Evaluation of gardenia yellow using crocetin from alkaline hydrolysis based on ultra high performance liquid chromatography and high‐speed countercurrent chromatography

Gardenia yellow is globally the most valuable spice and food color. It is generally a mixture of water‐soluble carotenoid glycosyl esters which consist of crocetin bis(gentiobiosyl) ester as the main component. Crocetin is a natural carotenoid dicarboxylic acid that may be a candidate drug for pharmaceutical development, however, it is either present in trace amounts or is absent in natural gardenia yellow products. We here propose that crocetin produced by alkaline hydrolysis can be used to qualitatively evaluate gardenia yellow products using an ultra high performance liquid chromatographic assay. A useful and efficient isolation technique for isolating high‐purity crocetin from gardenia yellow using high‐speed countercurrent chromatography is described. High‐speed countercurrent chromatographic fractionation followed by an ultra high performance liquid chromatographic assay showed that trans‐crocetin is easily converted to about 15% cis‐crocetin (85% trans‐crocetin). Crocetin in gardenia yellow was quantitatively evaluated. Our approach is based on the hydrolysis process for converting crocetin glycosyl esters to crocetin before evaluation and isolation using the ultra high performance liquid chromatographic and high‐speed countercurrent chromatographic methods. The combination of hydrolysis and chromatographic methods allows evaluation of the purity and quantity of crocetin in gardenia yellow.     

Abiesanol A, a novel biflavanol with unique six connective hexacyclic rings isolated from Abies georgei

A novel biflavanol with unique six connective hexacyclic rings, abiesanol A (1), was isolated from the aerial parts of Abies georgei together with four known flavanols. The structure of new compound was elucidated mainly by the analysis of 1D and 2D NMR spectroscopic data. In addition, single-crystal X-ray diffraction analysis was adopted to confirm the structure of abiesanol A (1). In biological assay for inhibitory activities against LPS-induced nitric oxide (NO) production in RAW264.7 macrophages, abiesanol A (1) showed potent effects at 50 μg/mL with the inhibition rate of 43.0%. Under the same concentration, abiesanol A (1) did not show any cytotoxicity against RAW264.7 macrophages.     

A new flavanone glycoside isolated from Tournefortia sibirica

A new flavanone glycoside, (2S)-dihydrooroxylin A 7-O-[β-D-apiosyl(1→2)]-β-D-glucoside (1), and four known compounds (2–5) were isolated from Tournefortia sibirica L. The chemical structures of these compounds were determined by 1?D and 2?D NMR and HR-ESI-MS spectra, and results were compared with data from the literature. These five compounds (1–5) were isolated from the family Boraginaceae for the first time. Anti-inflammatory effects of compounds (1–5) were evaluated in terms of inhibition of production of NO, TNF-α, and IL-6 in LPS-induced RAW 264.7 cells.     

A novel phenylpropanoid glycoside from Callicarpa kwangtungensis Chun

A novel phenylpropanoid glycoside,Callicarposide A has been isolated from the aerial parts of Callicarpa kwangtungensis Chun.The chemical structure is elucidated on the basis of spectral analysis.     

A novel glycoside lactone derivative with a 2-C-unsaturated diester substituent

The title 4,6-O-benzyl­idene-α-d -gluco­pyran­oside (systematic name: methyl 4-methoxy-2-oxo-8-phenyl-1,2,5a,6,9a,9b-hexa­hydro-4H,8H-7,9-dioxa­cyclo­penta­[c]­chromene-3-carboxyl­ate), C₁₈H₁₈O₈, has been synthesized from the reaction of methyl 4,6-O-benzyl­idene-α-d -2-ketogluco­pyran­oside with diethyl or di­methyl malonate. The compound adopts a chair–chair conformation. The newly formed five-membered ring is fused to the gluco­pyran­oside ring along the C₂—C₃ bond and is planar with an r.m.s. deviation of 0.0091 Å.     

A novel bioactive flavonol glycoside from Teramnus labialis spreng

A novel biologically active flavonol glycoside (1), C26H28O17, m.p. 216-217 degrees C, was isolated from the chloroform soluble fraction of the ethanol extract of the stems of Teramnus labialis. Its structure was characterized as 3,5,7,3',4',5'-hexahydroxyflavone-3-O-beta-D-glucopyranosyl(1-->3)-O-alpha-L-arabinopyranoside by spectral analysis. The chloroform extract of compound (1) showed antibacterial and antifungal activities.     

