Rutaceous alkaloids as models for the design of novel antitumor drugs

The chemical diversity of alkaloids in the Rutaceae is correlated with biosynthetic pathways involving various aromatic amino acid precursors, tyrosine, tryptophan, histidine, and anthranilic acid. The interest of rutaceous polyheteroaromatic alkaloids as models for the development of anticancer agents relies on their frequent ability to interact with DNA or with systems involved in the control of its topology, repair, and replication. Fagaronine and nitidine, from Zanthoxylum, demonstrate antileukemic activity, associated with topoisomerases inhibition. Evodiamine from Euodia rutaecarpa, displays antimetastatic properties. The pyranoacridone acronycine, from Sarcomelicope, exhibits antitumor activity against a broad spectrum of solid tumors. Development of synthetic analogues based on this latter natural product template followed the isolation of the unstable acronycine epoxide, which led to a hypothesis of bioactivation of acronycine by transformation of the 1,2-double bond into the corresponding oxirane. 1,2-Diacyloxy-1,2-dihydroacronycine derivatives exhibited antitumor properties, with a broadened spectrum of activity and an increased potency. The demonstration that acronycine interacted with DNA led to develop benzo[a], [b], and [c]acronycine analogs. Benzo[a] and [b] derivatives displayed significant antitumor activities. 1,2-Dihydroxy-1,2-dihydrobenzo[b]acronycine esters and diesters were active in human orthotopic models of cancers xenografted in nude mice. The activity of these compounds was correlated with their ability to give covalent adducts with DNA, involving reaction between the N-2 amino group of guanines and the ester group at the benzylic position of the drug. Cis-1,2-diacetoxy-1,2-dihydrobenzo[b]acronycine, currently developed under the code S23906-1, successfully underwent phase I and is currently under phase II clinical trials.     

Benzo(a)pyrene metabolism by purified forms of rabbit liver microsomal cytochrome P-450, cytochrome b5 and epoxide hydrase in reconstituted phospholipid vesicles

The roles of rabbit liver cytochrome b₅, epoxide hydrase and various forms of cytochrome P-450 in the NADPH-dependent metabolism of benzo(a)pyrene were examined. After incorporation of the purified enzymes into phospholipid vesicles, using the cholate gel filtration technique, the various types of cytochrome P-450 did exhibit different stereospecificities in the oxygenation of the substrate. Cytochrome P-450_LM2 was found to efficiently convert benzo(a)pyrene in the presence of epoxide hydrase to 4,5-dihydroxy-4,5-dihydrobenzo(a)pyrene whereas cytochrome P-450_LM4 primarily participated in the formation of 9,10-dihydroxy-9,10-dihydrobenzo(a)pyrene. By contrast, benzo(a)pyrene was not metabolized by cytochrome P-450_LM3. Cytochrome b₅ enhanced cytochrome P-450_LM2-catalyzed oxygenations 5-fold, whereas cytochrome P-450_LM4-dependent oxygenations proceeded at a 3 times higher rate when cytochrome b₅ was present in the membrane.     

Enantiomeric Composition of Trans-Dihydrodiols Formed from Meso-K-Region Arene Oxides by Microsomal Epoxide Hydrolase

Absolute configurations for the enantiomers of trans-4,5-dihydroxy-4,5-dihydrobenzo[e]pyrene were determined by the exciton chirality method and by correlation of physical properties of their (−)-(menthyloxy)acetyl diesters. Microsomal epoxide hydrolase catalyzed the hydrolysis of K-region arene oxides of benzo[e]pyrene, pyrene, and phenanthrene to trans-dihydrodiols containing 83 %, 86 %, and 42 % of the R,R enantiomer, respectively.     

