Study on Determination of Triterpenoids in Chaenomeles by High Performance Liquid Chromatography and Sample Preparation with Matrix Solid Phase Dispersion

A new method for the simultaneous determination of the major triterpenoids in Chaenomeles (Chinese medicinal herb) by high performance liquid chromatography (HPLC) and sample preparation with matrix solid phase dispersion (MSPD) was developed. A 0.1 g of sample was placed into an agate mortar and gently blended with 0.4 g silica gel to obtain a homogeneous mixture. This mixture was introduced into a Teflon cartridge, and the triterpenoids fraction was eluted from the cartridge with dichloromethane‐acetone (85:15). The residue was dissolved with methanol after the evaporation of the solvent (dichloromethane and acetone). The triterpenoids were separated on a ZORBAX Stable Bound (4.6 mm × 100 mm, 1.8 μm) C₁₈ column by gradient elution with acetonitrile and water as the mobile phase and detected with evaporative light scattering detection. This method provides good reproducibility and sensitivity for the quantification of seven major triterpenoids, namely erythodiol, betulin, acetyl ursolic acid, ursolic acid, oleanolic acid, betulinic acid, pomolic acid, respectively. The relative standard derivations of overall intra‐day variations were less than 2.0%, and the relative standard derivations of inter‐day variations were less than 2.5%. The standard recoveries (three different concentrations of markers: 0.1, 0.5 and 2.0 mg) ranged from 97‐103%. The results demonstrate that this method is simple, sensitive, selective, and suitable for the quality control of this commonly used Chinese medicinal herb.     

Phytochemical and Pharmacological Studies on Chinese Changzhu

In addition to twelve known compounds including triterpenoids, steroids, sesquiterpenoids and polyacetylenes, a new natural product, hinesolone was isolated from the rhizhome of Atractylodes chinensis (Compositae). The structure of hinesolone was elucidated on the basis of spectral evidence. Of the isolated compounds, only β‐Eudesmol showed a diuretic effect on S.D. rats.     

Selective functionalization of 2-oxoallobetulin derivatives

A new series of 2-oxoallobetulin derivatives has been synthesized by using various unique reactions. Site-specific or regio-selective functionalization of those compounds has been investigated. In all cases, the reactions only happened at C-3 position except the synthesis of lactam happened at C-1 position. The intermediates leading to the novel allobetulin derivatives have also been described.     

Archaeological resinous samples from Asian wrecks: Taxonomic characterization by GC-MS

Plant resins, and particularly dammars from the Dipterocarpaceae family, were widely used in the past, notably as part of caulking material. The organic composition of resins, already complicated, is not always preserved over time and can be considerably affected by ageing. Hence, their occurrence in archaeological items leads to the necessity to identify them taxonomically with precision. Resinous organic materials collected near and/or on wrecks discovered in South China Sea, supposed to contain dammar resins because of their geographical excavation context, were investigated by gas chromatography-mass spectrometry (GC-MS), together with freshly collected dammars, to establish taxonomic and alteration parameters allowing to identify dammar even in very altered samples or in mixtures together with other organic materials. This study specially focuses on three samples collected within or close to the M1J wreck, a Portuguese wreck lost in the Straight of Malacca during the 16th century. Our analyses establish that all three are made of dammar, two of them in association with pitch and bitumen. In addition, biodegradation biomarkers were detected in all these three samples, indicating that they were submitted to microbial degradation processes during their ageing.     

New Polyphenols and Triterpene from the Pseudobulbs of Pleione Formosana

Three new polyphenolic compounds including a dihydrophenanthrene, pleioanthrenin ( 1 ), two bibenzyls, pleiobibenzynin A ( 2 ) and B ( 3 ), and a new cycloartane triterpenoid, (24R)‐cyclomargenyl p‐coumarate ( 4 ), together with eight known compounds, were isolated from the pseudobulbs of Pleione formosana. The structures of the new compounds were elucidated by extensively spectroscopic analysis.     

Chemical Constituents of Polyalthia nemoralis

Three new natural products, the taraxastane‐type triterpenoid 1 , the azafluorene‐based constituent 2‐hydroxyonychine ( 2 ), and the diterpenoid nemoralisin ( 3 ) were isolated from the EtOH extract of Polyalthia nemoralis, along with five known compounds. The structures of the new compounds were established by in‐depth spectroscopic and mass‐spectrometric analyses, as well as by chemical transformation.     