Oryzamutaic acid A, a novel yellow pigment from an Oryza sativa mutant with yellow endosperm

Oryzamutaic acid A, a novel yellow pigment, was isolated from the endosperm of an Oryza sativa mutant. The structure and absolute configuration of oryzamutaic acid A were elucidated on the basis of spectroscopic analysis, single-crystal X-ray diffraction analysis, and biogenetic reason. Oryzamutaic acid A might be biogenetically derived from four l-amino acids because it contains three amino acid groups and one amine group.     

A novel lignan glycoside with antioxidant activity from Tinospora sagittata var. yunnanensis

A novel lignan glysocide, namely sagitiside A (1), together with two known ones, (+)-lyoniresinol-2α-O-β-D-glucopyranoside (2) and (+)-5'-methoxyisolariciresinol 3α-O-β-D-glucopyranoside (3), was isolated from the 95% ethanol extract of dry roots of Tinospora sagittata var. yunnanensis. The structure of the new compound (1) was determined based on MS, 1D and 2D NMR spectral data. Compounds 1-3 showed antioxidant activity with EC(50) values 55, 75 and 80?μM by 1,1-diphenyl-2-picryhydrazyl (DPPH) radical-scavenging assay.     

Acutifoliside,a novel benzoic acid glycoside from Salix acutifolia

Ultra high-performance liquid chromatography–mass spectrometry (UHPLC–MS) profiling of a polar solvent extract of juvenile stem tissue of Salix acutifolia Willd. identified a range of phenolic metabolites. Salicortin, 1, a well-known salicinoid, was the major compound present and the study identified young stem tissue of this species as a potential source of this compound for future studies. Three further known metabolites (salicin 2, catechin 3 and tremuloidin 4) were also present. The UHPLC–MS analysis also revealed the presence of a further, less polar, unknown compound, which was isolated via HPLC peak collection. The structure was elucidated by high-resolution mass spectroscopic analysis, 1- and 2-D NMR analysis and chemical derivatisation and was shown to be a novel benzoic acid glycoside 5, which we have named as acutifoliside.     

A novel dimeric flavonol glycoside from Cynanchum acutum subsp. sibiricum

A novel dimeric flavonol glycoside, Cynanflavoside A (1), together with six analogues, kaempferol-3-O-α-L-rhamnopyranosyl-(1→2)-β-D-glucopyranoside (2), quercetin-3-O-α-L-rhamnopyranosyl-(1→2)-β-D-glucopyranoside (3), kaempferol-3-O-α-L-rhamnopyranosyl-(1→2)-β-D-xylopyranoside (4), quercetin-3-O-α-L-rhamnopyranosyl-(1→2)-β-D-xylopyranoside (5), kaempferol-3-O-β-D-glucopyranosyl-7-O-α-L-rhamnopyranoside (6), and quercetin-3-O-galactoside (7) were isolated from the n-butyl alcohol extract of Cynanchum acutum subsp. sibiricum. Their structures were determined spectroscopically and compared with previously reported spectral data. All compounds were evaluated for their anti-complementary activity in vitro, and only compound 5 exhibited anti-complement effects with CH₅₀ value of 0.33 mM.     

Two novel alkaloids with a unique fused hexacyclic skeleton from Daphniphyllum subverticillatum

Two novel major alkaloids, deoxycalyciphylline B (1) and deoxyisocalyciphylline B (2) with a unique fused hexacyclic skeleton, together with a quite recently reported alkaloid calyciphylline B (3), were isolated from the stem of Daphniphyllum subverticillatum. Their structures were established by spectral methods and chemical evidence, especially 2D NMR techniques. The structure of 1 was further confirmed by a single-crystal X-ray diffraction determination.     

Lianqiaoxinoside B, a novel caffeoyl phenylethanoid glycoside from Forsythia suspensa

Chemical investigation of the 70% ethanol extract of the unripe fruits of Forsythia suspensa resulted in the isolation of a novel caffeoyl phenylethanoid glycoside, lianqiaoxinoside B, together with the known compound forsythoside H. The new compound was elucidated to be 1',2'-[β-(3,4,-dihydroxylphenyl)-α,β-dioxoethanol]-3'-O-caffeoyl-O-α-rhamnopyranosyl-(1→6)-O-β-glucopyranoside by extensive spectroscopic and chemical studies. Lianqiaoxinoside B and forsythoside H showed strong antioxidant and antimicrobial activities in vitro by the 2,2'-azinobis-3-ethylbenzothiazoline-6-sulphonate (ABTS) radical-scavenging assay and plate method. This study can be further extended to exploit for the possible application of caffeoyl phenylethanoid glycosides as the alternative antioxidants and antimicrobial agents of natural origin.     