柯拉斯那沉香的生物活性成分研究

为了解柯拉斯那(Aquilaria crassna)的化学成分,从其所产沉香中分离得到10个化合物,经波谱分析分别鉴定为:6,8-羟基-2-(2-苯乙基)色酮(1),6,8-二羟基-2-[2-(4-甲氧基苯)乙基]色酮(2),rel-(1a R,2R,3R,7b S)-1a,2,3,7b-tetrahydro-2,3-dihydroxy-5-(2-phenylethyl)-7H-oxireno[f][1]benzopyran-7-one(3),rel-(1a R,2R,3R,7b S)-1a,2,3,7b-tetrahydro-2,3-dihydroxy-[2-(4-methoxyphenyl)-ethyl]-7H-oxireno[f][1]benzopyran-7-one(4),rel-(1a R,2R,3R,7b S)-1a,2,3,7b-tetrahydro-2,3-dihydroxy-5-[2-(3-hydroxy-4-methoxyphenyl)-ethyl]-7H-oxireno[f][1]benzopyran-7-one(5),oxidoagarochromone B(6),oxidoagarochromone C(7),(5S,6R,7S,8R)-2-[2-(3′-hydroxy-4′-methoxyphenyl)ethyl]-5,6,7,8-tetrahydroxy-5,6,7,8-tetrahydrochromone(8),6,7-cis-dihydroxy-2-(2-phenylethyl)-5,6,7,8-tetrahydrochromone(9),N-trans-feruloyltyramine(10)。化合物3~5和8~10为首次从柯拉斯那沉香中分离得到。化合物1,3,6,7,9和10对乙酰胆碱酯酶具有一定的抑制活性,化合物4对人慢性髓原白血病细胞株K-562和人胃癌细胞株SGC-7901均具有较小的抑制作用,化合物1和3对人肝癌细胞株BEL-7402也有抑制活性。     

Aliphatic 3,4-epoxyalcohols: Metabolism by epoxide hydrase and mutagenic activity

Rabbit hepatic microsomal epoxide hydrase catalyzes the rapid hydrolysis of 1,2-epoxy-4-heptanol to 1,2,4-heptanetriol. Both diastereomers of the substrate are hydrolyzed, and both product diastereomers are formed. Similarly, both cis- and trans-3,4-epoxy-1-hexanol are hydrolyzed, albeit more slowly, to give 1,3,4-hexanetriol. The trans isomer gives exclusively one diastereomer (erythro) of the triol, while the cis isomer gives the other diastereomer (threo). The product expected if a primary cationic intermediate were to be formed and trapped intramolecularly during the hydrolysis of 1,2-epoxy-4-heptanol, 2-propyl-4-tetrahydrofuranol, was not observed. A comparison of the mutagenic activity in the Ames test of 1-heptane, 1-hepten-4-ol, 1,2-epoxyheptane, and 1,2-epoxy-4-heptanol revealed that only the latter is a detectable mutagen. A vicinal hydroxyl therefore does not interfere significantly with enzymatic epoxide hydrolysis, but it does enhance the bioalkylating potential of even an aliphatic epoxide.     

Synthesis and cytotoxicity of methyl-4,8-dihydrobenzo[1,2-b:5,4-b']dithiophene-4,8-dione derivatives.

2- and 3-Methyl-4,8-dihydrobenzo[1,2-b:5,4-b']dithiophene-4,8-dione and related derivatives were synthesized and evaluated in vitro by NCI against eight cancer types. Compounds 12-15 showed significant activity against melanoma, NCI-H23 non-small cell lung cancer, and MDA-MB-435 and MDA-N breast cancer cell lines; 2-hydroxymethyl-4,8-dihydrobenzo[1,2-b:5,4-b']dithiophene-4,8-dion e (13) showed the highest activity against melanoma (mean log GI50 = -7.74) and the highest overall potency (mean log GI50 = -6.99).     

Identification of metabolites from degradation of naphthalene by a Mycobacterium sp.

A Mycobacterium sp. isolated from oil-contaminated sediments was previously shown to mineralize 55% of the added naphthalene to carbon dioxide after 7 days of incubation. In this paper, we report the initial steps of the degradation of naphthalene by a Mycobacterium sp. as determined by isolation of metabolites and incorporation of oxygen from ¹⁸O₂ into the metabolites. The results indicate that naphthalene is initially converted to cis- and trans-1,2-dihydroxy-1,2-dihydronaphthalene by dioxygenase and monooxygenase catalyzed reactions, respectively. The ratio of the cis to trans-naphthalene dihydrodiol isomers was approximately 25:1. Thin layer and high pressure liquid chromatographic and mass spectrometric techniques indicated that besides the cis- and trans-1,2-dihydroxy-1,2-dihydronaphthalene, minor amounts of ring cleavage products salicylate and catechol were also formed. Thus the formation of both cis and trans-naphthalene dihydrodiols by the Mycobacterium sp. is unique. The down-stream reactions to ring cleavage products proceed through analogous dioxygenase reactions previously reported for the bacterial degradation of naphthalene.     

