Crotofolane-Type Diterpenoids: Crotocascarins R-V, Rearranged Trinorcrotofolane: Crotocascarin δ and a Phorbol Derivative from the Leaves of Croton cascarilloides.

Five new crotofolanes, named crotocascarins R-V (1-5), one rearranged trinorcrotofolane, crotocascarin δ, and one phorbol derivative were isolated from the EtOAc-soluble fraction of the MeOH extract of the leaves of Croton cascarilloides. Crotocascarins R (1), T (3), and U (4) possessed isobutyric acid as an acyl moiety and crotocascarin B (2) an acetyl group, whereas crotocascarin V (5) was elucidated to be a hydroxylated compound of crotocascarin K at the 9-position. Crotocascarin δ (6) was a trinor rearranged crotofolane with a tertiary hemiketal functional group at the 8-position. The absolute configuration of the 8-position was determined by the comparison of the experimental electronic circular dichroism (ECD) spectrum and calculated ECD spectra. Compound 7 was a phorbol ester derivative with a peroxide functional group. The fatty acid attached at the 12-position was found to be a single species-i.e., lauric acid (C-12)-from the evidence of the mass spectral data.

Ardisiatetrons A and B: tetronic acid derivatives and triterpenes from the leaves of Ardisia quinquegona and their biological activity.

From the leaves of Ardisia quinquegona, two alkylated tetronic acid derivatives, named ardisiatetrons A and B (1, 2), and four triterpenoids (3-6) were isolated together with one known compound (7) by a combination of various kinds of chromatography. The structure of new methyl migrated triterpene (3) was confirmed by X-ray crystallographic analysis. Compounds 2, 3, and 7 showed moderate anti-Leishmania activity and cytotoxicity towards A549 cells.

Zanthosides A-D: Four Aromatic Glucosides from the Leaves of Zanthoxylum ailanthoides.

From the leaves of Zanthoxylum ailanthoides, four new phenolic glucosides, termed zanthosides A-D (1-4), were isolated. Their structures were elucidated by means of spectroscopic evidence. Zanthoside A was enzymatically hydrolyzed and thus the aglycone obtained was found to be (1'S,2'R)-(-)-trans-decursidinol, isolated from Angelica decursiva.

Alkylated Benzoquinones: Quinquequinones A­H from the Leaves of Ardisia quinquegona and Their Anti-Leishmania Activity [corrected].

Eight alkylated benzoquinone derivatives, named ardisiaquinones A-H, were isolated together with four known compounds from the leaves of Ardisia quinquegona using a combination of different chromatography techniques. Their structures were elucidated by spectroscopy and by the preparation of methyl ethers. Anti-Leishmania activity and cytotoxicity of the isolated compounds were assayed. Some compounds showed moderate anti-Leishmania activity, however, always associated with cytotoxicity.

Phenolic compounds from the leaves of Breynia officinalis and their tyrosinase and melanogenesis inhibitory activities.

From the EtOAc-soluble fraction of a MeOH extract of the leaves of Breynia officinalis, five new compounds (1-5) along with 11 known compounds (6-16) were isolated. The structures of the new compounds were elucidated by spectroscopic methods and compounds 1-3 were found to be acylated hydroquinone apiofuranosylglucopyranosides, while compound 4 was an acylated hydroquinone glucopyranoside. Compound 5 was shown to be butyl p-coumarate and this seems to be its first isolation from a natural source. The tyrosinase inhibitory activity of all of the isolated compounds was assayed, and the activity was significant in p-coumarate derivatives. The most active compound, compound 3, also inhibited melanogenesis in an in vivo whole animal model, zebrafish.

Microtropins Q-W, ent-Labdane Glucosides: Microtropiosides G-I, Ursane-Type Triterpene Diglucoside and Flavonol Glycoside from the Leaves of Microtropis japonica.

Microtropins Q-W, (2S,3R)-2-ethyl-2,3-dihydroxybutyrate of various glucosides and glucose, as well as three ent-labdane diterpenoid glucosides, named microtropiosides G, H and I, an ursane-type triterpene diglucoside and a flavonoid glycoside were isolated from the MeOH extract of the leaves of Microtropis japonica. The structure of microtropioside A, also isolated from the branches of M. japonica, was elucidated spectroscopically in a previous experiment and was found to possess a rare seven-membered oxyrane ring. Its structure was confirmed by X-ray crystallographic analysis of its pentaacetate.

Aliphatic Glucoside, Zanthoionic Acid and Megastigmane Glucosides: Zanthoionosides A-E from the Leaves of Zanthoxylum ailanthoides.

