The methanol extract of the dried ripe fruits of Alpinia rafflesiana was investigated for its DPPH free radical scavenger constituents. 2',3',4',6'-Tetrahydroxychalcone (7), which has never been isolated from natural sources was found to be most active as a DPPH free radical scavenger with the IC50 value of 55 microM. Other known compounds isolated from this species include 5,6-dehydrokawain (1), flavokawin B (2). 1,7-diphenyl-5-hydroxy-6-hepten-3-one (3), (-)-pinocembrin (4), cardamonin (5) and (-)-pinostrobin (6). The DPPH free radical scavenger compounds were detected using TLC autographic analysis. The percentage inhibition of DPPH free radical scavenging activity was measured on isolates (5-7) using colorimetric analysis.
Two new garcinia acid derivatives, 2-(butoxycarbonylmethyl)-3-butoxycarbonyl-2-hydroxy-3-propanolide and 1',1"-dibutyl methyl hydroxycitrate, were isolated from the fruits of Garcinia atroviridis guided by TLC bioautography against the fungus Cladosporium herbarum. The structures of these compounds were established by spectral analysis. The former compound represents a unique beta-lactone structure and the latter compound is most likely an artefact of garcinia acid (= hydroxycitric acid). Both compounds showed selective antifungal activity comparable to that of cycloheximide (MID: 0.5 microg/spot) only against C herbarum at the MIDs of 0.4 and 0.8 microg/spot but were inactive against bacteria (Bacillus subtilis, methicillin-resistant Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli), other fungi (Alternaria sp., Fusarium moniliforme and Aspergillus ochraceous) including the yeast Candida albicans.
The oil of Adenanthera pavonina L. seeds was analysed by chromatographic and instrumental means. The oil was found to be rich in neutral lipids (86.2%), and low in polar lipids (13.8%). The neutral lipids consisted mainly of triacylglycerols (64.2%). Unsaturated fatty acids were found as high as 71%, while the percentage of saturated fatty acids was only 29%. GC and GC/MS analyses revealed linoleic, oleic and lignocerotic acid to be predominant among all fatty acids in the A. pavonina oil, whereas stigmasterol was the major steroid identified within this study. Subsequently, the oil was used for preparation of submicron oil-in-water (o/w) lipid emulsions. Lipid emulsions were formulated by using soybean lecithin (SL) to investigate their particle size, Zeta potential and stability at the different oil and SL ratios. The results obtained indicate possible applications of the tested oil in pharmaceutical and medical fields as drug and cosmetic active ingredient carriers.
Two new xanthones, characterized as 4-(1,1-dimethylprop-2-enyl)-1,3,5,8-tetrahydroxyxanthone (1) and penangianaxanthone (2), with three known xanthones, cudratricusxanthone H (3), macluraxanthone C (4) and gerontoxanthone C (5), as well as friedelin and stigmasterol were isolated from the leaves of Garcinia penangiana. Their structures were elucidated by analysis of spectroscopic data and comparison of the NMR data with the literature ones. Significant cytotoxicity against DU-145, MCF-7 and NCI-H460 cancer cell lines was demonstrated by compounds 1-5, with IC50 values ranging from 3.5 to 72.8 microM.
Nine derivatives of three natural diarylheptanoids, curcumin, demethoxycurcumin and bisdemethoxycurcumin, were prepared. Their antioxidant, free radical scavenging, nitric oxide (NO) inhibitory and cytotoxic activities were evaluated and compared with those of the respective natural compounds. Curcumin (1), demethoxycurcumin (2), demethyldemethoxy-curcumin (C3), diacetyldemethoxycurcumin (AC2) and triacetyldemethylcurcumin (AC5) exhibited higher antioxidant activity than quercetin while products from demethylation of 1 and 2 exhibited higher free radical scavenging activity. Compounds AC2 and AC5 were found to be most active in inhibiting breast cancer cells (MCF-7) proliferation with IC50 values of 6.7 and 3.6 microM, respectively. The activity of AC2 is almost doubled and of AC5 almost tripled as compared to curcumin. Their selectivity towards different cell lines is also more noticeable. Compounds AC2 and AC5 also showed increased activity against a human prostate cancer cell line (DU-145) and non-small lung cancer cell line (NCI-H460) with IC50 values of 20.4, 16.3 and 18.3, 10.7 microM, respectively.
