Phytochemical, Morphological, and Molecular Evidence for the Occurrence of the Neotropical Liverwort Plagiochila stricta in the Canary Islands, New to Macaronesia

Based on morphology and phylogenetical analyses of nrITS sequences, the Andean endemic Plagiochila (Jamesoniella) dependula is placed in Plagiochila sect. Fuscoluteae. Perianths, oil bodies and sporophytes are described for the first time. Morphologically, P. dependula is characterized by entire, dorsally mostly shortly decurrent, laterally appressed, reniform leaves which are covered by irregular papillae and membranous wax platelets, papillose oil bodies, intercalary androecia with opposite bracts that overlap dorsally, a plagiochilid perianth with an entire mouth, a 250 mm thick capsule wall with thickenings in all layers, large 1-4 celled spores, and bispiral elaters. Morphotypes of Plagiochila fuscolutea with laterally appressed leaves differ from P. dependula by an at least moderately decurrent, broad dorsal leaf base, a ¡smooth upper leaf surface, and by its often toothed leaf apices. Plagiochila wolframii is placed in the synonymy of P. fuscolutea. Maximum likelihood and parsimony analyses of 29 Plagiochila ITS sequences resolve P. dependula in a well-supported clade with several other representatives of P. sect. Fuscoluteae. Branch lengths within sect. Fuscoluteae point to a sudden diversification. Accessions of P. heterophylla s.str. from Great Britain (formerly known as P. atlantica) and Costa Rica form an unsupported monophyletic lineage.

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“…(Heinrichs et al, 2002c) and P. stricta of sect. Arrectae (Rycroft et al, 2002), P. boryana Steph. of sect.…”

Section: Discussionmentioning

confidence: 99%

The systematic position ofPlagiochila(Jamesoniella)dependula(Jungermanniopsida) inferred from nrITS sequences and morphology, with notes on its differentiation fromPlagiochila fuscolutea

Heinrichs¹,

Wilson²,

Feldberg³

et al. 2005

Journal of Bryology

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“…Rycroft et al, 11 detected aromatic and terpenoid compounds on the solvent extracts of two specimens from Tenerife and two from Ecuador. The aromatic profile was not uniform between the four specimens, although similar for the Tenerife specimens.…”

Section: P Strictamentioning

confidence: 99%

“…None of these compounds were detected in the Madeiran essential oils. Concerning the terpenoid fraction, Rycroft et al 11 also detected alloocimene, neo-allo-ocimene, peculiaroxide and bicyclogermacrene as the main terpenoid compounds.…”

Section: P Strictamentioning

confidence: 99%

Comparison of the essential oil composition of fourPlagiochila species:P. bifaria,P. maderensis,P. retrorsa andP. stricta

et al. 2005

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Essential oils isolated by distillation-extraction from P. bifaria, P. maderensis, P. retrorsa and P. stricta, collected on Madeira, were analysed by GC and GC-MS. Methyl everninate (1-35%), peculiaroxide (13-16%) and enteudesm-4(15)-ene-6-one (9-19%) were the main components in all P. bifaria specimens analysed. Terpinolene (34-60%) dominated the oils isolated from P. maderensis specimens. β β β β β-Phellandrene (16-46%) was the main component of two of the three specimens of P. retrorsa, allo-ocimene (15%), terpinolene (13%), peculiaroxide (12%) and neo-allo-ocimene (10%) being the main components of the third specimen. P. stricta oils were dominated by peculiaroxide (11-21%), allo-ocimene (7-19%), bicyclogermacrene (4-17%), neo-allo-ocimene (4-11%) and spathulenol (2-14%). Essential oil cluster analysis showed a high degree of similarity between three of the four species studied, the least correlated being P. maderensis oils.

