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 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
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
龙舌兰科(Agavaceae)龙舌兰属(Agave)、万年兰属(Furcraea)和丝兰属(Yucca)的肉质植物不仅形态相像,而且在园林中常用的种类均为外来种,造成这类观赏植物的命名比较混乱。通过查阅植物志以及世界著名植物园的网站,归纳总结了3属植物的...龙舌兰科(Agavaceae)龙舌兰属(Agave)、万年兰属(Furcraea)和丝兰属(Yucca)的肉质植物不仅形态相像,而且在园林中常用的种类均为外来种,造成这类观赏植物的命名比较混乱。通过查阅植物志以及世界著名植物园的网站,归纳总结了3属植物的识别要点,并对照图片、形态描述及在广州园林中常用种类的标本,对6种常用肉质观赏植物:金边龙舌兰(Agave americana var.marginata)、银边狭叶龙舌兰(A. angustifolia‘Marginata’)、剑麻(A. sisalana)、黄纹缝线麻(Furcraea foetida‘Striata’)、黄边万年兰(F. selloa var. marginata)和凤尾丝兰(Yucca gloriosa)等进行正名和描述。考虑到这类植物一生只开花一次、花后死亡或能多次开花但周期长的特性,尝试从茎、叶等营养器官的差异编制检索表,便于园林工作者在园林设计、施工和养护管理时准确地识别应用。展开更多
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.
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）.
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.
文摘龙舌兰科(Agavaceae)龙舌兰属(Agave)、万年兰属(Furcraea)和丝兰属(Yucca)的肉质植物不仅形态相像,而且在园林中常用的种类均为外来种,造成这类观赏植物的命名比较混乱。通过查阅植物志以及世界著名植物园的网站,归纳总结了3属植物的识别要点,并对照图片、形态描述及在广州园林中常用种类的标本,对6种常用肉质观赏植物:金边龙舌兰(Agave americana var.marginata)、银边狭叶龙舌兰(A. angustifolia‘Marginata’)、剑麻(A. sisalana)、黄纹缝线麻(Furcraea foetida‘Striata’)、黄边万年兰(F. selloa var. marginata)和凤尾丝兰(Yucca gloriosa)等进行正名和描述。考虑到这类植物一生只开花一次、花后死亡或能多次开花但周期长的特性,尝试从茎、叶等营养器官的差异编制检索表,便于园林工作者在园林设计、施工和养护管理时准确地识别应用。
