Massayoshi Yoshida

Antimalarial use of volatile oil from leaves of Virola surinamensis (Rol.) Warb. by Waiapi Amazon Indians

The Amazon Indians Waiãpi living in the West of Amapá State of Brazil, treat malaria with an inhalation of vapor obtained from leaves of Viola surinamensis. The essential oil obtained from adult and plantlet leaves was analyzed by GC/MS and 11 monoterpenes, 11 sesquiterpenes and three phenylpropanoids were identified. Plantlet essential oil caused 100% of growth inhibition after 48 h in the development of the young trophozoite to schizont stage and the sesquiterpene nerolidol (100 microg/ml) was identified as one of the active constituents (100% of growth inhibition was obtained). In addition, examination of [U14C]-glucose incorporation showed that activity of nerolidol is related to the inhibition of glycoprotein biosynthesis.

6-[ω-arylalkenyl]-5,6-dihydro-α-pyrones from Cryptocarya moschata (Lauraceae)

Eleven 6-[omega-arylalkenyl]-5,6-dihydro-alpha-pyrones, cryptomoscatones D2, E1, E2, E3 and F1 and cryptopyranmoscatones A1, A2, A3, B1, B2 and B4, in addition to goniothalamin and cryptofolione, were isolated from branch and stem bark of Cryptocarya moschata, Lauraceae. Their structures were established by spectroscopic methods.

Dibenzylbutyrolactone lignans from Virola sebifera

Abstract The fruits of Virola sebifera contain in the seed (2R, 3S)-3-(3,4-dimethoxybenzyl)-2-(3,4-methylenedioxybenzyl)-butyrolactone, in the pericarp (2R, 3R)-3-(3,4-dimethoxybenzyl)-2-(3,4-methylenedioxybenzyl)-butyrolactone, (2R, 3R)-2,3-di-(3, 4-dimethoxybenzyl)-butyrolactone and (2R, 3R)-2,3-di-(3,4-methylenedioxybenzyl)-butyrolactone.

Benzodioxane and β-aryloxy-arylpropane type neolignans from Licaria chrysophylla☆

Abstract Bark and fruit calyx of Licaria chrysophylla were found to contain five new benzodioxane type neolignans (eusiderins I, J, K, L, M), three new β-aryloxy-arylpropane type neolignans (virolongins E, F, G), besides dihydroconiferyl alcohol and its oxidative dimer dihydro-dehydrodiconiferyl alcohol.

Lipophyllic antioxidants from Iryanthera juruensis fruits

The phytochemical investigation of the hexane extract of Iryanthera juruensis (Myristicaceae) fruits led to the isolation of two tocotrienols and four lignans which exhibited antioxidant activity towards beta-carotene on TLC autographic assay. Two inactive quinones and three omega-arylalkanoic acids were also isolated. The isolates were investigated for their redox properties using cyclic voltammetry. The structure elucidation of the new compounds (one tocotrienol. one quinone and three omega-arylalkanoic acids) was based on analysis of spectroscopic data.

ω-ethyl, ω-ethenyl and ω-ethynyl-α-alkylidene-γ-lactones from Clinostemon mahuba

Abstract The trunk wood of Clinostemon mahuba contains eight (3R)-2-alkylidene-3-hydroxy-4-methylenebutanolides, seven (3R,4S)-2-alkylidene-3-hydroxy-4-methylbutanolides and seven (3S,4S)-2-alkylidene-3-hydroxy-4-methylbutanolides distinguished by the alkylidene side chains with respect to their E- or Z-geometry, ethenyl, ethynyl or ethyl terminals and lengths (C16 or C18).

Aryltetralone and arylindanone neolignans from Virola sebifera

Abstract The fruits of Virola sebifera contain several tetralone neolignans, including 2,4-dihydroxy-6,7-methylenedioxy-2,3-dimethyl-4-veratryltetralin-1-one. The 3-hydroxylated derivative of this compound may undergo a biosynthetic pinacol-pinacolone rearrangement to give 2-acetyl-3-hydroxy-2-methyl-5,6-methylenedioxy-3-veratrylindan-1-one which, together with other indanone neolignans, was also isolated.

Lignoids and arylalkanones from fruits of Virola elongata.

Abstract From the fruits of two Amazonian specimens of Virola elongata 52 compounds were isolated, 19 lignans, including six diarylfurofurans, two aryl-hydroxybenzylmethylfurans, three aryl-benzyl-hydroxymethylfurans, one dibenzylbutanodiol and seven dibenzylbutyrolactones; 25 neolignans, including six dibenzylbutanes, two aryl-dimethyltetralins, two aryl-dimethyldihydronaphthalenes, one aryl-dimethylnaphthalene, nine aryl-dimethyltetralones, two aryl-methylindanones, two aryl-dimethylsecotetralins and one dimer, eight arylalkanones, including two acylresorcinols, two acylphloroglucinols, one arylacylresorcinol, two arylacylphloroglucinols and one arylacyl-hydroxycyclohexadione. The distribution pattern in the fruit pericarp, aril, seed coat and kernel reveals the ecological role of these constituents.

Benzoyl esters and amides, styrylpyrones and neolignans from the fruits of Aniba riparia

Abstract The fruits of Aniba riparia contain a series of benzyl esters and phenylethyl amides of benzoic acids, accompanied by styrylpyrones and neolignans. This is the first report on the co-occurrence of representatives of the two latter classes of natural products in the same species.

Acylresorcinols from Virola sebifera and Virola elongata

Abstract The fruits of Virola sebifera and V. elongata (Myristicaceae) contain three ω-phenylundecanoyl-substituted compounds, a 2,6-dihydroxybenzene, a 2,6-dihydroxy-4-methoxybenzene and a 3-hydroxycyclohexan-2,6-dione. Three additional 2,6-dihydroxybenzenes are substituted by hexadecanoyl, hexadec-4 Z -enoyl and 8-hydroxyoctadec-4 Z -enoyl groups.