From the leaves of Zanthoxylum ailanthoides, 4'-O-p-E-coumaric acid esters of 2-propanol ß-D-glucopyranoside, megastigmane and megastigmane glucosides were isolated. Their structures were elucidated by spectroscopic evidence. The absolute configurations of the megastigmane and aglycone of megastigmane glucosides were determined by the octant rule and modified Mosher's method after protection of carboxylic acids by p-bromophenacyl esters and primary alcohols by pivaloyl esters.

Sulfated Glucosides of an Aliphatic Alcohol and Monoterpenes, and Megastigmanes from the Leaves of Meliosma pinnata spp. arnottiana.

Chemical study of the leaves of Meliosma pinnata spp. arnottiana afforded five sulfated glucosides of oct-1-en-3-ol (1) and cyclic linalool derivatives (2-5), and two megastigmanes (6, 7). Their structures were elucidated by extensive investigation of one- and two-dimensional NMR spectroscopic data, and the absolute structures of the megastigmanes were determined by the modified Mosher's method.

Megastigmane Glucosides and Megastigmanes from the Leaves of Meliosma lepidota ssp. squamulata.

From the leaves of Meliosma lepidota ssp. squamulata, megastigmane glucosides with spiro-structures and megastigmanes were isolated. Their structures were determined by X-ray crystallographic analyses and spectroscopic investigation. The absolute structures of the megastigmanes were determined by the modified Mosher's method.

Eight new diterpenoids and two new nor-diterpenoids from the stems of Croton cascarilloides.

From the stems of Croton cascarilloides, eight new diterpenoids, named crotocascarins A-H (1-8), having a crotofolane skeleton were isolated along with two new nor-diterpenoids (9 and 10), named crotocascarins α and ß, derived through rearrangement of the crotofolane skeleton. The structures of these compounds were elucidated by means of extensive one- and two-dimensional NMR spectroscopic analyses. The absolute structures of the diterpene moiety were determined by application of the circular dichroism (CD) rule for the γ-lactone ring. The relative structures of the two crotofolanes (1 and 2) and one rearranged compound (9) were confirmed by X-ray crystallographic analyses. Compounds 1, 2 and 9 possessed 2-methylbutyric acid in their molecules, the absolute configuration of which was found to be 2S by comparison of its HPLC behavior with that of an authentic sample. Therefore, the absolute structures of these crotocascarins (1, 2 and 9) were unambiguously determined. The absolute structures of crotofolanes are reported for the first time in this paper.

Tareciliosides N-S: further cycloartane saponins from the leaves of Tarenna gracilipes, and cytotoxicity of saponins and triterpenes.

Six cycloartane glycosides, named tareciliosides N-S, and a known iridoid glucoside, ixoroside, were isolated in further extensive studies on the 1-BuOH-soluble fraction of a MeOH extract of the leaves of Tarenna gracilipes. From the EtOAc-soluble fraction, three known triterpenes were isolated. Their toxicities toward A549 and Leishmania major trypanosome protozoa were assayed. Triterpenes were selectively active in the two organisms.

Glucosylated sesquiterpene alcohols from Fraxinus griffithii.

Phytochemical investigation of the leaves of Fraxinus griffithii has led to the isolation of two new glucosylated acyclic sesquiterpene alcohols, griffithosides D (1) and E (2), along with iridoid and secoiridoid glycosides. The molecular structures of these compounds were elucidated using NMR, MS and other spectroscopic techniques, as well as comparison with literature data. The isolated compounds were tested for radical-scavenging activity and cytotoxicity against A549 human lung adenocarcinoma cells and Leishmania major parasites.

Tareciliosides H-M: further cycloartane glycosides from leaves of Tarenna gracilipes.

From the 1-BuOH-soluble fraction of a MeOH extract of leaves of Tarenna gracilipes, collected in Okinawa, six further new cycloartane glycosides, named tareciliosides H-M (1-6), were isolated. Their structures were established through a combination of spectroscopic analyses.

Gallates of isoorientin and (2S)-1,2-propanediol glucoside from the leaves of Schoepfia jasminodora.

From the 1-BuOH-soluble fraction of a MeOH extract of the leaves of Schoepfia jasminodora collected from Okinawa Island, two new galloyl esters and 15 known compounds were isolated. The structures of the new compounds were elucidated by spectroscopic analysis to be isoorientin 4″-O-gallate and (2S)-1,2-propanediol 1-O-ß-D: -glucopyranoside 6'-O-gallate. The compounds possessing galloyl or cathechol moieties showed equal radical scavenging activity.

