Browse publications by year: 2003

A preliminary investigation of chitosan film as dressing for punch biopsy wounds in rats

Khan TA, Peh KK

J Pharm Pharm Sci, 2003 Jan-Apr;6(1):20-6.
PMID: 12753727

To investigate the wound healing efficacy of two chitosan films, Chit-AA and Chit-LA, in comparison with a commercial preparation, Omiderm, using punch biopsy wounds in rats.

MeSH terms: Animals; Biopsy; Chitin/analogs & derivatives*; Chitin/pharmacology*; Chitin/chemistry; Disease Models, Animal; Male; Wound Healing/drug effects*; Wound Healing/physiology; Rats, Wistar; Chitosan; Rats
Cloning and expression of a novel lipase gene from Bacillus sphaericus 205y

Rahman RN, Chin JH, Salleh AB, Basri M

Mol Genet Genomics, 2003 May;269(2):252-60.
PMID: 12756537

A Bacillus sphaericus strain (205y) that produces an organic solvent-tolerant lipase was isolated in Port Dickson, Malaysia. The gene for the lipase was recovered from a genomic library and sequenced. Phylogenetic analysis was performed based on an alignment of thirteen microbial lipase sequences obtained from the NCBI database. The analysis suggested that the B. sphaericus lipase gene is a novel gene, as it is distinct from other lipase genes in Families I.4 and I.5 reported so far. Expression in Escherichia coli under the control of the lacZ promoter resulted in an eight-fold increase in enzyme activity after a 3-h induction with 1 mM IPTG. The crude enzyme thus obtained showed a slight (10%) enhancement in activity after a 30-min incubation in 25% (v/v) n-hexane at 37 degrees C, and retained 90% of its activity after a similar period in 25% (v/v) p-xylene.

MeSH terms: Amino Acid Sequence; Bacillus/enzymology*; Bacillus/genetics*; Base Sequence; Chromosome Mapping; Cloning, Molecular; DNA/metabolism; DNA Restriction Enzymes/metabolism; Electrophoresis, Polyacrylamide Gel; Escherichia coli/metabolism; Lac Operon; Lipase/genetics; Lipase/chemistry; Models, Genetic; Molecular Sequence Data; Phylogeny; Plasmids/metabolism; Promoter Regions, Genetic; Time Factors; Gene Library; Open Reading Frames; Sequence Homology, Amino Acid; Databases as Topic; Protein Sorting Signals
A novel approach for collecting samples from fruit bats for isolation of infectious agents

Chua KB

Microbes Infect., 2003 May;5(6):487-90.
PMID: 12758277

During the outbreak of Nipah virus encephalitis involving pigs and humans in peninsular Malaysia in 1998/1999, a conventional approach was initially undertaken to collect specimens from fruit bats by mist-netting and shooting, as an integral part of wildlife surveillance of the natural reservoir host of Nipah virus. This study describes a novel method of collecting fruit bats' urine samples using plastic sheets for isolation of Nipah virus. This novel approach resulted in the isolation of several other known and unidentified infectious agents besides Nipah virus.

MeSH terms: Animals; Chiroptera/urine*; Chiroptera/virology*; Disease Reservoirs/veterinary; Specimen Handling/methods*; Paramyxovirinae/isolation & purification*
Prenatal exclusion of severe factor VII deficiency

Ariffin H, Millar DS, Cooper DN, Chow T, Lin HP

J Pediatr Hematol Oncol, 2003 May;25(5):418-20.
PMID: 12759632

A nonconsanguineous asymptomatic couple, were identified as carriers of factor VII (FVII) deficiency when two of their newborn children died of massive intracranial hemorrhage secondary to severe congenital FVII deficiency. Complete sequence analysis of the factor VII (F7) gene in this couple indicated that the mother was heterozygous for an A to G transition at position -2 of the exon 5 acceptor splice site, and the father was heterozygous for a G to T transversion at position +1 of the exon 6 donor splice site. This information allowed us to exclude a compound heterozygous deficiency state in a subsequent pregnancy using PCR/direct sequencing of the F7 gene using DNA obtained from chorionic villi at 10 weeks' gestation. Our experience with the family reported here further supports the conclusion that mutation-specific detection is reliable in the prenatal exclusion of severe bleeding disorders.

