Three new sesquiterpene alkaloids from the root of Tripterygium wilfordii

<正>Three new sesquiterpene alkaloids,1-desacetylwilforgine(1),1-desacetylwilforine(2),and 9′-hydroxy-2-nicotinoylwilforine (3) were isolated from the roots of Tripterygium wilfordii Hook f.,along with six known alkaloids.Their structures were established on the basis of spectral analysis.     

Chemical Constituents of the Aerial Part of Celastrus Hypoleucus

Fourteen compounds including eight triterpenoids, 12‐oleanaen‐3β‐ol (β‐amyrin) ( 1 ), 12‐oleanaen‐3β‐caffeate ( 2 ), 9(11),12‐oleanadien‐3β‐ol ( 3 ), 9(11),12‐oleanadien‐3‐one ( 4 ), 9(11),12‐oleanadien‐3 β‐caffeate ( 5 ), friedela‐3‐one (friedelin) ( 6 ), friedela‐3‐one‐29‐ol ( 7 ), and 12‐gammateraen‐3 β‐ol (tetrehymanol) ( 8 ); one steroid, β‐sitosterol ( 9 ); one long‐chain acid, octadecadienoic acid ( 10 ); two esters, ester of n‐octaolecyl‐4‐hydroxy‐cinnamate ( 11 ), and ester of n‐octadecyl‐caffeic acid ( 12 ); one diterpene, 8β,19‐dihydroxy‐3‐oxopimar‐15‐ene ( 13 ); one sesquiterpene, 1β,2β,9α‐trihydroxy‐β‐dihydroagarofuran ( 14 ) were isolated from the aerial part of Celastrus hypoleucus. These compounds were characterized and identified by physical and spectral methods. All compounds were isolated for the first time from this plant. Among them 12‐oleanaen‐3β‐caffeate ( 2 ) and 9(11),12‐oleanadien‐3β‐caffeate ( 5 ) are two new compounds, and ester of n‐octadecyl‐caffeic acid (12) possessed antilipoperoxidative effect by specifically scavenging the hydroxyl free radical (?OH) in vitro.     

Analysis of naturally occurring α-acetotriacylglycerides by gas chromatography — chemical ionization mass spectrometry

The seed oils of three Maytenus species have been examined by high temperature GLC using SOP-50 (methoxy-terminated) and OV-225-OH (OH-terminated) glasscapillary columns. The main compounds (71–76%) could be identified as α-mono-acetotriacylglycerols by a combination of high temperature GLC-MS in negative chemical ionization mode with a CH₄/N₂O mixture as reactant gas and other spectroscopical methods (infrared, ¹H- and ¹³C-nuclear magnetic resonance spectroscopy). The OV-225-OH phase demonstrated better separation properties that the SOP-50 phase for this substance class and up to eight species of α-monoacetotriacylglycerols could be separated. The content of usual triacyclglycerols was below 1%. The results of the analysis of the individual fatty acids as their methyl esters by GC and GC-MS are also presented.     

贵州芸香科、卫矛科等五个科药用植物种类与地理分布研究

通过野外调查、资料收集及标本鉴定,基本搞清了贵州芸香科、卫矛科、冬青科、猕猴桃科及葡萄科药用植物的种类与地理分布。结果发现贵州现有芸香科药用植物16属52种11变种1变型,卫矛科8属45种1变种1变型,冬青科1属25种2变种2变型,猕猴桃科3属15种8变种1变型,葡萄科8属35种12变种,其中1变种为贵州特有药用植物,32种7变种1变型为贵州药用新资源。     

A dihydro‐β‐agarofuran sesquiterpene from Maytenus boaria

The natural compound (1S ,4S ,5S ,6R ,7R ,8R ,9R ,10S )‐6‐acetoxy‐4,9,10‐trihydroxy‐2,2,5a,9‐tetramethyloctahydro‐2H‐3,9a‐methanobenzo[b ]oxepin‐5‐yl furan‐3‐carboxylate, C₂₂H₃₀O₉, (I), is a β‐agarofuran sesquiterpene isolated from the seeds of Maytenus boaria as part of a study of the secondary metabolites from Chilean flora. The compound presents a central structure formed by a decalin system esterified with acetate at site 1 and furan‐3‐carboxylate at site 9. The chirality of the skeleton can be described as 1S ,4S ,5S ,6R ,7R ,8R ,9R ,10S , which is consistent with that suggested by NMR studies. Unlike previously reported structures of sesquiterpenes containing a pure dihydro‐β‐agarofuran skeleton, (I) exhibits a three‐dimensional hydrogen‐bonded network.     

