Steroidal sapogenins. LVIII. Steroidal sapogenins from the Joshua tree

The Joshua tree,Yucca brevifolia, is distributed over parts of Arizona, California, Nevada, and Utah. A study of its steroidal sapogenins showed that the leaves contain practically none; the wood, small amounts of smilagenin; the seeds high amounts of hecogenin and tigogenin.     

Steroidal sapogenins from leaves of some species of Agave and Furcraea

The steroidal sapogenins yielded by the leaves of Agave aurea, A. avellanidens, A. cerulata, A. cerulata ssp. subcerulata, A. cocui, A. goldmaniana, A. shawii and Furcraeamacrophylla are recorded. In all these species, hecogenin and tigogenin were the major sapogenins isolated. Gitogenin was found in the extracts of all the leaf samples, except that of A. shawii, and manogenin and 9-dehydromanogenin in all but that of A. cocui. Chlorogenin was isolated from A. cocui, but was not detected in any of the other species examined. Qualitative and quantitative variations were found in the sapogenin contents of extracts of different regions of the same leaves of A. cocui and F. macrophylla. In particular, hecogenin predominated in the basal regions and tigogenin in the apical.     

Steroidal glycosides from Agave cantala.

Two new steroidal glycosides, agaveside A and B, isolated from the fruits of Agave cantala were characterized as 3 beta-O-[beta-D-xylopyranosyl-(1----2),beta-D-xylopyranosyl-(1----3), beta-D-glucopyranosyl-(1----3)-[beta-D-xylopyranosyl-(1----3)-beta-D- galactopyranosyl-(1----2)]-beta-D-glucopyranosyl]-(25R)-5 alpha-spirostane and 3 beta-O-[beta-D-xylopyranosyl-(1----2), beta-D-xylopyranosyl-(1----3)-beta-D-glucopyranosyl-(1----3)- [beta-D-galactopyranosyl-(1----2)]-beta-D-glucopyranosyl]-(25R)-5 alpha-spirostane. The structures were elucidated by a combination of 13CNMR spectroscopy, chemical degradation and fast atom bombardment mass spectrometry.     

Steroidal sapogenins. LXI. steroidal sapogenin content of seeds

A number of Yucca, Agave and Nolina seeds have been analyzed for steroidal sapogenins. The content of sapogenins in the seeds of several Yucca species is particularly high.     

Steroidal sapogenins from leaves of Agaveae species

The steroidal sapogenins yielded by the leaves of 34 species and 1 cultivar of Agave, 1 species of Beschorneria, 1 species of Doryanthes and 3 species of Furcraea have been studied. Steroidal sapogenins were found in extracts of most of the species examined. Smilagenin, sarsasapogenin, diosgenin, yamogenin, tigogenin, neotigogenin, gloriogenin, gentrogenin, hecogenin, sisalagenin, 9-dehydrohecogenin and gitogenin were detected. Gloriogenin was found only in A. ghiesbrechtii, yamogenin in A. horrida and A. rigidissima, neo-tigogenin in A. horrida and A. toneliana and gitogenin in A. filifera, F. cabua, F. gigantea and F. selloa cv marginata. The highest yield of smilagenin was obtained from both A. haynaldii and A. rigidissima, of sarsasapogenin from A. attenuata, of diosgenin from A. ellemeetiana, of tigogenin from A. haynaldii and of hecogenin from F. cabua.     

Post-harvest growth of Lechuguilla (Agave lecheguilla torr., Agavaceae) in Northeastern Mexico

Extraction of lechuguilla fiber (Agave lecheguilla) is often the only source of income for some rural inhabitants in arid zones of Mexico. A model for biomass estimation of lechuguilla by nondestructive techniques was developed and then applied to evaluate whether traditional harvesting had an effect on (1) biomass production of the bud (part of the plant traditionally collected to obtain fiber) and (2) plant density. Six months after harvesting, biomass production was higher for buds of harvested plants than for buds of unharvested plants, but there were no differences 1 year after harvesting. Number of new plants was not affected by harvesting. Hence it appears that at least in the short term the common practice for extracting lechuguilla fiber does not affect population density, but significantly increases growth of central buds.     