MeSH terms: Factor VII Deficiency/diagnosis*; Factor VII Deficiency/genetics; Female; Humans; Infant, Newborn; Male; Pregnancy; Prenatal Diagnosis*; Chorionic Villi Sampling; Polymerase Chain Reaction
The effects of drainage basin geomorphometry on minimum low flow discharge: the study of small watershed in Kelang River Valley in Peninsular Malaysia

Yunus AJ, Nakagoshi N, Salleh KO

J Environ Sci (China), 2003 Mar;15(2):249-62.
PMID: 12765268

This study investigate the relationships between geomorphometric properties and the minimum low flow discharge of undisturbed drainage basins in the Taman Bukit Cahaya Seri Alam Forest Reserve, Peninsular Malaysia. The drainage basins selected were third-order basins so as to facilitate a common base for sampling and performing an unbiased statistical analyses. Three levels of relationships were observed in the study. Significant relationships existed between the geomorphometric properties as shown by the correlation network analysis; secondly, individual geomorphometric properties were observed to influence minimum flow discharge; and finally, the multiple regression model set up showed that minimum flow discharge (Q min) was dependent of basin area (AU), stream length (LS), maximum relief (Hmax), average relief (HAV) and stream frequency (SF). These findings further enforced other studies of this nature that drainage basins were dynamic and functional entities whose operations were governed by complex interrelationships occurring within the basins. Changes to any of the geomorphometric properties would influence their role as basin regulators thus influencing a change in basin response. In the case of the basin's minimum low flow, a change in any of the properties considered in the regression model influenced the "time to peak" of flow. A shorter time period would mean higher discharge, which is generally considered the prerequisite to flooding. This research also conclude that the role of geomorphometric properties to control the water supply within the stream through out the year even though during the drought and less precipitations months. Drainage basins are sensitive entities and any deteriorations involve will generate reciprocals and response to the water supply as well as the habitat within the areas.

MeSH terms: Climate; Fresh Water*; Geography; Humans; Malaysia; Seasons; Water Supply*; Models, Statistical; Ecosystem*
Fragmented forest in tropical landscape--the case of the state of Selangor, Malaysia

Abdullah SA

J Environ Sci (China), 2003 Mar;15(2):267-70.
PMID: 12765270

This paper presents the pattern and changes of fragmented forest in relation with changes of total forest cover in the state of Selangor in three decades. In this study, inventoried forest cover maps of Selangor in 1971/1972, 1981/1982 and 1991/1992 produced by the Forestry Department of Peninsular Malaysia were digitized to examine the changes in area and number of fragmented forest. Results showed that in 1971/1972, 16 fragmented forests were identified in Selangor. All fragmented forests were identified as dipterocarp forest. A decade later the number of fragmented forests increased by approximately 44% (23). Of the 23 fragmented forests, two were peat swamp forests whereas the remaining were dipterocarp forests. In 1991/1992 the number of fragmented forests (12) was reduced by 47.8%. Two of the fragmented forests were identified as peat swamp forest, seven dipterocarp forest and the other three was mixed of dipterocarp forests and plantation forests. Fragmentation of both dipterocarp and peat swamp forests occurred profoundly during the period between 1971/1972 and 1981/1982, which consequently increased the number of fragmented forests compared with before the period of 1971/1972 where fragmentation happened only at dipterocarp forests. However, many fragmented forests vanished between the 1981/1982 and 1991/1992 periods.