Tricalysionoside A, a megastigmane gentiobioside, sulfatricalysines A-F, and tricalysiosides X-Z, ent-kaurane glucosides, from the leaves of Tricalysia dubia.

Further isolation work on the water-soluble fraction of a MeOH extract of Tricalysia dubia afforded one new megastigmane gentiobioside, named tricalysionoside A (1), and three sulfates, named sulfatricalysines A-C (2-4). Extensive isolation work on the 1-BuOH-soluble fraction of a MeOH extract of T. dubia yielded sulfatricalysines D-F (5-7) and three new ent-kaurane glucosides, named tricalysiosides X-Z (8-10). The structures of the new compounds were elucidated by analyses of one- and two-dimensional NMR spectroscopic data. The absolute stereochemistry of tricalysionoside A (1) was established by modified Mosher's method.

Prenylated flavonoid glucoside and two aliphatic alcohol glycosides from the leaves of Euodia meliaefolia (Hance) Benth.

A new prenylated flavonoid (1) and two new aliphatic glycosides (2, 3) have been isolated from leaves of Euodia meliaefolia (Hance) Benth., together with three known compounds, (2R,3R)-5,7,4'-trihydroxy-8-(3-methylbut-2-enyl)dihydroflavonol 7-O-ß-D: -glucopyranoside (phellamurin) (4), (2R,3R)-dihydroquercetin 3'-O-ß-D: -glucopyranoside (5), and (7R,8S)-dihydrodiconiferyl alcohol 4-O-ß-D: -glucopyranoside (6). Their structures were determined on the basis of the results of spectroscopic analysis.

A glycerol α-D-glucuronide and a megastigmane glycoside from the leaves of Guettarda speciosa L.

From the 1-BuOH-soluble fraction of a MeOH extract of the leaves of Guettarda speciosa L., two new compounds (1, 2) were isolated together with six known compounds. Spectroscopic analysis of 1 and 2 established their structures to be derivatives of a glycerol α-glucuronide and a megastigmane glycoside, respectively. HPLC analysis of the hydrolyzate of 1 confirmed the presence of D-glucuronic acid in the structure, and the modified Mosher's method established the absolute structure of 2.

Crotonionosides A-G: megastigmane glycosides from leaves of Croton cascarilloides Räuschel.

From the 1-BuOH-soluble fraction of a MeOH extract of leaves of Croton cascarilloides, collected in Okinawa, Japan, seven megastigmane glycosides, named crotonionosides A-G, were isolated together with three known megastigmane glucosides, dendranthemosides A and B, and citroside A. This structures were elucidated by a combination of spectroscopic analyses, HPLC analyses, and application of the modified Mosher's method.

Schefflerins A-G, new triterpene glucosides from the leaves of Schefflera arboricola.

From the 1-BuOH-soluble fraction of a MeOH extract of leaves of Schefflera arboricola, collected in Okinawa, six new lupane glucosides, named schefflerins A-F (1-6) and one new dammarane glucoside, named schefflerin G (7), were isolated together with three known compounds, citroside A (8), and oleanane saponins, oleanolic acid (9) and echinocystic acid (10) 3-O-α-L-rhamnopyranosyl(1→4')-O-ß-D-glucuronopynosides. Their structures were elucidated through a combination of spectroscopic analyses and the structure of schefflerin F (6) was determined by X-ray crystallographic method using SPring-8 synchrotron radiation.

Crotalionosides A-C, three new megastigmane glucosides, two new pterocarpan glucosides and a chalcone C-glucoside from the whole plants of Crotalaria zanzibarica.

From a 1-BuOH-soluble fraction of the MeOH extract of the leaves of Crotalaria zanzibarica collected in the Okinawa Islands, three new megastigmane glucosides, named crotalionosides A-C, two new pterocarpan glucosides and a chalcone C-glucoside were isolated together with two known flavonoid glycosides and one known megastigmane glucoside. The structures of the new compounds were elucidated by a combination of spectroscopic analyses. The absolute configurations of allenic megastigmane glucosides were determined by application of the modified Mosher's method. Those of the allenic moieties were determined by interpretation of the circular dichroism (CD) spectra of the reduction products derived from citrosides A and B. The aglycones of pterocarpan glucosides were found to be melilotocarpan B and the absolute structure of the chalcone C-glucoside was determined by comparison of the CD spectral behavior with the reported values.