Conversion of Laparoscopic to Open Cholecystectomy: Experience in A Tertiary Care Hospital.

Now-a-days Laparoscopic cholecystectomy is regarded as the gold standard treatment for benign gallbladder disease but in certain situations conversion to open cholecystectomy is extremely important for the safety of the patient. The objective of this study was to evaluate the reason for conversion of this operation to open surgery. This prospective study was carried out on 392 patients in a single unit of Department of Surgery, Bangabandhu Sheikh Mujib Medical University, Dhaka, Bangladesh and in a private hospital from July 2013 to December 2018. Maximum (28.3%) patients were 31-40 years age group. Majority (75.3%) was female and 24.7% were male. It was observed that only 2.1% were converted due to dense adhesion (n=3), severe inflammation (n=2), difficult to define anatomy of Calot's triangle (n=2) and Mirizzi syndrome (n=1). Meticulous dissection and proper case selection can reduce the rate of conversion to open surgery.

Hypotensive effect of chemical constituents from Aloe barbadensis.

Hypotensive effects of aloeemodin, aloin A, elgonica dimer A and bisbenzopyran from Aloe barbadensis have been studied. Aloeemodin has emerged as a potent hypotensive agent in current pharmacological investigations and caused 26 %, 52 %, and 79 % falls in mean arterial blood pressure at the corresponding doses of 0.5, 1, and 3 mg/kg in rats. The paper also describes the absolute configuration of elgonica dimer A (1).

Hypotensive action of coumarin glycosides from Daucus carota.

Daucus carota (carrot) has been used in traditional medicine to treat hypertension. Activity-directed fractionation of aerial parts of D. carota resulted in the isolation of two cumarin glycosides coded as DC-2 and DC-3. Intravenous administration of these compounds caused a dose-dependent (1-10 mg/kg) fall in arterial blood pressure in normotensive anaesthetised rats. In the in vitro studies, both compounds caused a dose-dependent (10-200 microg/ml) inhibitory effect on spontaneously beating guinea pig atria as well as on the K+ -induced contractions of rabbit aorta at similar concentrations. These results indicate that DC-2 and DC-3 may be acting through blockade of calcium channels and this effect may be responsible for the blood pressure lowering effect of the compounds observed in the in vivo studies.

Two insecticidal tetranortriterpenoids from Azadirachta indica.

Two new triterpenoids, 6 alpha-O-acetyl-7-deacetylnimocinol [24,25,26,27-tetra-norapotirucalla-(apoeupha)-6 alpha-acetoxy-7 alpha-hydroxy-1,14,20,22-tetraen-21,23-epoxy-3-one] (1) and meliacinol [24,25,26,27-tetranorapotirucalla-(apoeupha)-1 alpha-trimethylacryloxy-21,23-6 alpha,28-diepoxy-16-oxo-17-oxa-14,20,22-trien-3 alpha,7 alpha-diol] (2) were isolated from the methanolic extract of the fresh leaves of Azadirachta indica (neem). Their structures have been elucidated through spectral studies, including 2D-NMR (COSY-45, NOESY, HMQC and HMBC). The bioactivity of these as well as of nimocinol, reported earlier from the same source, is reported. The first compound and nimocinol showed toxicity on fourth instar larvae of mosquitoes (Aedes aegypti) with LC50 values of 21 and 83 ppm, respectively. The second compound had no effect upto 100 ppm.

Triterpenoids of the fruit coats of azadirachta indica

Three new triterpenoids, azadironolide [24,25,26, 27-tetranorapoeupha-7alpha-acetoxy-23xi-hydroxy-21,23-epoxy-1,14, 20(22)-trien-3,21-dione] (1), isoazadironolide [24,25,26, 27-tetranorapoeupha-7alpha-acetoxy-21xi-hydroxy-21,23-epoxy-1,14, 20(22)-trien-3,23-dione] (2), and azadiradionolide [24,25,26, 27-tetranorapoeupha-7alpha-acetoxy-21,23-epoxy-1,14,20(22)-trien-3, 16,21-trione] (3), were isolated from the fresh fruit coats of Azadirachta indica. Their structures have been elucidated through spectral analysis.

