Lignan, phenolic and iridoid glycosides from Stereospermum cylindricum

A lignan glycoside [(+)-cycloolivil 4'-O-beta-d-glucopyranoside], a phenolic glycoside [3,4-dimethoxyphenyl 1-O-beta-d-xylopyranosyl-(1-->6)-beta-d-glucopyranoside] and a iridoid glycoside (stereospermoside) were isolated from the leaves and branches of Stereospermum cylindricum, together with (+)-cycloolivil, (+)-cycloolivil 6-O-beta-d-glucopyranoside, (-)-olivil, (-)-olivil 4-O-beta-d-glucopyranoside, (-)-olivil 4'-O-beta-d-glucopyranoside, vanilloloside, decaffeoyl-verbascoside, isoverbascoside, 3,4,5-trimethoxyphenyl 1-O-beta-d-xylopyranosyl-(1-->6)-beta-d-glucopyranoside, ajugol, verminoside, and specioside. The structure elucidations were based on spectroscopic evidence.     

Lignan and megastigmane glycosides from Sauropus androgynus

A lignan diglycoside, (-)-isolariciresinol 3alpha-O-beta-apiofuranosyl-(1-->2)-O-beta-glucopyranoside, and a megastigmane glucoside, sauroposide, were isolated from the aerial part of Sauropus androgynus together with (+)-isolariciresinol 3alpha-O-beta-glucopyranoside, (-)-isolariciresinol 3alpha-O-beta-glucopyranoside, (+)-syringaresinol di-O-beta-glucopyranoside, guanosine and corchoionoside C. The structural elucidations were bases on analyses of physical and spectroscopic data.     

Unusual glycosides of pyrrole alkaloid and 4'-hydroxyphenylethanamide from leaves of Moringa oleifera

Glycosides of pyrrole alkaloid (pyrrolemarumine 4″-O-α-l-rhamnopyranoside) and 4′-hydroxyphenylethanamide (marumosides A and B) were isolated from leaves of Moringa oleifera along with eight known compounds; niazirin, methyl 4-(α-l-rhamnopyranosyloxy)benzylcarbamate, benzyl β-d-glucopyranoside, benzyl β-d-xylopyranosyl-(1 → 6)-β-d-glucopyranoside, kaempferol 3-O-β-d-glucopyranoside, quercetin 3-O-β-d-glucopyranoside, adenosine and l-tryptophan. Structure elucidations were based on analyses of chemical and spectroscopic data including 1D- and 2D-NMR.     

Triterpenoidal glycosides from Justicia betonica

dFrom the aerial portion of Justicia betonica L., four triterpenoidal glycosides (justiciosides A-D) were isolated. Their structures were established through chemical and NMR spectroscopic analyses as olean-12-ene-1beta,3beta,11alpha,28-tetraol 28-O-beta-D-glucopyranosyl-(1-->2)-beta-D-glucopyranoside, olean-12-ene-1beta,3beta,11alpha,28-tetraol 28-O-beta-D-glucopyranosyl-(1-->2)-beta-D-glucopyranosyl-(1-->2)-beta-D-glucopyranoside, 11alpha-methoxy-olean-12-ene-1beta,3beta,28-triol 28-O-beta-D-glucopyranosyl-(1-->2)-beta-D-glucopyranoside, 11alpha-methoxy-olean-12-ene-1beta,3beta,28-triol 28-O-beta-D-glucopyranosyl-(1-->2)-beta-D-glucopyranosyl-(1-->2)-beta-D-glucopyranoside, respectively.     

Cucurbitane, hexanorcucurbitane and octanorcucurbitane glycosides from fruits of Trichosanthes tricuspidata.

From the fruits of Trichosanthes tricuspidata, 14 cucurbitane glycosides (khekadaengosides A-J, M-N, cucurbitacin J 2-O-beta-glucopyranoside and cucurbitacin K 2-O-beta-glucopyranoside), a hexanorcucurbitane glucoside (khekadaengoside K) and octanorcucurbitane (khekadaengoside L) were isolated along with two known cucurbitane glucosides (cucurbitacin 2-O-beta-glucopyranoside and 25-O-acetyl-cucurbitacin 2-O-beta-glucopyranoside). Structural elucidations were based on chemical and spectroscopic analyses.     

Iridoid and phenolic diglycosides from Canthium berberidifolium

An iridoid diglycoside, 6-O-beta-D-apiofuranosyl-mussaenosidic acid, and four phenolic diglycosides, canthosides A-D, were isolated from the aerial part of Canthium berberidifolium, along with seven known compounds. Structural elucidations were based on analyses of spectroscopic data.     

Entrapment of 5‐aminolevulinic acid under edible composite film of konjac glucomannan and chitosan

5‐Aminolevulinic acid (5‐ALA) is a known plant regulator and growth promoter. It is a very sensitive and highly unstable compound that is easy to deteriorate. Here we propose a novel approach to stabilize 5‐ALA into a film. Films from konjac glucomannan (KGM), KGM treated with alkali solution (KGOH), chitosan (CHI) as well as blends between KGOH and CHI were fabricated for 5‐ALA entrapment. It was found that the efficiency of KGM film, KGOH film and CHI film for 5‐ALA entrapment was 55.7 ± 0.73%, 58.3 ± 0.36% and 60.3 ± 0.18 %, respectively. A 25:75 (%w/w) blended film (KGOH/CHI) showed the highest entrapment efficiency of 5‐ALA (65.9 ± 0.37%) versus other films. The possible mechanism for entrapment of 5‐ALA in blended film was postulated under two mechanisms. A secondary amide that leads to the interaction between the amino group of CHI and carboxyl group of 5‐ALA is proposed as the first mechanism. The fact that the 5‐ALA molecule was entrapped within the complexity of KGOH structure is proposed as the second mechanism. Therefore, stabilizing 5‐ALA in a film may be an alternative way to use and preserve 5‐ALA for further applications.     

Aromatic diglycosides from Cladogynos orientalis

Two unusual aromatic diglycosides with galloyl substitution, 4'-O-galloyl-violutoside and 4'-O-galloyl-benzyl-O-alpha-L-rhamnopyranosyl-(1-->6)-beta-D-glucopyranoside, were isolated from the aerial portion of Cladogynos orientalis along with isovitexin, apigenin 6-C-(2'-O-galloyl)-beta-D-glucopyranoside, apigenin 8-C-(2'-O-galloyl)-beta-D-glucopyranoside, syringic acid beta-D-glucopyranoside, 3,4,5-trimethoxyphenyl beta-D-glucopyranoside, (6S,9R)-roseoside, and violutioside. The structural elucidations were based on analyses of chemical and spectroscopic data by including 1D and 2D NMR analyses.     

Iridoid glucosides from Thunbergia laurifolia

Two iridoid glucosides, 8-epi-grandifloric acid and 3′-O-β-glucopyranosyl-stilbericoside, were isolated from the aerial part of Thunbergia laurifolia along with seven known compounds, benzyl β-glucopyranoside, benzyl β-(2′-O-β-glucopyranosyl) glucopyranoside, grandifloric acid, (E)-2-hexenyl β-glucopyranoside, hexanol β-glucopyranoside, 6-C-glucopyranosylapigenin and 6,8-di-C-glucopyranosylapigenin. Strucural elucidation was based on the analyses of spectroscopic data.