(+)-Eudesm-3-ene-6β,7α-diol from the liverwort Lepidozia reptans

The structure of a new sesquiterpene diol from the liverwort Lepidozia reptans has been established as eudesm-3-ene-6β,7α-diol on the basis of its ¹H and ¹³CNMR spectroscopic properties.     

Two sesquiterpene lactones from Trichogonia gardneri

The structures and stereochemistries of two sesquiterpene lactones from Trichogonia gardneri were established as (6R,7S,8S,9S,IOR)-4E-9,10-dihydroxy-8-tigloxygermacr-4-en-6,12-olide) and (5R*,6R*,7S*,8S*,9R*)-14-acetoxy-3-chloro-9-hydroxy-2-oxo-8-tigloxyguia-1(10),3-dien-6,12-of olide by a combination of NMR spectrometry and X-ray diffraction. The results show that the structures of several sesquiterpene lactones which were isolated previously from related species require revision.     

Eudesmane alcohols from jasonia glutinosa

Three new sesquiterpene alcohols have been isolated from Jasonia glutinosa. Their structures were elucidated by spectroscopic methods and chemical correlations as (?)-[11R]-4α,14-epoxyeudesm-11,12-diol, (?)-[11R]-eudesm-4(14)-en-5β,11,12-triol and (+)-[11R]-eudesm-4(14)-en-5α,11,12-triol and they are called α-epoxy kudtdiol, 5-epi-kudtriol and kudtriol respectively.     

Regulation of Morphogenesis and Biocontrol Properties in Trichoderma virens by a VELVET Protein,Vel1

Mycoparasitic strains of Trichoderma are applied as commercial biofungicides for control of soilborne plant pathogens. Although the majority of commercial biofungicides are Trichoderma based, chemical pesticides, which are ecological and environmental hazards, still dominate the market. This is because biofungicides are not as effective or consistent as chemical fungicides. Efforts to improve these products have been limited by a lack of understanding of the genetic regulation of biocontrol activities. In this study, using gene knockout and complementation, we identified the VELVET protein Vel1 as a key regulator of biocontrol, as well as morphogenetic traits, in Trichoderma virens, a commercial biocontrol agent. Mutants with mutations in vel1 were defective in secondary metabolism (antibiosis), mycoparasitism, and biocontrol efficacy. In nutrient-rich media they also lacked two types of spores important for survival and development of formulation products: conidia (on agar) and chlamydospores (in liquid shake cultures). These findings provide an opportunity for genetic enhancement of biocontrol and industrial strains of Trichoderma, since Vel1 is very highly conserved across three Trichoderma species.Trichoderma-based formulation products account for about 60% of the biofungicide market (35). Despite the use of Trichoderma-based biofungicides as an alternative and additive to chemical fungicides, the applications of these preparations are limited because their efficacy is lower than that of fungicides. A lack of understanding of the regulation of biocontrol has limited progress in enhancing the competitiveness of these fungi through genetic manipulation of desired traits. The success of a biocontrol agent also depends on the ability of researchers to develop an effective formulation based on active propagules that survive under the conditions that occur in nature and are effective against the target pathogens. Trichoderma spp. produce two types of propagules, conidia during solid-state fermentation and chlamydospores during liquid fermentation. Both types are used in commercial formulations depending on the growth conditions (17, 35). Thus, understanding how the two sporulation pathways are controlled is critical for obtaining an improved, balanced formulation product. Identification of a global regulator of morphogenesis and biocontrol properties (such as antibiosis and mycoparasitism) would provide an opportunity to manipulate the morphogenetic and antagonistic traits, leading to wider commercial acceptance of Trichoderma spp. in the long run.Trichoderma virens is a commercially formulated biocontrol agent that is effective against soilborne plant pathogens, such as Rhizoctonia solani, Sclerotium rolfsii, and Pythium spp.; its major direct mode of action is antibiosis and mycoparasitism (20, 36). This species has also been used as a model system for studies of biocontrol mechanisms, and the genome has recently been sequenced (http://genome.jgi-psf.org/Trive1). The role of beta-glucanases, chitinases, and proteases in biocontrol has been reported previously (2, 8, 29). Some strains of T. virens (designated Q strains) produce copious amounts of the antibiotic gliotoxin that is involved in biocontrol (10, 12, 39). In an attempt to identify regulators of biocontrol properties, the role of a mitogen-activated protein kinase (MAPK) pathway was studied previously (22, 24). Deletion of the TmkA/Tvk1 MAPK gene resulted in derepressed conidiation and different biocontrol behavior for two strains of T. virens; Mukherjee et al. (24) noted the reduced ability of these mutants to parasitize the sclerotia of S. rolfsii and R. solani, while Mendoza-Mendoza et al. (22) found that deletion of this MAPK gene improved the biocontrol activity of T. virens against R solani and P. ultimum. The production of secondary metabolites was not affected by deletion of this gene. To date, no gene that regulates the balance between conidiation or chlamydospore formation, secondary metabolism, and antagonistic or biocontrol properties has been identified in any Trichoderma sp.The Vel1 VELVET protein has been shown to be a regulator of morphogenesis and secondary metabolism in some filamentous fungi (6). In Aspergillus nidulans, VeA physically interacts with VelB and the regulator of secondary metabolism LaeA to form a complex that regulates secondary metabolism and sexual reproduction (3). Deletion of the VeA gene leads to an increase in asexual development (conidiation in the dark) and reduced biosynthesis of sterigmatocystin (the product of a polyketide synthetase [PKS]) and penicillin (the product of a nonribosomal peptide synthetase [NRPS]), while it reduces and delays sexual reproduction (15, 16). VeA is also required for the production of sclerotia and for aflatoxin biosynthesis in Aspergillus parasiticus (7). Deletion of the VeA gene in Neurospora crassa, like deletion of the VeA gene in A. nidulans, results in deregulated conidiation, while in Acremonium chrysogenum, loss of VeA leads to increased hyphal fragmentation and reduced cephalosporin production (4, 9). Deletion of the VeA gene in Fusarium verticilliodes resulted in a loss of hydrophobicity and an increased macroconidium-to-microconidium ratio; these defects could be restored by growing the organism on osmotically stabilized media (18). The mutants were also defective in production of the mycotoxins fumonisin and fusarin (25).To test the hypothesis that Vel1 is a global regulator of gene expression in T. virens, we examined the functions of Vel1 in this organism by using gene knockout and complementation. Here we report that in addition to a role in conidiation and secondary metabolism, Vel1 also regulates conidiophore aggregation, chlamydosporogenesis, mycoparasitism, and biocontrol efficacy in T. virens. Thus, we identified the first master regulator of morphogenesis and antagonistic properties in this economically important fungus.     