MeSH terms: Conservation of Natural Resources*; Environmental Monitoring/methods; Geography; Humans; Malaysia; Trees*; Tropical Climate; Ecosystem*; Theales
Tobacco and the Commonwealth: a call to action

Krishnan P, Mungherera M, Jones SB

Lancet, 2003 May 17;361(9370):1669-70.
PMID: 12767730 DOI: 10.1016/S0140-6736(03)13381-8
MeSH terms: Female; Forecasting; Health Policy/trends*; Health Promotion/organization & administration*; Humans; Male; Smoking/epidemiology*; Smoking/prevention & control*; Global Health; World Health Organization; Prevalence; Tobacco Industry/statistics & numerical data
Fulltext Factors related to the practice of breast self examination (BSE) and Pap smear screening among Malaysian women workers in selected electronics factories

Chee H, Rashidah S, Shamsuddin K, Intan O

BMC Womens Health, 2003 May 28;3(1):3.
PMID: 12769827

BACKGROUND: The Malaysian Ministry of Health promotes breast self-examination (BSE) for all women, and Pap smear screening every three years for all sexually active women ages 20 years and above. The objectives of this paper were to examine the practice of these two screening tests among women production workers in electronics factories, and to identify factors related to practice. METHODS: This was a cross-sectional survey of women production workers from ten electronics factories. Data was collected by a self-administered questionnaire from a total of 1,720 women. The chi-square test, odds ratio and binomial logistic regression were used in bivariate and multivariate analysis. RESULTS: Prevalence rates were 24.4% for BSE once a month, and 18.4% for Pap smear examination within the last three years. Women who were significantly more likely to perform BSE every month were 30 years and older, Malays, with upper secondary education and above, answered the BSE question correctly, and had a Pap smear within the last three years. The proportion of women who had a Pap smear within the last three years were significantly higher among those who were older, married, with young children, on the contraceptive pill or intra-uterine device, had a medical examination within the last five years, answered the Pap smear question correctly, and performed BSE monthly. CONCLUSION: Screening practice rates in this study were low when compared to national rates. Socio-demographic and health care factors significantly associated with screening practice are indicative of barriers which should be further understood so that more effective educational and promotional strategies could be developed.
Leptospirosis in "Eco-Challenge" athletes, Malaysian Borneo, 2000

Sejvar J, Bancroft E, Winthrop K, Bettinger J, Bajani M, Bragg S, et al.

Emerg Infect Dis, 2003 Jun;9(6):702-7.
PMID: 12781010

Adventure travel is becoming more popular, increasing the likelihood of contact with unusual pathogens. We investigated an outbreak of leptospirosis in "Eco-Challenge" multisport race athletes to determine illness etiology and implement public health measures. Of 304 athletes, we contacted 189 (62%) from the United States and 26 other countries. Eighty (42%) athletes met our case definition. Twenty-nine (36%) case-patients were hospitalized; none died. Logistic regression showed swimming in the Segama River (relative risk [RR]=2.0; 95% confidence interval [CI]=1.3 to 3.1) to be an independent risk factor. Twenty-six (68%) of 38 case-patients tested positive for leptospiral antibodies. Taking doxycycline before or during the race was protective (RR=0.4, 95% CI=0.2 to 1.2) for the 20 athletes who reported using it. Increased adventure travel may lead to more frequent exposure to leptospires, and preexposure chemoprophylaxis for leptospirosis (200 mg oral doxycycline/week) may decrease illness risk. Efforts are needed to inform adventure travel participants of unique infections such as leptospirosis.

