Seven aristololactams from Aristolochia argentina

Seven aristololactam alkaloids were isolated from Aristolochia argentina. Five are reported for the first time.     

Argentilactone,a novel 5- hydroxyacid lactone from Aristolochia argentina

Argentilactone, a new constituent of the rhizomes of Aristolochia argentina, was isolated and characterized as the (?)-(5R)-δ-lactone of 5-hydroxydodeca-Z,Z-2,6-dienoic acid.     

Aristololactams of Aristolochia argentina

Four new lactams have been isolated and characterized from the roots of Aristolochia argentina.     

Aristoloside,an aristolochic acid derivative from stems of Aristolochia manshuriensis

Aristoloside, a new companion aristolochic acid derivative isolated from stems of Aristolochia manshuriensis has been shown to be 6-O-β-d-glucopyranoside of aristolochic acid-D on chemical and physicochemical evidence. Three known acids, aristolochic acids I, IV (both as their corresponding methyl esters), and -D have also been characterized from stems of the plant.     

Two diterpene alcohols from Croton sublyratus

The isolation and structural elucidation of two diterpene alcohols from Croton sublyratus are described. These compounds are ent-3α-hydroxy-13-epimanool and ent-16β,17-dihydroxykaurane.     

16-Epivenenatine and 16-epialstovenine,new stereomers from Alstonia venenata

16-Epivenenatine and 16-epialstovenine have been isolated from Alstonia venenata. The structures and stereochemistry of these two new bases have been determined from spectral analysis, chemical studies and correlation experiments with venenatine and alstovenine.     

A diterpene acid from baccharis tucumanensis

The new clerodane diterpene 1 was isolated from the aerial parts of Baccharis tucumanensis (Compositae). Its structure has been determined from spectral data combined with chemical transformations.     

Phenolic meroterpenoids from the basidiomycete Albatrellus ovinus

From the lipophilic fraction of fresh Albatrellus ovinus, the following substances were isolated and identified: E,E-5-methyl-2-(3,7,11 -trimet     

Rivularinin,a new saponin from Anemone rivularis

A new saponin, rivularinin, has been isolated from the ethanolic extract of Anemone rivularis (Ranunculaceae). The saponin was shown to be [α-l-arabinofuranosyl(1→2)-α-l-rhamnopyranosyl (1→4)-β-d-glucopyranosyl(1→4)-β-d-glucuronopyranosyl(1→3)]-3β-hydroxy-olean-12-en-28-oic acid.     

Two new diterpene-based alkaloids from Icacina guesfeldtii

From Icacina guesfeldtii (leaves and roots), two new diterpene-based alkaloids have been isolated and identified as icaceine (2) and De-N-methylicaceine (3). Icacine (1) occurred both in the leaves and roots. Structure determination was performed by spectroscopic and chemical methods. As icacine (1), these two bases are the first alkaloids with a pimarane skeleton isolated from plants.     

Muellitol,a novel trialkenyl inositol from Evodiella muelleri

Muellitol has been isolated from the leaves of Evodiella muelleri and the structure established as 1,3,5-tri-(3-methyl-2-butenyl)cyclohexane-r-1-t-2-c-3-t-4-c-5-t-6-hexol. Chemical and spectroscopic examination of the compound and its derivatives showed it to be conformationally similar to scyllitol. This is the first report of the natural occurrence of a triprenylinositol.     

Glycoproteins from Ustilago tritici

A complex mixture of glycoproteins has been isolated from Ustilago tritici cells obtained from diseased Triticum vulgaris plants. Composition analysis and hemagglutination inhibition assay of the purified material shows the presence of an unusual glycoprotein in tbe fungal spore.     

Structural studies on some saponins from Lecaniodiscus cupanioides

Four triterpenoid saponins isolated from the stem bark of Lecaniodiscus cupanioides and denoted S-2,S-3,S-4 and S-5, were identified as follows. S-2:3-O-[α-l-arabinopyranosyl-(1→3)-α-l-rhamnopyranosyl-(1→2)-α-l-arabinopyranosyl]-hederagenin; S-3:3-O-[α-d-xylopyranosyl-(1→3)-α-l-rhamnopyranosyl-(1→2)-α-l-arabino-pyranosyl ]-hederagenin; S-4:3-O- [α-l-arabinopyranosyl-(1→3)-α-l-rhamnopyranosyl-(1→ 2)-α-l-arabinopyranosyl]-hederagenin; S-5:3-O- [α-l-rhamnopyranosyl-(1→2)-α-l-arabinopyranosyl ]-hederagenin. Of these, S-2 and S-4 are new substances.     

Trichoclin,a new furocoumarin from trichocline incana

The structure for trichoclin, (E)-8-(3-methyl-4-hydroxy-2-butenyloxy)-psoralen, a new furocoumarin isolated from Trichocline incana, has been established. Phellopterin and isopimpinellin were also obtained. The new side chain of trichoclin was confirmed by synthesis.     

Tropane alkaloids from Anthocercis and Anthotroche

In addition to known tropane alkaloids, 3α-iso-butyryloxytropan-6β-ol and 3α-n-butyryloxytropane have been characterized as respective components of the aerial parts of two subspecies of Anthocercis albicans. Aponoratropine, not previously recorded as a natural product, has been detected in the leaves of Anthotroche myoporoides and A. walcottii; similarly aponorhyoscine is indicated as a component of the roots of a subspecies of Anthocercis genistoides.     

Two new steryl glycosides from Lindenbergia indica

Two new saponins, α-L-rhamnopyranosyl (1 → 4) β-D-glucopyranosyl (1 → 3)sitosterol and α-L-rhamnopyranosyl (1 → 5) α-L-arabinofuranosyl (1 → 3)sitosterol, have been reported from Lindenbergia indica.     

Pterocarpans of Neorautanenia edulis and N. Amboensis

The root bark of Neorantanenia edulis and N. amboensis yielded six new natural pterocarpanoids, the structures of which have been determined mainly by physical methods and by partial syntheses. They include edulane, edudiol, neoraucarpan, neorautanin, edulenol, and neoraucarpanol.     

Metabolites of Cercospora. Taiwapyrone,an α-pyrone of unusual structure from Cercospora taiwanensis

(+)-Mellein (1), cis-3S,4S-4-hydroxymellein (3), and taiwapyrone (4), a new α-pyrone, have been isolated from the mycelium of Cercospora taiwanensis, grown on potato-agar. The structure and absolute configuration of (3) and (4) have been elucidated.     

Antitumor alkaloids in callus cultures of Cephalotaxus harringtonia

Leaves and stems of Cephalotaxus harringtonia were induced to callus on Murashige and Skoog medium supplemented with additional vitamins, hypoxanthine, naphthaleneacetic acid and kinetin. Analysis by GC-MS showed cephalotaxine and its antitumor esters (harringtonine, isoharringtonine and homoharringtonine) in both callus and medium, whereas deoxyharringtonine was present (in relatively large amounts) only in the medium. The amount of each alkaloid was 2 to 6 times greater at 6 months than at 3 months except for deoxyharringtonine, which was not increased. At 6 months, the total alkaloid production was 1–3% of levels reported for mature trees, but the pattern was the same: 60% cephalotaxine, 40% esters. The pattern of the parent plant was unique (5% cephalotaxine, 80% homoharringtonine, 15% other esters) and may more accurately represent that of fresh plant material. A new cephalotaxine ester, homodeoxyharringtonine, was also detected in the culture medium.