Unsymmetrical Phosphodiesters as GPR84 Antagonists with High Blood Exposure for the Treatment of Lung Inflammation.

GPR84 is a proinflammatory G protein-coupled receptor that mediates myeloid immune cell functions. Blocking GPR84 with antagonists is a promising approach for treating inflammatory and fibrotic diseases. Previously, a GPR84 antagonist 604c, with a symmetrical phosphodiester structure, has displayed promising efficacy in a mouse model of ulcerative colitis. However, the low blood exposure resulting from physicochemical properties prevented its uses in other inflammatory diseases. In this study, a series of unsymmetrical phosphodiesters with lower lipophilicity were designed and tested. The representative compound 37 exhibited a 100-fold increase in mouse blood exposure compared to 604c while maintaining in vitro activity. In a mouse model of acute lung injury, 37 (30 mg/kg, po) significantly reduced the infiltration of proinflammatory cells and the release of inflammatory cytokines and ameliorated pathological changes equally or more effectively than N-acetylcysteine (100 mg/kg, po). These findings suggest that 37 is a promising candidate for treating lung inflammation.

GPR84 regulates pulmonary inflammation by modulating neutrophil functions.

Acute lung injury (ALI) is an acute, progressive hypoxic respiratory failure that could develop into acute respiratory distress syndrome (ARDS) with very high mortality rate. ALI is believed to be caused by uncontrolled inflammation, and multiple types of immune cells, especially neutrophils, are critically involved in the development of ALI. The treatment for ALI/ARDS is very limited, a better understanding of the pathogenesis and new therapies are urgently needed. Here we discover that GPR84, a medium chain fatty acid receptor, plays critical roles in ALI development by regulating neutrophil functions. GPR84 is highly upregulated in the cells isolated from the bronchoalveolar lavage fluid of LPS-induced ALI mice. GPR84 deficiency or blockage significantly ameliorated ALI mice lung inflammation by reducing neutrophils infiltration and oxidative stress. Further studies reveal that activation of GPR84 strongly induced reactive oxygen species production from neutrophils by stimulating Lyn, AKT and ERK1/2 activation and the assembly of the NADPH oxidase. These results reveal an important role of GPR84 in neutrophil functions and lung inflammation and strongly suggest that GPR84 is a potential drug target for ALI.

Chemical constituents of Lindera aggregata and their bioactivities: a review / 中国中药杂志

The medicinal Lindera aggregata(Lindera, Lauraceae) boasts abundant resources, which is widely used in clinical settings. It has been found that the main chemical constituents of this medicinal species are sesquiterpenoids, alkaloids, sesquiterpenoid dimers, flavonoids, and phenolic acids. Some unreported novel structures, including lindenane-type sesquiterpene dimers and trimers, have been discovered from L. aggregata in recent years. The extracts and active components of L. aggregata have anti-tumor, anti-inflammatory, antalgic, liver-protecting, antioxidant, lipid-lowering, and glucose-lowering activities, and their mechanisms of action have been comprehensively investigated. This study summarizes the research on the chemical constituents and bioactivities of L. aggregata over the past decade, which is expected to serve as a reference for the future research and utilization of L. aggregata.

Phosphodiesters as GPR84 Antagonists for the Treatment of Ulcerative Colitis.

GPR84 is a proinflammatory G protein-coupled receptor associated with several inflammatory and fibrotic diseases. GPR84 antagonists have been evaluated in clinical trials to treat ulcerative colitis, idiopathic pulmonary fibrosis, and nonalcoholic steatohepatitis. However, the variety of potent and selective GPR84 antagonists is still limited. Through high-throughput screening, a novel phosphodiester compound hit 1 was identified as a GPR84 antagonist. The subsequent structural optimization led to the identification of compound 33 with improved potency in the calcium mobilization assay and the ability to inhibit the chemotaxis of neutrophils and macrophages upon GPR84 activation. In a DSS-induced mouse model of ulcerative colitis, compound 33 significantly alleviated colitis symptoms and reduced the disease activity index score at oral doses of 25 mg/kg qd, with an efficacy similar to that of positive control 5-aminosalicylic acid (200 mg/kg, qd, po), suggesting that compound 33 is a promising candidate for further drug development.

GPR84 signaling promotes intestinal mucosal inflammation via enhancing NLRP3 inflammasome activation in macrophages.