Metabolism of benzo[a]pyrene VI. Stereoselective metabolism of benzo[a]pyrene and benzo[a]pyrene 7,8-dihydrodiol to diol epoxides

(±)-7β,8α-Dihydroxy-9β,10β-epoxy-7,8,9,10-tetrahydrobenzo[a]pyrene (diol epoxide-1) and (±)-7β,8α-dihydroxy-9α,10α-epoxy-7,8,9,10-tetrahydrobenzo[a]pyrene (diol epoxide-2) are highly mutagenic diol epoxide diastereomers that are formed during metabolism of the carcinogen (±)-trans-7,8-dihydroxy-7,8-dihydrobenzo[a]pyrene. Remarkable stereoselectivity has been observed on metabolism of the optically pure (+)- and (?)-enantiomers of the dihydrodiol which are obtained by separation of the diastereomeric diesters with (?)-α-methoxy-α-trifluoromethylphenylacetic acid. The high stereoselectivity in the formation of diol epoxide-1 relative to diol epoxide-2 was observed with liver microsomes from 3-methylcholanthrene-treated rats and with a purified cytochrome P-448-containing monoxygenase system where the (?)-enantiomer produced a diol epoxide-2 to diol epoxide-1 ratio of 6 : 1 and the (+)-enantiomer produced a ratio of 1 : 22. Microsomes from control and phenobarbital-treated rats were less stereospecific in the metabolism of enantiomers of BP 7,8-dihydrodiol. The ratio of diol epoxide-2 to diol epoxide-1 formed from the (?)- and (+)-enantiomers with microsomes from control rats was 2 : 1 and 1 : 6, respectively. Both enantiomers of BP 7,8-dihydrodiol were also metabolized to a phenolic derivative, tentatively identified as 6,7,8-trihydroxy-7,8-dihydrobenzo[a]pyrene, which accounted for ～30% of the total metabolites formed by microsomes from control and phenobarbital-pretreated rats whereas this metabolite represents ～5% of the total metabolites with microsomes from 3-methylcholanthrene-treated rats. With benzo[a]pyrene as substrate, liver microsomes produced the 4,5-, 7,8- and 9,10-dihydrodiol with high optical purity (>85%), and diol epoxides were also formed. Most of the optical activity in the BP 7,8-dihydrodiol was due to metabolism by the monoxygenase system rather than by epoxide hydrase, since hydration of (±)-benzo[a]pyrene 7,8-oxide by liver microsomes produced dihydrodiol which was only 8% optically pure. Thus, the stereospecificity of both the monoxygenase system and, to a lesser extent, epoxide hydrase plays important roles in the metabolic activation of benzo[a]pyrene to carcinogens and mutagens.     

Beijerinckia sp strain B1: a strain by any other name . . . . .

Beijerinckia sp strain B1 grows with biphenyl as its sole source of carbon and energy. A mutant, strain B8/36, oxidized biphenyl to cis-(2S,3R)-dihydroxy-l-phenylcyclohexa-4,6-diene (cis-biphenyl dihydrodiol). Strain B8/36 oxidized anthracene, phenanthrene, benz[a]anthracene and benzo[a]pyrene to cis-dihydrodiols. Other substrates oxidized to cis-dihydrodiols were dibenzofuran, dibenzothiophene and dibenzo-p-dioxin. Biphenyl dioxygenase activity was observed in cells of Beijerinckia B1 and B8/36 after growth in the presence of biphenyl, m-, p-xylene and salicylate. Recent studies have led to the reclassification of Beijerinckia B1 as Sphingomonas yanoikuyae strain B1. Subsequent biotransformation studies showed that S. yanoikuyae B8/36 oxidized chrysene to a bis-cis-diol with hydroxyl substituents at the 3,4- and 9,10-positions. Dihydronaphthalene was oxidized to cis-1,2-dihydroxy-1,2,3,4-tetrahydronaphthalene, naphthalene, cis-1,2-dihydroxy-1,2-dihydronaphthalene and 2-hydroxy-1,2-dihydronaphthalene. Anisole and phenetole were oxidized to phenol. Thus the S. yanoikuyae biphenyl dioxygenase catalyzes cis-dihydroxylation, benzylic monohydroxylation, desaturation and dealkylation reactions. To date, the genes encoding biphenyl dioxygenase have not been cloned. However, the nucleotide sequence of a S. yanoikuyaeB1 DNA fragment contains five different α subunits as determined by conserved amino acids coordinating iron in a Rieske [2Fe-2S] center and mononuclear iron at the catalytic site. The specific role of the different putative oxygenases in biotransformation reactions catalyzed by S. yanoikuyae is not known and presents an exciting challenge for future studies. Received 29 May 1999/ Accepted in revised form 23 June 1999     