A phenyldilactone,bisnorsesquiterpene, and cytotoxic phenolics from Maytenus senegalensis leaves

Maytenus senegalensis Lam. (Celastraceae) leaves are traditionally used in West Africa for the management of cancer and other disorders associated with inflammation. In this study, bioactivity-guided fractionation of the methanol leaf extract of Maytenus senegalensis led to the isolation of 11 compounds, including the new phenyldilactone, maysedilactone (1). All isolated compounds were tested for cytotoxicity against mouse lymphoma cell line (L5178Y). Only (−) epigallocathechin showed high cytotoxicity and completely inhibited cell growth at the investigated dose of 10 μg/mL. This result supports the claimed efficacy of Maytenus senegalensis leaf extract in ethnomedicinal treatment of cancer.     

Polyphenolic profile by FIA/ESI/IT/MSn and antioxidant capacity of the ethanolic extract from the barks of Maytenus cajalbanica (Borhidi & O. Muñiz) Borhidi & O. Muñiz

Abstract

Medium and high polarity extracts from Maytenus species are known to contain polyphenolic compounds such as proanthocyanidins. The high polarity and structural complexity of these compounds make very difficult their isolation even by modern chromatographic techniques. Maytenus cajalbanica (Borhidi & O. Muñiz) Borhidi & O. Muñiz is endemic from Cuba. So far, there are reports neither of phytochemical work nor of biological evaluation of extracts from this subspecies. The goal of this work is to determine the polyphenolic profile and the antioxidant capacity of the ethanolic extract from the barks of Maytenus cajalbanica. FIA/ESI/IT/MSⁿ analysis allowed the identification of 5 flavan-3-ol monomers, 33 proanthocyanidins, 2 free flavonoids and their respective glycosides as major compounds of the ethanolic extract, which showed a strong radical scavenging capacity and a significant ferric reduction power. FIA/ESI/IT/MSⁿ technique led the rapid, effective and sensitive determination of the polyphenolic profile of Maytenus cajalbanica without previous separation.     

Dihydro-β-agarofurans from the Australian rainforest plant Denhamia celastroides that inhibit leucine transport in prostate cancer cells

Four new dihydro-β-agarofurans, denhaminols K–N ( 4 – 7 ), along with three known secondary metabolites, denhaminols A–C ( 1 – 3 ) were obtained from the large-scale isolation studies of the leaves of the Australian endemic rainforest plant, Denhamia celastroides. The structures of the previously undescribed compounds were determined by detailed 1D and 2D nuclear magnetic resonance spectroscopy, mass spectrometry, ultraviolet, and infrared data analysis. All compounds were found to inhibit the activity of leucine transport in a human prostate cancer cell line with IC₅₀ values ranging from 5.1–74.9 μM. Dihydro-β-agarofurans 1 – 7 showed better potency than the L-type amino acid transporter family inhibitor, 2-aminobicyclo[2.2.1]-heptane-2-carboxylic acid (BCH).     

Structural determination of 3beta-stearyloxy-urs-12-ene from Maytenus salicifolia by 1D and 2D NMR and quantitative 13C NMR spectroscopy

Six pentacyclic triterpenoids, 3beta-stearyloxy-urs-12-ene (1), friedelin (2), 3beta-friedelinol (3), alpha-amyrin (4), beta-amyrin (5), and lupeol (6), have been isolated from the hexane extract of Maytenus salicifolia Reissek (Celastraceae) leaves. The molecular and structural formula as well as the stereochemistry of a new pentacyclic triterpene (1) were determined using data obtained from 1H and 13C NMR spectra, DEPT135 and by 2D HSQC, HMBC, COSY and NOESY experiments. The molecular formula C48H84O2 was established using quantitative 13C NMR, and the molecular weight (692 Da) was confirmed by elemental analysis and mass spectrometry (GC-MS).