Hypotensive, hypoglycaemic and toxicological studies on the flavonol C-glycoside shamimin from Bombax ceiba.

Shamimin, a C-flavonol glucoside from Bombax ceiba leaves showed significant potency as a hypotensive agent at the doses of 15 mg/kg, 3 mg/kg, 1 mg/kg and significant hypoglycaemic activity at 500 mg/kg in Sprague-Dawley rats. Further studies revealed that it did not cause any mortality in mice at the dose of 1 g/kg but in rats 500 mg/kg is a lethal dose. Aqueous and methanolic extracts of Bombax ceiba leaves and one of its fractions were also subjected to pharmacological and toxicological screening.

Shamimin: a new flavonol C-glycoside from leaves of Bombax ceiba.

Shamimin a new flavonol C-glycoside has been isolated as a pale yellow powder from the ethanolic extract of fresh, undried leaves of Bombax ceiba. Its structure has been elucidated as 2-(2,4,5-trihydroxyphenyl)-3,5,7-trihydroxy-6-C- glucopyranosyloxy-4H-1-benzopyran-4-one through extensive spectroscopic methods (IR, mass, 1H- and 13C-NMR), and 2D-NMR experiments. Shamimin showed antimicrobial activity against a few bacteria and fungi.

Hypotensive constituents from the pods of Moringa oleifera.

Hypotensive activity of the ethanolic and aqueous extracts of Moringa oleifera whole pods and their parts, namely, coat, pulp, and seed was investigated. The activity of the ethanolic extract of both the pods and the seeds was equivalent at the dose of 30 mg/kg. The ethyl acetate phase of the ethanolic extract of pods was found to be the most potent fraction at the same dose. Its bioassay-directed fractionation led to the isolation of thiocarbamate and isothiocyanate glycosides which were also the hypotensive principles of the pods as observed in case of Moringa leaves. Two new compounds, O-[2'-hydroxy-3'-(2"-heptenyloxy)]-propyl undecanoate (1) and O-ethyl-4-[(alpha-L-rhamnosyloxy)-benzyl] carbamate (2) along with the known substances methyl p-hydroxybenzoate (3) and beta-sitosterol have also been isolated in the present studies. The latter two compounds and p-hydroxybenzaldehyde showed promising hypotensive activity. Structures of all these compounds have been deduced by spectroscopy and chemical reactions.

A new bisbenzopyran from Aloe barbadensis roots.

A new bisbenzopyran (1) has been isolated from the methanolic extract of roots of Aloe barbadensis through solvent separation and vacuum liquid chromatography. Based on spectral analysis including 2D-NMR (COSY, NOESY, J-resolved, HMQC, and HMBC) techniques, the structure of compound 1 was assigned as 3,3'-bis(3,4-dihydro-4-hydroxy-6-methoxy-2 H-1-benzopyran).

Fully acetylated carbamate and hypotensive thiocarbamate glycosides from Moringa oleifera.

Six new and three synthetically known glycosides have been isolated from the leaves of Moringa oleifera, employing a bioassay-directed isolation method on the ethanolic extract. Most of these compounds, bearing thiocarbamate, carbamate or nitrile groups, are fully acetylated glycosides, which are very rare in nature. Elucidation of the structures was made using chemical and spectroscopic methods, including 2D NMR techniques. Thiocarbamates showed hypotensive activity.

Isolation and structure elucidation of new nitrile and mustard oil glycosides from Moringa oleifera and their effect on blood pressure.

Bioassay-guided analysis of an EtOH extract of Moringa oleifera leaves showing hypotensive activity led to the isolation of two nitrile glycosides, niazirin [1] and niazirinin [2], and three mustard oil glycosides, 4-[(4'-O-acetyl-alpha-L-rhamnosyloxy)benzyl]isothiocyanate [4], niaziminin A, and niaziminin B. Glycoside 2 is a new compound. Niaziminins A and B have previously been obtained from the left extract as a mixture, while compound 4 is new from this source. Structural determination was accomplished by means of spectroscopic methods including appropriate 2D nmr experiments and chemical reactions. This is the first report of the isolation of nitriles, an isothiocyanate, and thiocarbamates from the same plant species. Isothiocyanate 4 and the thiocarbamate glycosides niaziminin A and B showed hypotensive activity while nitrile glycosides 1 and 2 were found to be inactive in this regard.

