Withasteroids of Physalis. IX. Physangulide — The first natural 22S-withasteroid

A new withasteroid — physangulide — has been isolated from the leaves ofPhysalis angulata L. It has been shown that physangulide is the first natural 22S-withanolide. Its structure has been determined as 3β,4β,20,24,25-pentahydroxy-1-oxo-5β,6β-epoxy-20R,22S,24S,25R-withanolide. Its¹H and¹³C NMR spectra, confirming this interpretation, are given. Institute of the Chemistry of Plant Substances, Uzbek SSR Academy of Sciences, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 366–371, May–June, 1990.     

Secondary metabolites of Ulocladium chartarum. Ulocladols A and B — New phytotoxins of terpenoid nature

Ulocladols A and B — new exometabolites having a mixed sesquiterpenoid-polyketide nature that are structurally close to the host-specific toxins ofAlternaria citri — have been isolated from the deuteromyceteUlocladium chartarum. Both substances inhibit the growth of cotton seeds. All-Union Scientific Research Institute of Phytopathology, Moscow Province, Golitsyno. M. V. Lomonosov Moscow State University. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 642–648, September–October, 1991.     

Triterpene glycosides of Thalictrum squarrosum. IV. Structures of squarrosides A1, A2, B1, and B2

Four new cycloartane glycosides have been isolated from a methanolic extract ofThalictrum squarrosum Stephan ex Willd.: squarroside A1 (I) — (21R, 22S, 23R)-3β-(β-D-glucopyranosyloxy)-21α-methoxy-21,23-epoxycycloart-24-ene-22β,30-diol, C₃₀H₆₀O₁₀; squarroside A2 (II) — the (21S)-epimer of compound (I); squarroside B1 (III) (21R, 22S, 23R)-3gb-[O-α-L-rhamnopyranosyl-(1 → 6)-β-D-glucopyranosyloxy]-21α-methoxy-21,23-epoxycycloart-24-ene-22β,30-diol, C₄₃H₇₀O₁₄; and squarroside B2 (IV) — the (21S)-epimer of compound (III). The proposed structures were determined on the basis of¹H and¹³C NMR spectroscopy, FAB mass spectrometry, and chemical transformations. Irkutsk Institute of Organic Chemistry, Siberian Branch, USSR Academy of Sciences. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 516–523, July–August, 1989.     

Crystal and molecular structure of 20S,24S-dihydroxydammar-25-en-3-one

The complete spatial structure of 20S,24S-dihydroxydammar-25-en-3-one — a triterpenoid isolated from the leaves of a Far-Eastern species of birch,Betula mandschurica — has been established. Intermolecular cooperative hydrogen bonds that are unusual for a triterpenoid system have been detected in crystals of 20S,24S-dihydroxydammar-25-en-3-one, with the participation of both hydroxy groups in one chain of bonds and an orientation of the associated molecules that is characteristic for a bimolecular layer. Pacific Ocean Institute of Bioorganic Chemistry, Far-Eastern Branch, Russian Academy of Sciences, Vladivostok. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 667–672, September–October, 1991.     

Cembrenolides of a soft coral Lobophytum sp. (coelenterata, octocorallia, alcyonacea)

The known cembrenolide sarcophin and its new acetoxy derivative — 13-acetoxy-7,8-epoxycembra-1(15),3,11-trien-2,16-olide — have been isolated from the soft coralLobophytum sp.. The compounds isolated are inhibitors of the activity of Na⁺K⁺-ATPase and are membranotropic agents. The structures of the compounds have been shown on the basis of the results of NMR spectroscopy.Pacific Ocean Institute of Bioorganic Chemistry, Far Eastern Branch, Academy of Sciences of the USSR, Vladivostok. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 762–765, November–December, 1990.     

Leuconine — A new alkaloid from Aconitum leucostomum and A. septentrionale

A new alkaloid — leuconine — has been isolated from the epigeal parts ofAconitum leucostomum andA. septentrionale, and its structure has been established on the basis of spectral characteristics. Institute of Chemistry of Plant Substances, Uzbekistan Academy of Sciences, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 538–540, September–October, 1992.     