A phytochemical investigation of the stem bark of Calophyllum canum resulted in the isolation of a new xanthone dimer identified as biscaloxanthone (1), together with four compounds; trapezifoliaxanthone (2), trapezifolixanthone A (3), taraxerone (4) and taraxerol (5). The structures of these compounds were determined via spectroscopic methods of IR, UV, MS and NMR (1D and 2D). The cytotoxicity of compounds 1-3 were screened against A549, MCF-7, C33A and 3T3L1 cell lines, wherein weak cytotoxic activities were observed (IC50 > 50 μm).
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.
This study was aimed to investigate the chemical compositions of the essential oils from Goniothalamus macrophyllus and Goniothalamus malayanus growing in Malaysia. The essential oils were obtained by hydrodistillation and fully characterized by gas chromatography (GC-FID) and gas chromatography-mass spectrometry (GC-MS). Analyses of the essential oils from G. macrophyllus and G. malayanus resulted in 93.6 and 95.4% of the total oils, respectively. The major components of G. macrophyllus oil were germacrene D (25.1%), bicyclogermacrene (11.6%), α-copaene (6.9%) and δ-cadinene (6.4%), whereas in G. malayanus oil bicyclogermacrene (43.9%), germacrene D (21.1%) and β-elemene (8.4%) were the most abundant components.
The rich and diversified Malaysian flora represents an excellent resource of new chemical structures with biological activities. The genus Xylopia L. includes aromatic plants that have both nutritional and medicinal uses. This study aims to contribute with information about the volatile components of three Xylopia species essential oils: Xylopia frutescens, Xylopia ferruginea, and Xylopia magna. In this study, essential oils were extracted from the leaves by a hydrodistillation process. The identification of the essential oil components was performed by gas chromatography (GC-FID) and gas chromatography-coupled mass spectrometry (GC-MS). The major components of the essential oils from X. frutescens were bicyclogermacrene (22.8%), germacrene D (14.2%), elemol (12.8%), and guaiol (12.8%), whereas components of the essential oils from X. magna were germacrene D (35.9%), bicyclogermacrene (22.8%), and spathulenol (11.1%). The X. ferruginea oil was dominated by bicyclogermacrene (23.6%), elemol (13.7%), guaiol (13.4%), and germacrene D (12.3%).
Polyalthia is one of the largest genera in the Annonaceae family, and has been widely used in folk medicine for the treatment of rheumatic fever, gastrointestinal ulcer, and generalized body pain. The present investigation reports on the extraction by hydrodistillation and the composition of the essential oils of four Polyalthia species (P. sumatrana, P. stenopetalla, P. cauliflora, and P. rumphii) growing in Malaysia. The chemical composition of these essential oils was determined by gas chromatography (GC-FID) and gas chromatography-mass spectrometry (GC-MS). The multivariate analysis was determined using principal component analysis (PCA) and hierarchical clustering analysis (HCA) methods. The results revealed that the studied essential oils are made up principally of bicyclogermacrene (18.8%), cis-calamenene (14.6%) and β-elemene (11.9%) for P. sumatrana; α-cadinol (13.0%) and δ-cadinene (10.2%) for P. stenopetalla; δ-elemene (38.1%) and β-cubebene (33.1%) for P. cauliflora; and finally germacrene D (33.3%) and bicyclogermacrene for P. rumphii. PCA score and HCA plots revealed that the essential oils were classified into three separated clusters of P. cauliflora (Cluster I), P. sumatrana (Cluster II), and P. stenopetalla, and P. rumphii (Cluster III) based on their characteristic chemical compositions. Our findings demonstrate that the essential oil could be useful for the characterization, pharmaceutical, and therapeutic applications of Polyalthia essential oil.
Chemical composition and anticholinesterase activity of the essential oil of Pavetta graciliflora Wall. ex Ridl. (Rubiaceae) was examined for the first time. The essential oil was obtained by hydrodistillation and was fully characterized by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). A total of 20 components were identified in the essential oil, which made up 92.85% of the total oil. The essential oil is composed mainly of β-caryophyllene (42.52%), caryophyllene oxide (25.33%), β-pinene (8.67%), and α-pinene (6.52%). The essential oil showed weak inhibitory activity against acetylcholinesterase (AChE) (I%: 62.5%) and butyrylcholinesterase (BChE) (I%: 65.4%) assays. Our findings were shown to be very useful for the characterization, pharmaceutical, and therapeutic applications of the essential oil from P. graciliflora.