In vitro studies of the antibacterial and antifungal activity of oxine and its derivatives.

Twenty-one derivatives of 8-hydroxyquinoline (oxine, 8H, CAS 148-24-3) were prepared and characterized by UV, IR, MS and NMR spectroscopy. Four of these derivatives, N-butyl, 8-butyloxyquinolinium bromide (HBD), 8-pentyloxyquinoline (HPEM), N-pentyl, 8-pentyloxyquinolinium bromide (HPED) and N-benzyl, 8-benzyloxy quinolinium chloride (HBED) are new and reported for the first time. The antimicrobial activity of these compounds was carried out in vitro against 11 Gram positive and 18 Gram negative bacteria, and 18 fungi including 9 dermatophytes, 7 other filamentous fungi and 2 Candida species. Three compounds namely, HPRD, HPED and HBED were found to possess significant antibacterial activity in order of HPED > HPRD > HBED, whereas 4 were found to possess significant antifungal activity in order of 8H > HT > HPEM > 8B.

Constituents of Azadirachta indica: isolation and structure elucidation of a new antibacterial tetranortriterpenoid, mahmoodin, and a new protolimonoid, naheedin.

Mahmoodin [1], a new limonoid, has been isolated from Azadirachta indica (neem) oil, along with seven known tetranortriterpenoids, azadirone, epoxyazadiradione, nimbin, gedunin, azadiradione, deacetylnimbin, and 17-hydroxyazadiradione. A new protolimonoid, naheedin [3], has been obtained from the neem fruits along with azadirachtol. Their structures have been elucidated through chemical and spectral analyses including 2D nmr studies. The absolute configuration of 1 was established by comparison of its cd spectrum with those of the known tetranortriterpenoids. Mahmoodin showed significant antibacterial activity against various Gram-positive and Gram-negative organisms. Four hydrocarbons, icosane, docosane, 2-methyltricosane, and docosene, have also been identified by gc-ms of the EtOH extract of the fruit coats. Only docosane has earlier been reported from neem, while the remaining three are unreported from this plant.

Inhibition of platelet activating factor by ajmaline in platelets: in vitro and in vivo studies.

The in vitro and in vivo effects of ajmaline and its derivatives on platelet aggregation and platelet-activating factor (PAF) induced death in rabbits was studied. Ajmalinc and acetyl ajmaline selectively inhibited PAF-induced aggregation in a concentration related manner. Weak or no inhibition of aggregation was observed when ADP, collagen or arachidonic acid were used as aggregating agents. Similarly ajmaline or acetyl ajmaline also inhibited the lethal effects of PAF in the rabbit. PAF (8-11 microg/kg i.v.) caused sudden death in rabbits due to platelet aggregation and cardiac failure. Pretreatment of rabbits with ajmaline (50 mg/kg i.p.) protected conscious rabbits from PAF (11 microg/kg i.v.)-induced death. Since PAF is a powerful inducer of platelet aggregation via stimulation of specific PAF membrane receptors, our data is suggestive that ajmaline (an anti-arrhythmic agent) could emerge as a new class of PAF antagonists.

Tricyclic Diterpenes from the Stem Bark of Azadirachta indica.

Two new diterpenoids, margosone and margosolone, have been isolated from the stem bark of AZADIRACHTA INDICA A. Juss (neem) and their structures established as 12,13-dihydroxy-14-isoporpylpodocarpa-8,11,13-trien-7-one and 13-hydroxy-12-methoxypodocarpa-8,11,13-trien-7-one, respectively, through chemical and spectroscopic studies.

Non-terpenoidal constituents from Azadirachta indica.

Studies on the acidic fraction of the fresh, uncrushed twigs of AZADIRACHTA INDICA JUSS (Meliaceae) (Neem) have resulted in the isolation and structure elucidation of one new and three unreported isocoumarins along with two unreported coumarins. The petroleum ether extract of the fresh leaves yielded a hydrocarbon fraction, the GC-MS of which led to the identification of eight saturated hydrocarbons. Fatty acid compositions of leaves, twigs, and fruits of neem have also been determined.