In vitro and in vivo Biological Evaluation of Newly Tacrine-Selegiline Hybrids as Multi-Target Inhibitors of Cholinesterases and Monoamine Oxidases for Alzheimer's Disease.

Purpose: Alzheimer's disease (AD) is the most common neurodegenerative disease, and its multifactorial nature increases the difficulty of medical research. To explore an effective treatment for AD, a series of novel tacrine-selegiline hybrids with ChEs and MAOs inhibitory activities were designed and synthesized as multifunctional drugs. Methods: All designed compounds were evaluated in vitro for their inhibition of cholinesterases (AChE/BuChE) and monoamine oxidases (MAO-A/B) along with their blood-brain barrier permeability. Then, further biological activities of the optimizing compound 7d were determined, including molecular model analysis, in vitro cytotoxicity, acute toxicity studies in vivo, and pharmacokinetic and pharmacodynamic property studies in vivo. Results: Most synthesized compounds demonstrated potent inhibitory activity against ChEs/MAOs. Particularly, compound 7d exhibited good and well-balanced activity against ChEs (hAChE: IC50 = 1.57 µM, hBuChE: IC50 = 0.43 µM) and MAOs (hMAO-A: IC50 = 2.30 µM, hMAO-B: IC50 = 4.75 µM). Molecular modeling analysis demonstrated that 7d could interact simultaneously with both the catalytic active site (CAS) and peripheral anionic site (PAS) of AChE in a mixed-type manner and also exhibits binding affinity towards BuChE and MAO-B. Additionally, 7d displayed excellent permeability of the blood-brain barrier, and under the experimental conditions, it elicited low or no toxicity toward PC12 and BV-2 cells. Furthermore, 7d was not acutely toxic in mice at doses up to 2500 mg/kg and could improve the cognitive function of mice with scopolamine-induced memory impairment. Lastly, 7d possessed well pharmacokinetic characteristics. Conclusion: In light of these results, it is clear that 7d could potentially serve as a promising multi-functional drug for the treatment of AD.

Three New Xanthones from Hypericum scabrum and Their Quorum Sensing Inhibitory Activities against Chromobacterium violaceum.

Quorum sensing (QS) plays an important role in the production of virulence factors and pathogenicity in pathogenic bacteria and is, therefore, a hopeful target to fight against bacterial infections. During our search for natural QS inhibitors, two new xanthonolignoids (1 and 2), each existing as a racemic mixture, one new simple oxygenated xanthone (7), and eight known analogs (3-6, 8-11) were isolated from Hypericum scabrum Linn. Chiral separation of 1 yielded a pair of enantiomers 1a and 1b. The structures of these compounds were elucidated by spectroscopic analysis and ECD (electrostatic circular dichroism) calculations. All isolates were evaluated for their QS inhibitory activity against Chromobacterium violaceum. Both 9 and 10 exhibited the most potent QS inhibitory effects with minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values of 31.25 and 62.5 µM, respectively. Crystal violet staining was used to further evaluate the biofilm inhibition potential of compounds 7, 9 and 10, and the formation of biofilms increased with decreasing drug concentration in a classic dose-dependent manner. The results of a cytotoxicity assay revealed that compounds 7, 9 and 10 exhibited no cytotoxic activity on PC-12 cells at the tested concentration.

Monoterpenoid Glycosides from the Leaves of Ligustrum robustum and Their Bioactivities.