MeSH terms: Adult; Disease Outbreaks*; DNA, Bacterial/analysis; Female; Fever/microbiology; Fever/epidemiology; Fresh Water/microbiology; Humans; Leptospira/genetics; Leptospira/isolation & purification; Leptospirosis/diagnosis; Leptospirosis/epidemiology*; Malaysia/epidemiology; Male; Middle Aged; Risk Factors; Sports; Travel*; Water Microbiology
Analysis of two additional loci in Neurospora crassa related to Spore killer-2

Turner BC

Fungal Genet. Biol., 2003 Jul;39(2):142-50.
PMID: 12781673

Two new loci found in one strain of Neurospora crassa (P2604) collected in Malaya are related to the meiotic drive system Spore killer Sk-2. Sk-2 was found in Neurospora intermedia and introgressed into N. crassa. P2604 showed high resistance to killing when crossed to Sk-2. This resistance was found to be linked to, but not allelic to, resistance locus r(Sk-2) on LGIIIL. Analysis showed that the high resistance phenotype of P2604 requires resistance alleles at two different loci on LGIIIR. Strains carrying a resistance allele at only the proximal or the distal locus, respectively, were obtained and intercrossed. Highly resistant strains were obtained by rejoining the two genes. The proximal locus alone confers a low level of resistance. This locus was named pr(Sk-2) for partial resistance to Sk-2. The distal locus was named mod(pr) because its only known phenotype is to modify pr(Sk-2).

MeSH terms: Alleles; Chromosome Mapping; Crosses, Genetic; Genes, Fungal*; Genetic Markers; Malaysia; Meiosis; Neurospora crassa/cytology; Neurospora crassa/genetics*; Spores, Fungal/genetics
Spectrum of breast cancer in Malaysian women: overview

Hisham AN, Yip CH

World J Surg, 2003 Aug;27(8):921-3.
PMID: 12784146

Breast cancer is the most common cancer among Malaysian women. Nonetheless, in Malaysia there is a marked geographical difference in the incidence of breast cancer with advanced stage of presentation. The breast clinic in Kuala Lumpur Hospital diagnosed approximately 150 to 200 new cases of breast cancer a year. This number, however, represents only 12.0% to 15.0% of all breast disease seen annually in Kuala Lumpur Hospital. Between 1998 and 2001, of a total of 774 cases of newly diagnosed breast cancer in Kuala Lumpur Hospital, only 5.0% (40/774) were impalpable breast cancers. The peak age group for the three major ethnic distributions (Malay, Chinese, and Indian) ranged from 40 to 49 years. The mean tumor size at presentation was 5.4 cm (range: 1-20 cm), and the advanced stage of breast cancer is observed to be highest among the Malay ethnic group. Although it appears that the incidence of breast cancer in Malaysia is lower than in the developed countries, the difference may be attributable to the difficulty in getting accurate statistics and to underreporting of cases. Nonetheless, from the available data, it is clear that breast cancer continues to be the most common cancer among Malaysian women. The strongly negative social-cultural perception of the disease, made worse by the geographical isolation of many rural areas, accounts for the delayed diagnosis and the often advanced stage of disease at presentation. A prospective population-based study is called for to verify the demographic patterns of breast cancer, particular in Malaysia and other developing countries. The findings of such a study may have implications for future breast screening programs and for facilitating the understanding of differing risks of breast cancer among women around the world.

MeSH terms: Age Factors; Culture; Female; Health Education; Humans; Malaysia/epidemiology
Styrylpyrone derivative induces apoptosis through the up-regulation of Bax in the human breast cancer cell line MCF-7

Chien AL, Pihie AH

J. Biochem. Mol. Biol., 2003 May 31;36(3):269-74.
PMID: 12787481

In the fight against cancer, novel chemotherapeutic agents are constantly being sought to complement existing drugs. Various studies have presented evidence that the apoptosis that is induced by these anticancer agents is implicated in tumor regression, and Bcl-2 family genes play a part in apoptosis following treatment with various stimuli. Here, we present data that a styrylpyrone derivative (SPD) that is extracted from the plant Goniothalamus sp. showed cytotoxic effects on the human breast cancer cell line MCF-7. SPD significantly increased apoptosis in MCF-7 cells, as visualized by phase contrast microscopy and evaluated by the Tdt-mediated dUTP nick end-labeling assay and nuclear morphology. Western blotting and immunostaining revealed up-regulation of the proapoptotic Bax protein expression. SPD, however, did not affect the expression of the anti-apoptotic protein, Bcl-2. These results, therefore, suggest SPD as a potent cytotoxic agent on MCF-7 cells by inducing apoptosis through the modulation of Bax levels.

