Sterols and triterpenes of Ilex aquifolium

Sterols of male and female flowers from Ilex aquifolium were found to be mainly 24-ethylcholesterol, with trace amounts of cholesterol, 24-methylcholesterol and 24-ethyl-5,22-cholestadien-3β-ol. Several pentacyclic triterpenes were partially characterized.     

Antimycobacterial,docking and molecular dynamic studies of pentacyclic triterpenes from Buddleja saligna leaves

Buddleja saligna (family Buddlejaceae) is a medicinal plant endemic to South Africa. Two isomeric pentacyclic triterpenes, oleanolic acid and ursolic acid, were isolated from the leaves of B. saligna using silica gel column chromatography. Compounds oleanolic acid and ursolic acid were subjected to derivatization with acetic anhydride in the presence of pyridine to obtain oleanolic acid-3-acetate and ursolic acid-3-acetate, respectively. The structures of these compounds were fully characterized by detailed nuclear magnetic resonance (NMR) investigations, which included ¹H and ¹³C NMR. Molecular docking studies predicted the free binding energy of the four triterpenes inside the steroid binding pocket of Mycobacterium tuberculosis fadA5 thiolase compared to a reported inhibitor. Thus, their ability to inhibit the growth of M. tuberculosis was predicted and was confirmed to possess significant antimycobacterial activity when tested against Mycobacterium smegmatis, M. tuberculosis H₃₇Rv (ATCC 25177), clinical isolates of multi-drug-resistant M. tuberculosis (MDR-TB) and extensively drug-resistant M. tuberculosis (XDR-TB) using the Micro Alamar Blue Assay. Ursolic acid was isolated from this plant for the first time.     

Four new triterpenoidal saponins from Ilex cornuta and their cytotoxic activities

Four new triterpenoidal saponins (1–4), oleanolic acid 3β-O-α-l-arabinopyranosyl-(1 → 2)-β-d-glucuronopyranoside-6-O-butyl ester (1), oleanolic acid 3β-O-[α-l-arabinopyranosyl-(1 → 2)-β-d-glucuronopyranoside-6-O-butyl ester]-28-O-β-d-glucopyranoside (2), 19α-hydroxy oleanolic acid 3β-O-β-d-glucuronopyranoside-6-O-methyl ester (3), and 19α-hydroxy urs-12-en-28-oic acid 3β-O-α-l-arabinopyranosyl-(1 → 2)-β-d-glucuronopyranoside-6-O-methyl ester (4) were isolated from the roots of Ilex cornuta. Their structures were determined by means of extensive spectroscopic analyses (IR, ESIMS, HRESIMS, 1D and 2D NMR). Compounds 1–9 were tested for their cytotoxic activities by MTT assay, and 1, 3, 5 and 6 showed moderate cytotoxic activities against HeLa, SMMC-7721, and HL-60 human tumor cell lines.     

Two new triterpene saponins from the roots of Ilex pubescens

Two new triterpene saponins, namely, ilexpublesnin S (1) and T (2), and six known saponins were isolated from the roots of Ilex pubescens. The structures of the new compounds were elucidated through extensive spectroscopic methods (IR, HR-ESI-MS, 1D and 2D NMR). Sugar residues obtained after acid hydrolysis were identified through TLC and HPLC. Compound 1 contains a 24-aldehyde group, which is rare for triterpene saponins from Ilex.     

Triterpene acids from Salvia and Teucrium species

The pentacyclic triterpene acids ursolic acid, oleanolic acid, micromeric acid, maslinic acid and 3-epi-maslinic acid have been isolated from several Salvia and Teucrium species.     

Two pentacyclic triterpenes from Rubia cordifolia

Rubicoumaric acid and rubifolic acid isolated from Rubia cordifolia have been shown to be 30-hydroxy-3β-p-hydroxycoumaryloxy-urs-12-ene-28-oic acid and 3β,30-dihydroxy-urs-12-ene-28-oic acid(30-hydroxyursolic acid) respectively on the basis of ¹H NMR, ¹³C NMR and mass spectral and chemical evidence.     

New triterpenes from the leaves of Olea europaea

The terpene fraction from the leaves of Olea europaea has been shown to contain the known oleanolic and maslinic acids, together with oleanane hydroxy acids which have never been found before in nature.     

Four New Triterpenoid Saponins from the Root of Ilex centrochinensis

One new siaresinolic acid saponin ( 1 ) and three new rotundic acid saponins ( 2 – 4 ) were isolated from the roots of Ilex centrochinensis. Their structures were confirmed by detailed analysis of standard spectroscopic data (IR, MS, 1D and 2D NMR). Compounds 1 – 4 exhibited anti-inflammatory activity by inhibiting nitric oxide production in a lipopolysaccharide-induced RAW264.7 cell inflammatory model. However, they showed no significant lipid-lowering activity against the production of triglycerides in the lipid-accumulation model of HepG2 cells induced by oleic acid.     

