Chemical constituents from Eucalyptus citriodora Hook leaves and their glucose transporter 4 translocation activities

Bioassay-guided phytochemical investigation of the EtOAc fraction from the leaves of a Chinese medicinal herb, Eucalyptus citriodora Hook, resulted in the isolation of a new compound rhodomyrtosone E (1), along with 12 known compounds (2–13). The structure of the new compound was established by 1D and 2D NMR, MS data and X-ray crystallographic analysis. Betulinic acid (2) and corosolic acid (5) increased glucose transporter 4 (GLUT-4) translocation by 2.38 and 1.78-fold, respectively.     

Chemical constituents from Celastrus aculeatus Merr.

Phytochemical investigation of Celastrus aculeatus Merr. led to the isolation of nine compounds. Their structures were identified to be dulcitol (1), β-sitosterol (2), n-tritriacontane (3), nimbidiol (4), pristimerin (5), p-hydroxybenzoic acid (7), vanillic acid (8), 3, 5-dimethoxy-4-hydroxybenzoic acid (9) and a new compound named pristimerol (6) on the basis of mass and NMR spectra. This is the first report of phenolic acids (compounds 7–9) from C. aculeatus Merr. We present the HR-MS, 1D NMR (¹H, ¹³C NMR, DEPT) and 2D NMR (HMBC) data of the new compound (6).     

Bacillus subtilis SSE4 produces subtulene A, a new lipopeptide antibiotic possessing an unusual C15 unsaturated β-amino acid

Subtulene A, a new cyclic lipopeptide, was isolated from the culture broth of Bacillus subtilis SSE4. This antibiotic compound contained the seven common α-amino acids, l-Asn-1, d-Tyr-2, d-Asn-3, l-Gln-4, l-Pro-5, d-Asn-6, l-Ser-7 and the unique β-amino acid-8 present in the iturin family. 1D and 2D NMR, as well as MS analyses, identified the β-amino acid as 3-amino-13-methyltetradec-8-enoic acid, an Iso C15 long chain β-amino acid. B. subtilis SSE4 was also found to produce iturin A. B. subtilis SSE4 culture filtrate exhibited both antifungal and antibacterial activities.     

Phylloflavan,a characteristic constituent of Phyllocladus species

Selective visualization of 2D TLC of extracts of Phyllocladus species with vanillin—hydrochloric acid showed a characteristic pattern of constituents attributable to catechin, epicatechin and phylloflavan, a new flavanoid compound. Optical rotation measurements showed that while catechin and epicatechin are of the normal type with the 2R configurations, the flavan moiety in phylloflavan is of the opposite 2S configuration. Spectroscopic data of the new compound and its hydrolysis products showed phylloflavan to be ent-epicatechin-3-δ-(3,4-dihydroxyphenyl)-β-hydroxypentanoate.     

Chemical constituents from Alnus mandshurica (Callier) Hand.-Mazz. and their chemotaxonomic significance

A new phenol compound, (9S)-9-hydroxy-9-[(2-hydroxyphenyl)methoxy]-nonanoic acid methyl ester (1) was isolated from the stem bark of Alnus mandshurica (Callier) Hand.-Mazz., along with eight known compounds (2–9). The structure of compound 1 was determined by spectral analyses, including HR-ESI-MS, 1D and 2D NMR (COSY, HMQC and HMBC) experiments. All the isolated compounds were reported for first time from A. mandshurica. Furthermore, compounds 3–9 were found in the family Betulaceae for the first time.     

Biotransformation of methyl cholate by Aspergillus niger

Biotransformation of methyl cholate using Aspergillus niger was investigated. This led to the isolation of two derivatives: methyl 3α,7α,12α,15β-tetrahydroxy-5β-cholan-24-oate identified as a new compound, and a known compound methyl 3α,12α-dihydroxy-7-oxo-5β-cholan-24-oate. The structure elucidation of the new compound was achieved using 1D and 2D NMR, MS and X-ray diffraction.     