The leaves of Ligustrum robustum have been applied as Ku-Ding-Cha, a functional tea to clear heat, remove toxins, and treat obesity and diabetes, in Southwest China. The phytochemical research on the leaves of L. robustum led to the isolation and identification of eight new monoterpenoid glycosides (1-8) and three known monoterpenoid glycosides (9-11). Compounds 1-11 were tested for the inhibitory activities on fatty acid synthase (FAS), α-glucosidase, α-amylase, and the antioxidant effects. Compound 2 showed stronger FAS inhibitory activity (IC50: 2.36 ± 0.10 µM) than the positive control orlistat (IC50: 4.46 ± 0.13 µM), while compounds 1, 2, 5 and 11 displayed more potent ABTS radical scavenging activity (IC50: 6.91 ± 0.10~9.41 ± 0.22 µM) than the positive control L-(+)-ascorbic acid (IC50: 10.06 ± 0.19 µM). This study provided a theoretical basis for the leaves of L. robustum as a functional tea to treat obesity.

Spectral data of nicotabaflavonoidglycoside.

The dataset addressed in this article relates to the research article entitled"Nicotabaflavonoidglycoside, the first example of cembranoid and flavonoid heterodimer from Nicotiana tabacum" (Yang et al., 2018) [1]. The dataset presents the MS4(879-571-421-335), MS n fragment pathways, (+) HR-ESI-MS, (-) HR-ESI-MS, UV, IR, 1H NMR, 13C NMR, HSQC, 1H-1H COSY, HMBC, ROESY, ORD and ECD data of Nicotabaflavonoidglycoside. The MS4(879-571-421-335), (+) HR-ESI-MS, (-) HR-ESI-MS, UV, IR, 1H NMR, 13C NMR, HSQC, 1H-1H COSY, HMBC, ROESY, ORD and ECD data were collected by experimental methods, and the MSn fragment pathways were acquired by analyses.

Nicotabaflavonoidglycoside, the first example of cembranoid and flavonoid heterodimer from Nicotiana tabacum.

Nicotabaflavonoidglycoside (1), a novel cembrane-type diterpenoid and flavonoid heterodimer had been isolated from the leaves of Nicotiana tabacum. Its structure was elucidated as (1″S, 6″S) or (1″R, 6″R)-8-[6″-((-)-(1″S, 2″E, 4″Z, 7″E, 11″E)-cembra-2″, 4″, 7″, 11″-tetraenyl)]-rutin by comprehensive analyses of the NMR and HRESIMS spectra. Its absolute configurations of C-1″ and C-6″ were assigned as (1″S, 6″S) by its biogenesis and electronic circular dichroism (ECD). A possible biogenesis involving eliminate reaction of (1S, 2E, 4S, 6R, 7E, 11E)-2, 7, 11-cembratriene-4, 6-diol or its 4R isomer, as well as electrophilic substitution reaction of rutin was postulated.

[Chemical structure and bioactivity of cis-5'-oxopropylnicotine].

In this paper, the chemical constituents and bioactivities of leaves of Nicotiana tabacum were investigated. Six compounds were isolated by means of various chromatographic techniques (silica gel, Sephadex LH-20, MCI GEL CHP-20P and HPLC), and their structures were elucidated as cis-5'-(2-oxopropyl)-nicotine (1), 3-O-(9, 12, 15-octadecatrienoyl)-glyceryl-ß-D-galactppyranoside (2), (l'R, 2R, 5S, 10R)-2-(1', 2'-dihydroxy-l'-methylethyl)-6, 10-dimethylspiro [4, 5] dec-6-en-8-one (3), (l'S, 2R, 5S, l0R)-2-(1', 2'-dihydroxy-l'-methylethyl)-6, 10-dimethylspiro [4, 5] dec-6-en-8-one (4),2, 3-dihydroxypropyl-ß-D-galactoside (5) and phenylethyl ß-D-glucopyranoside (6) by extensive spectroscopic analyses (UV, IR, MS, 1D- and 2D-NMR). Among them, compound 1 is a new alkaloid, and compounds 2-6 are isolated for the first time from N. tabacum. Compounds 1 and 2 were assayed for agitating activities on transient receptor potential vanilloid 1 (TRPV1), melatonin receptor 1 and 2 (MT1 and MT2), 1 showed agitating rate of 55.41% (1.53mmol•L⁻¹) on MT2 and 2 possessed agitating rate of 128.11% (0.59 mmol•L⁻¹) and 52.00% (0.73mmol•L⁻¹) on TRPV1 and MT1, respectively.

