New Diphenol and Isocoumarins from the Aerial Part of Lawsonia inermis and Their Inhibitory Activities against NO Production

New Triterpenoids and Anti-Inflammatory Constituents from Glinus oppositifolius

Three new triterpenoids-spergulagenin B (1), spergulagenin C (2), and spergulagenin D (3)-were isolated from the aerial part of Glinus oppositifolius, along with 17 known compounds (4-20). The structures of these new compounds were identified by spectroscopic and MS analyses. Compounds 3, 5, 19, and 20 were evaluated for inhibition of nitric oxide production in LPS-stimulated RAW 264.7 cells with IC₅₀ values of 17.03, 18.21, 16.30, and 12.64 μM, respectively. Compounds 3, 5, and 20 exhibited inhibitory effects on LPS-induced nitric oxide production in RAW 264.7 cells with IC₅₀ values of 18.35 ± 1.34, 17.56 ± 1.41, and 14.27 ± 1.29 μM, respectively.

Flavanols from Nature: A Phytochemistry and Biological Activity Review

Flavanols, a common class of secondary plant metabolites, exhibit several beneficial health properties by acting as antioxidant, anticarcinogen, cardioprotective, anti-microbial, anti-viral, and neuroprotective agents. Furthermore, some flavanols are considered functional ingredients in dairy products. Based on their structural features and health-promoting functions, flavanols have gained the attention of pharmacologists and botanists worldwide. This review collects and summarizes 121 flavanols comprising four categories: flavan-3-ols, flavan-4-ols, isoflavan-4-ols, and flavan-3,4-ols. The research of the various structural features and pharmacological activities of flavanols and their derivatives aims to lay the groundwork for subsequent research and expect to provide mentality and inspiration for the research. The current study provides a starting point for further research and development.

Natural isocoumarins: Structural styles and biological activities, the revelations carry on …

Isocoumarins and dihydroisocoumarins are lactonic phytochemicals plentiful in microbes and higher plants. These are an amazing small scaffolds consecrated with all types of pharmacological applications. Our previous review covered the period 2000-2016, documenting the then known natural products of this class; the current article is a critical account of discovery of known as well as undescribed structural types and pharmacological activities reported in the course of 2016-2020. The classification revealed in our previous review based on the biogenetic origin is further buttressed by discovery of new members of each class and some new structural types hitherto unknown have also been identified. Similarly, the biological activities and SAR conclusions identified were found to be valid as well, nonetheless with new accompaniments. The most recent available literature on the structural diversity and biological activity of these natural products has been included. The information documented in this article are collected from scientific journals, books, electronic search engines and scientific databases.

Benzophenone and Benzoylphloroglucinol Derivatives from Hypericum sampsonii with Anti-Inflammatory Mechanism of Otogirinin A

Three new compounds, 4-geranyloxy-2-hydroxy-6-isoprenyloxybenzophenone (1), hypericumone A (2) and hypericumone B (3), were obtained from the aerial parts of Hypericum sampsonii, along with six known compounds (4–9). The structures of these compounds were determined through spectroscopic and MS analyses. Hypericumone A (2), sampsonione J (8) and otogirinin A (9) exhibited potent inhibition (IC₅₀ values ≤ 40.32 μM) against lipopolysaccharide (LPS)-induced nitric oxide (NO) generation. Otogirinin A (9) possessed the highest inhibitory effect on NO production with IC₅₀ value of 32.87 ± 1.60 μM. The well-known proinflammatory cytokine, tumor necrosis factor-alpha (TNF-α) was also inhibited by otogirinin A (9). Western blot results demonstrated that otogirinin A (9) downregulated the high expression of inducible nitric oxide synthase (iNOS). Further investigations on the mechanism showed that otogirinin A (9) blocked the phosphorylation of MAPK/JNK and IκBα, whereas it showed no effect on the phosphorylation of MAPKs/ERK and p38. In addition, otogirinin A (9) stimulated anti-inflammatory M2 phenotype by elevating the expression of arginase 1 and Krüppel-like factor 4 (KLF4). The above results suggested that otogirinin A (9) could be considered as potential compound for further development of NO production-targeted anti-inflammatory agent.

Virtual Screening, Docking, Synthesis and Bioactivity Evaluation of Thiazolidinediones as Potential PPARγ Partial Agonists for Preparation of Antidiabetic Agents

Background:

Peroxisome proliferator-activated receptor gamma (PPARγ) is one of the key targets of insulin resistance research, in addition to being ligand-activated transcription factors of the nuclear hormone receptor superfamily with a leading role in adiposeness activation and insulin sensitivity. They regulate cholesterol and carbohydrate metabolism through direct actions on gene expression. Despite their therapeutic importance, there are dose limiting side effects associated with PPARγ drug treatments, thus a new generation of safer PPARγ drugs are being actively sought after treatment.

Methods:

In this study, we used computer aided drug design to screen new series of PPARγ ligands, and synthesized a series of potential thiazolidinedione derivatives such as 5,7- dibenzyloxybenzyl-3-hydroxymethyl-4H-coumarin-4-ketone, using 4-steps to synthesize the target compounds and built streptozotocin (STZ) induced insulin resistance rat model to measure their antidiabetic activity.

