An overview of the anti-HIV potential of thiazolidinone derivatives

Abstract:

Human immunodeficiency virus (HIV) is the cause of acquired immunodeficiency syndrome (AIDS), an immunosuppressive, life-threatening condition that frequently results in other potentially fatal opportunistic infections in affected patients. Despite advancements in anti-retroviral therapy, AIDS remains the main reason for worldwide mortality. Although various anti-HIV drugs have profoundly enhanced the quality of life for AIDS patients, some patients develop resistance to the drugs, and the long-term anti-HIV treatments, and their adverse effects, prevail as major therapeutic failure causes. Therefore, concerted efforts by the scientific community are crucial to identifying new candidates for anti-HIV therapies. In this respect, the thiazolidinone moiety has acquired prominence in drug discovery and development due to its antifungal, antiviral, antidepressant, anticancer, and antibacterial properties. This moiety also demonstrated significant anti-HIV activity as a core heterocycle or derivative of substituted heterocycles. To expedite the synthesis of more novel anti-HIV drugs containing a thiazolidinone nucleus, we compiled a list of thiazolidinone-containing previously documented anti-HIV compounds. We hope that this could serve as a guide for future researchers in their design of effective thiazolidine-containing compounds showing anti-HIV activity.

Bioactivity Evaluation of Leucas zeylanica and its Phytochemicals

Leucas zeylanica belongs to the Lamiaceae family has high medicinal value. The phytochemicals screening results showed that terpenoids, flavonoids, tannins, saponins, phenols and alkaloids are present in aerial part of L. zeylanica.Vacuum liquid chromatography (VLC) and column chromatography (CC) techniques were used in fractionation and purification of the crude extracts.

Development and validation of a new vision screening test algorithm for public use mobile application- A pilot study

OBJECTIVES

To design and develop a simple vision test algorithm for mobile application and perform a pilot study to determine its validity and reliability as a tool for vision test in the community.

METHODS

A simple visual acuity test algorithm in the form of a single letter E display was designed as the optotype for development of a mobile application. The standardised optotype is presented at random to test visual acuity for corresponding level of 3/60, 6/60, 6/18, and 6/12. The final result is auto-generated based on the classification of the WHO for visual impairment and blindness. The Snellen chart was used as the gold standard to determine its validity while five different users were involved to determine its inter-rater reliability. A pilot study was performed between April till November 2019, in the Universiti Sultan Zainal Abidin Medical Centre (UMC) at Kuala Nerus and Mooris Optometrist Centre at Marang, Terengganu. A total of 279 participants aged four years old and above were involved in this study.

RESULTS

The highest sensitivity was found at the vision level cut-off point of 6/12 with the percentage of 92.7% and 86.8% for the right and left eye, respectively. The specificity was more than 89% for all vision levels in both eyes. The Krippendorff's alpha value for the inter-rater reliability was 0.87 and 0.83.

CONCLUSION

The relatively high level of validity and reliability obtained indicate the feasibility of using the designed optotype to develop a valid and reliable mobile app for vision test. The app can be used to screen vision by nonmedical persons, at anytime and anywhere to help improve public awareness and capability to correctly determine their visual status.

Chemical Compositions and Tyrosinase Activity of the Essential Oils of Alpinia aquatica

The essential oils obtained from the fresh rhizome, leaf, and pseudostem of Alpinia aquatica Roscoe. were hydrodistillated and analyzed using capillary gas chromatography (GC) and gas chromatography-mass spectroscopy (GC-MS). β-Pinene (11.7%), α-humulene (8.9%), aromadendrene (8.7%), and sabinene (7.7%) were the major components in the rhizome oil. The most abundant components of the leaf oil were germacrene D (21.3%), β-pinene (15.6%) and sabinene (12.1%), while α-humulene (19.8%), germacrene D (15.2%) and β-caryophyllene (8.7%) were the main constituents in the pseudostem oil. Antityrosinase assay revealed that all the three essential oils exhibited weak tyrosinase inhibition activities. The rhizome oil showed the highest inhibition activity with the value of 9.5% for the L-DOPA oxidation.

Chemical Composition, Antioxidant, Antimicrobial, and α-Glucosidase Activities of Essential Oils of Hornstedtia scyphifera (Zingiberaceae)

The essential oil compositions of the rhizomes, flowers, leaves, and pseudostems of Hornstedtia scyphifera (J. Koenig) Steud were studied for the first time. A total of forty three constituents were identified from the rhizome, flower, leaf, and pseudostem oils, representing 90.9%, 82.4%, 79.7%, and 82.6%, respectively. α-Selinene was found dominant in the flower (10.8%) and pseudostem (12.4%) oils, while the rhizome and leaf oils contained germacrene D (15.5%) and camphor (12.6%) as the main constituents, respectively. The rhizome, flower, and leaf oils showed moderate activity against Gram positive bacteria with MIC values of 225 to 450 μg/mL and inhibition zones of 8.4 to 10.0 mm. The leaf oil showed good β-carotene bleaching inhibition activity (64.8%) and a low IC50 value for DPPH radical scavenging activity (650.4 μg/mL). The flower oil showed potential α-glucosidase inhibitory activity with an IC50 value of 21.44 μg/mL.

