New sesquiterpene hydroxylactones from Lactarius species

Four γ-hydroxybutenolide sesquiterpenes have been isolated from Lactarius scrobiculatus, L. blennius and L. pallidus. Their structures and absolute stereochemistry were determined by spectral data and by conversion to known compounds.     

Stereochemistry of blennin A and blennin D from Lactarius blennius

From the ethanolic extract of Lactarius blennius, a new sesquiterpene blennin D (2-hydroxyblennin A) was isolated and its structure elucidated together with the stereochemistry of the already known blennin A. Treatment of blennin A mesylate with DBU afforded a compound with a new skeleton.     

Desangeloylshairidin,a sesquiterpene lactone from Guillonea scabra

From the roots of Guillonea scabra a new sesquiterpene lactone has been isolated. Its structure has been established by spectroscopic means as desangeloylshairidin.     

l-2-Amino-4-methylpimelic acid: A new amino acid from Lactarius species

A PC survey revealed the occurrence of an unusual amino acid in fruit bodies of the mushroom Lactarius quietus Fr. and a related species. This was identified as l-2-amino-4-methylpimelic acid, which has not been previously reported as a naturally occurring compound.     

A new sesquiterpene lactone from Elephantopus scaber

A methanolic extract of the plant Elephantopus scaber was found to contain lupeol, stigmasterol and a new germacranolide dilactone 11,13-dihydrodeoxyelephantopin.     

Sesquiterpenes from Lactarius blennius

Six sesquiterpene lactones were isolated from Lactarius blennius. The structures of two new sesquiterpenes, blennin A and blennin B were determinated by spectroscopic methods and the structure of the seco-compound, blennin C, is revised. The two known furan sesquiterpenes and lactarorufin A were also identified.     

15-oxo-zoapatlin,a diterpene lactone from Viguiera maculata

The isolation of a new diterpene lactone and two known diterpenoid acids from the aerial parts of Viguiera maculata is reported.     

Argophyllone-B,a sesquiterpene lactone from Helianthus argophyllus

The sesquiterpene lactone, 2-methyl-2-butenoic acid dodecahydro-4-(hydroxymethyl)-10a-methyl-8-methylene-3,7-dioxooxineno[5,6]cyclodeca[1,2-b]furan-9-yl ester [1aR^*-[1aS^*,4R^*,5aS^*,8aR^*,9R^*(E)]], argophyllone-B, was isolated from acetone extracts from the leaves of Helianthus argophyllus. Its structure has been determined by single crystal X-ray analysis. Complete ¹H NMR and ¹³C NMR assignments have been made.     

Hypochaerin: a new sesquiterpene lactone from Hypochaeris setosus

Hypochaeris setosus contains desacetoxymatricarin, achillin, 1-hydroxy-6β,7α,11β-H-eudesm-4-en-6,12 olide, jacquinelin and hypochaerin, a new guaianolide, established as 3-oxo-4β,5α,6β,7α,11β-H-guai-1(2)-en-6,12 olide.     

Angeloylcumambrin-B,an antimicrobial sesquiterpene lactone from Chrysanthemum ornatum var. Spontaneum

Angeloylcumambrin-B, a new antimicrobial guaianolide sesquiterpene lactone, was isolated from Chrysanthemum ornatum and the structure was determined by a combination of chemical and physical methods.     

1,2-Dehydrolactarolide A, a new plant growth regulatory lactarane sesquiterpene from Lactarius vellereus

A new lactarane sesquiterpene, 1,2-dehydrolactarolide A (1), together with lactarorufin A (2), 3-O-ethyllactarolide A (3) and 3-O-ethyllactarolide B (4), was isolated from a mushroom of the Russulaceae family, Lactarius vellereus. Additionally, two lactarane sesquiterpenes, lactarorufin A (2) and lactarolide A (5) were isolated from L. subpiperatus. 1,2-Dehydrolactarolide A (1) showed promotional activity (152% at 3.6 x 10(1) microM) toward radicle elongation in lettuce seedlings.     

11β,13-Dihydrolactucin,a sesquiterpene lactone from Launaea mucronata

The roots of Launaea mucronata afforded, in addition to lactucin, lactucin-8-O-acetate and the corresponding dihydro derivative, 11β,13-dihydrolactucin.     

A new triterpene lactone from Gymnocladus dioica

2β,23-Dihydroxyacacic acid lactone was isolated from Gymnocladus dioica as an artifact from 2β, 3β 16β, 21β, 23-pentahydroxyolean-12-ene-28-oic acid.     

Arteannuin-C,a sesquiterpene lactone from Artemisia annua

Artemisia annua, a medicinal plant native to China has been introduced into India. In addition to known monoterpenoids, novel sesquiterpenoids including artemisinin, arteannuin-B and flavonoids the plant yielded a new sesquiterpene lactone now named as arteannuin-C.     

A further sesquiterpene lactone esterified with a sesquiterpenic acid

The roots of Hypochoeris oligocephala afforded in addition to known compounds a further sesquiterpene lactone esterified with a sesquiterpenic acid as well as the corresponding free acid.     

Three new sesquiterpene lactone dimers from Carpesium faberi

Three new 2,4-linked sesquiterpene lactone dimers (SLDs), faberidilactones F-H (1–3), have been isolated from Carpesium faberi. Unlike 1 and 2, 3 was a modified Diels-Alder adduct, characteristic by a 1′-OH and a Δ^5′(6′) double bond. Furthermore, the relative configuration of 1′-OH in 3 was assigned as β-configuration by comparison the experimental NOESY data with those of its two possible epimers. The exo/endo stereochemistry of 1–3 was determined by the spectrographic features of 2,4-linked SLDs that we discovered in our previous works. Compounds 1 and 2 showed potent cytotoxicity against human leukemia (CCRF-CEM) cells with IC₅₀ value of 5.62 and 3.74 μM, respectively.