Structures of two new diterpenoids from Teucrium polium

Two new acids of the neoclerodane series have been isolated fromTeucrium polium L. (Lamiaceae); they have been called tepolin A and tepolin B and their structures have been established on the basis of spectral characteristics as 7,12,19-trihydroxy-6,18:15,16-diepoxycleroda-3,13(16),14-triene-9-carboxylic acid and 12,19-dihydroxy-6,18:15,16-diepoxycleroda-3,13(16)-14-triene-9-carboxylic acid, respectively. Institute of Fine Organic Chemistry, Armenian Academy of Sciences, Erevan. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 503–508, September–October, 1992.     

Novel 6,7-seco-6,11-cyclolabdane diterpenes from cluytia richardiana

Two novel 6,7-seco-6,11-cyclolabdane diterpenoids, richardianidin-1 and 2, were isolated from the leaves of Cluytia richardiana L. The structure and stereochemistry of 1 and 2 were established to be 6- (acetyloxy)-15,16-epoxy-2,12-dihydroxy-6,7-seco-6,11-cyclolabda-8,13(16),14-triene-7,18-dioic acid γ-lactone δ-lactone and 6-(acetyloxy)-15,16-epoxy-1,12-dihydroxy-6,7-seco-6,11-cyclolabda-8,13(16),14-triene-7,18-dioic acid di-δ-lactone based on spectroscopy and X-ray data.     

Hydroxy acids of the reserve lipids of Galeopsis bifida

The structures of fatty monohydroxy acids of the lipids of the seeds ofGaleopsis bifida Boenn. have been studied by the methods of chromatographic, spectral, and chemical analysis. (31) Acids with chain lengths of from 14 to 20 carbon atoms, with from 0 to 3 double bonds, and with the hydrolyls in positions characteristic for the products of the direct hydroxylation and the lipoxygenase and photosensitized oxidation of unsaturated fatty acids were detected. Of them, the 13-OH-9Z, 11E-17:2, the 15-OH-9, 12-18:2, the 16-OH-9, 12-18:2, and 17-OH-11, 14-20:2 acids were new, while this is the first time that the 15-OH-9Z, 12Z, 16E-18:3 acid has been described as a natural compound. The behavior of the TMS derivatives of the hydroxy acids on a polyester phase in GLC is discussed.Institute of the Chemistry of Plant Substances, Academy of Sciences, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 744–753, November–December, 1991.     

Oxygenated acids of the reserve lipids of Rumex paulsenianus

The composition of the fatty mono- and dihydroxy acids of the fruit ofRumex paulsenianus Rech. fil. (familyPolygonaceae) has been determined by a combination of IRS, UVS, GLC, and mass-spectrometric methods. (22) Monohydroxy acids of the C₁₄–C₂₀ series, including isomers and isologues, and four dihydroxy acids from C₁₈ to C₂₀, including a new isomeric 9-OH-10, 12–17:2 acid have been detected.Institute of the Chemistry of Plant Substances, Uzbek Academy of Sciences, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 762–765, November–December, 1991.     

An unusual bisnor-clerodane diterpenoid from Polyalthia simiarum

The stem bark of Polyalthia simiarum has yielded a new bisnor-type clerodane diterpenoid, 2-oxo-14,15-bisnor-3,11E-kolavadien-13-one (1), and three previously known clerodane derivatives, kolavenic acid (2), 16beta-hydroxycleroda-3,13(14)Z-dien-15,16-olide (3), and 16-oxocleroda-3,13(14)E-dien-15-oic acid (4). The structures of these compounds were unambiguously determined by extensive NMR studies as well as by comparison with related compounds. Till now this is the second report of the occurrence of any unusual C-18 clerodane diterpenoid from nature. The crude light petroleum extract and the purified compound 3 demonstrated moderate free radical scavenging activity with IC50 values of 21.5 and 23.5 microg/mL, respectively.     

Crotocaudin; a rearranged labdane type norditerpene from Croton caudatus geisel

The structure and stereochemistry of crotocaudin, a new norditerpene occurring as a minor constituent in Crotoncaudatus Geisel (Euphorbiaceae) have been established as ent-8S,10S-15,16-epoxy-19-norcleroda-4,11,13(16), 14-tetraene 18,6S: 20,12-diolactone 7 from the detailed studies of ¹H NMR spectra using lanthanide shift reagents, decoupling experiments and chemical reactions. The congener, teucvidin, ent-10S-15,16-epoxy-19-norcleroda-4,13(16), 14-triene-18,6S: 20,12R-diolactone 1 was obtained as a major component besides several triterpenoids viz taraxerone 2, taraxerol 3 and taraxeryl acetate 4. ¹³C NMR and ¹H NMR spectra and a few novel reactions of teucvidin and its conversion to teucvin, ent-(6R,12R)-15,16-epoxy-19-nor-9,4-friedolabda-4,13(16),14-triene-18,6:20, 12-diolactone 6 are also reported.     