The putative medium-chain free fatty acid receptor GPR84 is a G protein-coupled receptor primarily expressed in myeloid cells that constitute the innate immune system, including neutrophils, monocytes, and macrophages in the periphery and microglia in the brain. The fact that GPR84 expression in leukocytes is remarkably increased under acute inflammatory stimuli such as lipopolysaccharide (LPS) and TNFα suggests that it may play a role in the development of inflammatory and fibrotic diseases. Here we demonstrate that GPR84 is highly upregulated in inflamed colon tissues of active ulcerative colitis (UC) patients and dextran sulfate sodium (DSS)-induced colitis mice. Infiltrating GPR84+ macrophages are significantly increased in the colonic mucosa of both the UC patients and the mice with colitis. Consistently, GPR84-/- mice are resistant to the development of colitis induced by DSS. GPR84 activation imposes pro-inflammatory properties in colonic macrophages through enhancing NLRP3 inflammasome activation, while the loss of GPR84 prevents the M1 polarization and properties of proinflammatory macrophages. CLH536, a novel GPR84 antagonist discovered by us, suppresses colitis by reducing the polarization and function of pro-inflammatory macrophages. These results define a unique role of GPR84 in innate immune cells and intestinal inflammation, and suggest that GPR84 may serve as a potential drug target for the treatment of UC.

Research progress on chemical constituents and biological activities of Sarcandra glabra / 中国中药杂志

Sarcandra glabra, a medicinal plant in family Chloranthaceae, has been taken as an important raw material for multiple Chinese patent drugs due to its diverse indications. Considering the diversified chemical constituents and rich biological activities of S. glabra, numerous phytochemical and pharmacodynamic investigations were conducted to explore the material basis for its medicinal use. It has been found that its main chemical constituents were sesquiterpenoids, sesquiterpenoid polymers, phenolic acids, coumarins, and flavonoids. As revealed by pharmacological research, it possesses multiple biological activities like anti-inflammation, anti-bacteria, anti-tumor, anti-oxidation, and neuroprotection. Some unreported novel structures, including polymers of lindenane sesquiterpenes and monoterpenes, sesquiterpene trimers, and adducts of flavonoids and monoterpenes, have been identified from S. glabra in recent years. Moreover, biological studies relating to its anti-tumor, anti-inflammatory, and anti-oxidant activities have been deepened. This paper reviewed the chemical constituents and bioactivities of S. glabra explored over the past ten years, so as to provide a scientific basis for further development and utilization of this plant.

Research progress on chemical constituents from Chloranthus plants and their biological activities / 中国中药杂志

The genus Chloranthus has 13 species and 5 varieties in China, which can be found in the southwest and northeast regions. Phytochemical studies on Chloranthus plants have reported a large amount of terpenoids, such as diterpenoids, sesquiterpenoids, and sesquiterpenoid dimers. Their anti-inflammation, anti-tumor, antifungal, antivirus, and neuroprotection activities have been confirmed by previous pharmacological research. Herein, research on the chemical constituents from Chloranthus plants and their biological activities over the five years was summarized to provide scientific basis for the further development and utilization of Chloranthus plants.

Chemical constituents of sesquiterpenes from Chloranthus multistachys / 中国中药杂志

With repeated silica gel, octadecyl silica(ODS), and Sephadex LH-20 column chromatography, normal-phase and reverse-phase high performance liquid chromatography(HPLC), etc., a pair of new enantiomers and 5 known compounds were separated from the 95% ethanol extract of Chloranthus multistachys. These compounds were identified by the nuclear magnetic resonance spectroscopy(including 1 D-NMR and 2 D-NMR), single-crystal X-ray diffraction, circular dichroism(CD) spectroscopy, mass spectrometry(MS), and some other methods as(1R,4R,5R,8S,10R)-chloraeudolide H(1 a),(1S,4S,5S,8R,10S)-chloraeudolide H(1 b), hydroxyisogermafurenolide(2), 4α-hydroxy-5α,8β(H)-eudesm-7(11)-en-8,12-olide(3), chloraniolide A(4), chlorantene D(5), 4α,8β-dihydroxy-5α(H)-eudesm-7(11)-en-8,12-olide(6). Compounds 1 a and 1 b are a pair of new eudesmane-type sesquiterpene enantiomers, and compounds 2-4 were isolated from C. multistachys for the first time.