龙舌兰发酵叶汁中的一个新甾体皂苷

从龙舌兰（Agave americana)的发酵叶汁中分离到一个新甾体皂苷。结合波谱和化学方法,新化合物的结构鉴定为替告皂苷元3－O－α－L－鼠李吡喃糖基－（1→3)－β-D-葡萄吡喃糖基－（1→2）-[β-D-葡萄吡喃糖基－（1→3)-β－D－葡萄吡喃糖基－（1→4）－β－D－半乳吡喃糖苷。     

The occurrence of dicotyledonar embryos in Agave tequilana

Agave tequilana Weber is a monocot plant species member of the Asparagaceae family. One of the characteristics of monocot species is that their embryos show only one cotyledon. In this work, the occurrence of embryos with two cotyledons and fused cotyledons in A. tequilana is reported for the first time. The occurrence of dicotyledonar embryos in a species that by definition should have only one cotyledon could bring an opportunity to elucidate the mechanisms that have given the origin to the only one cotyledon present in monocots. Syncotyly is considered in this work as the possible mechanism that gave rise to the only cotyledon mostly present in this species.     

A New Steroidal Saponin from Fermented Leaves of Agave americana*

A new steroidal saponin and two known steroidal compounds were isolated fermented leaves of Agaue americana .The structufe of the new steroidal saponin was elucidated as tigogenin 3-0-a-L-rham-nopyranosyl-(1→3)-β-D-glucopyranosyl-(1→2)-]β-D-glucopyranosyl-(1→3)-β-D-glucopyranosyl-(1→4)-β-D-giucopyranoside dy spectroscopic data and chemical method .     

Protokoll der LXVIII. Monats-Sitzung

Ohne Zusammenfassung     

A morphometric analysis of a putative hybrid between Agave marmorata Roezl and Agave kerchovei Lem.: Agave peacockii Croucher

A supposed hybrid population ( Agave peacockii ) between Agave marmorata and Agave kerchovei in a semiarid ecosystem at Zapotitlán Salinas, in the Mexican State of Puebla, was investigated, and its hybrid status corroborated in morphometric terms. A Stepwise Discriminant Analysis of the ratios: Number of leaved Rosette diameter, Leaf width/Leaf length, Number of spines/Leaf length, Distance between the upper spine and the tip of the leaf/Leaf length, and Distance between the upper spine and the tip of the leaf/Number of spines, supported our hypothesis of the existence of these naturally occurring hybrids, which are intermediate and distinct from the parental species. A null model was constructed to contrast the real case with a possible artifact, and the results also supported our hypothesis. The possible meaning of this kind of hybridization is discussed.     

Bile acids. LXVIII. Allylic and benzylic photo-chemical oxidation of steroids

To provide 7-oxocholesterol derivatives in yields superior to those obtained by chemical oxidation, the preparation of steroidal allylic or benzylic ketones was studied. Air-induced oxidation was investigated with a highly selective low energy UV lamp in the presence of mercuric bromide. With this procedure cholesteryl acetate, 5-cholestene-3β, 27-diol diacetate, 24(R)-24-methyl-5-cholesten-3β-yl acetate, 24(R)-24-ethyl -5-cholesten-3β-yl acetate and 24(R)-24-ethyl-(22E)-cholesta-5, 22-dien -3β-yl acetate were oxidized to the allylic keto-derivative in good yields; estradiol-17β diacetate was similarly converted to the 6-oxo-product in improved yield. This method can be very useful in the synthesis of 7-oxocholesteryl acetate and its analogs and 6-oxoestratrienes.     

Ethnobotany ofAgave lecheguilla andYucca carnerosana in Mexico’s Zona ixtlera

In the drylands of northcentral Mexico campesinos known as ixtleros or talladores gather ixtle, a hard fiber derived from the uncultivated plants lechuguilla (Agave lecheguilla Torr.), and palma samandoca (Yucca carnerosana [Trel.] McKelv.). Ixtleros sell most of the fiber they collect, and the region in which ixtle is currently exploited for commercial purposes is called the Zona Ixtlera. Unsold fiber is converted into rope and brushes in ixtlero communities and used for a variety of purposes. Various parts of lechuguilla and palma samandoca are also employed to meet local construction, cleansing, and dietary needs.