Usnic acid derivatives from Leprocaulon microscopicum

In addition to known dibenzofuran derivatives such as (?)-usnic acid, (?)-isousnic acid and (?)-placodiolic acid, a Leprocaulon microscopicum acetone extract yielded a new compound, (±)-9-O-methylplacodiolic acid in a keto-enol equilibrium focused on the C-ring. Structures were established using mass spectrometry and combination of 1D and 2D NMR spectral data. ¹³C assignments of placodiolic acid were revised. Tautomers of the (±)-9-O-methylplacodiolic acid were only separated by GC and a thorough fragmentation study confirmed the structural features. To complete the study, evaluation of antiproliferative effects on HT-29 human colorectal cancer cells showed moderate activity for (?)-usnic acid only.     

Chemical constituents from the root bark of Dictamnus dasycarpus Turcz. (Rutaceae) and their chemotaxonomic significance

This work described the isolation and characterization of seven compounds from Dictamnus dasycarpus Turcz., including one new ester, (2R)-4-(2,2-dimethyl-5-oxotetrahydrofuran-3-yl)-2-hydroxypent-3-anoic acid ethyl ester (1); and six known glycosides (2–7). The structure of compound 1 was elucidated on the basis of extensive spectral analyses, including IR, HR-ESIMS, 1D and 2D NMR (NOESY, HMBC and HSQC). All these compounds were described here for the first time from the genus Dictamnus. Moreover, the results provide further information about the diversity of compounds in the genus Dictamnus.     

Simplex centroid mixture design,DI-ESI-MS,and chemometric analysis-guided isolation of parinarioidin C from bark of Brosimum parinarioides (Moraceae)

Brosimum parinarioides, a plant species native to the Amazonian region, is used in folk medicine for the treatment of several diseases. However, knowledge regarding its phytochemical content is scarce. In order to investigate the phytochemical composition of B. parinarioides, an integrative approach based on simplex-centroid design, direct infusion electrospray ionization mass spectrometry (DI-ESI-MS), and chemometric analysis was adopted. According to simplex-centroid design, dichloromethane (DCM), ethyl acetate (AcOEt), and ethanol-based (EtOH) extracts were prepared and analyzed using DI-ESI-MS, and their chemical profile was submitted to principal component analysis (PCA) and hierarchical cluster analysis (HCA). The AcOEt extract from the bark was obtained on a large scale and subjected to chromatographic separation. The multivariate analysis indicated the formation of three groups and highlighted isoliquiritigenin (1), licoagrochalcone A (2), caffeic acid glucoside (3), epicatechin-glycoside (4), caffeic acid (5), and one unknown compound, as being responsible for the segregation of these groups. Thus, the new compound was isolated and characterized using 1D and 2D nuclear magnetic resonance spectroscopy (NMR) and high-resolution mass spectrometry (HR-MS) as parinarioidin C (10). In addition, parinarioidin A (6), parinarioidin B (7), 3-O-caffeoylquinic acid (8), and kanzonol C (9) were tentatively identified based on manual interpretation of MS/MS spectra. Overall, the integrative approach proposed in the study provided a simple and effective model to dereplicate known compounds and guide the isolation of a new compound from a native amazon species, thus improving the knowledge regarding the phytochemical content of B. parinarioides.     

Epiphorellic acids 1 and 2, two diaryl ethers from the lichen Cornicularia epiphorella

From the lichen Cornicularia epiphorella two new diaryl ethers, epiphorellic acids 1 and 2, were isolated besides the known compound atranorin. The structures of the new compounds were established by spectroscopic evidence and chemical transformations. The structure of epiphorellic acid 1 was also confirmed by correlation with a known compound.     

The benzofuran norwedelic acid from Wedelia calendulaceae

A new compound norwedelic acid [5,6-dihydroxy-2(2′,4′,6′-trihydroxyphenyl)-benzofuran-3-carboxylic acid] has been isolated from fresh leaves of Wedelia calendulaceae apart from norwedelolactone, a compound previously found in Eclipta alba.     

傣族药用植物盆架树中的三萜

从傣族药用植物盆架树(Winchia calophylla A. DC.)茎皮的石油醚可溶部分分离到9个化合物,经现代波谱技术证明,其中之一为新化合物,命名为盆架酸(winchic acid).另8个已知化合物分别为羽扇豆烯酮、乙酸羽扇豆酯、桦木酸、乙酸-α-香树醇酯、乌索酸、ptiloepoxide、β-香树醇和cycloeucalenol.     

