Studies in carotenogenesis. 29. Attempts to detect lycopersene in higher plants

Lycopersene: A review on extraction, identification and purification and applications

Lycopersene is a stable and safe triterpenoid. Lycopersen had utilized as an antioxidant, antimutagenic, antiproliferative, cytotoxicity, antibacterial and pesticide. Obtaining pure Lycopersene from natural sources is very important for fundamental research and the above applications. The present overview provides an up-to-date and comprehensive summary of the various methods used for extraction, isolation and purification of Lycopersene from natural sources with its applications in food, cosmetics and pharmaceutical fields. Many different extraction methods ranging from conventional techniques (e.g. Soxhlet extraction, Maceration and Rotary evaporator) and other advanced extraction technologies (e.g. Solid-phase microextraction, steam distillation with Clevenger, Clevenger apparatus, Chromatography on SiO₂ column, centrifuge, sonication) had been used to obtain Lycopersene from flora and fauna. Purification techniques, alone or in combination, have been investigated for isolation and purification of Lycopersene from crude extracts in various natural sources. The review of Lycopersene identified cap areas like purity and application in various fields.

Biosynthesis of carotenoids and plant triterpenes

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Attempts to detect lycopersene formation in yeast

1. beta-Ionone vapour has been shown to cause an increase in the more saturated carotenes and a decrease in the less saturated carotenes of Rhodotorula glutinis. Lycopersene (dihydrophytoene) has been proposed as a precursor to phytoene. Attempts were made to isolate lycopersene from beta-ionone-treated cultures of R. glutinis. 2. Large samples of beta-ionone-treated cultures were examined for the presence of lycopersene. Spots were detected on silicic acid plates that could not be differentiated from synthetic lycopersene on the basis of column and thin-layer chromatographic separations and staining techniques. The lycopersene-like substance could be obtained from non-treated pigmented yeast as well as baker's yeast. 3. An extraction of bacterial-grade yeast extract also yielded a lycopersene-like substance. The extracts of R. glutinis cells cultured on media not containing yeast extract did not contain the lycopersene-like compound. 4. No significant carbon was incorporated into the lycopersene zone from (14)C-labelled mevalonate, acetate and glucose by R. glutinis and baker's yeast. 5. These results indicate that compounds may exist with chromatographic properties similar to lycopersene, but that lycopersene could not be detected in either a pigmented or a non-pigmented yeast.

Nature, intracellular distribution and formation of terpenoid quinones in maize and barley shoots

1. Maize and barley shoots have been shown to contain phylloquinone, plastoquinone, alpha-tocopherol (and gamma-tocopherol in maize), alpha-tocopherolquinone and ubiquinone-9. 2. No solanesol was detected in any tissue examined. 3. In maize shoots plastoquinone and alpha-tocopherolquinone were localized in the chloroplast; ubiquinone was in the mitochondria. 4. Etiolated (dark-grown) shoots contained smaller amounts of phylloquinone and plastoquinone; alpha-tocopherolquinone was entirely absent; ubiquinone and alpha-tocopherol concentrations were unaffected. 5. On illumination of etiolated shoots the chloroplastidic quinones phylloquinone, plastoquinone and alpha-tocopherolquinone were synthesized in step with chloroplast development. alpha-Tocopherolquinone was not formed at the immediate expense of alpha-tocopherol.

The biosynthesis of sterols in higher plants

1. [2-(14)C]Mevalonate was incorporated into squalene and the major phytosterols of pea and maize leaves; it was also incorporated into compounds belonging to the 4,4-dimethyl and 4alpha-methyl steroid groups and which may be possible phytosterol intermediates. 2. l-[Me-(14)C]Methionine was incorporated into the major sterols and also into the 4,4-dimethyl and 4alpha-methyl steroid groups. No radioactivity was detected in squalene. 3. Under anaerobic conditions incorporation of [2-(14)C]-mevalonate into the non-saponifiable lipid of pea leaves was drastically decreased but radioactive squalene was accumulated. 4. Cycloartenol, 24-methylenecycloartanol, 24-methylenelophenol, 24-ethylidenelophenol, fucosterol, beta-sitosterol, stigmasterol and campesterol have been identified by gas-liquid chromatography in pea leaves. 5. The significance of these results in connexion with phytosterol biosynthesis and the introduction of the alkyl group at C-24 into phytosterols is discussed.

The stereospecific biosynthesis of plant sterols and alpha- and beta-amyrin

1. A preparation of pea seedlings has been obtained that will incorporate [2-(14)C]mevalonate into squalene, alpha- and beta-amyrin and the phytosterols. 2. The (14)C/(3)H ratio in alpha- and beta-amyrin biosynthesized in the presence of [2-(14)C,4R-(3)H]-mevalonate is the same as in the starting material and in squalene; this gives experimental support to the mechanism for the cyclization of squalene proposed by Ruzicka for the formation of these pentacyclic triterpenoids. 3. The (14)C/(3)H ratio for beta-sitosterol was 5:3, the same as that in cholesterol in liver. 4. As the absence of (3)H from C-3 in beta-sitosterol was demonstrated (3)H must be present in the side chain and thus the H at C-24 is not lost during alkylation of the side chain; it probably migrates to C-25.

Incorporation of [14C] carbon dioxide and [2-14C] mevalonic acid into terpenoids of higher plants during chloroplast development

1. The incorporation of (14)CO(2) and dl-[2-(14)C]mevalonic acid into various terpenoids in developing chloroplasts in a number of seedlings has been studied. 2. beta-Carotene and phytol (from chlorophyll) tend to be heavily labelled from (14)CO(2), whereas sterols and beta-amyrin are only slightly labelled; with dl-[2-(14)C]mevalonic acid the situation is reversed. 3. The incorporation of (14)CO(2) into terpenoids is dependent on the stage of chloroplast development, whereas that of mevalonic acid is independent of chloroplast development. 4. The uptake of (14)CO(2) into beta-carotene and phytol in mature chloroplasts is very low in monocotyledons but somewhat greater in dicotyledons. 5. The results are discussed in relation to the view that terpenoid biosynthesis in developing chloroplasts is regulated by a combination of enzyme segregation and specific membrane permeability.