Lignans from the Fruits of Melia toosendan and Their Agonistic Activities on Melatonin Receptor MT1.

Investigation on the fruits of Melia toosendan afforded seven new lignans (1-7), along with seventeen known compounds (8-24). The structures of the new compounds, involving four neo-lignans (1-4), two sesquilignans (5-6), and a nor-lignan (7), were elucidated based on extensive spectroscopic analyses (high-resolution electrospray ionization mass spectra, ultraviolet, infrared, one-dimensional and two-dimensional nuclear magnetic resonance). Compound 24 exhibited activity on melatonin receptor type 1 with an agonistic rate of 57.77% at 1.02 mM according to the assay on HEK293 cell lines in vitro.

Bioactivity-guided isolation of anti-hepatitis B virus active sesquiterpenoids from the traditional Chinese medicine: Rhizomes of Cyperus rotundus.

ETHNOPHARMACOLOGICAL RELEVANCE: The rhizome of Cyperus rotundus (C. rotundus) is a well-known traditional Chinese medicine to cure hepatitis in many formulae, but the active components responsible for hepatitis have not been elucidated. According to our bioassay on HepG2.2.15 cell line in vitro, the ethanol extract of C. rotundus demonstrated potent anti-HBV activity. This current study was designed to isolate and identify the anti-HBV active constituents from the rhizomes of C. rotundus. MATERIAL AND METHODS: Bioactivity and LC-MS guided fractionation on the extract of C. rotundus using various chromatographic techniques including open-column, Sephadex LH-20 and semi-preparative high performance liquid chromatography led to the isolation and identification of thirty-seven sesquiterpenoids. Structural elucidation of the isolates was carried out by extensive spectroscopic analyses (UV, IR, HRMS, 1D- and 2D -NMR). The anti-HBV activity and cytotoxicity were evaluated on the HBV-transfected HepG2.2.15 cell line in vitro. The cytotoxicity effects of the isolates were assessed by a MTT assay. The secretions of HBsAg and HBeAg in the culture medium were detected by ELISA method, and the load of HBV DNA was quantified by real-time fluorescent PCR technique. RESULTS: Five new patchoulane-type sesquiterpenoids, namely cyperene-3, 8-dione (1), 14-hydroxy cyperotundone (2), 14-acetoxy cyperotundone (3), 3ß-hydroxycyperenoic acid (4) and sugetriol-3, 9-diacetate (5), along with 32 known sesquiterpenoids were isolated from the active fractions of C. rotundus. Compounds 2 and 3 were the first cyperotundone-type sesquiterpenoids with a hydroxyl group at C-14 position. Nine eudesmane-type sesquiterpenoids (15-21 and 23-24) significantly inhibited the HBV DNA replication with IC50 values of 42.7±5.9, 22.5±1.9, 13.2±1.2, 10.1±0.7, 14.1±1.1, 15.3±2.7, 13.8±0.9, 19.7±2.1 and 11.9±0.6 µM, respectively, of which, compounds 17, 21, 23 and 24 possessed high SI values of 250.4, 125.5,>259.6 and 127.5, respectively. Two patchoulane-type sesquiterpenoids (4 and 7) effectively suppressed the secretion of HBsAg in a dose-dependent manner with IC50 values of 46.6±14.3 (SI=31.0) and 77.2±13.0 (SI=1.7) µM, respectively. Compounds 2, 8, 12, 15, 17 and 25 possessed moderate activities against HBeAg secretion with IC50 values of 162.5±18.9 (SI=13.3), 399.2±90.0 (SI=10.6), 274.7±70.8 (SI=5.2), 313.9±87.5 (SI=7.2), 334.0±70.4 (SI=9.9) and 285.3±20.9 (SI=15.5) µM, respectively. CONCLUSIONS: This is the first study to reveal the anti-HBV constituents of C. rotundus, demonstrating that the eudesmane-type sesquiterpenoids might contribute to the anti-HBV activity of the rhizomes of C. rotundus.

