- Nonequivalent labeling of the phytyl side chain of chlorophyll a in callus of the hornwort Anthoceros punctatus
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Callus cultures of the hornwort Anthoceros punctatus were induced from the apical portions of the gametophytes. Calli can accumulate rosmarinic acid, which is suggested as an intermediate for anthocerotonic acid, a rare phenylpropanoid dimer with a cyclobutane ring, indicating that calli possess the ability to produce secondary metabolites found primarily in intact plants. Biosynthesis of chloroplastidic terpenoids of liverworts showed preferential labeling of the farnesyl diphosphate (FPP)-derived portion in the phytyl side chain of chlorophyll a (1) when calli of A. punctatus are incubated with 2H- and 13C-labeled mevalonate. This finding suggests either that cytoplasmic FPP (or isopentenyl diphosphate, IPP) is taken into chloroplasts and condensed with endogenous IPP derived from a nonmevalonate pathway, or that FPP is synthesized within chloroplasts from extraplastidically formed IPP (or mevalonate) and then condensed with endogenous IPP in a different subplastidic fraction.
- Itoh, Daisuke,Karunagoda, Renuka Praxide,Fushie, Takashi,Katoh, Kenji,Nabeta, Kensuke
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- Phytol derivatives as drug resistance reversal agents
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Phytol was chemically transformed into fifteen semi-synthetic derivatives, which were evaluated for their antibacterial and drug resistance reversal potential in combination with nalidixic acid against E. coli strains CA8000 and DH5α. The pivaloyl (4), 3,
- Upadhyay, Harish C.,Dwivedi, Gaurav R.,Roy, Sudeep,Sharma, Ashok,Darokar, Mahendra P.,Srivastava, Santosh K.
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- Scalable green approach toward fragrant acetates
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The advantageous properties of ethylene glycol diacetate (EGDA) qualify it as a useful substitute for glycerol triacetate (GTA) for various green applications. We scrutinised the lipase-mediated acetylation of structurally diverse alcohols in neat EGDA furnishing the range of naturally occurring fragrant acetates. We found that such enzymatic system exhibits high reactivity and selectivity towards activated (homo) allylic and non-activated primary/secondary alcohols. This feature was utilised in the scalable multigram synthesis of fragrant (Z)-hex-3-en-1-yl acetate in 70percent yield. In addition, the Lipozyme 435/EGDA system was also found to be applicable for the chemo-selective acetylation of (hydroxyalkyl) phenols as well as for the kinetic resolution of chiral secondary alcohols. Lastly, its discrimination power was demonstrated in competitive experiments of equimolar mixtures of two isomeric alcohols. This enabled the practical synthesis of 1-pentyl acetate isolated as a single product in 68percent yield from the equimolar mixture of 1-pentanol and 3-pentanol.
- Puchl'Ová, Eva,Szolcsányi, Peter
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- Antimalarial activity of phytol derivatives: in vitro and in vivo study
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Severe malaria is one of the leading causes of mortality among children and pregnant woman globally. Resistance development against the frontline antimalarial drugs has created an alarming situation, which requires intensive drug discovery to develop effective, affordable, and accessible antimalarial agents possessing novel modes of action. As a part of our drug discovery program for antimalarial agents from plants, phytol a very commonly occurring diterpene alcohol in the plant was investigated for its antimalarial potential. In vitro antiplasmodial activity against the chloroquine-sensitive Plasmodium falciparum NF54 by measuring the parasite specific lactate dehydrogenase (pfLDH), showed moderate activity (IC50 211.5 ± 0.93 μM). Further, phytol was chemically converted into thirteen derivatives, which were evaluated for their antiplasmodial potential. All the derivatives were moderate active, but among all the derivatives palmitoyl (PhY-3; IC50 12.13 ± 0.31 μM) has found most active without any cytotoxic effect on macrophage cells. PhY-3 was further validated in an in vivo system for its efficacy and safety profile in mice. Oral administration of PhY-3 showed significant reduction of parasitemia and increased mean survival time. It also attributed significant increase in blood glucose and hemoglobin level, when compared with vehicle-treated P. berghei infected mice without any toxic effect on normal mice at a higher dose. These findings confirm suitability of the phytol derivatives as new chemical entities for further investigation towards the management of malaria.
- Saxena, Archana,Upadhyay, Harish C.,Cheema, Harveer S.,Srivastava, Santosh K.,Darokar, Mahendra P.,Bawankule, Dnyaneshwar U.
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p. 1345 - 1354
(2018/04/10)
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- Antimycobacterial agent, (E)-phytol and lauric amide from the plant Lagascea mollis
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Chemical examination of aerial parts of the plant, Lagascea mollis has resulted in the isolation of two compounds, an acyclic diteipene alcohol which has been identified as (￡)-phytol 1 and lauric amide 3. Their structures have been elucidated by spectral data and chemical transformations. This is the first report of isolation of both these compounds from this plant. It is noteworthy that compound 1 has been found to be a potent antimycobacterial agent and thus, L. mollis could be exploited as an alternative source.