Three New Triterpenoids from Dracocephalum forrestii

From the whole plant of Dracocephalum forrestii (Labiatae), three new and nine known triterpenoids were isolated. The new compounds were identified as (3β,18β)‐20,28‐epoxy‐3‐hydroxyurs‐21‐en‐28‐one ( 1 ), (3β,18β)‐urs‐21‐ene‐3,20,28‐triol ( 2 ), and (3β,18α,19α)‐ursane‐3,20,28‐triol ( 3 ) by means of in‐depth spectroscopic analysis.     

Antibacterial activity of flavonoids and triterpenoids isolated from the stem bark and sap of Staudtia kamerunensis Warb. (Myristicaceae)

The chemical investigation of the ethyl acetate extract of the stem bark of Staudtia kamerunensis and sap led to the isolation of six compounds which included three isoflavonoids: biochanin A (1), formononetin (2) and 3-(1,3-benzodioxol-5-yl)-5,6,7-trimethoxy-4H-1-benzopyran-4-one (3), one flavonoid: (-) epicatechin (4) and two pentacyclic triterpenoids (oleanan-12-ene-2α,3β -diol (5) and 2α,3β-dihydroxylup-20-ene (6). They were characterized by HREIMS (High Resolution Electron Ionisation Mass Spectrometry), NMR spectroscopy (1D and 2D) and comparison with existing data in literature. The crude extract and isolates were tested against twelve bacterial strains namely; Bacillus subtilis, Staphylococcus epidermidis, Enterococcus faecalis, Mycobacterium smegmatis, Staphylococcus aureus, Enterobacter cloacae, Klebsiella oxytoca, Pseudomonas aeruginosa, Proteus vulgaris, Escherichia coli, Proteus mirabilis and Klebsiella pneumonia. Streptomycin, nalidixic acid and ampicillin were used as standard antibacterial drugs. The results revealed significant antibacterial activity for both the ethyl acetate partition and for the tested compounds, with the lowest MIC value being 15.625 μg/mL. A synergistic activity of the isolated triterpenoids was evaluated with interesting results. On a general note, the antibacterial activity of compound 5 was doubled specifically against Gram-negative bacterial strains. This could be a therapeutic antimicrobial pathway in face of the rising bacterial resistance. To the best of our knowledge, it is the first time that flavonoids and triterpenoids are isolated from this genus and species. It is also the first report of antibacterial studies on this species.     

Triterpenoids from the Leaves of Ilex hainanensis

Phytochemical investigation on the leaves of Ilex hainanensis Merr . led to the isolation of four new ursane‐ and oleanane‐based triterpenoids, ilexhainanins A–D ( 1 – 4 ), as well as two known compounds, 2α,3β,19α‐trihydroxyurs‐12‐ene‐23,28‐dioic acid and 2α,3β,19α‐trihydroxyolean‐12‐ene‐23,28‐dioic acid. Their structures were elucidated on the basis of chemical and spectroscopic evidence, and by comparison with literature data.     

Noroleanane Triterpenoids from the Aerial Parts of Lantana camara

Two novel triterpenoids, lantadienone ( 1 ) and camaradienone ( 2 ), were isolated from the aerial parts of Lantana camara, along with seven known compounds, lantadene A, lantadene B, β‐sitosterol 3‐(β‐D ‐glucopyranoside), camaric acid, lantanilic acid, lantanolic acid, and camangeloyl acid. Their structures were elucidated as (3β,22β)‐3,25‐epoxy‐3‐hydroxy‐22‐{[(2Z)‐2‐methyl‐1‐oxobut‐2‐enyl]oxy}‐28‐noroleana‐12,17‐dien‐11‐one ( 1 ) and (3β)‐3,25‐epoxy‐3‐hydroxy‐28‐noroleana‐12,17‐dien‐11‐one ( 2 ), respectively, by means of spectral studies. The triterpenoids 1 and 2 represent 28‐noroleananes oxidized at C(11) and C(22) or at C(11), reported for the first time.