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I Muhammad

Publications and source records attributed to I Muhammad.

At least 19 recordsLinked to original sources
PubMed2001

Investigation of Uña De Gato I. 7-Deoxyloganic acid and 15N NMR spectroscopic studies on pentacyclic oxindole alkaloids from Uncaria tomentosa.

The C-8-(S) isomer of deoxyloganic acid (7-deoxyloganic acid), together with beta-sitosteryl glucoside, five known stereoisomeric pentacyclic oxindole alkaloids and the tetracyclic oxindole isorhyncophylline, were isolated from the inner bark of Uncaria tomentosa. Structures of the isolated compounds were based on 1H and 13C NMR data, mainly 2D NMR experiments, including 1H-13C HMBC and 1H-1H NOESY correlation. Furthermore, the hitherto unreported 15N chemical shifts of the isomeric oxindole alkaloids, using 1H-15N HMBC experiments, were utilized to facilitate their characterization. Uncarine D showed weak cytotoxic activity against SK-MEL, KB, BT-549 and SK-OV-3 cell lines with IC(50) values between 30 and 40 microg/ml, while uncarine C exhibited weak cytotoxicity only against ovarian carcinoma (IC(50) at 37 microg/ml).

Alkaloids↗
PubMed2001

Dihydroagarofuran alkaloid and triterpenes from Maytenus heterophylla and Maytenus arbutifolia.

The antimicrobially active EtOH extracts of Maytenus heterophylla yielded a new dihydroagarofuran alkaloid,1beta-acetoxy-9alpha-benzoyloxy-2beta,6alpha-dinicotinoyloxy-beta-dihydroagarofuran, together with the known compounds beta-amyrin, maytenfolic acid, 3alpha-hydroxy-2-oxofriedelane-20alpha-carboxylic acid, lup-20(29)-ene-1beta,3beta-diol, (-)-4'-methylepigallocatechin, and (-)-epicatechin. In addition, beta-amyrin, (-)-epicatechin and (-)-4'-methylepigallocatechin were isolated from Maytenus arbutifolia. The structure elucidation of the isolated compounds was based primarily on 1D and 2D NMR analyses, including HMQC, HMBC, and NOESY correlations. Maytenfolic acid showed moderate antimicrobial activity by inhibiting the growth of Candida albicans, Cryptococcus neoformans, Staphylococcus aureus and Pseudomonas aeruginosa.

Alkaloids↗
PubMed2001

Antimalarial, cytotoxic, and antifungal alkaloids from Duguetia hadrantha.

Bioassay-guided isolation of Duguetia hadrantha yielded two new 4,5-dioxo-1-azaaporphinoids, hadranthine A (1) and hadranthine B (2), together with the known alkaloids imbiline-1 (3), sampangine (4), and 3-methoxysampangine (5), whose structures were determined primarily from 2D-NMR 1H-13C HMBC, and 1H-15N HMBC experiments. This is the first report of the co-occurrence of the copyrine alkaloids 4 and 5, as well as the first report of either copyrine or imbiline type alkaloids from a Duguetia species. Compounds 1, 4, and 5 demonstrated in vitro antimalarial activity against Plasmodium falciparum (W-2 clone), while 2 was inactive. Instead, 2 showed in vitro cytotoxicity to selected human cancer cell lines (IC50 = 3-6 microg/mL against SK-MEL, KB, BT-549, and SK-OV-3), and 4 was also cytotoxic to human malignant melanoma (IC50 = 0.37 microg/mL). Sampangine (4) also inhibited cell aggregation with a MIC value of <0.15 microg/mL, while 3-methoxysampangine (5) was only weakly active.

Alkaloids↗
PubMed2001

Antimalarial (+)-trans-hexahydrodibenzopyran derivatives from Machaerium multiflorum.

Bioassay-guided fractionation of Machaerium multiflorum yielded the hitherto unreported (+)-trans-hexahydrodibenzopyrans machaeriol A (1) and machaeriol B (2), as well as the known guaiane sesquiterpene (-)-kessane. Structure elucidation was based on (1)H and (13)C NMR data, mainly 2D NMR (1)H-(1)H COSY, (1)H-(13)C HMQC, (1)H-(13)C HMBC, and (1)H-(1)H NOESY experiments. This is the first report of the hexahydrodibenzopyrans from a higher plant other than the genus Cannabis. The cannabimimetic activity was thus evaluated by radioligand binding assay for cannabinoid receptor CB1, which indicated, notably, that both 1 and 2 were inactive. In addition, the cross reactivity of 1 and 2 toward antibodies designed for urinary metabolites of cannabinoids was evaluated with the EMIT and On Line cannabinoids assays. Both compounds showed no response at 100 000 ng/mL in both assays. Machaeriol B (2) demonstrated in vitro antimalarial activity (IC(50) = 120 ng/mL) against Plasmodium falciparum W-2 clone.

Amphotericin B↗
PubMed2001

Haematuria in Africa: is the pattern changing?