A new sesquiterpene alcohol from Pterocarpus marsupium

The petrol extract of Pterocarpus marsupium afforded a new sesquiterpene alcohol of the eudesmane type, selin-4(15)-en-1β,11-diol, besides β-eudesmol, erythrodiol-3-monoacetate and pterostilbene.     

Nuclear metabolism of benzo(a)pyrene and of (±)-trans-7,8-dihydroxy-7,8,-dihydrobenzo(a)pyrene: Comparative chromatographic analysis of alkylated DNA

Rat liver nuclei were incubated with [¹⁴C]benzo(a)pyrene (BP) or [³H](±)-trans-7,8-dihydrodiol of BP (³H-BP-7,8-diol) in the presence of a NADPH-generating system. The nuclei were able to form from BP the 9,10-, 4,5- and 7,8-dihydrodiols, the 3,6- and 1,6-quinones as well as the 3- and 9-phenols. The total nuclear metabolism was stimulated 11-fold by prior administration to the rats of 3-methylcholanthrene (3MC). BP-7,8-dihydrodiol formation, under these circumstances, was enhanced 29-fold. The rat liver nuclei were also able to form from [³H]BP-7,8-diol, (±)-7β,8α-dihydroxy-9β,10β-epoxy-7,8,9,10-tetrahydro BP (diol epoxide 1), (±)-7β,8α-dihydroxy-9α,10α-epoxy-7,8,9,10-tetrahydro BP (diol epoxide 2), as well as three unknown metabolites. Diol epoxides 1 and 2 represented 23 and 65% of the total metabolites produced during the control nuclear incubation. Pretreatment of the rats with 3MC resulted in 4-fold increase in nuclear metabolic activity. Under the latter circumstances, the diol epoxides 1 and 2 represented 43 and 38%, respectively, of the total nuclear metabolites. Incubation of liver nuclei with labeled BP or BP-7,8-diol in the presence of NADPH resulted in alkylation of DNA. The alkylated deoxyribonucleosides were separated by Sephadex LH-20 chromatography. Two peaks of radioactivity were noted after incubation with the parent polycyclic hydrocarbon while only one peak was seen after incubation with the diol derivative. These results emphasize the importance of nuclei in the metabolism of BP and in the subsequent alkylation of DNA, reactions which may be related to mutagenesis or carcinogenesis.     