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“…Compound II is a non-conjugated diene and is therefore incapable of undergoing cycloaddition according to Diels-Alder; on the other hand, it was expected to react following the Alder-ene reaction scheme. Conjugated triene III (which is always present in natural sources [8,9] and synthetic samples [10] as a mixture of E and Z isomers IIIa and IIIb) readily gives rise to Diels-Alder adducts with participation of only E isomer IIIa, whereas Z isomer IIIb (neoalloocimene) reacts only at elevated temperature after isomerization into the E isomer [11]. The failure of neoalloocimene to react according to the Diels-Alder pattern, which is typical of dienes with analogous configuration, is related to the fact that planar cisoid conformation of the diene fragment therein (which is necessary for such reactions) is unfavorable for steric reasons.…”

mentioning

confidence: 99%

1-Methylcycloprop-2-ene-1-carbonitrile in tandem alder-ene and diels-alder reactions

Лодочникова

Ashirov²,

Appolonova³

et al. 2010

Russ J Org Chem

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The reactions of 1-methylcycloprop-2-ene-1-carbonitrile with cyclohexa-1,4-diene and alloocimene gave the corresponding 2 : 1 addition products as a result of consecutive (conjugate) Alder-ene and Diels-Alder reactions. 1-Methylcycloprop-2-ene-1-carbonitrile acts initially as enophile, and in the second step, as dienophile. The structure of the adducts was determined by X-ray analysis. Fig. 1. Structure of the molecule of 8-(2-cyano-2-methylcyclopropyl)-3-methyltricyclo[3.2.2.0 2.4 ]non-6-ene-3-carbonitrile (IV) according to the X-ray diffraction data.We previously demonstrated fairly high and versatile reactivity of 1-methylcycloprop-2-ene-1-carbonitrile (I) as dienophile in Diels-Alder reactions [1-5]; in addition, compound I was recently found to be capable of reacting with some olefins according to the Alder-ene pattern [6,7].With a view to elucidate the synthetic potential of cyclopropene I as cyclopropanating (prenylating) agent in reactions with olefins we examined reactions of I with cyclohexa-1,4-diene (II) and 2,6-dimethylhexa-2,4,6-triene (III, alloocimene). Compound II is a non-conjugated diene and is therefore incapable of undergoing cycloaddition according to Diels-Alder; on the other hand, it was expected to react following the Alder-ene reaction scheme. Conjugated triene III (which is always present in natural sources [8,9] and synthetic samples [10] as a mixture of E and Z isomers IIIa and IIIb) readily gives rise to Diels-Alder adducts with participation of only E isomer IIIa, whereas Z isomer IIIb (neoalloocimene) reacts only at elevated temperature after isomerization into the E isomer [11]. The failure of neoalloocimene to react according to the Diels-Alder pattern, which is typical of dienes with analogous configuration, is related to the fact that planar cisoid conformation of the diene fragment therein (which is necessary for such reactions) is unfavorable for steric reasons.The reactions of cyclopropene I with compounds II and III were carried out by heating the reactants at 100-120°C in an inert atmosphere in the presence of hydroquinone in a sealed ampule. According to the GC-MS data, the reaction mixture obtained from cyclopropene I and diene II contained mainly (~87%) a product with a molecular weight of 238.1470 (C 16 H 18 N 2 ) which corresponds to addition of two 1-methylcycloprop-2-ene-1-carbonitrile molecules to cyclohexa-1,4-diene. By column chromatography on silica gel the major product was isolated as a crystalline substance, and recrystallization from ethanol gave single crystals suitable for X-ray analysis. The X-ray

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Phytochemical, Morphological, and Molecular Evidence for the Occurrence of the Neotropical Liverwort Plagiochila stricta in the Canary Islands, New to Macaronesia

Abstract: Abstract. Plant material from the Canary Islands similar to

Cited by 32 publications

References 31 publications

The systematic position ofPlagiochila(Jamesoniella)dependula(Jungermanniopsida) inferred from nrITS sequences and morphology, with notes on its differentiation fromPlagiochila fuscolutea

The systematic position ofPlagiochila(Jamesoniella)dependula(Jungermanniopsida) inferred from nrITS sequences and morphology, with notes on its differentiation fromPlagiochila fuscolutea

Comparison of the essential oil composition of fourPlagiochila species:P. bifaria,P. maderensis,P. retrorsa andP. stricta

1-Methylcycloprop-2-ene-1-carbonitrile in tandem alder-ene and diels-alder reactions

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