OBJECTIVE: To study the aetiological factors and clinical presentation of haematuria as seen in a tertiary healthcare centre in a developing country in Africa. PATIENTS AND METHODS: The study comprised a retrospective review of the diagnostic indices and notes of patients with macroscopic haematuria presenting at the Ahmadu Bello University Teaching Hospital, Zaria, Nigeria, over a 7-year period from 1985 to 1991. RESULTS: Of a total of 2726 urology patients and 11 232 surgical patients, 482 had haematuria (17.7% and 4.3%, respectively, 387 males and 95 females, ratio 4.1 : 1, mean age 44.8 years, range 6-80). Many presented late with advanced malignant disease (T3, T4). Investigations useful in the diagnosis were urinary cytology, intravenous urography and cysto-urethroscopy. Common causes of haematuria were bladder carcinoma in 142 (31%), benign prostatic hypertrophy in 64 (14%) and urinary stones in 54 (12%). CONCLUSION: Recurrent haematuria in patients over 30 years of age in this environment should be considered or deemed to be caused by malignancy until confirmed otherwise. An educational programme is required to alert the population to the significance of haematuria as a symptom demanding a thorough investigation before treatment. This would need support by a haematuria service for accelerated diagnosis and treatment.

Adolescent↗
PubMed2001

Inhibitory effects of maesanin and analogs on arachidonic acid metabolizing enzymes.

The substituted 1,4-benzoquinone, maesanin (1), is a potent 5-lipoxygenase (5-LO) inhibitor present in the fruit of Maesa lanceolata Forssk. Thirteen natural, synthetic, semisynthetic, and microbially transformed analogs of 1 were tested for their in vitro inhibition of 5-lipoxygenase (5-LO) and cyclooxygenase-1 (COX-1). Maesanin was the most active 5-LO inhibitor. All other analogs were inactive or less active than the natural products as 5-LO inhibitors. None of the tested compounds was strongly active in the COX-1 inhibition assay.

Animals↗
PubMed2001

Improved method for the determination of oxindole alkaloids in Uncaria tomentosa by high performance liquid chromatography.

This Paper describes an improved HPLC method for the determination of pentacyclic oxindole alkaloids in Uncaria tomentosa (Cat's Claw). Six of the isomeric compounds could be baseline separated at room temperature within less than 30 min by using 3 microm C-18 column material and a mobile phase consisting of 10 mM phosphate buffer at pH 7.0 and acetonitrile. At a wavelength of 245 nm all standard compounds could be detected at concentrations as low as 0.63 microg/ml. Different samples of U. tomentosa bark and market products containing Cat's Claw were extracted with a modified procedure ensuring the integrity of the alkaloids and analyzed successfully. The results indicated accuracy and consistency of the new method, and showed variations in the total alkaloid content in products from 0.156 to 0.962%.

Alkaloids↗
PubMed2001

Two stereoisomeric pentacyclic oxindole alkaloids from Uncaria tomentosa: uncarine C and uncarine E.

The chloroform solvate of uncarine C (pteropodine), (1'S,3R,4'aS,5'aS,10'aS)-1,2,5',5'a,7',8',10',10'a-octahydro-1'-methyl-2-oxospiro[3H-indole-3,6'(4'aH)-[1H]pyrano[3,4-f]indolizine]-4'-carboxylic acid methyl ester, C(21)H(24)N(2)O(4).CHCl(3), has an absolute configuration with the spiro C atom in the R configuration. Its epimer at the spiro C atom, uncarine E (isopteropodine), (1'S,3S,4'aS,5'aS,10'aS)-1,2,5',5'a,7',8',10',10'a-octahydro-1'-methyl-2-oxospiro[3H-indole-3,6'(4'aH)-[1H]pyrano[3,4-f]indolizine]-4'-carboxylic acid methyl ester, C(21)H(24)N(2)O(4), has Z' = 3, with no solvent. Both form intermolecular hydrogen bonds involving only the oxindole, with N.O distances in the range 2.759 (4)-2.894 (5) A.

Alkaloids↗
PubMed2001

Influence of HIV infection on presentation of Kaposi's sarcoma.

We report a retrospective review of 57 patients with endemic Kaposi's sarcoma (EKS) seen between 1981 and 1990 and 40 prospectively diagnosed patients with and without human immunodeficiency virus (HIV) infection seen between 1991 and 1995. In the retrospective study 52 patients were males and five were females. Their ages ranged between 15 and 62 years with a mean of 39 years.Thirty-five (61%) patients had symptoms for more than 1 year. Nodular KS was seen in 75% of the patients. In the prospective study 26 patients had EKS while 14 had AIDS associated KS (AAKS). Among the patients with EKS 24 were males and two were females. The mean duration of symptoms was 20 months. The CD4 count done on nine patients ranged between 900 and 1300 cells/mm3 and there was no mortality within 1 year of presentation. Eleven of the patients with AAKS were males and three were females. Their ages ranged between 22 months and 41 years with a mean of 26. Nine patients had symptoms for less than 6 months. Ten patients had peripheral lymphadenopathy. CD4 counts done on 11 patients ranged between 200 and 800 cells/mm3. Five patients (35%) died within 6 months of presentation. Between 1991 and 1995, 486 patients were seen with HIV infection. Patients with AAKS present with fulminant disease which seemed quickly fatal.