A new cembranoid diterpene from Olibanum / 中国中药杂志

Five compounds were isolated from the alcohol extract of Olibanum by MCI, silica gel, ODS, and Sephadex LH-20 column chromatographies and preparative high-performance liquid chromatography(HPLC). On the basis of spectral data and literature data, the compounds were identified as:(1S,3R,4S,7R,11S,12R)-1:12,4:7-diepoxisonane-8(19)-ene-3,11-diol(1), boscartin A(2),(+)-resinolin(3),(+)-5-hydroxy-3,4-dimethyl-5-pentylfuran-2(5H)-one(4), and acerogenin A(5). Compound 1 is a new compound, and compounds 3-5 were isolated from Olibanum for the first time. The structure of compound 1 was determined by spectroscopic analysis and single-crystal X-ray diffraction. Compounds 1 and 2 were tested for PC12 neurotoxicity, and the results showed that they were both safe compounds.

A new sesquiterpene from Chloranthus henryi / 中国中药杂志

Eight sesquiterpenes were isolated and purified from the ethanol extract of Chloranthus henryi by column chromatographies over silica gel, ODS and Sephadex LH-20,and preparative HPLC. Their chemical structures were established by spectral data and physiochemical properties as(1S,6S,8S,10R)-8-ethoxy-10-methoxychlomultin C(1),tianmushanol(2),multistalide A(3),myrrhterpenoid N(4),1α,9α-dihydroxy-8,12-expoxy-eudesma-4,7,11-trien-6-one(5),4β,10α-aromadendranediol(6),oplopanone(7),10α-hydroxycadinan-4-en-3-one(8). Among them, compound(1) was a new compound, and compounds 2-8 were isolated from Chloranthus henryi for the first time.

Studies on chemical constituents of Chloranthus fortunei / 中草药

Objective: To study the antitumor constituents from Chloranthus fortunei. Methods: Various chromatographic techniques and spectroscopic methods were applied to investigate the chemical constituents from C. fortunei, and some of the compounds were screened for their antitumor activities by MTT method. Results: Sixteen compounds were obtained from the whole plants of C. fortunei and identified as rosmarinic acid (1), 2’-hydroxy-4,3’,4’,6’-tetramethoxychalcone (2), flavokawain A (3), cycloshizukaol A (4), atractylenolide III (5), 4β-hydroxy-8,12-epoxyeudesma-7,11-diene-1,6-dione (6), (8α)-6,8-dihydroxycadina-7 (11),10 (15)-dien-12-oic acid γ-lactone (7), curcolonol (8), 11-hydroxyldrim-8,12-en-14-oic acid (9), friedelin (10), isovanillic acid (11), 6β-hydroxystigmast-4-en-3-one (12), 3,4-dihydroxybenzoic acid (13), shikimic acid (14), scopolin (15) and N-acetyltyramine 1-O-β-D-glucoside (16). Compounds 4 and 5 showed weak cytotoxicity with IC50 ranged from 46 to 85 μmol/L. Conclusion: Compounds 2, 10, 11, and 13-15 are obtained from the genus Chloranthus for the first time and compounds 1-3 and 6-16 are isolated from C. fortunei for the first time. Some sesquiterpenoids from C. fortunei exhibited weak antitumor activities.

A pair of enantiomeric sesquiterpenoids with neuroprotective effects from Chloranthus henryi / 药学学报

An ethanol extract of Chloranthus henryi (Chloranthaceae) was subjected to various chromatographic procedures including silica gel column chromatography, MCI column chromatography, Sephadex LH-20 column chromatography, and preparative HPLC. Five purified sesquiterpenes analyzed by spectroscopic analyses (MS, IR, NMR) and single crystal X-ray diffraction were elucidated as (1S,6S,8R)-8-ethoxychlomultin C (1a), (1R,6R,8S)-8-ethoxychlomultin C (1b), (+)-phaeocaulin D (2), atractylenolide Ⅰ (3), and 8-β-ethoxyasterolid (4). Compounds 1a and 1b were a new pair of sesquiterpene enantiomers and compounds 2-4 were isolated from this plant for the first time. Compounds 1a, 1b, 2 and 3 increased cell viability in H2O2-treated PC12 cells from (43.41 ± 1.59) % to (61.71 ± 7.56) %, (66.05 ± 5.61) %, (74.34 ± 3.32) % and (69.58 ± 5.02) % at 10 μmol·L-1, respectively.

PD-L1 expression levels on tumor cells affect their immunosuppressive activity.