[Chemical constituents of Lepidium meyenii].

To study the chemical constituents of Lepidium meyenii, the air-dried rhizome of L. meyenii was extracted with 70% EtOH. The extract was condensed to a small amount of volume and extracted with petroleum ether, EtOAc and n-BuOH, successively. The compounds were isolated and purified by column chromatography, and identified based on spectral analyses (1H-NMR, 13C-NMR, HRESIMS). Eighteen compounds were isolated from L. meyenii, including 7 alkaloids and 4 fatty acids and 7 other compounds. They were characterized as (3-hydroxybenzyl) carbamic acid(1), phenylmethanamine(2), N-benzylformamide (3), N-benzylacetamide (4), pyridin-4-ylmethanamine(5), n-(4-methoxybenzyl) aniline(6), uracil(7), succininc acid(8), decanedioic acid(9), n-hexa- decanoic acid methyl ester(10), heptanoic acid(11), solerole(12), pyromucic acid methyl ester(13), 5-hydroxymethyl-2-furancar- boxadehyde(14), 5-(methoxymethyl)-1H-pyrrole-2-carbaldehyde(15), 1,7-dihydroxy-2,3, 4-trimethoxyxanthone (16), 1,7-di- hydroxy-3,4- dimethoxy-xanthone(17), (+)-pinoresinol(18). Meanwhile, compounds 1-18 were obtained from L. neyenii for the first time.

Two new sesquiterpenoid glycosides from Nicotiana tabacum.

Two new sesquiterpenoid glycosides, nicotabalactonecoside (1) and nicotabadiolcoside (2), along with four known terpenoids (3-6) were isolated from the leaves of Nicotiana tabacum. The structures of compounds 1 and 2 were determined as dihydrodeacetylphytuberin-2-one 11-O-ß-D-glucopyranoside and 1,2-dehydro-4-epieremophil-9-ene-11,12-diol 12-O-ß-D-glucopyranoside by extensive spectroscopic analyses (HR-ESI-MS, UV, IR, 1D, and 2D NMR) and chemical method. Compound 1 is an unusual phytuberin-type sesquiterpenoid with a 6/5/5 tricyclic system.

Noreudesmane sesquiterpenoids from the leaves of Nicotiana tabacum.

Six new 14-noreudesmane sesquiterpenoids, nicotabacosides A-F (1-6), along with five known sesquiterpenoids (7-11), were isolated from the leaves of Nicotiana tabacum. The structures of compounds 1-6 were elucidated as isorishitin 3-O-ß-D-glucopyranoside (1), rishitin 3-O-ß-D-glucopyranoside (2), rishitin 2-O-ß-D-glucopyranoside (3), 1, 6-dehydro-rishitin 3-O-ß-D-glucopyranoside (4), 2-hydroxyl-ligudentatol 3-O-ß-D-glucopyranoside (5) and oxyglutinosone 3-O-ß-D-glucopyranoside (6) based on extensive spectroscopic analyses (HRESIMS, UV, IR, 1D and 2D NMR). Their absolute configurations were determined by X-ray single-crystal diffraction and comparison of their electronic circular dichroism (ECD) spectra.

(±)-Paeoveitol, a pair of new norditerpene enantiomers from Paeonia veitchii.

(+)-Paeoveitol and (-)-paeoveitol, a pair of new norditerpene enantiomers, were isolated from the root of Paeonia veitchii. Their structures and absolute configurations were determined on the basis of extensive analysis of 1D and 2D NMR spectra, crystal X-ray diffraction, and electronic circular dichroism (ECD). A possible biogenesis involving two molecules of paeoniflorin was postulated.