Anthocyanins of holly fruits

Anthocyanin distribution in the fruits of Ilex closely followed an accepted taxonomic classification. Within the evergreen subgenus Aquifolium, species belonging to section Lioprinus produced only cyanidin pigments while in section Aquifolium, pelargonidin was the major anthocyanin. Likewise, in the deciduous subgenus Prinos, species of section Prinoides contained cyanidin pigments and those of section Euprinus had pelargonidin compounds. Exceptions to this pattern and the bearing of pigment studies on breeding are discussed.     

Minor triterpenes from Orthopterygium huancuy

Two new triterpenes, 3-oxo-20-hydroxy-lupan-28-oic and 3β,6β-dihydroxy-olean-18-en-28-oic acids, along with oleanonic, morolic and sumaresinolic acids have been isolated from Orthopterygium huancuy. The structure of the first new terpene was determined by single crystal X-ray analysis.     

Tetracyclic triterpenes from Parthenium fruticosum

The shrub Parthenium fruticosum was shown to contain the three isomeric tetracyclic triterpenes fruticin A, fruticin B and the known incanilin. Fruticins A and B are new substances with lanostane and cycloartane skeletons, respectively. Their structures were determined by chemical and spectroscopic methods. The stereochemistry of fruticin B was established by X-ray diffraction analysis.     

Triterpene Saponins from the Roots of Ilex asprella

Six new triterpene saponins, ilexasprellanosides A–F ( 1 – 6 , resp.), together with eleven known compounds were isolated from the roots of Ilex asprella. The new saponins were characterized as ursa‐12,18‐dien‐28‐oic acid 3‐O‐β‐D ‐xylopyranoside ( 1 ), 19α‐hydroxyursolic acid 3‐O‐β‐D ‐(2′‐O‐acetylxylopyranoside) ( 2 ), 19α‐hydroxyursolic acid 3‐O‐β‐D ‐glucuronopyranoside ( 3 ), 3β,19α‐dihydroxyolean‐12‐en‐23,28‐dioic acid 28‐O‐β‐D ‐glucopyranoside ( 4 ), 19α‐hydroxyoleanolic acid 3‐O‐β‐D ‐(2′‐O‐acetylxylopyranoside) ( 5 ), 19α‐hydroxyoleanolic acid 3‐O‐β‐D ‐glucuronopyranoside ( 6 ). The structures of the new compounds were elucidated by analysis of their spectroscopic data and chemical degradation. Compounds 2, 4 , oleanolic acid 3‐O‐β‐D ‐glucuronopyranoside, 3‐β‐acetoxy‐28‐hydroxyurs‐12‐ene, and pomolic acid showed significant cytotoxic activities against human tumor cell line A549 (IC₅₀ values of 1.87, 2.51, 1.41, 3.24, and 5.63 μM , resp.).     

Gas chromatography-mass spectrometry of oleanane- and ursane-type triterpenes—application to Chenopodium quinoa triterpenes

Nine trimethylsilylated pentacyclic triterpenes were separated by GLC on an OV-101 column employing temperature programming. Characteristic retro-Diels-Alder fragmentation was observed in their mass spectra. The fragmentation patterns allowed individual characterization except for certain isomers which, nevertheless, were resolved by GLC, thus permitting their identification. Oleanolic acid and hederagenin were confirmed to be major triterpenes of Chenopodium quinoa seed saponins.     

Three triterpenes and other terpenoids from Catha cassinoides

The investigation of stems and leaves of Catha cassinoides afforded, in addition to sitosterol, β-amyrin, ursolic acid, lup-20(29)-en-3β,30-diol and friedelin, three new pentacyclic triterpenes: 30-hydroxyfriedelan-3-one, 29-hydroxyfriedelan-3-one and 3-oxo-friedelan-29-oic acid. The structures ofthese were determined by spectral studies and correlations, and were confirmed by X-ray analysis of 29-hydroxyfriedelan-3-one acetate.     

Obtusilobinin and obtusilobin,two new triterpene saponins from Anemone obtusiloba

Obtusilobinin and obtusilobin, two new saponins, have been isolated from the ethanolic extract of Anemone obtusiloba (Ranunculaceae). The structural elucidation of obtusilobinin and obtusilobin have showed them to be olean-12-ene-28-oic-3-O-(α-l-arabinofuranosyl 1→2) (α-l-rhamnopyranosyl 1→4)-β-d-glucopyranoside and olean-12-ene-28-oic-3-O-α-l-rhamnopyranosyl 2→1-O-α-l-arabinofuranoside, respectively.