Five new prenylated chalcones from Desmodium renifolium

Biomimetic total syntheses of renifolin F and antiarone K

The first biomimetic and concise racemic total syntheses of renifolin F and antiarone K, accomplished in 8 and 7 linear steps, respectively, are presented in this article. Our synthetic approach commences with substituted aldehydes to produce prenylated aldol products followed by ene-type intramolecular cyclization affording a five-member core ring. This key step mediated by InCl3·4H2O is a novel procedure first utilized in prenylated systems which directly culminates mainly into tertiary alcohols.

Sophoraflavanone G: A review of the phytochemistry and pharmacology

Bioactive compounds derived from natural sources have long been investigated for the prevention and treatment of human diseases. Sophoraflavanone G (SFG), a lavandulyl flavanone naturally occurring in several Sophora plant species, belongs to the group of prenylated flavonoids that have garnered significant interest in contemporary research. The natural molecule exhibits a wide range of pharmacological properties and shows remarkable efficacy. Its ability to effectively suppress a range of malignant tumor cells, such as leukemia, breast cancer, and lung cancer, is attributed to its multi-target, multi-pathway, and multi-faceted mechanisms of action. Simultaneously, it can also alleviate various inflammatory diseases by mediating inflammatory mediators and molecular pathways. Furthermore, it has the capability to combat antibiotic resistance, exhibit synergistic antibacterial properties with diverse antibiotics, and prevent and treat various agricultural pests. Theoretically, it can bring benefits to human health and has potential value as a drug. Nevertheless, the drawbacks of poor water solubility and inadequate targeting cannot be overlooked. To comprehensively assess the current research on SFG, leverage its structural advantages and pharmacological activity, overcome its low bioavailability limitations, expedite its progression into a novel therapeutic drug, and better serve the clinic, this article presents a overall retrospect of the current research status of SFG. The discussion includes an analysis of the structural characteristics, physicochemical properties, bioavailability, pharmacological activities, and structure-activity relationships of SFG, with the goal of offering valuable insights and guidance for future research endeavors in this field.

A review of natural products and small-molecule therapeutics acting on central nervous system malignancies: Approaches for drug development, targeting pathways, clinical trials, and challenges

In 2021, the World Health Organization released the fifth edition of the central nervous system (CNS) tumor classification. This classification uses histopathology and molecular pathogenesis to group tumors into more biologically and molecularly defined entities. The prognosis of brain cancer, particularly malignant tumors, has remained poor worldwide, approximately 308,102 new cases of brain and other CNS tumors were diagnosed in the year 2020, with an estimated 251,329 deaths. The cost and time-consuming nature of studies to find new anticancer agents makes it necessary to have well-designed studies. In the present study, the pathways that can be targeted for drug development are discussed in detail. Some of the important cellular origins, signaling, and pathways involved in the efficacy of bioactive molecules against CNS tumorigenesis or progression, as well as prognosis and common approaches for treatment of different types of brain tumors, are reviewed. Moreover, different study tools, including cell lines, in vitro, in vivo, and clinical trial challenges, are discussed. In addition, in this article, natural products as one of the most important sources for finding new chemotherapeutics were reviewed and over 700 reported molecules with efficacy against CNS cancer cells are gathered and classified according to their structure. Based on the clinical trials that have been registered, very few of these natural or semi-synthetic derivatives have been studied in humans. The review can help researchers understand the involved mechanisms and design new goal-oriented studies for drug development against CNS malignancies.

Methylene C(sp3 )-H Arylation Enables the Stereoselective Synthesis and Structure Revision of Indidene Natural Products

The divergent synthesis of two indane polyketides of the indidene family, namely (±)-indidene A (11 steps, 1.7 %) and (+)-indidene C (13 steps, 1.3 %), is reported. The synthesis of the trans-configured common indane intermediate was enabled by palladium(0)-catalyzed methylene C(sp3 )-H arylation, which was performed in both racemic and enantioselective (e.r. 99 : 1) modes. Further elaboration of this common intermediate by nickel-catalyzed dehydrogenative coupling allowed the rapid installation of the aroyl moiety of (±)-indidene A. In parallel, the biphenyl system of (±)- and (+)-indidene C was constructed by Suzuki-Miyaura coupling. These investigations led us to revise the structures of indidenes B and C.

Phytochemistry and pharmacology of natural prenylated flavonoids

Prenylated flavonoids are a special kind of flavonoid derivative possessing one or more prenyl groups in the parent nucleus of the flavonoid. The presence of the prenyl side chain enriched the structural diversity of flavonoids and increased their bioactivity and bioavailability. Prenylated flavonoids show a wide range of biological activities, such as anti-cancer, anti-inflammatory, neuroprotective, anti-diabetic, anti-obesity, cardioprotective effects, and anti-osteoclastogenic activities. In recent years, many compounds with significant activity have been discovered with the continuous excavation of the medicinal value of prenylated flavonoids, and have attracted the extensive attention of pharmacologists. This review summarizes recent progress on research into natural active prenylated flavonoids to promote new discoveries of their medicinal value.