Tvbgn3, a β-1,6-Glucanase from the Biocontrol Fungus Trichoderma virens, Is Involved in Mycoparasitism and Control of Pythium ultimum

Even though β-1,6-glucanases have been purified from several filamentous fungi, the physiological function has not been conclusively established for any species. In the present study, the role of Tvbgn3, a β-1,6-glucanase from Trichoderma virens, was examined by comparison of wild-type (WT) and transformant strains in which Tvbgn3 was disrupted (GKO) or constitutively overexpressed (GOE). Gene expression analysis revealed induction of Tvbgn3 in the presence of host fungal cell walls, indicating regulation during mycoparasitism. Indeed, while deletion or overexpression of Tvbgn3 had no evident effect on growth and development, GOE and GKO strains showed an enhanced or reduced ability, respectively, to inhibit the growth of the plant pathogen Pythium ultimum compared to results with the WT. The relevance of this activity in the biocontrol ability of T. virens was confirmed in plant bioassays. Deletion of the gene resulted in levels of disease protection that were significantly reduced from WT levels, while GOE strains showed a significantly increased biocontrol capability. These results demonstrate the involvement of β-1,6-glucanase in mycoparasitism and its relevance in the biocontrol activity of T. virens, opening a new avenue for biotechnological applications.     

Triterpenoids of Pterocarpus santalinus: Constitution of a new lupene diol

The bark of Pterocarpus santalinus has been found to contain β-amyrone, lupenone, epi-lupeol, lupeol, sitosterol and a new lupene diol whose constitution has been established as lup-(20)29-en-2α,3α-diol.     

New neutral diterpenes from southern pine tall oil

Five new diterpene natural products isolated from southern pine (Pinus spp.) tall oil were characterized as 8(14),15-pimaradiene-3β,18-diol, 19-hydroxy-15,16-dinorlabd-8(17)-en-13-one, 8,13β-epoxy-14-labden-6α-ol, 8,11, 13-abietatriene-15,18-diol and 9,10-secoabieta-8,11,13-trien-18,10-olide.     

Sesquiterpene lactones and a sesquiterpene diol from jamaican ambrosia peruviana

A new sesquiterpene diol and four pseudoguaianolides have been isolated from the aerial part of a Jamaican collection of Ambrosia peruviana. The structures have been identified as alloaromadendrane-4β, 10α-diol, psilostachyins C and B, ambrosin and damsin, respectively, by chemical and spectroscopic means.     

Diterpenoids of Halimium viscosum

From the neutral fraction of the hexane extract of Halimium viscosum the following components were isolated; 7-labdene-3β,l5-diol, 15-acetoxy-7-labden-3β-ol and a new diterpene-lactone with a rearranged ent-labdane skeleton, 13S-ent-9, 1-friedo-labd-1(10)-en-15-acetoxy-2R,18-olide. From the non-saponifiable part, beside 7-labdene-3β, 15-diol and 7, 13E-labdadiene-3β, 15-diol, the new diterpene 8(17)-labdene-3β, 7α, 15-triol was extracted. The structures were elucidated by spectroscopic methods, correlations or synthesis.     

Antiparkinsonian activity of some 9-N-, O-, S- and C-derivatives of 3-methyl-6-(prop-1-en-2-yl)cyclohex-3-ene-1,2-diol

Earlier it was found, that (1R,2R,6S)-3-methyl-6-(prop-1-en-2-yl)cyclohex-3-ene-1,2-diol (1) possess high antiparkinsonian activity. The N-, O-, S- and C-derivatives at the C-9 position of diol 1 were synthesized in this work. The antiparkinsonian activity of these compounds was studied in MPTP mice models. As a rule, the introduction of substituents containing nitrogen atoms at the C-9 position led to a considerable decrease or loss of antiparkinsonian activity. A derivative of 2-aminoadamantane 8 significantly decreased the locomotor activity time, thus enhancing the symptoms of the parkinsonian syndrome. However the introduction of butyl or propylthio substituents at the C-9 position of diol 1 did not diminish the antiparkinsonian activity comparing to parent compound. This information is important when choosing a route for immobilization of compound 1 to find possible targets.     