Biotransformation of anisole and phenetole by aerobic hydrocarbonoxidizing bacteria

Wild type, mutant, and recombinant bacterial strains capable of oxidizing aromatic hydrocarbons were screened for their ability to oxidize anisole (methoxybenzene) and phenetole (ethoxybenzene). Toluene-induced cells ofPseudomonas putida F39/D transformed anisole to a compound tentatively identified ascis-1,2-dihydroxy-3-methoxyclohexa-3,5-diene (anisole-2,3-dihydrodiol), 2-methoxyphenol, catechol, and trace amounts of phenol while phenetole was converted primarily tocis-1,2-dihydroxy-3-ethoxycyclohexa-3,5-diene (phenetole-2,3-dihydrodiol) and 2-ethoxyphenol. Induced cells ofPseudomonas sp. NCIB 9816/11 andBeijerinckia sp. B8/36 transformed anisole to phenol, and phenetole to phenol and ethenyloxybenzene. Toluene-induced cells ofP. putida BG1 converted anisole to phenol but did not oxidize phenetole. In contrast, toluene-induced cells ofP. mendocina KR1, which oxidize toluene via monooxygenation at thepara position, transformed anisole to 4-methoxyphenol, and phenetole to 2-, 3- and 4-ethoxyphenol. The involvement of toluene and naphthalene dioxygenases in the reactions catalyzed by strains F39/D and NCIB 9816/11, respectively, was confirmed with recombinantE. coli strains expressing the cloned dioxygenase genes. The results show that the oxygenases from differentPseudomonas strains oxidize anisole and phenetole to different hydroxylated products.     

Alkaloid profile and antimicrobial activity of <Emphasis Type="Italic">Lupinus angustifolius</Emphasis> L. alkaloid extract

Purpose of the present study was to evaluate alkaloid profile of the aerial parts of Lupinus angustifolius growing in Turkey by capillary gas chromatography-mass spectrometry (GC-MS). Fifteen alkaloids were identified by capillary GC-MS. 13α-Hydroxylupanine (50.78%) and lupanine (23.55%) were determined as the main alkaloids in the aerial parts of L. angustifolius. Ammodendrine, isoangustifoline, tetrahydrorhombifoline, angustifoline, α-isolupanine, 5,6-dehydrolupanine, 11,12-dehydrolupanine, 13α-acetoxylupanine, 13α-isovaleroyloxylupanine, 13α-valeroyloxylupanine, 13α-tigloyloxylupanine, 13α-cis-cinnamoyloxylupanine and 13α-cis-cinnamoyloxy-17-oxolupanine were identified as the minor alkaloids of the plant. Furthermore, antibacterial and antifungal activities of L. angustifolius alkaloid extract were tested against standard strains of the following bacteria; Escherichia coli, Pseudomonas aeruginosa, Bacillus subtilis and Staphylococcus aureus as well as the fungi; Candida albicans and C. krusei. The alkaloid extract showed significant activity on B. subtilis, S. aureus and P. aeruginosa while it was weakly active on E. coli. On the other hand, the extract possessed moderate activity against C. albicans and C. krusei.     

Resolution of optical isomers by high-pressure liquid chromatography: The separation of benzo[a]pyrene trans-diol derivatives

The optical isomers of (±)r-7,t-8-dihydroxy-7,8-dihydrobenzo[a]pyrene and its synthetic precursor (±)r-7,t-8-dihydroxy-7,8,9,10-tetrahydrobenzo[a]pyrene were resolved as their di-(−)menthoxyacetates using high-pressure liquid chromatography. Saponification of the resolved diesters yielded the corresponding enantiomers. The specific rotation, CD spectra, and ORD curves are reported. The resolution of these optical isomers permits detailed studies on the enzymatic intermediates and the mechanism of benzo[a]pyrene activation to its carcinogenic form. The method is of general usefulness for the resolution of optical isomers.     

