A new benzoylphloroglucinol derivative with an adamantyl skeleton and other constituents from Garcinia multiflora: effects on neutrophil pro-inflammatory responses

A review on natural products with cage-like structure

Natural products with diverse structures and significant biological activities are essential sources of drug lead compounds, and play an important role in the research and development of innovative drugs. Cage-like compounds have various structures and are widely distributed in nature, especially caged xanthones isolated from Garcinia genus, paeoniflorin and its derivatives isolated from Paeonia lactiflora Pall, tetrodotoxin (TTX) and its derivatives, and so on. In recent years, the development and utilization of cage-like compounds have been a research hotspot in chemistry, biology and other fields due to their special structures and remarkable biological activities. In this review, we mainly summarized the cage-like compounds with various structures found and isolated from natural drugs since 1956, summarized its broad biological activities, and introduced the progress in the biosynthesis of some compounds, so as to provide a reference for the discovery of more novel compounds, and the development and application of innovative drugs.

Polyprenylated Acylphloroglucinols With Different Carbon Skeletons From the Fruits of Garcinia multiflora

Eleven new polycyclic polyprenylated acylphloroglucinols (PPAPs, 1-11) and three new monocyclic polyprenylated acylphloroglucinols (MPAPs, 12-14), together with ten known analogues were isolated from the fruits of Garcinia multiflora. These PPAPs belong to three types including the bicyclic polyprenylated acylphloroglucinols (BPAPs), the caged PPAPs, and the complicated PPAPs. Their structures and absolute configurations were determined through HRESIMS, NMR spectroscopy data, electronic circular dichroism (ECD) calculations, and gauge-independent atomic orbital (GIAO) NMR calculations with DP4+ analyses. Moreover, compounds 2 and 7 exhibited moderate cytotoxicity against three human cancer lines (MCF-7, T98, and HepG2) with IC50 values ranging from 9.81 ± 1.56 to 17.00 ± 2.75 μM.

Combination of high-resolution accurate mass spectrometry and network pharmacology provides a new method for the chemical constituents' study and target prediction in vivo of Garcinia multiflora

Garcinia multiflora is a kind of evergreen tree which is widely distributed in the south of China. However, few researches focused on the constituents in different parts of G. multiflora as well as their potential targets and pathways in vivo. To clarify the chemical constituents of G. multiflora rapidly and predict the potential targets as well as pathways in vivo that this plant may have effects on, a feasible and accurate strategy was developed to identify the chemical constituents in fruits, leaves, and branches of G. multiflora by ultra-high performance liquid chromatography with Q-Exactive hybrid quadrupole-orbitrap high-resolution accurate mass spectrometry. Network pharmacology was then employed and a "compounds-targets-diseases" network was established. Sixty-one compounds including polycyclic polyprenylated acylphloroglucinols, xanthones, and flavonoids were finally identified in different parts of G. multiflora, and the contents of seven constituents were quantified, respectively. On the basis of the network pharmacology analysis results, compounds in this plant were speculated to have potential pharmacodynamic effect on cancer, inflammatory, respiratory diseases, cardiovascular diseases, and metabolic diseases. This research will provide a new method for the advanced study on the pharmacodynamic materials basis of G. multiflora, and offer valuable evidences for medicinal purpose of this plant.

Adamantyl and homoadamantyl derivatives from Garcinia multiflora fruits

Nine undescribed caged polycyclic polyprenylated acylphloroglucinols (PPAPs), including adamantane type PPAPs (1–2) and homoadamantane type PPAPs (3–9), were isolated from the fruits of Garcinia multiflora.

