Agave americana Var. Marginata Hort. （Agavaceae） is a perennial herb. This paper summarized its classification, distribution, morphological characteristics, habit, flowering and fruiting, cultivation and reproductio...Agave americana Var. Marginata Hort. （Agavaceae） is a perennial herb. This paper summarized its classification, distribution, morphological characteristics, habit, flowering and fruiting, cultivation and reproduction, as well as multiple uses in daily life, which provided references for the exploitation and utilization of Agave americana Vat. Marginata Hort. （Agavaceae）.展开更多
Two new C-22 steroidal lactone glycosides, named dracaenoside A and B were isolated from the methanol extract of the fresh stem of Dracaena cochinchinensis. Their structures were established as (20S)3b,14a,16b-trihyd...Two new C-22 steroidal lactone glycosides, named dracaenoside A and B were isolated from the methanol extract of the fresh stem of Dracaena cochinchinensis. Their structures were established as (20S)3b,14a,16b-trihydroxy pregn-5-ene-22-carboxylic acid (22,16)-lactone 3-O-a- L-rhamnopyranosyl (1→2)[ a-L-rhamnopyranosyl (1→4)]-b-D-glucopyranoside and (20S)3b, 14a, 16b-trihydroxy pregn-5-ene-22-carboxylic acid (22,16)-lactone 3-O-a-L-rhamnopyranosyl (1→2) [b-D-glucopyranosyl(1→3)]-b-D-glucopyranoside by means of 2D NMR spectral and chemical methods. It is the first time that steroidal lactone glycosides were isolated from the genus Dracaena.展开更多
Agave guiengola Gentry is an endemic plant from a very small locality in Oaxaca,Mexico.Its conservation status is fragile and can rapidly worsen.Because of its scarcity,this agave has been used solely for ornamental p...Agave guiengola Gentry is an endemic plant from a very small locality in Oaxaca,Mexico.Its conservation status is fragile and can rapidly worsen.Because of its scarcity,this agave has been used solely for ornamental purposes,but it could have other uses if more plants were available.In vitro propagation by enhanced axillary sprouting from stem segments was attained using Murashige and Skoog Basal Medium(MS)as well as basal medium supplemented with cytokinins 6-Benzylaminopurine(BA)or 6-(γ,γ-Dimethylallylamino)purine(2iP).The best treatment for shoot induction in semisolid medium consisted in MS supplemented with 2 mg l^(–1) BA,obtaining a mean of 3.7 shoots per explant.Other interesting responses were observed,such as nodular callus induction using combinations of BA and 2,4-Dichlorophenoxyacetic acid(2,4-D);root induction without Plant Growth Regulators(PGR);and generation of shoot clusters.These clusters constituted an excellent explant for micropropagation in temporary immersion bioreactors,obtaining a propagation rate of 43 shoots per explant with 1 min immersion and 6 h immersion frequencies.All new plants rooted and survived the transfer to soil.This study developed an in vitro propagation scheme to produce individuals that can be used either for reforestation,economical purposes,or to carry out studies in this species to assess its full potential,avoiding exploitation from wild plants.展开更多
文摘Agave americana Var. Marginata Hort. （Agavaceae） is a perennial herb. This paper summarized its classification, distribution, morphological characteristics, habit, flowering and fruiting, cultivation and reproduction, as well as multiple uses in daily life, which provided references for the exploitation and utilization of Agave americana Vat. Marginata Hort. （Agavaceae）.
文摘Two new C-22 steroidal lactone glycosides, named dracaenoside A and B were isolated from the methanol extract of the fresh stem of Dracaena cochinchinensis. Their structures were established as (20S)3b,14a,16b-trihydroxy pregn-5-ene-22-carboxylic acid (22,16)-lactone 3-O-a- L-rhamnopyranosyl (1→2)[ a-L-rhamnopyranosyl (1→4)]-b-D-glucopyranoside and (20S)3b, 14a, 16b-trihydroxy pregn-5-ene-22-carboxylic acid (22,16)-lactone 3-O-a-L-rhamnopyranosyl (1→2) [b-D-glucopyranosyl(1→3)]-b-D-glucopyranoside by means of 2D NMR spectral and chemical methods. It is the first time that steroidal lactone glycosides were isolated from the genus Dracaena.
基金This work was supported financially by project AGS-2015-02-01-267656,Fondo Mixto CONACYT-Gobierno del Estado de Aguascalientes,and project PIBT-18-2,Universidad Autónoma de Aguascalientes,México.
文摘Agave guiengola Gentry is an endemic plant from a very small locality in Oaxaca,Mexico.Its conservation status is fragile and can rapidly worsen.Because of its scarcity,this agave has been used solely for ornamental purposes,but it could have other uses if more plants were available.In vitro propagation by enhanced axillary sprouting from stem segments was attained using Murashige and Skoog Basal Medium(MS)as well as basal medium supplemented with cytokinins 6-Benzylaminopurine(BA)or 6-(γ,γ-Dimethylallylamino)purine(2iP).The best treatment for shoot induction in semisolid medium consisted in MS supplemented with 2 mg l^(–1) BA,obtaining a mean of 3.7 shoots per explant.Other interesting responses were observed,such as nodular callus induction using combinations of BA and 2,4-Dichlorophenoxyacetic acid(2,4-D);root induction without Plant Growth Regulators(PGR);and generation of shoot clusters.These clusters constituted an excellent explant for micropropagation in temporary immersion bioreactors,obtaining a propagation rate of 43 shoots per explant with 1 min immersion and 6 h immersion frequencies.All new plants rooted and survived the transfer to soil.This study developed an in vitro propagation scheme to produce individuals that can be used either for reforestation,economical purposes,or to carry out studies in this species to assess its full potential,avoiding exploitation from wild plants.