A unique and novel cyclopropylmethyl cation intermediate: a DFT study

Some physical organic aspects of the intermediates that result from the interaction between phenylmethylenecyclopropane (substituted derivatives are important in synthesizing cyclobutenes) and platinum and palladium halides have been studied using B3LYP. Geometrical aspects, values of atom polarizable tensor charges (APT), effect of substituents, selected transition states activation barriers, and molecular orbital calculations are presented. These calculations suggest a novel organometallic cyclopropylmethyl cation, which is characterized by the presence of a highly polarized and unusually long sigma bond between the benzylic carbon and coordinating halogen atom.     

A new steroidal glycoside and a new phenyl glycoside from a ripe cherry tomato

A new steroidal glycoside and a new phenyl glycoside have been isolated from a ripe cherry tomato [Lycopersicon esculentum var. cerasiforme (DUNAL) ALEF., Solanaceae] along with two known steroidal alkaloid glycosides, esculeoisides A and B, and five aromatic compounds, zizibeoside I, benzyl alcohol beta-gentiobioside, rutin, methyl caffeate, and phenylalanine. Their chemical structures were determined on the basis of spectroscopic data as well as chemical evidence.     

Anti-inflammatory activity of a novel flavonol glycoside from the Bauhinia variegata Linn

Bauhinia variegata Linn. (Leguminosae) is commonly known as 'Kachnar' in Hindi. It is distributed almost throught India. Its powdered bark is traditionally used for tonic, astrain, ulcers. It is also useful in skin diseases. The roots are used as antidote to snake poison. The present article deals with the isolation and structural elucidation of a novel flavonol glycoside 5,7,3',4'-tetrahydroxy-3-methoxy-7-O-alpha-L-rhamnopyranosyl(1-->3)-O-beta-galactopyranoside (1) from the roots of Bauhinia Variegata and its structure was identified by spectral analysis and chemical degradations. The novel compound (1) showed anti-inflammatory activity.     

NMR-based characterization of a novel yellow chlorophyll catabolite, Ed-YCC,isolated from Egeria densa

A novel yellow chlorophyll catabolite, Ed-YCC, was isolated from leaves detached from Egeria densa shoots, in which chlorophyll degradation and anthocyanin synthesis were induced in 0.1 M fructose solution under light illumination as a plant senescence process, a model of autumnal leaf coloration. Structure elucidation was accomplished by various NMR techniques including 2D-INADEQUATE.     

Lancifodilactone G: a unique nortriterpenoid isolated from Schisandra lancifolia and its anti-HIV activity

[structure: see text]. Lancifodilactone G (1), a novel, highly oxygenated nortriterpenoid featuring a partial enol structure and a spirocyclic moiety, was isolated from the medicinal plant Schisandra lancifolia. Its structure and stereochemistry were determined from extensive one- and two-dimensional NMR and mass spectral data, coupled with single-crystal X-ray analysis. Compound 1 exerted minimal cytotoxicity against C8166 cells (CC50 > 200 microg/mL) and showed anti-HIV activity with EC50 = 95.47 +/- 14.19 microg/mL and a selectivity index in the range of 1.82-2.46.     

A novel hexanordammarane glycoside from the leaves and stems of Panax quinquefolium L

One novel hexanordammarane glycoside, ginsenoside R(10), was isolated from the leaves and stems of Panax quinquefolium L. as a minor constituent. It is the first time that a hexanordammarane glycoside isolated from the plant of Panax quinquefolium L. Its structure was elucidated as 3-O-β-D-glucopyranosyl-3β, 12β-dihydroxy-22, 23, 24, 25, 26, 27-hexanordammarane-20-one (1), by the combination analysis of one-dimensional NMR, two-dimensional NMR and mass spectrometry.     

A novel iridoid glycoside from the aerial parts of the Tunisian Prasium majus

Repeated fractionation of the acetylated methanol extract of Prasium majus afforded acetylated derivatives of a new iridoid glycoside hamighriprasin (1), myoporoside (2), beta-D-glycopyranose (3) and saccharose (4). The structures of 1 and 2 were established by interpretation of 1D and 2D NMR data of their corresponding acetylated derivatives and by comparison with the literature.