MeSH terms: Antineoplastic Agents/pharmacology; Breast Neoplasms/metabolism; Breast Neoplasms/pathology; Cell Survival/drug effects; Dose-Response Relationship, Drug; Humans; Proto-Oncogene Proteins/metabolism*; Pyrones/pharmacology*; Styrenes/pharmacology*; Time Factors; Up-Regulation/drug effects; Apoptosis/drug effects*; Proto-Oncogene Proteins c-bcl-2*; Cell Line, Tumor; bcl-2-Associated X Protein
Phylogeny and characterization of three nifH-homologous genes from Paenibacillus azotofixans

Choo QC, Samian MR, Najimudin N

Appl Environ Microbiol, 2003 Jun;69(6):3658-62.
PMID: 12788777

In this paper, we report the cloning and characterization of three Paenibacillus azotofixans DNA regions containing genes involved in nitrogen fixation. Sequencing analysis revealed the presence of nifB1H1D1K1 gene organization in the 4,607-bp SacI DNA fragment. This is the first report of linkage of a nifB open reading frame upstream of the structural nif genes. The second (nifB2H2) and third (nifH3) nif homologues are confined within the 6,350-bp HindIII and 2,840-bp EcoRI DNA fragments, respectively. Phylogenetic analysis demonstrated that NifH1 and NifH2 form a monophyletic group among cyanobacterial NifH proteins. NifH3, on the other hand, clusters among NifH proteins of the highly divergent methanogenic archaea.

MeSH terms: Amino Acid Sequence; Bacillaceae/genetics*; Bacillaceae/metabolism; Bacterial Proteins/genetics*; Bacterial Proteins/metabolism; Bacterial Proteins/chemistry; Cloning, Molecular; Molecular Sequence Data; Nitrogen Fixation; Oxidoreductases/genetics*; Oxidoreductases/metabolism; Oxidoreductases/chemistry; Phylogeny*; Sequence Alignment; Sequence Homology, Amino Acid*; Sequence Analysis, DNA*
Evaluation of different promoters driving the GFP reporter gene and selected target tissues for particle bombardment of Dendrobium Sonia 17

Tee CS, Marziah M, Tan CS, Abdullah MP

Plant Cell Rep, 2003 Jan;21(5):452-8.
PMID: 12789448

Three different morphological callus types, identified as type A, B and C, and tips of in vitro inflorescences were used as target tissues for genetic transformation. Five different DNA plasmids carrying a synthetic green fluorescent protein (gfp) gene driven by different promoters, CaMV 35S, HBT, and Ubi1 were tested for the genetic transformation of Dendrobium Sonia 17. 35S-sgfp-TYG-nos (p35S) with the CaMV 35S promoter showed the highest GFP transient expression rate, while the HBT and Ubi1 promoters showed a relatively lower expression rate in all of the target tissues tested. The highest number of GFP-expressing cells was observed on day 2 post-bombardment, and the number declined gradually over the course of the next 2 weeks. Type A and B callus were found to be the best potential target tissues for genetic transformation.

MeSH terms: Luminescent Proteins/genetics; Luminescent Proteins/metabolism; Promoter Regions, Genetic/genetics*; Recombinant Fusion Proteins/genetics; Recombinant Fusion Proteins/metabolism; Genes, Reporter/genetics; Gene Expression Regulation, Plant; Plants, Genetically Modified; Dendrobium/genetics*; Dendrobium/metabolism; Culture Techniques; Green Fluorescent Proteins
Recent trends in elderly suicide rates in a multi-ethnic Asian city

Kua EH, Ko SM, Ng TP

Int J Geriatr Psychiatry, 2003 Jun;18(6):533-6.
PMID: 12789675

There are a few reports on the trends of elderly suicide rates in western countries but none from Asian countries.

