Phytochemical screening and antioxidant activity of Psidium guajava

Psidium guajava or commonly known as guava is useful to treat gastroenteritis, dysentery, stomach pain and indigestion. In this study, the leaves of this species were screened for its phytochemical and antioxidant activity. The phytochemicals were extracted by sequential maceration by using n-hexane, chloroform and methanol, while phytochemical screening was performed using various chemical tests. Meanwhile, its antioxidant activity was assessed by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay. Steroids and terpenoids were found to be present in the n-hexane extract, while phenols and terpenoids were detected in the chloroform extract. The methanol extract contained flavonoids, steroids, saponins, phenols and terpenoids. Among the tested extracts, the methanolic extract demonstrated strong DPPH radical scavenging activity with an IC50 value of 45.52 μg/mL.\ ******************************************************************************************************************************************** Psidium guajava atau dikenali sebagai jambu batu berguna bagi mengubati gastroenteritis, disenteri, sakit perut dan masalah pencernaan. Dalam kajian ini, daun spesis ini telah disaring untuk fitokimia dan aktiviti antioksidan. Fitokimia telah diekstrak menggunakan rendaman berturutan menggunakan n-heksana, kloroform dan metanol, manakala saringan fitokimia telah dijalankan menggunakan pelbagai ujian kimia. Sementara itu, aktiviti antioksidan telah dinilai menggunakan kaedah 2,2-difenil1-pikrilhidrazil (DPPH). Steroid and terpenoid telah didapati hadir di dalam ekstrak n-heksana, manakala fenol dan terpenoid telah dikesan di dalam ekstrak kloroform. Ekstrak metanol telah mengandungi flavonoid, steroid, saponin, fenol dan terpenoid. Di kalangan ekstrak yang diuji, ekstrak metanol menunjukkan aktiviti perencatan radikal DPPH yang kuat dengan nilai IC50 45.52 μg/mL

Phytochemical screening and antioxidant activity of Psidium guajava

Psidium guajava or commonly known as guava is useful to treat gastroenteritis, dysentery, stomach pain and indigestion. The leaves of P. guajava was screened for phytochemical and antioxidant activity. The phytochemicals were extracted by sequential maceration using n-hexane, chloroform and methanol, while phytochemical screening was performed using various chemical tests. Antioxidant activity was assessed by 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay. Steroids and terpenoids were present in the n-hexane extract, while phenols and terpenoids were detected in the chloroform extract. The methanol extract was found to contain flavonoids, steroids, saponins, phenols and terpenoids. Among the tested extracts, the methanolic extract demonstrated strong DPPH radical scavenging activity with an IC50 value of 51.07 µg/mL

Development of HPLC method and quantification of amentoflavone from leaves extracts of three Calophyllum species

This study described the development and validation of a method that can quantify amentoflavone in the methanol extracts of leaves of three Malaysian Calophyllum species via high performance liquid chromatography (HPLC) technique. Chromatographic analysis was conducted using a reverse phase C18 column with water and acetonitrile (55:45) as the mobile phase. The flow rate was 1.0 mL/min and detection by ultraviolet-visible detector at 270 nm. The developed method was validated in terms of linearity, precision and accuracy in accordance to International Conference on Harmonization (ICH) guidelines. The calibration curve showed good linearity (r2 > 0.9998) in a concentration range of 2.5 – 100 μg/mL with low limit of detection and limit of quantification at 1.33 and 4.02 μg/mL, respectively. The percentage of coefficient of variation for intra-day and inter-day precision was less than 2% while percentage of recovery was more than 90% indicating the precision and accuracy of the method. The developed HPLC method was proved as suitable and reliable for its intended application. The amount of amentoflavone quantified from C. incrassatum, C. canum and C. rubiginosum leaves extracts by using the developed method was 9.42, 30.39 and 24.23 μg/mL, respectivel

Green synthesis of metal nanoparticles using Garcinia extracts: a review

The demand for nanoparticles has been increasing rapidly in recent years due to their unique properties of interest for a wide range of applications. Several physical, chemical, or microorganisms-based methods can be employed in the synthesis of nanoparticles. However, classical processes are time-consuming, complicated, and raise environmental concerns due to the use of high energy and toxic chemicals. Synthesis using plant extract outweighs some classical methods because it is rapid, simple, and eco-friendly. Therefore, plant extract appears promising to produce nanoparticles. Here we review the use of extracts from various species and plant parts of Garcinia for the green synthesis of metal nanoparticles. Garcinia gummi-gutta is a tropical species of Garcinia native to Indonesia. Common names include Garcinia cambogia, as well as brindleberry, Malabar tamarind, Goraka, and kudam puli. The fruit looks like a small pumpkin and is green to pale yellow. We present the major metabolites responsible for metal ions reduction and nanoparticles stabilisation, the synthesis mechanism, the types of metal nanoparticles formed, and their potential applications. Advantages and challenges of Garcinia extract utilisation are also discussed

Design of xanthorrhizol derivatives using in silico fragment-based drug design (FBDD) approach as lipoxygenase inhibitors

