Three New Xanthones from and Their Quorum Sensing Inhibitory Activities against .

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 ( and ), each existing as a racemic mixture, one new simple oxygenated xanthone (), and eight known analogs (-, -) were isolated from Linn. Chiral separation of yielded a pair of enantiomers and .

Monoterpenoid Glycosides from the Leaves of and Their Bioactivities.

The leaves of 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 led to the isolation and identification of eight new monoterpenoid glycosides (-) and three known monoterpenoid glycosides (-). Compounds - were tested for the inhibitory activities on fatty acid synthase (FAS), -glucosidase, -amylase, and the antioxidant effects.

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 " (Yang et al., 2018) [1]. The dataset presents the MS(879-571-421-335), MS fragment pathways, (+) HR-ESI-MS, (-) HR-ESI-MS, UV, IR, H NMR, C NMR, HSQC, H-H COSY, HMBC, ROESY, ORD and ECD data of Nicotabaflavonoidglycoside.

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).

[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.

[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-β-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-β-D-galactoside (5) and phenylethyl β-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.

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.

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.

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-β-D-glucopyranoside and 1,2-dehydro-4-epieremophil-9-ene-11,12-diol 12-O-β-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-β-D-glucopyranoside (1), rishitin 3-O-β-D-glucopyranoside (2), rishitin 2-O-β-D-glucopyranoside (3), 1, 6-dehydro-rishitin 3-O-β-D-glucopyranoside (4), 2-hydroxyl-ligudentatol 3-O-β-D-glucopyranoside (5) and oxyglutinosone 3-O-β-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.