Anticomplement cycloartane triterpene glycosides from Beesia calthaefolia (Maxim.)

Investigation of the n-BuOH extract of the whole plant of Beesia calthaefolia led to the isolation of three new cycloartane triterpenoids (1–3) and two known compounds (4, 5). Their structures were elucidated by 1D and 2D NMR, HRESIMS and optical rotation spectral data. All of the isolates were investigated for their inhibitory effects on the classical pathway of the complement system. Among them, compound 3 showed stronger inhibitory activity (IC₅₀ 148.0 μM) than the positive control (rosmarinic acid, IC₅₀ 181.8 μM), while other compounds (1, 2, 4 and 5) showed moderate activity. The chemical compound studied in this article was rosmarinic acid (PubChem CID: 5281792).     

7′-hydroxy (−)-R-abscisic acid: A metabolite of feeding (−)-R-abscisic acid to Xanthium strumarium

Feeding of(±)-abscisic acid to leaves of Xanthium strumarium resulted in formation of a new metabolite. The compound was identified as 7′-hydroxy (−)-R-abscisic acid by high resolution mass spectrometry of its methyl ester and monoacetate, and by optical rotary dispersion. The numbering system for abscisic acid has been extended to include the exocyclic methyl groups. Feeding racemic [2-¹⁴C]abscisic acid to Xanthium leaves resulted in ca 20% conversion of the radiolabelled compound into the new metabolite. Evidence is presented that, in Xanthium, only the synthetic (−)-R-enantiomer of abscisic acid is hydroxylated at the 7′-position.     

New cucurbitacins from Phormium tenax and Marah oreganus

Cucurbitacins I and D and two new cucurbitacins, isocucurbitacin D and 3-epi-isocucurbitacin D, were isolated from Phormium tenax. A new cucurbitacin, dihydroisocucurbitacin B, was isolated from Marah oreganus. The acid sensitivity of the 2β-hydroxy-3-keto system found in cucurbitacin D was demonstrated.     

A dehydrotrimer of ferulic acid from maize bran

A new phenolic acid trimer was detected by coupled liquid chromatography/mass spectroscopy in alkali extracts of maize bran. The trimer was purified by preparative silica gel chromatography. The structure of the new compound was elucidated on the basis of 1D and 2D NMR and corresponded to a 4-O-8', 5'-5" dehydrotriferulic acid.     

A new flavonoid from the stem bark of Acer tegmentosum

A new flavonoid, 6-carboxyl-(−)-catechin methyl ester (1) was isolated from the stem bark of Acer tegmentosum, along with six known flavonoids (2–7). The structure of compound 1 was determined by spectral analyses, including HR-ESI-MS, 1D and 2D NMR (COSY, HMQC and HMBC) experiments. From present investigation, compound 7 was isolated for the first time from the Aceraceae family.     

Stereochemistry of blennin A and blennin D from Lactarius blennius

From the ethanolic extract of Lactarius blennius, a new sesquiterpene blennin D (2-hydroxyblennin A) was isolated and its structure elucidated together with the stereochemistry of the already known blennin A. Treatment of blennin A mesylate with DBU afforded a compound with a new skeleton.     

2-O-Methylconfluentinsäure: Ein neues depsid aus Lecidea fuscoatra

The lichen, Lecidea fuscoatra contains the new depside 2-O-methylconfluentinic acid. The structure of this compound follows front spectroscopical data and hydrolysis of its methyl ester to give olivetonic acid dimethyl ether and 2-O-methyl olivetol carboxylic acid.     

Chemical constituents from Nuxia congesta and their chemotaxonomic significance

A phytochemical investigation of the aerial parts of Nuxia congesta led to the isolation and identification of fifteen compounds, including a new flavonoid, nuxiacin (5-hydroxy-3,8-dimethoxy flavone-7-O-β-D-glycopyranoside) (1). The structure of the new compound was determined using various spectroscopic data including 1D and 2D NMR and mass spectroscopy. All compounds were isolated from N. congesta for the first time. The chemotaxonomic significance of the isolated compounds in the family Stilbaceae and order Lamiales are discussed herein.