The sterols and triterpenes of Sorghum vulgare grains

A complex mixture containing more than 20 4-demethylsterols, 4-monomethylsterols and triterpenes was isolated from the grains of Sorghum vulgare. Seventeen of these compounds were identified using a combination of GLC, GC-MS, IR and NMR.     

Effect of constituents of the foliar wax of Didymopanax vinosum on the foraging activity of the leaf-cutting ant Atta sexdens rubropilosa

Leaf epicuticular waxes may affect substrate selection by leaf-cutting ants, and host recognition by several phytophagous insects. The influence of the crude epicuticular wax of Didymopanax vinosum E. March. (Araliaceae), and its major constituents lupeol and free primary alcohols, on substrate selection by the leaf-cutting ant Atta sexdens rubropilosa Forel, was investigated. Two ant colonies were used in laboratory bioassays. Corn flakes (zea) were impregnated with chloroform solutions of the substances being tested and fed to the adults. One of the colonies gave results, in most of the tests, not significantly different from the controls. The other colony, however, discriminated against the crude wax, a strong deterrent effect being observed from the first of a series of eight trials. The same colony was able to discriminate against lupeol after the second trial. The fraction of primary n-alcohols (22% C₂₈, 66% C₃₀ and 12% C₃₂) deterred feeding only after the fifth trial. The results demonstrate that some constituents of epicuticular waxes may deter the foraging activity of A. sexdens rubropilosa, depending, however, on the colony under observation. It is suggested that lupeol, of the foliar wax of D. vinosum, is an important deterrent to leaf-cutting ants, although with less pronounced effects than those observed in tests with the crude wax.     

A guaianolide and other constituents from Lychnophora species

A new guaianolide, 11 β,13-dihydroeremanthine, together with a caryophyllene derivative and pentacyclic triterpenes, has been isolated from Lychnophora species.     

Chemical Constituents of Lac Host,Acacia suma

Six crystallin compounds were isolated from the stem bark of Acacia surna BuchHam. ex. Wall. Based on spectral and chemical evidences, four of them were demonstrated as triacontanol, β-sitosterol, daucosterin and lupeol heptylate. All were firstly reported from the plant. Among them lupeol heptylate was a new compound.     

3,5,7,3′,5′-Pentahydroxyflavan and 3α-methoxyfriedelan from Humboldtia laurifolia

The leaf, bark and timber extractives of Humboldtia laurifolia were investigated and the following compounds have been isolated: O-acetyloleanolic aldehyde, a sitosteryl ester, lupeol, sitosterol, a fatty acid, 5,7,4′-trihydroxyflavone (apigenin), (2R,3R)-3,5,7,3′,5′-pentahydroxyflavan and 3α-methoxyfriedelan. The latter two compounds are new natural products.     

Lupeol long-chain fatty acid esters and other triterpenoid constituents from Plumeria obtusifolia

From the bark of Plumeria obtusifolia was isolated a series of lupeol fatty esters with the carbon numbers 16, 18,20 and 21–28 in the fatty acid part. Furthermore, lupeol, lupeol acetate, sitosterol, stigmasterol and campesterol were also identified.     

Engineering the unicellular alga Phaeodactylum tricornutum for high‐value plant triterpenoid production

Plant triterpenoids constitute a diverse class of organic compounds that play a major role in development, plant defence and environmental interaction. Several triterpenes have demonstrated potential as pharmaceuticals. One example is betulin, which has shown promise as a pharmaceutical precursor for the treatment of certain cancers and HIV. Major challenges for triterpenoid commercialization include their low production levels and their cost‐effective purification from the complex mixtures present in their natural hosts. Therefore, attempts to produce these compounds in industrially relevant microbial systems such as bacteria and yeasts have attracted great interest. Here, we report the production of the triterpenes betulin and its precursor lupeol in the photosynthetic diatom Phaeodactylum tricornutum, a unicellular eukaryotic alga. This was achieved by introducing three plant enzymes in the microalga: a Lotus japonicus oxidosqualene cyclase and a Medicago truncatula cytochrome P450 along with its native reductase. The introduction of the L. japonicus oxidosqualene cyclase perturbed the mRNA expression levels of the native mevalonate and sterol biosynthesis pathway. The best performing strains were selected and grown in a 550‐L pilot‐scale photobioreactor facility. To our knowledge, this is the most extensive pathway engineering undertaken in a diatom and the first time that a sapogenin has been artificially produced in a microalga, demonstrating the feasibility of the photo‐bio‐production of more complex high‐value, metabolites in microalgae.     

Lupeol and its ester ameliorate the cyclophosphamide provoked cardiac lysosomal damage studied in rat

Cyclophosphamide (CP), an alkylating agent widely used in cancer chemotherapy causes fatal cardiotoxicity. Lupeol, a pentacyclic triterpene, isolated from Crataeva nurvala stem bark and its ester, lupeol linoleate possess a wide range of medicinal properties. The effect of lupeol and its ester was evaluated in CP-induced myocardial toxicity in rats. Male albino rats of Wistar strain were categorized into six groups. Group I served as control. Rats in groups II, V and VI animals were injected intraperitoneally with a single dose of CP (200 mg/kg body weight) dissolved in saline. CP-treated groups V and VI received lupeol and lupeol linoleate (50 mg/kg body weight), respectively, dissolved in olive oil for 10 days by oral gavage. CP-administered rats showed a significant increase (p < 0.001) in the activities of lysosomal hydrolases in serum and heart, a decrease (p < 0.001) in the levels of cellular thiols and myofibres were swollen with loss of myofilaments in electron microscopical analysis in heart. Lupeol and its ester showed reversal of the above alterations induced by CP. These findings demonstrate that the supplementation with lupeol and its ester could preserve lysosomal integrity, improve thiol levels, highlighting their protective effect against CP-induced cardiotoxicity.     

Triterpenoids from Salvia pinnata

A new and four known triterpenoids have been isolated from the leaves of Salvia pinnata. The structures of these compounds have been established by spectral data and by some chemical reactions.