Programmed cell death 1 (PD-1) is an immuno-checkpoint receptor which is primarily expressed on T cells, monocytes, natural killer cells and macrophages. Programmed death-ligand 1 (PD-L1) is the primary ligand of PD-1 and is constitutively expressed on antigen presenting cells, mesenchymal stem cells and bone marrow-derived mast cells. In addition, PD-L1 is also expressed on a wide range of tumor cells, including lung cancer, breast cancer and melanoma. PD-1 and PD-L1 are important members of the immunoglobulin super-family and participate in immune regulation. In the present study, the immune-suppressive effects of a number of tumor cell lines were determined. The breast tumor cell lines MCF-7 and MDA-MB-231 displayed the largest inhibitory effects on T-cell activation and cytokine secretion in a co-culture system. The HepG2, A549 and A375 cells displayed limited inhibitory effects. MCF-7 and MDA-MB-231 cells expressed the highest level of PD-L1 among the cells used, which may explain their higher immuno-suppressive effects. Compound A0-L, a small molecule inhibitor of the PD-1/PD-L1 interaction, restored T cell functions. Additionally, it was demonstrated that the tumor cells with higher levels of PD-L1 expression suppressed signaling pathways involved in T-cell activation, such as the T-cell receptor- zeta chain of T cell receptor associated protein kinase ZAP70-RAS-GTPase-extracellular-signal-regulated kinases and CD28-PI3K-Akt serine/threonine kinases pathways. These findings suggest that tumor cells with higher expression levels of PD-L1 may exhibit higher immuno-suppressive activity, and that drugs targeting the PD-1/PD-L1 interaction may have improved therapeutic effects on tumors expressing higher levels of PD-L1.

Flavonoids from the aerial parts of Lespedeza cuneata / 药学学报

The chemical constituents of the aerial parts of Lespedeza cuneata (Dum. Cour.) G. Don were investigated using chromatographic techniques, such as silica gel, reversed phase MPLC and preparative HPLC. Five compounds were isolated and their structures were elucidated by spectroscopic data and physicochemical properties, which were identified as 7-O-glucosyllaburnetin (1), kaempferol-3-O-β-D-galactopyranoside (2), kaempferol-3-O-α-L-rhamnoside (3), vitexin (4), and isovitexin (5). Among those, compound 1 is a new compound, compounds 2-3 were isolated from this plant for the first time. Compounds 1-5 were tested for their anti-ulcerative colitis activity by dual luciferase report gene assay targeting xbp1. Compared with control group, compound 1 showed a certain activity on activating the transcription of xbp1, with its relative activating ratio being 1.80 times.

New triterpenoid saponins from the leaves of Panax notoginseng / 药学学报

Five triterpene saponins were isolated from the aqueous extract of the leaves of Panax notoginseng (Burk.) F.H.Chen via various chromatographic approaches, including HPD-100 macroporous resin, silica gel, reverse phase C18 and so on. Spectroscopic and chemical methods were used to elucidated their structures, which were determined to be 3-O-β-D-glucopyranosyl-(1→2)-β-D-glucopyranosyl-12β,23(R)-epoxydammara-24-ene-3β,6α,20(S)-triol 20-O-α-L-arabinofuranosyl-(1→6)-β-D-glucopyranoside (1), 3-O-β-D-glucopyranosyl-(1→2)-β-D-glucopyranosyl-12β,23(R)-epoxydammara-24-ene-3β,6α,20(S)-triol 20-O-α-L-arabinopyranosyl-(1→6)-β-D-glucopyranoside (2), notoginsenoside FP2 (3), gypenoside Ⅸ (4), ginsenoside Rg1 (5). Compounds 1 and 2 are new compounds and named as notoginsenoside Fh8 and notoginsenoside Fh9.

Chemical constituents from roots of Chloranthus serratus / 中草药

Objective: To study chemical constituents contained in the ethanol extracts from the roots of Chloranthus serratus. Methods: Fifteen compounds were separated from the roots of M. serratus by using various chromatographic techniques. Results: Their structures were identified on the basis of physicochemical properties and spectral data as 1α, 9α-dihydroxy-8,12-expoxy-eudesma-4,7,11-trien-6-one (1), 1β, 5α-guaiane-4β, 10α-diol-6-one (2), zedoalactone E (3), multistalactone C (4), 1β, 8β-dihydroxy-eudesman-3,7(11)-dien-8α, 12-olide (5), 1β, 8β-dihydroxy-eudesman-4(15), 7(11)-dien-8α, 12 olide (6), sobrerol (7), umbelliferone (8), isofraxidin (9), 5-methoxy-6,7-methylene-dioxy coumarin (10), trans-N-p-coumaroyl tyramine (11), N-trans-feruloyl tyramin (12), N-cis-feruloyl tyramin (13), catechin (14), and 7-hydroxy-5,8-dimethoxyflavanone (15). Conclusion: Compounds 2,5-7,10,14 an 15 are obtained from the plants of Chloranthus Sw. for the first time, and compounds 1,3, and 4 are isolated from C. serratus for the first time.