Results:

We found that 10 mg/kg concentration of compound 0701C could significantly decrease blood glucose and serum PPARγ, serum insulin levels in insulin resistance model rat.

Conclusion:

We would conclude that compound 0701C might serve as a potential PPARγ partial agonist.

Anti-invasive Activity of Lawsonia inermis Branch and Its Potential Target Protein

The methanolic extract from the branch of Lawsonia inermis was found to inhibit the invasion of HT1080 cells strongly. The extract and its EtOAc- and 1-BuOH-soluble fractions strongly inhibited the enzyme activities and the secretions of MMPs from HT1080 cells. We, therefore, tried to examine and estimate the active constituents among the constituents isolated. However, there are no active compound among the isolated compounds. Next, we tried to identify the selective binding protein of whole constituents of their extracts. As a result, ribosomal protein S18 (RPs S18, human), 60S ribosomal protein L18 isoform 1 (60S RPs L18 i1, human) and eukaryotic elongation factor 2 (eEF2, human) were detected as their selective binding and potential target proteins. To confirm that the proteins are target proteins or not, we examined the effects of their proteins on synthesis of MMPs using siRNA method. With the treatment of siRNA for RPs S18, 60S RPs L18 i1 and eEF2 proteins, the MMP-2 protein synthesis were downregulated in HT1080 cells. MMP-9 productions were also downregulated with the treatment of siRNA for RPs S18 and eEF2. From the results, we reached a conclusion that the extract was considered to have the potential to inhibit the production of MMPs proteins via inhibition of RPs S18 and eEF2 proteins, leading to inhibit the invasion in HT1080 cells.

Natural Products Research in China From 2015 to 2016

This review covers the literature published by chemists from China during the 2015-2016 on natural products (NPs), with 1,985 citations referring to 6,944 new compounds isolated from marine or terrestrial microorganisms, plants, and animals. The emphasis is on 730 new compounds with a novel skeleton or/and significant bioactivity, together with their source organism and country of origin.

Isoflavones and anti-inflammatory constituents from the fruits of Psoralea corylifolia

The fruits of Psoralea corylifolia, known as Psoraleae Fructus (Buguzhi in Chinese), are traditionally used for the treatment of spermatorrhea, nephritis, asthma, pollakiuria, and various inflammatory diseases. Three previously undescribed isoflavone derivatives, 7-O-methylcorylifol A, 7-O-isoprenylcorylifol A, and 7-O-isoprenylneobavaisoflavone, have been isolated from the fruits of P. corylifolia, together with 9 known compounds. The structures of these compounds were determined through spectroscopic and MS analyses. Among the isolated compounds, 7-O-methylcorylifol A and psoralen exhibited potent inhibition (IC₅₀ values ≤ 10.89 μM) of superoxide anion generation by human neutrophils in response to N-formyl-L-methionyl-L-leucyl-L-phenylalanine/cytochalasin B (fMLP/CB). 7-O-Isoprenylcorylifol A, 7-O-isoprenylneobavaisoflavone, and 12,13-dihydro-12,13-epoxybakuchiol inhibited fMLP/CB-induced elastase release with IC₅₀ values ≤ 14.30 μM. In addition, 7-O-isoprenylcorylifol A, bakuchiol, 12,13-dihydro-12,13-epoxybakuchiol, and psoralidin showed potent inhibition with IC₅₀ values ≤ 36.65 μM, against lipopolysaccharide (LPS)-induced nitric oxide (NO) generation.

A pair of new isocoumarin epimers from soil fungus Hypoxylon sp

In our research on novel secondary metabolites from micro-organisms, two new (1-2) and four known dihydroisocoumarins (3-6) were derived from soil fungus Hypoxylon sp. Their structures were determined with extensive NMR data analysis and ECD calculation comparing with those of experimental CD spectra. Interestingly, compounds 1 and 2 possessed the same planar structure and very similar NMR data, suggesting 1 and 2 were a pair of epimers at either C-3 or at C-4, confirmed by the totally opposite cotton effect around 250 nm in the CD spectra of 1 and 2. Moreover, for the first time, we revealed that the CD absorption peak at 250 nm was dominated by C-3 orientation, rather than the orientation of C-3 substituents, by intensive ECD investigations.

New Benzenoid Derivatives and Other Constituents from Lawsonia inermis with Inhibitory Activity against NO Production

Three new benzenoid derivatives, lawsoinermone (1), inermidioic acid (2), and inermic acid (3) have been isolated from the aerial part of Lawsonia inermis, together with 11 known compounds (4-14). The structures of three new compounds were determined through spectroscopic and MS analyses. Compounds 1, 4-6, 13 and 14 were evaluated for inhibition of nitric oxide production in LPS-stimulated product of nitrite in RAW 264.7 cells with IC₅₀ values of 6.12, 16.43, 18.98, 9.30, 9.30 and 14.90 μg/mL, respectively.