Research Progress of Polycyclic Polyprenylated Acylphloroglucinols

Polycyclic polyprenylated acylphloroglucinols (PPAPs) are a class of hybrid natural products sharing the mevalonate/methylerythritol phosphate and polyketide biosynthetic pathways and showing considerable structure and bioactivity diversity. This review discusses the progress of research into the chemistry and biological activity of 421 natural PPAPs in the past 11 years as well as in-depth studies of biological activities and total synthesis of some PPAPs isolated before 2006. We created an online database of all PPAPs known to date at http://www.chem.uky.edu/research/grossman/PPAPs . Two subclasses of biosynthetically related metabolites, spirocyclic PPAPs with octahydrospiro[cyclohexan-1,5'-indene]-2,4,6-trione core and complicated PPAPs produced by intramolecular [4 + 2] cycloadditions of MPAPs, are brought into the PPAP family. Some PPAPs' relative or absolute configurations are reassigned or critically discussed, and the confusing trivial names in PPAPs investigations are clarified. Pharmacologic studies have revealed a new molecular mechanism whereby hyperforin and its derivatives regulate neurotransmitter levels by activating TRPC6 as well as the antitumor mechanism of garcinol and its analogues. The antineoplastic potential of some type B PPAPs such as oblongifolin C and guttiferone K has increased significantly. As a result of the recent appearances of innovative synthetic methods and strategies, the total syntheses of 22 natural PPAPs including hyperforin, garcinol, and plukenetione A have been accomplished.

Acylphloroglucinol and tocotrienol derivatives from the fruits of Garcinia multiflora

A new regioisomeric pair of garcimultine A (1) and B (2), and one new tocotrienol derivative garcimultine C (8) from the fruits of Garcinia multiflora showed moderate cytotoxicity on four human tumor cell lines.

Antagonism of human formyl peptide receptor 1 with natural compounds and their synthetic derivatives

Formyl peptide receptor 1 (FPR1) regulates a wide variety of neutrophil functional responses and plays an important role in inflammation and the pathogenesis of various diseases. To date, a variety of natural and synthetic molecules have been identified as FPR1 ligands. Here, we review current knowledge on natural products and natural product-inspired small molecules reported to antagonize and/or inhibit the FPR1-mediated responses. Based on this literature, additional screening of selected commercially available natural compounds for their ability to inhibit fMLF-induced Ca(2+) mobilization in human neutrophils and FPR1 transfected HL-60 cells, and pharmacophore modeling, natural products with potential as FPR1 antagonists are considered and discussed in this review. The identification and characterization of natural products that antagonize FPR1 activity may have potential for the development of novel therapeutics to limit or alter the outcome of inflammatory processes.

The natural compound Guttiferone F sensitizes prostate cancer to starvation induced apoptosis via calcium and JNK elevation

Background

In a cytotoxicity screen in serum-free medium, Guttiferone F showed strong growth inhibitory effect against prostate cancer cells.

Methods

Prostate cancer cells LNCaP and PC3 were treated with Guttiferone F in serum depleted medium. Sub-G1 phase distributions were estimated with flow cytometry. Mitochondrial disruption was observed under confocal microscope using Mitotracker Red staining. Gene and protein expression changes were detected by real-time PCR and Western blotting. Ca²⁺ elevation was examined by Fluo-4 staining under fluorescence microscope. PC3 xenografts in mice were examined by immunohistochemical analysis.

Results

Guttiferone F had strong growth inhibitory effect against prostate cancer cell lines under serum starvation. It induced a significant increase in sub-G1 fraction and DNA fragmentation. In serum-free medium, Guttiferone F triggered mitochondria dependent apoptosis by regulating Bcl-2 family proteins. In addition, Guttiferone F attenuated the androgen receptor expression and phosphorylation of ERK1/2, while activating the phosphorylation of JNK and Ca²⁺ flux. Combination of caloric restriction with Guttiferone F in vivo could increase the antitumor effect without causing toxicity.

Conclusions

Guttiferone F induced prostate cancer cell apoptosis under serum starvation via Ca²⁺ elevation and JNK activation. Combined with caloric restriction, Guttiferone F exerted significant growth inhibition of PC3 cells xenograft in vivo. Guttiferone F is therefore a potential anti-cancer compound.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-015-1292-z) contains supplementary material, which is available to authorized users.

Garcimultiflorone G, a novel benzoylphloroglucinol derivative from Garcinia multiflora with inhibitory activity on neutrophil pro-inflammatory responses

A novel benzoylphloroglucinol derivative, garcimultiflorone G (1), was isolated from the fruits of Garcinia multiflora. The structure of 1 was determined through extensive 1D- and 2D-NMR, and MS analyses. Garcimultiflorone G (1) showed inhibitory effects against superoxide anion (O·2(-) generation and elastase release by human neutrophils in response to formyl-L-methionyl-L-leucyl-L-phenylalanine/cytochalasin B (fMLP/CB), with IC50 values of 6.97 ± 1.56 and 11.70 ± 1.58 μM, respectively.