The current study describes the chemical composition, antifungal, antibiofilm, antibacterial and molecular docking studies of Syzygium dyerianum growing in Malaysia. The essential oil was obtained through hydrodistillation and characterized using gas chromatography (GC-FID) and gas chromatography-mass spectrometry (GC-MS). The antifungal and antibacterial activities were developed using the broth microdilution assay, whereas the effect on the microbial biofilms was determined using a semi-quantitative static biofilm assay. A total of 31 components were identified, which represent 99.5 % of the essential oil. The results revealed that the essential oil consisted mainly of β-pinene (15.6 %), α-terpineol (13.3 %), α-pinene (11.1 %), caryophyllene oxide (8.8 %), limonene (8.1 %), borneol (6.0 %) and viridiflorol (5.1 %). The results of the microdilution method showed that essential oil exhibited activity against Candida albicans and Streptococcus mutans with minimal inhibitory concentration values of 125 and 250 μg/mL, respectively. Furthermore, essential oil decreased the biofilm of C. albicans and S. mutans by 20.11 ± 0.27 % and 32.10 ± 4.81 % when treated with 250 μg/mL. The best docking energy was observed with viridiflorol (-29.7 kJ/mol). This study highlights that essential oil can potentially be a natural antifungal, antibacterial, and antibiofilm agent that could be applied in the pharmaceutical and food industries.
Diabetes mellitus (DM) is a disorder which is raised at the alarming level and it is characterized by the hyperglycemia results from the impaired action of insulin, production of insulin or both of these simultaneously. Consequently, it causes problems or failure of different body organs such as kidneys, heart, eyes, nerve system. Since this disease cannot be completely cured until now, we aimed to design series of enzymes inhibitors and tested them for DM treatment. In this series, benzimidazole-based thiazolidinone bearing chalcone derivatives completed in a four step reaction and their structures were confirmed through various spectroscopic techniques. A significant efficacy on antidiabetic enzymes was observed, with IC50 values ranging from 25.05 ± 0.04 to 56.08 ± 0.07 μM for α-amylase and 22.07 ± 0.02 to 53.06 ± 0.07 μM for α-glucosidase. The obtained results were compared to those of the standard glimepiride drug (IC50 = 18.05 ± 0.07 µM for α-amylase and IC50 = 15.02 ± 0 .03 µM for α-glucosidase). The synthesized compounds showed promising antidiabetic potency. Moreover, a molecular docking study was conducted on the most active analogs of the compounds to better understand their interactions with the active sites of the targeted enzymes.
Hoja santa (Piper auritum) refers to an important presence in Mexican cuisine. The information of this review article was gathered from several electronic sources such as Scopus, Medline, Scielo, ScienceDirect, SciFinder, Web of Science, Google Scholar and Lilacs. Phytochemical studies have revealed the presence of benzoic acid derivatives, phenylpropanoids and triterpenoids, while the essential oils have shown its richness in safrole, hence it has several activities, such as antioxidant, toxicity, insecticidal, anti-diabetic and cytotoxic properties. This review is expected to draw the attention of medical professionals and the general public towards P. auritum as well as to open the door for detailed research in the future.
Knema is one of the genera in the Myristicaceae family. The genus includes 60 species in Southeast Asia and is traditionally used for treating skin disorders. Here, for the first time, the essential oil, anti-tyrosinase, and molecular docking studies of Knema intermedia were evaluated. The essential oil was obtained by hydrodistillation and fully characterized by gas chromatography (GC-FID) and gas chromatography-mass spectrometry (GC-MS). Anti-tyrosinase activity was evaluated against mushroom tyrosinase, whereas molecular docking studies were performed using Autodock vina embedded in PyRx to evaluate the binding interactions of major components. A total of 37 components (97.3%) were successfully identified in the essential oil, which was characterized by high amounts of t-muurolol (20.1%), α-copaene (14.4%), δ-cadinene (13.9%), germacrene B (9.5%), and δ-selinene (7.0%). The essential oil displayed moderate inhibitory activity towards tyrosinase with an IC50 value of 70.2 μg/mL. The best docking energy was observed with δ-selinene (-7.8 kcal/mol), and it also forms interactions with His85, His263, and His244 which are important amino acid residues of the tyrosinase receptor. Hence, this study provides valuable scientific data on K. intermedia as potential candidate for the development of natural antiaging formulations.