Inhibitors of sterol biosynthesis. Syntheses of 14α-alkyl substituted 15-oxygenated sterols

The chemical syntheses of a number of 14α-alkyl substituted 15-oxygenated sterols have been pursued to permit evaluation of their activity in the inhibition of the biosynthesis of cholesterol and other biological effects. Described herein are the first chemical syntheses of 14α-ethyl-5α-cholest-7-en-3β-ol-15-one, bis-3β,15α-acetoxy-14α-ethyl-5α-cholest-7-ene, 3β-acetoxy-14α-ethyl-5α-cholest-7-en-15β-ol, 14α-ethyl-5α-cholest-7-en-3β,15β-diol, 14α-ethyl-5α-cholest-7-en-3β,15α-diol, 3β-hexadecanoyloxy-14α-ethyl-5α-cholest-7-en-15α-ol, 3β-hexadecanoyloxy-14α-ethyl-5α-cholest-7-en-15β-ol, bis-3β,15α-hexadecanoyloxy-14α-ethyl-5α-cholest-7-ene, 3β-hexadecanoyloxy-14α-ethyl-5α-cholest-7-en-15-one, 3α-benzoyloxy-14α-ethyl-5α-cholest-7-en-15-one, 14α-ethyl-5α-cholest-7-en-3α-ol-15-one, 14α-ethyl-5α-cholest-7-en-15-on-3β-yl pyridinium sulfate, 14α-ethyl-5α-cholest-7-en-15-on-3β-yl potassium sulfate (monohydrate), 14α-ethyl-5α-cholest-7-en-15-on-3α-yl pyridinium sulfate, 14α-ethyl-5α-cholest-7-en-15-on-3α-yl potassium sulfate (monohydrate), 3β-ethoxy-14α-ethyl-5α-cholest-7-en-15-one, 3β-acetoxy-14α-n-propyl-5α-cholest-7-en-15-one, 14α-n-propyl-5α-cholest-7-en-3β-ol-15-one, bis-3β, 15α-acetoxy-14α-n-propyl-5α-cholest-7-ene, 3β-acetoxy-14α-n-propyl-5α-cholest-7-en-15β-ol, 14α-n-propyl-5α-cholest-7-en-3β, 15α-diol, 14α-n-propyl-5α-cholest-7-en-3β, 15β-diol, 14α-n-butyl-5α-cholest-7-en-3β-ol-15-one, 3β-acetoxy-14-α-n-butyl-5α-cholest-7-en-15-one, bis-3β,15α-acetoxy-14α-n-butyl-5α-cholest-7-ene, 3β-acetoxy-14α-n-butyl-5α-cholest-7-en-15β-ol, 14α-n-butyl-5β-cholest-7-en-3β, 15β-diol, and 14α-n-butyl-5α-cholest-7-en-3β, 15α-diol.     

The effect of manganese and ferric ions on the in vitro formation of dihydrodihydroxy metabolites of benzo(a)pyrene

The effect of ferric and manganese ions on the in vitro metabolism of benzo(a)pyrene (BP) to dihydrodihydroxy (diol) metabolites by rat liver microsomal preparations was studied. Of the 3 diols separated by high-pressure liquid chromatography (HPLC) and called diols 1, 2 and 3 in order of elution, diol 1 was identified by its U.V. spectrum as the 9,10-diol; diols 2 and 3 have not yet been identified positively but are probably the 4,5- and 7,8-diols respectively. Higher concentrations of both metals altered the diol profile; 10 and 50 mumol Fe3+ per incubation caused the disappearance of diols 1 and 2 and an increase in diol 3; 10 mumol Mn2+ caused a significant decrease in diol 2 while 50 mumol reduced diol 2 to a negligible amount and inhibited the formation of diol 1; both concentrations caused a relative increase in diol 3. If the tentative identification of diol 3 as the 7,8-diol is correct, manganese and ferric ions could be significant in the metabolism of BP to the active metabolite, the 7,8-diol-9,10-epoxide.     

Steroidal constituents of Solanum xanthocarpum

From the extract of the fruits of Solanum xanthocarpum (Solanaceae), five new steroidal compounds were isolated and characterized: 4α-methyl-24ξ-ethyl-5α-cholest-7-en-3β,22ξ-diol (1), 3β,22ξ-dihydroxy-4α-methyl-24ξ-ethyl-5α-cholest-7-en-6-one (2), 3β-benzoxy-14β,22ξ-dihydroxy-4α-methyl-24ξ-ethyl-5α-cholest-7-en-6-one (3), 3β-benzoxy-14α,22ξ-dihydroxy-4α-methyl-24ξ-ethyl-5α-cholest-7-en-6-one (4) and 3β-(p-hydroxy)-benzoxy-22ξ-hydroxy-4α-methyl-24ξ-ethyl-5α-cholest-7-en-6-one (5).     

