Kolavenic Acid Research Articles

Cytotoxic Clerodane Diterpenes fromPolyalthia longifolia

Bioassay-directed chemical investigation of the stem bark of Polyalthia longifolia Thw. (Annonaceae) has led to a novel clerodane diterpene, 16-oxo-cleroda-3, 13(14)Z-dien-15-oic acid, which was named polyalthialdoic acid (3). The bioassays also led to the previously known related diterpenes, kolavenic acid (2) which has not been reported as a constituent of this plant, and 16 alpha-hydroxy-cleroda-3,13(14)Z-dien-15,16-olide (1) which is previously known to be in this plant. These structures were identified by chemical and spectroscopic methods. All three compounds (1-3) were significantly bioactive in the brine shrimp bioassay; they strongly inhibited the growth of crown gall tumors on potato discs; and they were cytotoxic in three human tumor cell lines. These activities suggest potential antitumor applications. Compound 3 was the most active (ED50 values ca. 6 x 10(-1) micrograms/ml in the human tumor cell culture systems).

Stereochemistry of clerodanes. X-Ray structure of a key diterpenoid from Solidago arguta Ait

X-Ray structural studies of the diterpenoid (1) from Solidago arguta have confirmed the relative stereo-chemistries assigned to (1) and a large group of related compounds including marrubiaside (3), (–)- hardwickiic acid (4), and kolavenic acid (5).

Structure of Diterpene Lactones from Solidago altissima L.

Neutral components of S. altissima L. roots were repeatedly chromatographed on silica gel to give four oily bitter principles and two crystalline bitter principies. These six compounds have an outstanding strutural feature in common, a B-substituted B-butenolide ring (IR) 1785, 1750, 1645cm-1, 54.65(2 H, d), 5.72(I H, bs).The hydrolysis of the simplest compound, solidagolactone (7) (CacH3eO2, bp 160-170 C/O.007mmHg, la D -73.4) gave aldehyde-carboxyiic acid (17), which was reduced by the Huang-Minlon method and methylated with diazomethaneto give methyl ester (18) (Eal D -44.70).(18) was identical with methyl dihydrokblavenate (20) (aD -32.6) derived from kolavenic acid (1). Based on the above chemica1 evidences and the spectral properties of derivatives, the structure (7) wasdetermined.In the other four compounds, solidagolactone II(8), III(9), IV(10)(C2H3003, mp 134)and V(11) (C2 g H2gO3 mp 105-106C), the presenee of substituentsat C(G) was revealed in NIVIIil data, compared to those of the corresponding coinpounds of kolavenate series. Spectral data allow assignment of provisionalstructure (12) to the remaining compound, solidagolactone VI.

The Structure and the Stereochemistry of Solidagonic Acid

Abstract A new bitter principle, solidagonic acid C22H34O4, was isolated from the root of Solidago altissima L. It is a bicyclic diterpene carboxylic acid, having an acetoxyl group and two double bonds, and was formulated as II on the basis of chemical and spectroscopic studies. The other constituents of the root, kolavenic acid (XXIV) and kolavenol (XXVIII) were also isolated, and they were chemically correlated to II. The absolute configurations of II, XXIV and XXVIII were established by application of the octant rule on the ORD curves for some ketonic compounds derived from them.