Involucrasin C, Anti-inflammatory 2,3-Dihydro-1H-indene Derivative from Chinese Dai ethnic medicine Shuteria involucrata

(±)-Involucrasin C (1), a pair of new 2,3-Dihydro-1H-indene enantiomers, along with an enantiomeric analogue (2) were isolated from Shuteria involucrata. Their structures were established by the basis of comprehensive spectroscopic data analysis and X-ray crystallographic diffraction. Both 1 and 2 significantly inhibited the secretion of pro-inflammatory cytokines IL-6, TNF-α, and IL-1β, suggesting that these two natural 2,3-Dihydro-1H-indene derivatives may be active components of S. involucrata and may block inflammation in the initial stage.

Therapeutic Effect of Renifolin F on Airway Allergy in an Ovalbumin-Induced Asthma Mouse Model In Vivo

Renifolin F is a prenylated chalcone isolated from Shuteria involucrata, a traditional minority ethnic medicine used to treat the respiratory diseases and asthma. Based on the effects of the original medicine plant, we established an in vivo mouse model of allergic asthma using ovalbumin (OVA) as an inducer to evaluate the therapeutic effects of Renifolin F. In the research, mice were sensitized and challenged with OVA to establish an allergic asthma model to evaluate the effects of Renifolin F on allergic asthma. The airway hyper-reactivity (AHR) to methacholine, cytokine levels, ILC2s quantity and mircoRNA-155 expression were assessed. We discovered that Renifolin F attenuated AHR and airway inflammation in the OVA-induced asthmatic mouse model by inhibiting the regulation of ILC2s in the lung, thereby, reducing the upstream inflammatory cytokines IL-25, IL-33 and TSLP; the downstream inflammatory cytokines IL-4, IL-5, IL-9 and IL-13 of ILC2s; and the co-stimulatory factors IL-2 and IL-7; as well as the expression of microRNA-155 in the lung. The findings suggest a therapeutic potential of Renifolin F on OVA-induced airway inflammation.

Nickel-Catalyzed Regioselective Alkenylarylation of γ,δ-Alkenyl Ketones via Carbonyl Coordination

We disclose a nickel-catalyzed reaction, which enabled us to difunctionalize unactivated γ,δ-alkenes in ketones with alkenyl triflates and arylboronic esters. The reaction was made feasible by the use of 5-chloro-8-hydroxyquinoline as a ligand along with NiBr2 ⋅DME as a catalyst and LiOtBu as base. The reaction proceeded with a wide range of cyclic, acyclic, endocyclic and exocyclic alkenyl ketones, and electron-rich and electron-deficient arylboronate esters. The reaction also worked with both cyclic and acyclic alkenyl triflates. Control experiments indicate that carbonyl coordination is required for the reaction to proceed.

Naturally occurring prenylated chalcones from plants: structural diversity, distribution, activities and biosynthesis

Covering: up to July 2020Naturally occurring chalcones carrying up to three modified or unmodified C5-, C10-, and C15-prenyl moieties on both rings A and B as well as at the α- and β-carbons are widely distributed in plants of the families of Fabaceae, Moraceae, Zingiberaceae and Cannabaceae. Xanthohumol and isobavachalcone being the most investigated representatives, exhibit diverse and remarkable biological and pharmacological activities. The present review deals with their structural characters, biological activities and occurrence in the plant kingdom. Biosynthesis of prenylated chalcones and metabolism of xanthohumol are also discussed.

Three new C-alkylated flavonoids from Desmodium oblongum

Three new C-alkylated flavonoids, 4'-hydroxy-8-isobutyryl-7-methoxy-6-methyl-flavone (1), 4',7-dimethoxy-8-isobutyryl-6-methyl-flavone (2), and 4',7-dimethoxy-8-isobutyryl-flavone (3), together with three know ones luteolin (4), kaemferol (5), and quercetin (6), were isolated from Desmodium oblongum. Their structures were elucidated by spectroscopic methods, including extensive 1D- and 2D-NMR techniques. Compound 1 showed cytotoxicity against NB4, SHSY5Y, and MCF7 cell lines with IC₅₀ values of 8.5, 6.5, and 7.8 μM; compound 2 showed cytotoxicity against SHSY5Y and PC3 cell lines with IC₅₀ values of 5.0 and 6.8 μM; compound 3 displayed cytotoxicity against SHSY5Y and MCF7 cell lines with IC₅₀ values of 6.4 and 9.4 μM, respectively.

Flemingin-Type Prenylated Chalcones from the Sarawak Rainforest Plant Desmodium congestum

In an ongoing program to identify new anti-infective leads, an extract derived from whole plant material of Desmodium congestum collected in the Sarawak rainforest was found to have anti-MRSA activity. Bioassay-guided isolation led to the isolation of two new prenylated chalcones, 5'-O-methyl-3-hydroxyflemingin A (1) and 5'-O-methylflemingin C (2), which were closely related to the flemingins previously isolated from various Flemingia species. Chalcones 1 and 2, which were determined to be 4:6 enantiomeric mixtures by chiral HPLC, exhibited moderate activity against a panel of Gram-positive bacteria and were also cytotoxic to the HEK293 human embryonic kidney cell line.