Synthesis of 24-ethylcholesta-7, 22E-diene-3β, 5β-triol — A natural trihydroxysteroid from the bryozoan Myriapora truncata

24-Ethylcholesta-7, 22E-diene-3β,5α,6β-triol — a natural trihydroxysteroid from the bryozoanMyriapora truncata — has been synthesized from stigmasterol. Institute of Bioorganic Chemistry, Academy of Sciences of the Belorussian SSR, Minsk. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 664–669, September–October, 1989.     

Interaction of immobilized 2,8,14,20-tetramethyl-4,6,10,12,16,18,22,24-octahydroxycalix[4]arene with Na+, Cs+, and NH4 + ions and organic cations

The equilibrium in the system water—electrolyte—cross-linked polymer containing immobilized 2,8,14,20-tetramethyl-4,6,10,12,16,18,22,24-octahydroxycalix[4]arene was studied. Immobilized calixarene 1 was shown to form 1∶1, 1∶2, 1∶3, and 1∶4 compounds with inorganic cations (Na⁺, Cs⁺, and NH₄ ⁺), and with organic cations (hexamethylen-tetramine and β-diethylaminoethylp-aminobenzoate) 1∶1 compounds are formed. The affinity of immobilized calixarene1 increases in the series of cations: hexamethylenetetramine <Na⁺, Cs⁺, NH₄ ⁺<β-diethylaminoethylp-aminobenzoate. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2214–2216, November, 1998.     

Triterpene glycosides of alfalfa. V. Medicoside H

A new triterpene glycoside — medicoside H — has been isolated from the roots ofMedicago sativa L. (Fabaceae), and on the basis of chemical transformations and spectral characteristics its structure has been established as medicagenic acid 3-O-β-D-glucopyranoside 28-O-[O-α-L-rhamnopyronosyl-(1 → 2)-β-L-arabino-pyranoside]. Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 673–677, September–October, 1989.     

Components of Matricaria discoidea — Geranyl isovalerate,trans-β-farnesene,and herniarin

In a study of the components of theMatricaria discoidea DC. growing in Estonia, three individual compounds have been isolated from the essential oil. On the basis of spectral characteristics, their structures have been shown as geranyl isovalerate, trans-β-farnesene, and herniarin. Tartu State University, and Institute of Chemical and Biological Physics, Academy of Sciences of the Estonian SSR, Tallin. Translated from Khimiya Prirodynkh Soedinenii, No. 6, pp. 804–806, November–December, 1988.     

Triterpene glycosides of Astragalus and their genins XXXIX. Cycloaraloside D from Astragalus amarus

The structure of a triterpene glycoside of the cycloartane series — cycloaraloside D, isolated from the roots ofAstragalus amarus Pall. (Leguminosae) — has been established on the basis of chemical transformations and spectral characteristics. Cycloaraloside D is 20R, 24S-epoxycycloartane-3β, 6α, 16β, 25-tetraol 3-0-[0-α-L-rhamnopyranosyl-(1 → 2)-β-D-glucopyranoside]. Institute of Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 526–528, July–August, 1991.     

Synthesis of the α-monoglyceride oftrans-O-methylmarmesic acid and its modified derivatives—The phosphate and citrate

The α-monoglyceride of trans-O—methylmarmesinic acid and its phosphate and citrate derivatives have been synthesized. The structures of the compounds have been confirmed by IR, UV, PMR and¹³C and³¹P spectroscopies. A. B. Bekturova Institute of Chemical Sciences, Academy of Sciences of the Republic of Kazakhstan, Almaty, fax (3272) 61 57 65. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 452–455, July–August, 1998.     

Structures of four new triterpene glycosides from the holothurian Cucumaria japonica

Four new triterpene glycosides of the holostane series have been isolated from an alcoholic extract of the economically important Pacific Ocean holothurianCucumaria japonica: cucumariosides A₁-2 (I), A₂-3 (II), A₂-4 (III), and A₄-2 (IV). The structures of these substances have been established by the methods of carbohydrate chemistry and¹³C NMR spectroscopy. Pacific Ocean Institute of Bioorganic Chemistry, Far Eastern Branch, Academy of Sciences of the USSR, Vladivostok. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 787–793, November–December, 1990.     