Antioxidant and α-Glucosidase Inhibitory Constituents from Hornstedtia Species of Malaysia

Seven compounds were isolated from the n-hexane and chloroform extracts of the flowers and leaves of four Hornstedtia species and their structures were identified using spectroscopic techniques as 3,7,4'-trimethylkaempferol (1), 3,7-dimethylkaempferol (2), 7,4'-dimethylkaempferol (3), 3,5-dimethylkaempferol (4), 3-methylkaempferol (5), stigmast-4-en-3-one (6), and 6-hydroxy-stigmast-4-en-3-one (7). Compounds 1 to 7 were isolated from these species for the first time. They were assayed for free radical scavenging and α-glucosidase inhibition activities. The DPPH assay showed that 3-methylkaempferol (5) was the most potent antioxidant agent with an IC50 value 78.6 µM, followed by 7,4'-dimethylkaempferol (3) (IC50 = 86.1 µM). For α-glucosidase inhibition activity, 3-methylkaempferol (5) exhibited significant inhibitory activity with an IC50 value 21.0 µM. The present study revealed that Hornstedtia species have potential activities as antioxidant and α-glucosidase inhibitors.

Antioxidant and α-Glucosidase Inhibitory Constituents from Hornstedtia Species of Malaysia

Seven compounds were isolated from the n-hexane and chloroform extracts of the flowers and leaves of four Hornstedtia species and their structures were identified using spectroscopic techniques as 3,7,4′-trimethylkaempferol (1), 3,7-dimethylkaempferol (2), 7,4′-dimethylkaempferol (3), 3,5-dimethylkaempferol (4), 3-methylkaempferol (5), stigmast-4-en-3-one (6), and 6-hydroxy-stigmast-4-en-3-one (7). Compounds 1 to 7 were isolated from these species for the first time. They were assayed for free radical scavenging and α-glucosidase inhibition activities. The DPPH assay showed that 3-methylkaempferol (5) was the most potent antioxidant agent with an IC50 value 78.6 μM, followed by 7,4′-dimethylkaempferol (3) (IC50 = 86.1 μM). For α-glucosidase inhibition activity, 3-methylkaempferol (5) exhibited significant inhibitory activity with an IC50 value 21.0 μM. The present study revealed that Hornstedtia species have potential activities as antioxidant and α-glucosidase inhibitors.

Chemical Compositions and Antimicrobial Activity of the Essential Oils of Hornstedtia havilandii (Zingiberaceae)

The chemical compositions and antimicrobial activity of the fresh rhizome and flower oils of Hornstedtia havilandii were studied. The components present were analyzed using GC and GC-MS. A total of forty-eight constituents were successfully identified from the flower and rhizome oils, representing 93.4% and 89.6%, respectively. The most abundant components of the flower oil were β-pinene, (19.5%), β-elemene, (10.0%), β-cubebene, (6.2%), α-pinene, (5.6%), γ-cadinene, (4.3%) and germacrene D, (3.3%), while α-copaene, (10.2%), β-selinene, (8.4%), β-elemene, (7.0%), γ-cadinene, (6.9%), β-cubebene, (5.3%) and germacrene D, (5.3%) were found as the main components of the rhizome oil. The essential oils were tested for antimicrobial activity against Gram-positive bacteria, Gram-negative bacteria and yeasts. Both oils showed activity against the Gram-positive bacterium, Staphylococcus aureus, with moderate MIC values of 112.5 μg/mL, however, for Gram-negative bacteria, the flower oil showed weak antimicrobial activity with a MIC value of 225 μg/mL. Only very weak activity was shown against the yeasts Candida albicans and C. glabrata, with MIC values of 900–1800 μg/mL.

Chemical compositions and antimicrobial activity of the essential oils of Hornstedtia havilandii (Zingiberaceae)

The chemical compositions and antimicrobial activity of the fresh rhizome and flower oils of Hornstedtia havilandii were studied. The components present were analyzed using GC and GC-MS. A total of forty-eight constituents were successfully identified from the flower and rhizome oils, representing 93.4% and 89.6%, respectively. The most abundant components of the flower oil were beta-pinene, (19.5%), beta-elemene, (10.0%), beta-cubebene, (6.2%), alpha-pinene, (5.6%), gamma-cadinene, (4.3%) and germacrene D, (3.3%), while alpha-copaene, (10.2%), beta-selinene, (8.4%), beta-elemene, (7.0%), gamma-cadinene, (6.9%), beta-cubebene, (5.3%) and germacrene D, (5.3%) were found as the main components of the rhizome oil. The essential oils were tested for antimicrobial activity against Gram-positive bacteria, Gram-negative bacteria and yeasts. Both oils showed activity against the Gram-positive bacterium, Staphylococcus aureus, with moderate MIC values of 112.5 micro/mL, however, for Gram-negative bacteria, the flower oil showed weak antimicrobial activity with a MIC value of 225 microg/mL. Only very weak activity was shown against the yeasts Candida albicans and C. glabrata, with MIC values of 900-1800 microg/mL.