MeSH terms: Aged; Aged, 80 and over; China/ethnology; Female; Humans; India/ethnology; Malaysia/ethnology; Male; Singapore/epidemiology; Suicide/trends*; Suicide/statistics & numerical data; Age Distribution; Sex Distribution
The prevalence of Anopheles (Diptera: Culicidae) mosquitoes in Sekong Province, Lao PDR in relation to malaria transmission

Vythilingam I, Phetsouvanh R, Keokenchanh K, Yengmala V, Vanisaveth V, Phompida S, et al.

Trop Med Int Health, 2003 Jun;8(6):525-35.
PMID: 12791058

A longitudinal study was conducted on the prevalence of Anopheles in three malaria endemic villages in Sekong province, in the southern region of Lao PDR, from August 2000 to October 2001. All night, human landing collections took place in August and October 2000 and April and October 2001, and blood smears were taken for malaria parasites during the same period. Mosquitoes were tested for sporozoite antigen using enzyme-linked immunosorbent assay. In August 2000 (wet season) and April 2001 (dry season) the ovaries of the mosquitoes were examined for parity. A total of 16 species of Anopheles were caught in the study sites of which An. dirus A, An. maculatus sl and An. jeyporiensis were positive for sporozoites. The entomological inoculation rate (EIR) ranged from 0.06 to 0.25. There was a good correlation between EIR and vectorial capacity in the wet season, especially in Pai Mai where the prevalence of malaria was also high during the wet seasons (11.8 and 10.53). An. dirus A showed ambivalence in their choice of feeding as approximately 50% attacked man indoors and an equal proportion outdoors. An dirus A was the main vector in Pai Mai. The parous rate did not significantly differ between the wet and dry season, although it was higher in the dry season. In Takaio the parasite prevalence ranged from 8.7% (dry season) to 37.1% (wet season) and An. jeyporiensis was the vector, and the risk of infection was 0.85 in the dry season while 0.99 in the wet season. In Toumgno An. maculatus sl was the vector and infection was found only in August and October 2000. However, malaria prevalence ranged from 9.69 to 20.4% and was equally high in the dry season. Cattle were also present close to the houses in all the villages and this might be a contributory factor in the prevalence of malaria.

MeSH terms: Animals; Anopheles/classification; Anopheles/parasitology*; Behavior, Animal; Female; Humans; Insect Bites and Stings/epidemiology; Insect Vectors/classification; Insect Vectors/parasitology*; Laos/epidemiology; Life Expectancy; Longitudinal Studies; Malaria/epidemiology; Malaria/transmission*; Parity; Plasmodium/isolation & purification*; Seasons; Species Specificity; Prevalence; Endemic Diseases
Sexual selection on land snail shell ornamentation: a hypothesis that may explain shell diversity

Schilthuizen M

BMC Evol. Biol., 2003 Jun 05;3:13.
PMID: 12791170

BACKGROUND: Many groups of land snails show great interspecific diversity in shell ornamentation, which may include spines on the shell and flanges on the aperture. Such structures have been explained as camouflage or defence, but the possibility that they might be under sexual selection has not previously been explored.
PRESENTATION OF THE HYPOTHESIS: The hypothesis that is presented consists of two parts. First, that shell ornamentation is the result of sexual selection. Second, that such sexual selection has caused the divergence in shell shape in different species.
TESTING THE HYPOTHESIS: The first part of the hypothesis may be tested by searching for sexual dimorphism in shell ornamentation in gonochoristic snails, by searching for increased variance in shell ornamentation relative to other shell traits, and by mate choice experiments using individuals with experimentally enhanced ornamentation. The second part of the hypothesis may be tested by comparing sister groups and correlating shell diversity with degree of polygamy.
IMPLICATIONS OF THE HYPOTHESIS: If the hypothesis were true, it would provide an explanation for the many cases of allopatric evolutionary radiation in snails, where shell diversity cannot be related to any niche differentiation or environmental differences.

