of 64.0 µg/mL each and corresponding IC₅₀ values of 11.06 µg/mL, 26.47 µg/mL and 15.68 µg/mL, respectively. The essential oil did not inhibit the growth of Pseudomonas aeruginosa ATCC 15442, Salmonella enterica and the yeast Candida albicans ATCC 10231.

Plumbago europaea L. belongs to the family Plumbaginaceae, which has many medicinal and nutritional applications. It is among the significant medicinal herbs used widely in folk medicine in Syria to treat skin diseases such as eczema and psoriasis. There are no previous studies of the aerial parts' essential oils of this plant. So, herein we report on determining the chemical composition of essential oils extracted from the aerial parts of P. europaea L., which were collected from a mountainous area in Latakia Province, Syria, by utilising the GC-MS technique. The major compounds identified in the flower's essential oils were: plumbagin (32.4%), hexadecanoic acid (13.79%), heneicosane (9.03%) and 2,6-di-tert-butyl-4-ethylphenol (8.40%). While in the leaves' essential oils were phytol (17.97%), dibutyl phthalate (15.45%), heneicosane (6.91%) and hexahydrofarnesyl acetone (6.72%). In addition, according to the published literature, most of the identified compounds have been reported to exhibit significant biological activities.

Two new monoterpene indole alkaloids, Eleganine A (1) and Eleganine B (2), along with 11 known compounds (3-13) were isolated from the stems and leaves of Gelsemium elegans. Compound 1 is a gelsenicine-related monoterpenoid indole alkaloid possessing an iridoid unit. Their structures and absolute configurations of 1-2 were established by UV, IR, HR-ESI-MS, NMR spectroscopy, and electronic circular dichroism data analyses. All isolated compounds were evaluated for their anti-inflammatory and inhibiting glucose-induced mesanginal cell proliferation activities. None of them showed activity with IC₅₀ far beyond 50 μM.

Mikania micrantha Kunth is widely known as potential herbal medicine, although it is an invasive alien species in Southeast Asia. In this study, the essential oils from leaves and stems of M. micrantha were extracted by hydrodistillation method, and the chemical profiles of essential oils were then analysed by gas chromatography (GC) and gas chromatography coupled with mass spectrometry (GC/MS). It was found that there were similarities and differences in chemical compositions and their percentage between the essential oils obtained from these two parts. The dominant components of leaves essential oil are β-Cubebene, Germacrene D, and α-Zingiberene, accounting for 11.34%, 10.96%, and 10.76%, respectively. Additionally, the major components of stems essential oils are D-Limonene (16.99%), β-Pinene (7.91%), and α-Zingiberene (7.26%). The research sheds fresh light on the chemical makeup of M. micrantha essential oils, emphasising their potential for the future.

A new tetrahydroimidazopyridine named butyl (5R,6R,7S,8S)-5,6,7,8-tetrahydro-6,7,8-trihydroxy-5-(hydroxymethyl)imidazo[1,2-a]pyridine-2-carboxylate(1), together with eight known compounds (2-9), were isolated from the fermentation broth of a marine-derived fungus Paraconiothyrium sp. YK-03. Their chemical structures were elucidated by extensive analysis of one-dimensional and two-dimensional NMR spectroscopy, HR-ESIMS and optical rotation. Among these compounds, compound 1 represented a rare tetrahydroimidazopyridine, and compounds 2-7 were isolated from the Paraconiothyrium species for the first time. A plausible biosynthetic pathway for compound 1 was proposed.

A new benzophenone derivative, 8'-hydroxymonomethylsulochrin (1), together with eighteen known compounds (2-19) were produced by the endophytic fungus Aspergillus fumigatus WJ-131, isolated from the stem of Gardenia jasminoides. The structure of 1 was determined by extensive spectroscopic analysis and X-ray crystallography. Under the condition of concentration of 20.0 μM, the splenic lymphocytes proliferation rates of compounds 1 and 7 induced by LPS were 39.4% and 38.1% (LPS, the splenic lymphocytes cell proliferation rates of 21.3%), and the splenic lymphocytes proliferation rate of compounds 7 induced by ConA is 44.6% (ConA, the splenic lymphocytes proliferation rates of 28.9%). Therefore, compounds 1 and 7 promoted the proliferation of ConA/LPS-stimulated splenic lymphocytes at 20.0 μM in vitro. In addition, compound 1 showed weak antibacterial activity against Fusarium oxysporum.

A new 12-membered resorcylic acid lactone, cochliomycin H (1), and one known resorcylic acid lactone, O-demethylated-zeaenol (2), were isolated from sponge-derived fungus Curvularia sp. ZYX-Z-4. The structure of 1 was elucidated by 1D and 2D NMR spectroscopic as well as HR-ESI-MS analysis. The configuration of 1 was established by the NMR chemical shifts calculation followed by DP4+ analysis and ECD calculation. Compounds 1 and 2 were evaluated for the antifungal and neuroprotective activities and compound 2 showed comparable neuroprotective effect on the H₂O₂ injured SH-SY5Y cells to that of trolox.

The scope for natural colours is increasing because of the awareness of allergic, toxic, and hazardous reactions associated with synthetic dyes. Natural colours are extracted from sources that are naturally available, such as flora, fauna, and minerals. Nature sourced us multiple possibilities of colours with varied shades and hues that are subtle and harmonious when combined. Reasons like the instability of natural colours during industrial processing, seasonal availability of raw materials, fading of colour over time, cost of the benefit, and struggles in attaining sustainability have reduced commercialisation success as synthetic colours. Some plants that yield natural colours are also included in crop rotation practice. Natural dye extraction is a source of employment for the countrified subdivisions of poor developing countries. Indigenous technologies on natural colour extraction are available and have been practiced over the years; due to a lack of documentation and information on colour-yielding plants or products from horticultural crops, and their extraction methods, the use of natural colours is diminishing day by day. Even in recent years, emerging techniques have been adopted in research and development, and the information has not been brought together for the use of industries and allied sectors. Several modern approaches, such as Ultrasonication, microwave, enzymatic, supercritical, pressurised liquid extraction, etc., have proven to give better results in extracting natural colours. Thereby, having instantaneous information will help to go green, be eco-friendly, and effectively utilise all the resources without compromising industrial benefits. Reviewing the availability of natural colours from horticultural crops, classifications, recent trends in their extraction process, and applications in various fields will help achieve the above.