Thrombin Inhibitory Constituents from Duranta repens

The C‐alkylated flavonoids 3,7,4′‐trihydroxy‐3′‐(4‐hydroxy‐3‐methylbutyl)‐5,6‐dimethoxyflavone ( 1 ), 3,7‐dihydroxy‐3′‐(4‐hydroxy‐3‐methylbutyl)‐5,6,4′‐trimethoxyflavone ( 2 ) and the trans‐clerodane diterpenoids 6β‐hydroxy‐15,16‐epoxy‐5β,8β,9β,10α‐cleroda‐3,13(16),14‐trien‐18‐oic acid ( 3 ) and 2β‐hydroxy‐15,16‐epoxy‐5β,8β,9β,10α‐cleroda‐3,13(16),14‐trien‐18‐oic acid ( 4 ) were isolated from Duranta repens. Their structures and the relative configuration of 3 and 4 were determined by spectroscopic methods (¹H‐ and ¹³C‐NMR, IR, and MS) and 2D‐NMR experiments. The known flavonoid 5 is also reported for the first time from this species. The compounds 1 , 3 , and 5 showed significant enzyme‐inhibitory activity against thrombin.     

Clerodane Diterpenoids from an Edible Plant Justicia insularis: Discovery,Cytotoxicity, and Apoptosis Induction in Human Ovarian Cancer Cells

Objectives: The toxicity of chemotherapeutic anticancer drugs is a serious issue in clinics. Drug discovery from edible and medicinal plants represents a promising approach towards finding safer anticancer therapeutics. Justicia insularis T. Anderson (Acanthaceae) is an edible and medicinal plant in Nigeria. This study aims to discover cytotoxic compounds from this rarely explored J. insularis and investigate their underlying mechanism of action. Methods: The cytotoxicity of the plant extract was evaluated in human ovarian cancer cell lines and normal human ovarian surface epithelia (HOE) cells using a sulforhodamine B assay. Bioassay-guided isolation was carried out using column chromatography including HPLC, and the isolated natural products were characterized using GC-MS, LC-HRMS, and 1D/2D NMR techniques. Induction of apoptosis was evaluated using Caspase 3/7, 8, and 9, and Annexin V and PI based flow cytometry assays. SwissADME and SwissTargetPrediction web tools were used to predict the molecular properties and possible protein targets of identified active compounds. Key finding: The two cytotoxic compounds were identified as clerodane diterpenoids: 16(α/β)-hydroxy-cleroda-3,13(14)Z-dien-15,16-olide (1) and 16-oxo-cleroda-3,13(14)E-dien-15-oic acid (2) from the Acanthaceous plant for the first time. Compound 1 was a very abundant compound (0.7% per dry weight of plant material) and was shown to be more potent than compound 2 with IC₅₀ values in the micromolar range against OVCAR-4 and OVCAR-8 cancer cells. Compounds 1 and 2 were less cytotoxic to HOE cell line. Both compounds induced apoptosis by increasing caspase 3/7 activities in a concentration dependent manner. Compound 1 further increased caspase 8 and 9 activities and apoptosis cell populations. Compounds 1 and 2 are both drug like, and compound 1 may target various proteins including a kinase. Conclusions: Clerodane diterpenoids (1 and 2) in J. insularis were identified as cytotoxic to ovarian cancer cells via the induction of apoptosis, providing an abundant and valuable source of hit compounds for the treatment of ovarian cancer.     

Amarisolide monohydrate,a 2‐(β‐glu­cosyl)­neoclerodane

The absolute configuration of the neoclerodane glycoside amarisolide, presented here as the monohydrate, C₂₆H₃₆O₉·H₂O, has been determined by association with the known configuration of the glucose moiety. Its structure was established as 2β‐(O‐β‐d ‐gluco­pyran­osyl)­neocleroda‐3,13(16),14‐trien‐15,16‐epoxy‐18,19‐olide. Extensive hydrogen bonding among the hydroxyl groups of the sugar moiety forms layers which are interconnected by water mol­ecules.     