Adolescent↗
PubMed2000

Bioactive 12-oleanene triterpene and secotriterpene acids from Maytenus undata.

The aerial parts of Maytenus undata yielded four new 12-oleanene and 3,4-seco-12-oleanene triterpene acids, namely, 3-oxo-11alpha-methoxyolean-12-ene-30-oic acid (1), 3-oxo-11alpha-hydroxyolean-12-ene-30-oic acid (2), 3-oxo-olean-9(11), 12-diene-30-oic acid (3), and 3,4-seco-olean-4(23),12-diene-3, 29-dioic acid (20-epi-koetjapic acid) (5), together with the known 3, 11-dioxoolean-12-ene-30-oic acid (3-oxo-18beta-glycyrrhetinic acid) (4), koetjapic acid (6), and the 12-oleanene artifact 3-oxo-11alpha-ethoxyolean-12-ene-30-oic acid (7). Koetjapic acid (6) inhibited the growth of Staphylococcus aureus, methicillin-resistant S. aureus, and Pseudomonas aeruginosa, with an MIC range of 3.125-6.25 microg/mL. The new 3,4-secotriterpene acid 20-epi-koetjapic acid (5) potently inhibited rat neonatal brain microglia phorbol ester-stimulated thromboxane B(2) (IC(50) = 0.5 microM) and superoxide anion (IC(50) = 1.9 microM) generation.

Anti-Bacterial Agents↗
PubMed1996

Burns in children under 3 years of age: the Zaria experience.

This is a retrospective study of 84 children aged 36 months and less who were admitted for burns care from January 1980 to December 1989. Fifty-four (64%) had scalds, 28 (33%) had flame burns and in two children the cause was not known. The upper extremities were most commonly involved. Sixty-five per cent of the children were admitted during the cool, dry Harmattan season. Associated factors included cooking at floor level, bedside fires, epileptic fits in the mothers and general architectural factors. Wound infection was the commonest complication. The overall mortality rate was 27.4%. Burns prevention demands improvement in the design of houses, cooking methods, treatment of epilepsy and abandoning puerperal bathing by mothers.

Burns↗
PubMed1996

Major limb amputation in adults, Zaria, Nigeria.

Over a period of 10 years, a total of 320 limb amputations were performed on adults at the Ahmadu Bello University Hospital, Nigeria. The major indication for upper limb amputation was trauma and post-fracture splintage gangrene (57%). In the lower limb the most common indication for amputation was advanced squamous cell carcinoma of the skin involving the bone. There was no case of peripheral vascular disease in these patients other than diabetic ulcers. The fitting of prosthesis was uncommon. Most of these amputations were certainly preventable. The need is for early and effective management of fractures, and the excision and grafting of non-healing leg ulcers before they become chronic.

Adolescent↗
PubMed1995

Limb amputation in children in Zaria, Nigeria.

Over a period of 10 years, a total of 118 limb amputations were performed in children at the Ahmadu Bello University Hospital, Zaria, Nigeria. The major indication for limb amputation was trauma and gangrene following post-fracture splintage by traditional healers. There was no case of peripheral vascular disease in these patients. None of the patients had a prosthesis applied. The very high number of limb amputations is certainly preventable by early and effective management of fractures.

Adolescent↗
PubMed1994

Clothing burns in Zaria.

From 1980 to 1989, 45 patients with clothing burn injuries were admitted into the Ahmadu Bello University Teaching Hospital, Zaria, Nigeria. Children aged 15 years and below numbered 30 and adults aged 16 years and above totalled 15. There was a female preponderance in the ratio of 1.8:1. The cumulative monthly frequency between October and February recorded the highest number of admissions (77 per cent) with a peak in January (31 per cent). The involvement of women and children especially those below the age of 5 years is noteworthy. Eighty per cent of the patients had a major injury with a total mortality of 42 per cent. The improvement in the economic standard of the populace shown by the improvement in cooking methods, the proper use of gas cookers and kerosene lanterns, the avoidance of bedside fires during the night, the guarded use of loose indigenous garments, and the use of nursery schools for the care of children below 5 years of age will help to lower the incidence of clothing burn injuries in our environment.

Accidents, Home↗
PubMed1991

Spontaneous rupture of primary hepatocellular carcinoma in Zaria, Nigeria.

Primary hepatocellular carcinoma more often presents acutely with rupture and haemoperitoneum in Africa and Asia where the tumour is more common than in the Western world. This detailed report on 35 patients with ruptured primary hepatocellular carcinoma describes the clinical features of this phenomenon in the savannah zone of Northern Nigeria. A third of the patients arrived in the hospital in hypovolaemic shock and although haemostasis was achieved by wedge excision and suture in most cases, 16 (46%) of the patients died in hospital.

Abdominal Pain↗