- Bhattacharya, Asish K,Rana, Kalpeshkumar C
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p. 901 - 903
(2013/08/15)
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- A new route to vitamin E Key-intermediates by olefin cross-metathesis
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Ru-Catalyzed olefin cross-metathesis (CM) has been successfully applied to the synthesis of several phytyl derivatives (2b, 2d-f, 3b) with a trisubstituted C=C bond, as useful intermediates for an alternative route to α-tocopheryl acetate (vitamin E acetate; 1b) (Scheme 1). Using the second-generation Grubbs catalyst RuCl2(C21H 26N2)(CHPh)PCy3, (Cy = cyclohexyl; 4a) and Hoveyda-Grubbs catalyst RuCl2(C21H26N 2){CH-C6H4(O-iPr)-2} (4b), the reactions were performed with various C-allyl (5a-f, 7a,b) and O-allyl (8a-d) derivatives of trimethylhydroquinone-1-acetate as substrates. 2,6,10,14-Tetramethylpentadec-1-ene (6a) and derivatives 6c-e of phytol (6b) as well as phytal (6f) were employed as olefin partners for the CM reactions (Schemes 2 and 5). The vitamin E precursors could be prepared in up to 83% isolated yield as (E/Z)-mixtures.
- Malaise, Gregory,Bonrath, Werner,Breuninger, Manfred,Netscher, Thomas
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p. 797 - 812
(2007/10/03)
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- A NEW ROUTE TO α-TOCOPHEROL, α-TOCOPHERYL ALKANOATES AND PRECURSORS THEREOF
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The present invention is concerned with a novel process for the manufacture of (E/Z)-4-alkanoyloxy-3,5,6-trimethyl-2-phytylphenyI esters and silyl ethers, precursors of α- tocopherol and α-tocopheryl alkanoates, by cross-metathesis reaction of 2-alkenyl-3,5,6-trimethylhydroquinone dialkanoates or 4-alkanoyloxy-2-alkenyl-3,5,6-trimethylphenyI silylethers with 2,6,10,14-tetramethylpentadecene or a phytol derivative, e.g. phytyl acetate, in the presence of a cross-metathesis catalyst. As the cross-metathesis catalyst especially ruthenium metal carbene complexes are suitable which possess (a) ruthenium metal center(s), have an electron count of 16 or 18 and are penta- or hexa- coordinated. A further object of the invention is a process for the manufacture of α-tocopherol and α-tocopheryl alkanoates comprising this reaction.
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Page/Page column 17
(2008/06/13)
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- A NEW ROUTE TO α- TOCOPHERYL ALKANOATES AND PERCURSORS THEROF
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The present invention is concerned with a novel process for the manufacture of 4alkanoyloxy-2,3,5-trimethylphenyI (E/Z)-phytyl ethers, precursors of α.-tocopheryl alkanoates, by cross-metathesis reaction of alkenyl ethers of 1-alkanoyloxy-2,3,6-trimethylhydroquinone with 2,6,10,14-tetramethylpentadecene or a phytol derivative, e.g. an ester, an ether or a silyl ether, in the presence of a cross-metathesis catalyst. As the crossmetathesis catalyst especially ruthenium metal carbene complexes are suitable which possess (a) ruthenium metal center(s), have an electron count of 16 or 18 and are penta- or hexa- coordinated. A further object of the invention is a process for the manufacture of αtocopheryl alkanoates comprising this reaction.
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Page/Page column 17
(2008/06/13)
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- DITERPENE MALONATES AND OTHER TERPENES FROM NARDIA SUCCULENTA AND N. SCALARIS
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Nardia succulenta and N. scalaris afforded a series of 12 diterpene malonates: ent-kaur-16-en-15β-yl hydrogen malonate; ent-labda-8(17),13-dien-15-yl hydrogen malonate; bis-ent-kaur-16-en-15β-yl malonate; bis-ent-labda-8(17),13-dien-15-yl malonate; ent-kaur-16-en-15β-yl ent-labda-8(17),13-dien-15-yl malonate; ent-kaur-16-en-15β-yl phytyl malonate; 14-ent-kaur-16-en-14-yl hydrogen malonate; bis-14-ent-kaur-16-en-14-yl malonate; (14R)-ent-kaur-16-en-14-yl phytyl malonate; (14R)-ent-kaur-16-en-14-yl epi-bornyl malonate; ent-kaur-16-en-15-yl epi-bornyl malonate and (14R)-ent-kaur-16-en-14-yl fenchyl malonate; besides (1,2)-bis-nor-phytone and two diastereomeric 3,6-peroxo-cupar-1-enes. Key words: Nardia succulenta; N. scalaris; Jungermanniales; liverworts; kauranes; labdanes; malonates.
- Langenbahn, Ulrich,Burkhardt, Gunther,Becker, Hans
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p. 1173 - 1180
(2007/10/02)
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- SELECTIVE REDUCTION OF THE DISTANT DOUBLE BOND(S) IN GERANYL, FARNESYL AND GERANYL GERANYL DERIVATIVES.
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Selective addition of hydrogen chloride on the non-proximal double bond(s) of the title compounds followed by hydrogenolysis led to selective hydrogenation of these double bond(s).
- Julia, Marc,Roy, Pierre
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p. 4991 - 5002
(2007/10/02)
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