Metabolism of naphthalene by the biphenyl-degrading bacterium Pseudomonas paucimobilis Q1

Pseudomonas paucimobilis Q1 originally isolated as biphenyl degrading organism (Furukawa et al. 1983), was shown to grow with naphthalene. After growth with biphenyl or naphthalene the strain synthesized the same enzyme for the ring cleavage of 2,3-dihydroxybiphenyl or 1,2-dihydroxynaphthalene. The enzyme, although characterized as 2,3-dihydroxybiphenyl dioxygenase (Taira et al. 1988), exhibited considerably higher relative activity with 1,2-dihydroxynaphthalene. These results demonstrate that this enzyme can function both in the naphthalene and biphenyl degradative pathway.Abbreviations DHBP dihydroxybiphenyl - DHBPDO 2,3-dihydroxybiphenyl dioxygenase - DHDHNDH 1,2-dihydroxy-1,2-dihydronaphthalene dehydrogenase - DHN 1,2-dihydroxynaphthalene - DHNDO 1,2-dihydroxynaphthalene dioxygenase - HBP cis-2-hydroxybenzalpyruvate - HOPDA 2-hydroxy-6-oxo-6-phenylhexa-2,4-dienoate - PCB polychlorinated biphenyl - 2NS naphthalene-2-sulfonic acid     

Synthesis,Antiproliferative, and Antiviral Evaluation of Certain Acyclic 6-Substituted Pyrrolo[2,3-D]-pyrimidine Nucleoside Analogs Related to Sangivamycin and Toyocamycin

Abstract

A number of 6-substituted 7-[(2-hydroxyethoxy)methyl]pyrrolo[2,3-d]pyrimidine and 7-[(1,3-dihydroxy-2-propoxy)methyl]pyrrolo[2,3-d]pyrimidine derivatives related to the nucleoside antibiotics toyocamycin and sangivamycin were prepared and tested for their biological activity. Treatment of 2-amino-5-bromo-3,4-dicyanopyrrole (2) with triethylorthoformate, followed by alkylation via the sodium salt method with either 2-(acetoxyethoxy)methyl bromide or (1,3-diacetoxy-2-propoxy)methyl bromide, furnished the corresponding N-substituted pyrroles 3a and 3b. These compounds were then smoothly converted to the requisite deprotected 4-amino-6-bromopyrrolo[2,3-d]-pyrimidine-5-carbonitriles 5a and 5b (toyocamycin analogs) by methanolic ammonia. The 6-amino-derivatives were obtained by a displacement of the bromo group with liquid ammonia. Conventional functional group transformations involving the 5-cyano group furnished the 5-carboxamide (sangivamycin) and 5-thioamide analogs. Compounds substituted at the 7-position with a ribosyl moiety were active against human cytomegalovirus (HCMV) at micromolar concentrations, but the apparent activity was not selective. The 7-ribosyl compounds also had no activity against human immunodeficiency virus (HIV), though they were all cytotoxic. The new compounds were also evaluated against HCMV, herpes simplex virus type I (HSV-1), HIV, and also for their ability to inhibit the growth of L1210 murine leukemic cells in vitro. None of these compounds with (2-hydroxyethoxy)methyl substituents or 7-(1,3-dihydroxy-2-propoxy)methyl substituent at N-7 showed significant cytotoxicity toward L1210, or toward uninfected human foreskin fibroblasts (HFF cells), and KB cells. Nor were they cytotoxic in human lines CEM or MT2. Only compound 4a was found to be active against HCMV, having an IC₅₀ of 32 μM.     

A novel enantioselective epoxide hydrolase for (R)-phenyl glycidyl ether to generate (R)-3-phenoxy-1,2-propanediol

Bacillus sp. Z018, a novel strain producing epoxide hydrolase, was isolated from soil. The epoxide hydrolase catalyzed the stereospecific hydrolysis of (R)-phenyl glycidyl ether to generate (R)-3-phenoxy-1,2-propanediol. Epoxide hydrolase from Bacillus sp. Z018 was inducible, and (R)-phenyl glycidyl ether was able to act as an inducer. The fermentation conditions for epoxide hydrolase were 35°C, pH 7.5 with glucose and NH₄Cl as the best carbon and nitrogen source, respectively. Under optimized conditions, the biotransformation yield of 45.8% and the enantiomeric excess of 96.3% were obtained for the product (R)-3-phenoxy-1,2-propanediol.     

Synthesis of Theaspirone

β-Ionone (I) was oxidized to 2,3-epoxy-/β-ionone (II), which was converted to 2,3-dihydroxy-β-ionone (III) by acid treatment. III was reduced to 4-(1,2-dihydroxy-2,6,6-trimethylcyclohexan-1-yl)-2-butanol (V), which was converted, by oxidation, to cis- and trans-theaspirone (1-oxa-8-oxo-2,6,10,10-tetramethyl spiro-(4,5)-6-decene) (VII-A), (VII-B) and dihydroactinidiolide (2-hydroxy-2,6,6-trimethylcyclohexyliden-1-acetic acid lactone) (IX).     