Sterol biosynthesis: Establishment of the structure of 3β-p-bromobenzoyloxy-5α-cholest-8(14)-en-15β-ol

Previous studies have established that hydride reduction of 3β-benzoyloxy-5α-cholest-8(14)-en-15-one yields two epimers (at C-15) of 5α-cholest-8(14)-en-3β,15-diol which were designated as diol A and B. Efficient enzymatic conversion of both compounds to cholesterol was observed. To determine the absolute configuration of the 15-OH function in the two compounds, the 3β-p-bromobenzoyl ester of diol B was prepared from 3β-p-bromobenzoyloxy-5α-cholest-8(14)-en-15-one by reduction with sodium borohydride. Crystals of the derivative were found to belong to the space group P1, with unit cell parameters; $\text{a = 9.24}\text{A}\text{?}$, $\text{b = 12.61}\text{A}\text{?}$, $\text{c = 7.03}\text{A}\text{?}$, α = 93.05°, β = 100.27°, γ = 90.82°, and one molecule per unit cell. Least-squares refinement of the structure was carried out to final R value of 0.14. The configuration of the hydroxyl group at the 15 position of diol B has been determined to be β.     

Ent-kauren-19-oic acid derivatives from the stem bark of Croton pseudopulchellus Pax

Two new ent-kauren-19-oic acid derivatives, ent-14S*-hydroxykaur-16-en-19-oic acid and ent-14S*,17-dihydroxykaur-15-en-19-oic acid together with eleven known compounds ent-kaur-16-en-19-oic acid, ent-kaur-16-en-19-al, ent-12β-hydroxykaur-16-en-19-oic acid, ent-12β-acetoxykaur-16-en-19-oic acid, 8R,13R-epoxylabd-14-ene, eudesm-4(15)-ene-1β,6α-diol, (?)-7-epivaleran-4-one, germacra-4(15), 5E,10(14)-trien-9β-ol, acetyl aleuritolic acid, β-amyrin, and stigmasterol were isolated from the stem bark of Croton pseudopulchellus (Euphorbiaceae). Structures were determined using spectroscopic techniques. Ent-14S*-hydroxykaur-16-en-19-oic acid, ent-kaur-16-en-19-oic acid, ent-12β-hydroxykaur-16-en-19-oic acid, ent-12β-acetoxykaur-16-en-19-oic acid and 8R,13R-epoxylabd-14-ene were tested for their effects on Semliki Forest virus replication and for cytotoxicity against human liver tumour cells (Huh-7 strain) but were found to be inactive. Ent-kaur-16-en-19-oic acid, the major constituent, showed weak activity against the Plasmodium falciparum (CQS) D10 strain.     

New diterpenes from Sideritis sicula

Two new diterpenes have been isolated from Sideritis sicula: sideripol, ent-18-acetoxy-7α-hydroxykaur-15-ene and epoxysideritriol, ent-15β,16β-epoxykauran-7α,17,18-triol. The previously known diterpene eubol, ent-7α-acetoxykaur-16-en-15β,18 diol has also been obtained from the same source.     

Mutagenicity of non-K-region diols and diol-epoxides of benz(a)anthracene and benzo(a)pyrene in S. typhimurium TA 100

When incubated with a 9,000 x g rat-liver supernatant, benzo(a)pyrene 7,8-diol and benz(a)anthracene 8,9-diol were more active than the parent hydrocarbons in inducing his⁺ revertant colonies of S. typhimurium TA 100. Benzo(a) pyrene 9,10-diol was less active than benzo(a)pyrene; the K-region diols, benz(a)anthracene 5,6-diol and benzo(a)pyrene 4,5-diol, were inactive. None of the diols was active when the cofactors for the microsomal mono-oxygenase were omitted. The diol-epoxides benzo(a)pyrene 7,8-diol 9,10-oxide, benz(a)anthracene 8,9-diol 10,11-oxide and 7-methylbenz(a)anthracene 8,9-diol 10,11-oxide and the K-region epoxides, benzo(a)pyrene 4,5-oxide and benz(a)anthracene 5,6-oxide, were mutagenic without further metabolism.