MeSH terms: Animals; Models, Biological; Selection, Genetic*; Sexual Behavior, Animal/physiology*; Snails/genetics*; Models, Animal*
Copper vapour laser ID labelling on metal dentures and restorations

Ling BC, Nambiar P, Low KS, Lee CK

J Forensic Odontostomatol, 2003 Jun;21(1):17-22.
PMID: 12793127

Denture marking is accepted as a means of identifying dentures and persons in geriatric institutions, or post-mortem during war, crimes, civil unrest, natural and mass disasters. Labelling on the acrylic resin component of the denture can easily be damaged or destroyed by fire but on cobalt-chromium components it would be more resistant. A copper vapour laser (CVL) can be used to label the cobalt-chromium components of dentures and metal restorations easily, and legibly, and miniaturised for the incorporation of more personal particulars necessary for the identification of the deceased person. The CVL beam is focussed by its optics and delivered to the material surface by the two-axis scanner mounted with mirrors. A personal computer controls the movement of the scanner and the firing of the CVL. The high peak power of the pulsed CVL is focussed to very high energy density producing plasma ablation of the alloy surface. Very fine markings of a few microns width can be produced enabling the storage of detailed information of the deceased person on a metal surface for the purpose of rapid identification.

MeSH terms: Chromium Alloys/chemistry; Copper/chemistry; Dentures*; Dental Restoration, Permanent*; Denture Identification Marking/instrumentation; Denture Identification Marking/methods*; Forensic Dentistry; Humans; Lasers*; Miniaturization; Volatilization
1-Acetyl-4'-ethyl-2a'-phenyl-2',2a',5',5a'-tetrahydrospiro[1H-indole-3,2'-oxeto[5,4-b]oxazol]-2(3H)-one and 1-acetyl-4',5a'-diphenyl-2',2a',5',5a'-tetrahydrospiro[1H-indole-3,2'-oxeto[5,4-b]oxazol]-2(3H)-one

Usman A, Fun HK, Wang L, Zhang Y, Xu JH

Acta Crystallogr C, 2003 Jun;59(Pt 6):o305-7.
PMID: 12794346

In the title compounds, C(21)H(18)N(2)O(4) and C(25)H(18)N(2)O(4), respectively, the five-membered ring of the indole system is almost planar. The oxetane and oxazole rings are individually planar. The orientations of the indole, oxetane, oxazole and phenyl moieties are conditioned by the sp(3) nature of the spiro-C atoms. In both compounds, the relative orientation of the indole and oxazole rings is opposite.

MeSH terms: Ethers, Cyclic; Indoles; Oxazoles
9,10-Diphenyl-9,10-epidioxyanthracene and 9,10-dihydro-10,10-dimethoxy-9-phenylanthracen-9-ol

Usman A, Fun HK, Li Y, Xu JH

Acta Crystallogr C, 2003 Jun;59(Pt 6):o308-10.
PMID: 12794347

9,10-Diphenyl-9,10-epidioxyanthracene, C(26)H(18)O(2), (I), was accidentally used in a photooxygenation reaction that produced 9,10-dihydro-10,10-dimethoxy-9-phenylanthracen-9-ol, C(22)H(20)O(3), (II). In both compounds, the phenyl rings are approximately orthogonal to the anthracene moiety. The conformation of the anthracene moiety differs as a result of substitution. Intramolecular C-H.O interactions in (I) form two approximately planar S(5) rings in each of the two crystallographically independent molecules. The packing of (I) and (II) consists of molecular dimers stabilized by C-H.O interactions and of molecular chains stabilized by O-H.O interactions, respectively.

MeSH terms: Anthracenes; Biphenyl Compounds; Molecular Conformation

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