Insect phermones and their analogues XXXVIII. Synthesis of (±)-3-methylheneicosan-2-one and (±)-2-acetoxy-3,7-dimethylpentadecane using the reductive β-vinylation of α-olefins

Schemes are proposed for the synthesis of (±)-3-methylheneicosan-2-one and (±)-2-acetoxy-3,7-dimethylpentadecane — racemic analogues of the sex pheromones of the common cockroach (Blatella germanica) and of plane sawflies of the generaDiprion andNeodiprion, respectively, using the reductive β-vinylation of α-olefins. Institute of Chemistry of the Bashkir Scientific Center, Urals Division of the Russian Academy of Sciences, Ufa. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 567–571, September–October, 1992.     

Synthesis of natural triisopentenylated flavanone, euchrenone a2

Euchrenone a₂ (7) isolated from the roots ofEuchresta japonica has been synthesised from 3-prenylphloroacetophenone (1) by other workers. We carried out its cyclodehydrogenation with dichloro dicyano quinone (DDQ) to obtain 6-acetyl-5,7-dihydroxy-2,2-dimethylchromene (2) which was ethoxymethylated in the 7-position to give 6-acetyl-7-ethoxymethoxy-5-hydroxychromene (3). Chalcone condensation of3 and 4-ethoxymethoxy-3-C-prenylbenzaldehyde (4) gave 4,6′-bisethoxymethoxy-2′-hydroxy-6″, 6″-dimethyl-3-C-prenylpyrano (2″, 3″–4,3) chalcone (5) which cyclised with methanolic sodium acetate to give protected 5,4′-bisethoxymethoxy-6″, 6″-dimethyl-3′-C-prenylpyrano (2″, 3″–7,8) flavanone (6). Deprotection of6 with 4% methanolic HCl yielded (7) with melting point and spectral data identical to that of the natural compound.     

GC-MS analysis of total diterpene alkaloids from roots of Aconitum septentrionale

For the first time, using a MS 25RF chromato-mass spectrometer with a Carlo Erba 5160 chromatograph and a packed column, the possibility of the partial separation of the mixture of diterpene alkaloids of various types from the roots ofAconitum septentrionale has been shown. From their chromatographic parameters and mass-spectral characteristics 18 bases have been detected, including a new one with M⁺ 407 which was probably deoxydelcorine, while 6-O-methyldelcorine and 6-O-methyleldelidine have been found in plants for the first time. Institute of the Chemistry of Plant Substances, Uzbek SSR Academy of Sciences, Tashkent. Translated from Khimiya Prirodynkh Soedinenii, No. 4, pp. 538–543, July–August, 1989.     

Influence of Amino Acid Composition and Phosphorylation on the Ion Yields of Peptides in MALDI-MS

The influence of arginine (Arg), lysine (Lys), and phenylalanine (Phe) residues and phosphorylation on the molecular ion yields of model peptides have been quantitatively studied using matrix-assisted laser desorption/ionization (MALDI) mass spectrometry in both positive- and negative-ion mode. The results obtained from these experiments have been interpreted from the standpoint of two different components, namely, desorption and ionization, on the basis of the physicochemical properties of constituent amino acids of the model peptides. The presence of basic residues such as Arg and Lys enhanced the ion yields of protonated molecules [M + H]⁺. An N-terminal rather than a C-terminal Arg residue was advantageous for the formation of both [M + H]⁺ and [M – H]^–. The presence of the Phe residue resulted in the increase of the ion yields of both [M + H]⁺ and [M – H]^–. In contrast, the presence of phosphate group(s) contributed to the suppression of the yields of both [M + H]⁺ and [M – H]^– due to the loss of phosphate group. The detection limits for both [M + H]⁺ and [M – H]^– of model peptides have been evaluated.     

Natural antioxidants. Furanoeremophilanes from Cacalia roots

Sesquiterpene compounds of the furanoeremophilane series have been isolated from extracts of the roots ofCacalia sp. growing in the Soviet Far East. The presence of antioxidant and antiradical activities in two representatives of the series has been established. Pacific Ocean Institute of Bioorganic Chemistry, Far Eastern Branch, Academy of Sciences of the USSR, Vladivostok. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 643–646, September–October, 1989.     

Secondary metabolites of Pyricularia oryzae II. Polyketide metabolites

A number of exometabolites have been isolated from the deuteromycetePyricularia oryzae Cav., of which harman and O-demethyldiaporthin have been isolated from this species for the first time. The latter is the first example of a hexaketide from fungi of the genusPyricularia, for which only penta- and heptaketides have previously been described. All-Union Scientific-Research Institute of Phytopathology, Moscow. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 471–475, July–August, 1991.