PURPOSE: Xanthorrhizol (XNT), a natural product isolated from Curcuma xanthorrhiza is known for its anti-inflammatory properties, through inhibition of pro-inflammatory enzymes, such as cyclooxygenase (COX) and inducible nitric oxide synthase (iNOS). Due to its small molecular weight (MW=281.33 g/mol) and biological activity, XNT is a suitable candidate to be further optimized as a more potent anti-inflammatory agent. Preliminary in vitro inhibitory studies showed that XNT exhibited mild activity (50.01% inhibition at concentration 100 µg/mL) against lipoxygenase (sLOX), an enzyme responsible for the eicosanoids biosynthesis pathway to form leukotrienes, that can induce inflammatory response towards human body. Hence, we aimed to improve the activity of XNT towards sLOX by modifying its hydroxyl functionality using combination of in silico methods, which are molecular docking and fragment-based drug design (FBDD) approach. In this study, a total of 1887 new XNT derivatives were generated as sLOX inhibitors by using LigBuilder software. Then, only the top 50 derivatives which exhibit binding energies, ranging from -8.4 to -9.0 kcal/mol were screened to remove duplicates. The number of derivates were further narrowed based on its ADME and druglikeness properties. Five promising XNT derivatives were chosen, consisting of different long alkyl chain with different heteroatoms, as potential Hyal inhibitors to be synthesized in the future. This work provided a more efficient approach for drug modification to produce more potent novel compounds using computational methods

Molecular docking and adme profiling of xanthorrhizol derivatives as hyaluronidase inhibitors

Hyaluronidase (Hyal) enzyme is one of the potential biological targets for the development of anti-inflammatory agents. Xanthorrhizol, a bisabolene sesquiterpenoid isolated from Curcuma xanthorrhiza has been reported showing anti-inflammatory activities against cyclooxygenase (COX), inducible nitric oxide synthase (iNOS), and interleukins (IL). However, the activity of xanthorrhizol as a Hyal inhibitor has not been exploited. In this study, a total of 26 xanthorrhizol derivatives having structural modifications at R1 - R4 scaffold were chosen. The molecular docking was performed to virtually screened their SAR activities towards Hyal while the ADME prediction was done to predict their pharmacokinetic profile. All derivatives bind to the active site of Hyal1 with binding energies ranging from -5.7 kcal/mol to -8.5 kcal/mol. Derivatives 24, and 14 having benzyloxy moiety at R1 position and polar moieties at R3 and R4 position showed lower binding energies (-8.3, and -7.9 kcal/mol, respectively) compared to apigenin, 28 and xanthorrhizol, 1. These derivatives also fulfilled all ADME and drug-likeness properties suggesting them as potential Hyal inhibitors. Through this work, the activity of xanthorrhizol derivatives against Hyal1 can be predicted and screened as a basis for future modifications of xanthorrhizol as potential Hyal inhibitor

Biotransformation of curcumin and structure–activity relationship (SAR) of its analogues: a systematic review

Curcumin has been widely acclaimed for several pharmacological properties, such as antioxidant, antimicrobial, anticancer, and anti-inflammation. Curcumin’s poor aqueous solubility, bioavailability, and cellular uptake hamper its ability to display maximum pharmacological effect in the human body. Synthesis of curcumin analogues to enhance its properties can be achieved through biotransformation. Greener, simpler, and higher selectivity and specificity make biotransformation an alternative approach when preparing curcumin analogues for the structure– activity relationship (SAR) study intended for drug design. This work systematically reviews the biotransformation of curcumin by utilizing fungi, gut microbiota, and enzymes. The SAR study of curcumin and its analogues for several bioactivities is also highlighted

Cytotoxic and antibacterial activities of constituents from Calophyllum ferrugineum ridley

This study evaluated the chemical composition of Calophyllum ferrugineum, cytotoxicity against human breast cancer (MCF-7) and human lung carcinoma (A-549) cell lines as well as antibacterial activities against two Gram-positive bacteria, S. aureus and B. subtilis and two Gram-negative bacteria, P. aeruginosa and E. coli. Phytochemical investigations of the bark extract yielded isoapetalic acid (1), apetalic acid (2), 6-hydroxy-2-methoxyxanthone (3) and ent-epicatechin (4). Meanwhile, betulinic acid (5), protocatechuic acid (6) and amentoflavone (7) were isolated from the leave extract. Isoapetalic acid (1) and apetalic acid (2) exhibited cytotoxic activities towards both cancer cell lines and both Gram-positive bacteria. Compounds (3-7) were inactive or showed moderate activities towards cytotoxic and antibacterial tests. This study presents the first report on the phytochemicals investigation from C. ferrugineum and all compounds are reported for the first time from this source

Antibacterial and antioxidant activities of extracts from Calophyllum ferrugineum and Calophyllum incrassatum

Calophyllum is a pan-tropical genus belongs to the Guttiferae family and locally known in Malaysia as ‘bintangor’. There has been a continual interest to further investigate the phytochemistry of Calophyllum sp since this genus is a rich source of active secondary metabolites which showed anti-HIV, cytotoxicity and antimicrobial properties. In this study, antibacterial and antioxidant activities of barks and leaves of C. ferrugineum and C. incrassatum were investigated. Cold extraction method employing dichloromethane, ethyl acetate and methanol as solvent was performed. All extracts were tested for their total phenolic content and antioxidant activities by DPPH radical scavenging and Ferric Reducing Antioxidant Power (FRAP) assays. The methanol extract from the leaves of C. ferrugineum showed the highest TPC value at 122.08 mg GAE/g and the lowest DPPH SC50 value at 11.80 µg/mL. The methanol extract from the barks of C. ferrugineum was found to have the highest FRAP value among all extracts. The antibacterial activity of all extracts was tested by minimum inhibition concentration (MIC) test against Bacillus subtilis, Staphylococcus aureus, Escheria coli and Pseudomonas aeruginosa. Only the dichloromethane extract from bark of C. ferrugineum showed moderate MIC value against Gram positive bacteria, B. subtilis and S. aureus at 125 µg/mL