Triterpene glycosides of Thalictrum squarrosum. II. Molecular and crystal structure of squarrofuric acid

The structure of squarrofuric acid (an artifactual genin fromThalictrum squarrosum) has been confirmed by x-ray structural analysis and the configurations of the C13, C14, C17, C20, and C22 asymmetric centers have been established, which has enabled this compound to be assigned to the lanostane series with the following structure: 3,30-dihydroxy-20(S),22(S)-22,25-epoxylanost-9(11)-en-21-oic acid.Novosibirsk Institute of Organic Chemistry, Siberian Branch of the USSR Academy of Science. Irkutsk Institute of Organic Chemistry, Siberian Branch of the USSR Academy of Sciences. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 533–537, July–August, 1987.     

A Benzofuranoid and Two Clerodane Diterpenoids from Pulicaria wightiana

Methyl 5‐formyl‐1‐benzofuran‐6‐carboxylate ( 1 ) and the two clerodane diterpenes, methyl 6‐oxocleroda‐3,13‐dien‐15,16‐olid‐18‐oate ( 2 ) and 2β‐(2‐methylbutanoyl)cleroda‐3,13‐dien‐15,16‐olid‐18‐oic acid ( 3 ), together with 15 known compounds, were isolated from the aerial parts of Pulicaria wightiana. The structures of the new compounds 1, 2 , and 3 were established by spectroscopic (mainly 1D‐ and 2D‐NMR) methods.     

Lipids of the seeds of Cynoglossum officinale

The compositions of the lipids and fatty acids of the seeds ofCynoglossum officinale, familyBoraginaceae have been established. The bulk of the lipids consisted of netural compounds (95.2%), while the amounts of glycolipids and phospholipids were 3.1 and 1.7%, respectively. Among the fatty acids, in addition to the usual components, acids characteristic for theBoraginaceae family have been found: 18:3 (6, 9, 12), 18:3 (9, 12, 15), 18:4 (6, 9, 12, 15), 20:1 (11), 22:1 (13), and 24:1 (15).Institute of the Chemistry of Plant Substances, Uzbek Academy of Sciences, Tashkent. South Urals Reservation, Bashkir. Institute of Chemistry, Bashkir Scientific-Center, Urals Branch, Russian Academy of Sciences, Ufa. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 758–762, November–December, 1991.     

Refinement of the structure of asperumine

Summary 1. Asperumine has been isolated from the combined alkaloids ofSymphytum caucasicum.2. The hydrolysis and hydrogenolysis of asperumine has given heliotridine, acetone, and angelic and asperuminic acids.3. The structure of asperumine has been refined on the basis of the products of hydrolysis and hydrogenolysis and also of features of the mass and NMR spectra.4. It has been established that asperumine is an isomer of heliosupine in the 2,3,4-trihydroxy-2-methylpentane-3-carboxylic acid moiety.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 478–480, July–August, 1974.     

Synthesis of isoagathane aldehydes representing metabolites of the spongeSpongia officinalis

The synthesis has been performed of (14R)-15-acetoxyisoagath-12-en-16-al and of (14R)- and (14S)-isoagath-12-ene-15,16-dials, which are metabolites of the marine spongeSpongia officinalis, and alos of a number of substances related to them starting from (14R)- and (14S)-isoagath-12-en-15-ols.Institute of Chemistry, Academy of Sciences of the Moldavian SSR, Kishinev. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 45–51, January–February, 1985.     

Lipids of the fruit ofAcanthopanax sessiliflorus

In the lipids of the seeds and pericarp of the introduced speciesAcanthopanax sessiliflorus (Rupr. et Maxim.) Seem (familyAraliaceae), 23 classes of compounds have been detected, of which 19 have been identified. Sixteen of the classes have been studied. The lipids of the pericarp contain a more complex set of components than the seeds. Hydroxyacyldiacylglycerides, fatty acid methyl esters, and a complex group of pthalicacidesters have been detected in the familyAraliaceae for the first time. The fatty acid compositions of the seed and pericarp lipids are characterized by a high level of petroselinic acid.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 760–766, November–December, 1985.     

Alkaloids of four species of Argemone

The alkaloid compositions of four species of plants of the genusArgemone (A. mexicana L.,A. alba L.,A. platyceras Link et Otto., andA. hybrida) collected in the flowering phase in the Tashkent Botanical Garden have been studied. They have yielded 16 alkaloids. Corydine and isocorydine have been detected in plants of this genus for the first time, and O-methyl-platycerine has been found in nature for the first time.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 204–206, March–April, 1986.     

Phospholipase A2 from the venom of the spider Eresus niger

A phospholipase A₂ with a molecular mass of 12–14 kDa has been isolated from the venom of the spiderEresus niger by three-stage column chromatography. Asparagine has been identified as the N-terminal amino acid.Institute of Physiology, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 557–560, July–August, 1991.