Degradation 1,2-dimethylbenzene by Corynebacterium strain C125

In an attempt to obtain bacteria growing on 1,2-dimethylbenzene as sole carbon and energy source two different strains were isolated. One was identified as an Arthrobacter strain, the other as a Corynebacterium strain. Corynebacterium strain C125 was further investigated. The organism was not capable to grow on 1,3- and 1,4-dimethylbenzene. cis-1,2-Dihydroxycyclohexa-3,5-diene oxidoreductase and 3,4-dimethylcatechol-2,3-dioxygenase activity was found in cell extracts. When 3,4-dimethylcatechol was added to cell extract of 1,2-dimethylbenzene-grown cells, first a compound with the spectral properties of 2-hydroxy-5-methyl-6-oxo-2,4-heptadienoate was formed and subsequently acetate was produced. It is proposed that dioxygenases are involved in the initial steps of 1,2-dimethylbenzene degradation, and ring opening proceeds via meta-cleavage.     

Synthesis,cytotoxic activity,and DNA binding properties of antitumor cis-1,2-dihydroxy-1,2-dihydrobenzo[b]acronycine cinnamoyl esters

Monocinnamoyl esters at position 2 of (±)-cis-1,2-dihydroxy-6-methoxy-3,3,14-trimethyl-1,2,3,14-tetrahydro-7H-benzo[b]pyrano[3,2-h]acridin-7-one and their acetyl derivatives at position 1 were prepared as stabilized analogues of the anticancer alkylating agent S23906-1. Monocinnamoyl esters at position 2 were slower DNA alkylators than the reference 2-monoacetate. Mixed esters bearing an acetyl ester group at position 1 and a cinnamoyl ester group at position 2 alkylated DNA slower than S23906-1. A strong correlation was observed between cytotoxicity and DNA alkylation kinetics, with slower alkylators displaying more potent antiproliferative activities. The most cytotoxic compounds proved to be significantly active in vivo against murine C-38 adenocarcinoma implanted in mice, but less potent than S23906-1.     

The Production of Catechols from Benzene and Toluene by Pseudomonas Putida in Glucose Fed-Batch Culture

Catechol and 3-methylcatechol were produced from benzene and toluene respectively using different mutants of Pseudomonas putida. P. putida 2313 lacked the extradiol cleavage enzyme, catechol 2,3-oxygenase, allowing overproduction of 3-methylcatechol from toluene to a level of 11.5 mM (1.27 g·1^-1) in glucose fed-batch culture. P. putida 6(12), a mutant of P. putida 2313, lacked both catechol-oxygenase and catechol 1,2-oxygenase, and accumulated catechol from benzene to a level of 27.5mM(3g·1^-1).

In both biotransformations product formation ceased within 10 hours of feeding the aromatic substrate, and this was due to product inhibition by the catechols. The primary site of catechol toxicity was inhibition of the aromatic dioxygenase. Neither cis-toluene dihydrodiol cis-1,2-dihydroxy-3-methylcyclohexa-3,5-diene), nor cis-benzene dihydrodiol (cis-l,2-dihydroxy-3-methylcyclohexa-3,5-diene) dehydrogenase was significantly inhibited by catechol overproduction whereas both ring activating dioxygenases were inhibited within 4-6 hours of the maximum product concentration being attained.

3-Methylcatechol overproduction from toluene was also studied using a continuous product removal system. Granular activated charcoal removed 3-methylcatechol efficiently and was easily regenerated by washing with ethyl acetate. Using P. putida 2313, it was shown that the final product concentration increased approximately fourfold. Additional products were formed and the significance of these are discussed.     

Insecticidal compound isolated from Syzygium lineare Wall. (Myrtaceae) against Spodoptera litura (Lepidoptera: Noctuidae)

A new crystal compound 2,5-diacetoxy-2-benzyl-4,4,6,6-tetramethyl-1,3-cyclohexanedione was isolated from the leaves of Syzygium lineare. The insecticidal activity of the compound was assessed against fourth instar larvae of Spodoptera litura. Its activity was better than the positive control azadirachtin. The compound was responsible for growth inhibition on S. litura. It induced larval, pupal and adult deformities even at low concentration. The compound may be useful as a botanical pesticide.