Xanthones: A Class of Heterocyclic Compounds with Anticancer Potential.

Xanthones (9H xanthen-9-one) are an important class of heterocyclic compounds containing oxygen and a moiety of gamma-pirone, dense with a two-benzene ring structure, distributed widely in nature. Naturally occurring xanthones are found in micro-organisms and higher plants as secondary metabolites in fungi and lichens. Compounds of the family Caryophyllaceae, Guttiferae and Gentianaceae, are the most common natural source of xanthones. The structure of the xanthones nucleus, coupled with its biogenetic source, imposes that the carbons are numbered according to the biosynthetic pact. The characteristics oxygenation pattern of xanthones earlier is mixed shikimateacetate biogenesis. The major class of xanthones includes simple oxygenated, non-oxygenated, xanthonolignoids, bisxanthones, prenylated and related xanthones, miscellaneous xanthones. Their great pharmacological importance and interesting scaffolds were highly encouraged by scientists to investigate either the synthesis design or natural products for cancer treatment. Because currently used antitumor drugs possess high toxicity and low selectivity, efficacious treatment may be compromised. This review is limited to the antitumor activity of xanthones and the chemistry of xanthone core, which may help provide fundamental knowledge to the medicinal chemist for new and advanced research in drug development.

Nanoparticles in clinical trials of COVID-19: An update.

Once the World Health Organization (WHO) declared the COVID-19 (Coronavirus Infectious Disease-19) outbreak to be pandemic, massive efforts have been launched by researchers around the globe to combat this emerging infectious disease. Strategies that must be investigated such as expanding testing capabilities, developing effective medicines, as well as developing safe and effective vaccines for COVID-19 disease that produce long-lasting immunity to human system. Now-a-days, bio-sensing, medication delivery, imaging, and antimicrobial treatment are just a few of the medical applications for nanoparticles (NPs). Since the early 1990s, nanoparticle drug delivery methods have been employed in clinical trials. Since then, the discipline of nanomedicine has evolved in tandem with expanding technological demands to better medicinal delivery. Newer generations of NPs have emerged in recent decades that are capable of performing additional delivery tasks, allowing for therapy via novel therapeutic modalities. Many of these next generation NPs and associated products have entered clinical trials and have been approved for diverse indications in the present clinical environment. For systemic applications, NPs or nanomedicine-based drug delivery systems have substantial benefits over their non-formulated and free drug counterparts. Nanoparticle systems, for example, are capable of delivering medicines and treating parts of the body that are inaccessible to existing delivery systems. As a result, NPs medication delivery is one of the most studied preclinical and clinical systems. NPs-based vaccines delivering SARS-CoV-2 antigens will play an increasingly important role in prolonging or improving COVID-19 vaccination outcomes. This review provides insights about employing NPs-based drug delivery systems for the treatment of COVID-19 to increase the bioavailability of current drugs, reducing their toxicity, and to increase their efficiency. This article also exhibits their capability and efficacy, and highlighting the future aspects and challenges on nanoparticle products in clinical trials of COVID-19.

Phytochemistry and Pharmacological Activities of Dracaena cinnabari Resin.

Dracaena cinnabari (D. cinnabari) is an endemic plant located in Socotra Island, Yemen. Deep red resin attained from different plant species including D. cinnabari is commonly known as dragon's blood. In folk medicine, it is prescribed for the treatment of traumatic dermal, dental, and eye injuries as well as blood stasis, pain, and gastrointestinal diseases in humans. Numerous studies have investigated that this resinous medicine has antidiarrheal, antiulcer, antimicrobial, antiviral, antitumor, anti-inflammatory, analgesic, wound healing, and antioxidant activity. Several phytochemicals have been isolated from D. cinnabari, including the biflavonoid cinnabarone, triflavonoids, metacyclophanes, chalcones, chalcanes, dihydrochalcones, sterols, and terpenoids. The present review highlights the structures and bioactivities of main phytochemicals isolated from D. cinnabari regarding the botany and pharmacological effects of the resin derived from this plant.

In Vivo Antinociceptive, Muscle Relaxant, Sedative, and Molecular Docking Studies of Peshawaraquinone Isolated from Fernandoa adenophylla (Wall. ex G. Don) Steenis.

Fernandoa adenophylla (Wall. ex G. Don) Steenis is traditionally used to cure various diseases and can be included as an ingredient in massage oils, which are supposed to comfort muscular tension and pain. This study was designed to assess the antinociceptive, muscle relaxant, and molecular docking properties of a novel compound, namely, (5aR,5a1R,6R,7aS,14bR,15R)15-hydroxy-7a-methyl-6-(2-methylprop-1-en-1-yl)-7,7a,14b,15-tetrahydro-5H-t-5a,15methanobenzo[g]benzo[5,6]azuleno[1,8-bc]chromene-5,9,14,16(5a1H,6H)- tetraone (peshawaraquinone), isolated from the methanolic extract of F. adenophylla in an animal model. The chemical structure of the isolated compound was elucidated using advanced spectroscopic techniques and further confirmed by XRD analysis. Compound 1 was tested against hot plate-induced noxious stimuli at various doses (2.5, 5, 10, and 15 mg/kg i.p.). The muscle relaxation potency of compound 1 was evaluated in the inclined and traction test, while the open-field test was used for the determination of sedative potential. The isolated compound was also subjected to acute toxicity analysis. The compound was then subjected to molecular docking analysis to determine the exact mechanism of action. Compound 1 demonstrated significant (p < 0.05) analgesic effect in a dose-dependent manner. A noticeable muscle relaxant effect was observed with the passage of time in both experimental models. The compound 1 showed a significant (p < 0.05) sedative effect, and in an acute toxicity study, the compound 1 was devoid of any noxious effects. The docking studies showed preferential affinity for µ-opioid and GABAA receptors. Hence, the prospective antinociceptive and muscle relaxant and sedative properties are probably mediated through these two target interactions.