The research examined the molecular interaction between nirmatrelvir (NIR), a drug used to treat COVID-19, and human serum albumin (HSA) using various techniques, viz., isothermal titration calorimetry (ITC), absorption, fluorescence, CD spectroscopy, and atomic force microscopy (AFM). ITC analysis showed that the NIR-HSA system possessed a moderate binding affinity, with a K a value of 6.53 ± 0.23 × 104 M-1 at a temperature of 300 K. The thermodynamic values demonstrated that the NIR-HSA complex was stabilized by hydrophobic contacts, hydrogen bonds, and van der Waals forces. The research also discovered modifications in the UV-Vis absorption spectrum of the protein as well as swelling of the HSA molecule when exposed to NIR, based on AFM results. The three-dimensional fluorescence spectral data indicated changes in the microenvironment around HSA's Trp and Tyr residues. Alterations in the protein structure (both secondary and tertiary structures) of HSA after NIR binding were verified using CD spectral studies in the far-UV and near-UV regions. The identification of the NIR binding site in subdomain IB (Site III) of HSA was predicted through competitive displacement experiments.
The current study involves the synthesis of Schiff bases based on 1,2,4-triazoles skeleton and assessing their α-amylase and α-glucosidase profile. Furthermore, the precise structures of the synthesized derivatives were elucidated using various spectroscopic methods such as 1H-NMR, 13C-NMR and HREI-MS. Using glimepiride as the reference standard, the in vitro α-glucosidase and α-amylase inhibitory activities of the synthesized compounds were evaluated in order to determine their potential anti-diabetic properties. All analogues showed varied range of inhibitory activity having IC50 values ranging from 17.09 ± 0.72 to 45.34 ± 0.03 μM (α-amylase) and 16.35 ± 0.42 to 42.31 ± 0.09 μM (α-glucosidase), respectively. Specifically, the compounds 1, 7 and 8 were found to be significantly active with IC50 values of 17.09 ± 0.72, 19.73 ± 0.42, and 23.01 ± 0.04 μM (against α-amylase) and 16.35 ± 0.42, 18.55 ± 0.26, and 20.07 ± 0.02 μM (against α-glucosidase) respectively. The obtained results were compared with the Glimepiride reference drug having IC50 values of 13.02 ± 0.11 μM (for α-glucosidase) and 15.04 ± 0.02 μM (for α-amylase), respectively. The structure-activity relationship (SAR) studies were conducted based on differences in substituent patterns at varying position of aryl rings A and B may cause to alter the inhibitory activities of both α-amylase and α-glucosidase enzymes. Additionally, the molecular docking study was carried out to explore the binding interactions possessed by most active analogues with the active sites of targeted α-amylase and α-glucosidase enzymes.
This study aimed to investigate the chemical composition, and anticholinesterase and anti-tyrosinase activities of the essential oil extracted from the leaves of Piper frustratum Boerl., growing in Malaysia. Nineteen chemical components were identified using gas chromatography-flame ionization detection (GC-FID) and gas chromatography-mass spectrometry (GC-MS), accounting for 99.6 % of the essential oil. The identified major components include β-caryophyllene (12.6 %), β-asarone (10.7 %), myristicin (10.4 %), α-copaene (9.6 %), methyl eugenol (7.2 %), and β-cubebene (6.5 %). Anticholinesterase activity was assessed using the Ellman's method, while anti-tyrosinase activity was evaluated against mushroom tyrosinase. The essential oil demonstrated moderate inhibitory activity against acetylcholinesterase (IC50 value of 84.2 μg/mL), butyrylcholinesterase (IC50 value of 98.5 μg/mL), and tyrosinase (IC50 value of 95.4 μg/mL) enzymes. This study is the first to report the chemical composition and bioactivities of the essential oil obtained from P. frustratum, which may have implications on the characterization, pharmaceutical, and therapeutic applications of Piper essential oils.