FTIR spectral correlation with alpha-glucosidase inhibitory activities of selected leafy plants extracts

Fourier transform infrared spectroscopy (FTIR) is a simple, rapid analytical technique used for the identification of organic functional groups of biomolecules. This study aimed to investigate the use of FTIR spectroscopy method for rapid detection of the α-glucosidase inhibitory activity of crude extracts of edible leafy plants, characterization of functional groups of chemical components present in crude extracts, and identification of possible biomolecules responsible for α-glucosidase inhibitory activity. Powdered leaves of five different plants, namely Le-kola pala (LE) (Premna procumbens), Kora kaha (KK) (Memecylon umbellatum), Koppa (KO) (Polyscias scutellaria), Stevia (ST) (Stevia rebaudiana), and Yaki naran (YK) (Atlantia ceylanica) were sequentially extracted with hexane, ethyl acetate (EtOAc) and methanol (MeOH). The FTIR spectra of crude plant extracts were obtained following the KBr pellet method, within the range of 4000-500 cm-1. The plant extracts were subjected to assay the α-glucosidase inhibitory activity. Further, the multivariate predictive models for α-glucosidase inhibitory activity were developed using partial least square (PLS) regression analysis. The highest Rc2 (0.96), Rcv2 (0.87), Rp2 (0.93), and the lowest RMSEC (24.10), RMSECV (41.70), and RMSEP (81.04) values were noticed for spectral region range from 1700 cm-1 to 1800 cm-1, indicating the strongest correlation to the α-glucosidase inhibitory activity, while the spectral region range from 1500 cm-1 to 1700 cm-1 was found to have the lowest Rc2 (0.71), Rcv2 (0.52), Rp2 (0.45) and the highest RMSEC (61.14) and RMSECV (80.21), indicating the lowest correlation to the α-glucosidase inhibitory activity. As the peak appearing in the range of 1700-1800 cm-1 is usually ascribed to C=O stretching vibration of ester groups, ketones, and carboxylic acids, there was a strong correlation between α-glucosidase inhibitory activity with those organic functional groups. The present study suggests that FTIR spectral analysis together with PLS regression analysis would be a convenient, rapid tool to determine α-glucosidase inhibitory activity of plant extracts

Blood cancer care in a resource limited setting during the Covid-19 outbreak; a single center experience from Sri Lanka

BackgroundThe Covid-19 pandemic has caused significant morbidity and mortality among patients with cancer. Most countries employed measures to prevent spread of Covid-19 infection which include shielding, quarantine, lockdown, travel restrictions, physical distancing and the use of personal protective equipment. This study was carried out to assess the change in patient attendance and the efficacy of newly implemented strategies to mitigate the impact of Covid-19 on services at the Lanka Hospital Blood Cancer Centre (LHBCC) in Colombo, Sri Lanka.MethodologyTelephone consultation, infection control, personal protective measures and emergency admission policy were implemented with the aim of having a Covid-19 free ward and to prevent cross-infections. This descriptive cross-sectional study was conducted with 1399 patient episodes (in-patient care or day-case review). We analysed patients treated as in-patient as well as day-case basis between 01st April 2020 and 31st December 2020.ResultsThere were 977 day-case based episodes and 422 in-patient based episodes. There was a 14% drop in episode numbers compared to same period in 2019. There was no cross infection and no patients with Covid-19 related symptoms or positive test results entered the LHBCC during the study period.ConclusionServices in blood cancer care were maintained to prevent late stage presentation and adverse outcome. Measures implemented to prevent Covid-19 were effective to allow continuation of treatment. This study highlights the importance of implementing strict protocols, clinical screening, use of appropriate personal protective equipment in delivering blood cancer care during the Covid-19 pandemic. This is the only documented study relating to outcome and successful applicability of measures to prevent spread of Covid-19 infection and maintaining services among blood cancer patients in Sri Lanka

Response and Survival Estimates of Patients With Plasma Cell Myeloma in a Resource-Constrained Setting Using Protocols From High-Income Countries:A Single-Center Experience From Sri Lanka

There is a significant disparity in global cancer care and outcome between countries. Progress in the treatment of symptomatic plasma cell myeloma (PCM) in high-income countries is not seen in low- and middle-income countries. MATERIALS AND METHODS: This is was a retrospective cohort study of all patients diagnosed with PCM between May 1, 2013, and September 30, 2021, at the first hemato-oncology center in Sri Lanka. We aimed to provide data on clinicopathologic characteristics, response, and survival estimates. RESULTS: A total of 79 patients with PCM received first-line therapy during the study period. The median age was 64 years, and approximately one third (33%) of patients were older than 70 years. There were 42 (53%) males and 37 females. Hypercalcemia, renal impairment, anemia, and bone disease were detected in 36.7%, 38%, 72.1%, and 81%, respectively. Thirty-nine, 34, and six patients received a combination of cyclophosphamide, thalidomide, and dexamethasone; bortezomib, thalidomide, and dexamethasone; and other treatments, respectively. The overall response rate (≥ partial response) was approximately 97% for both cyclophosphamide, thalidomide, and dexamethasone and bortezomib, thalidomide, and dexamethasone. Twenty-three (29%) of these patients died during the study period, but only 14 (18%) died due to PCM or associated sepsis. After a median follow-up of 40.6 months (range, 35.2-59.07 months), the median overall survival was 84.2 months (95% CI, 60.87 to not available). The 5-year estimated overall survival was 65%. CONCLUSION: To our knowledge, this is the only well-characterized study on long-term survival of patients with PCM in Sri Lanka. We have shown that it is possible to successfully apply Western treatment and supportive care protocols to the local population. These published data will help to benchmark and improve the treatment and develop blood cancer care in the local setting

Approaches to the synthesis of the macrolactone pyrrolizidine alkaloids (-)-integerrimine and (+)-usaramine

A formal total synthesis of the macrolactone pyrolizidine alkaloid (-)-integerrimine (2), from R-(+)-citronellal (93) is described. Aldehyde 93 was converted to exo methylene derivative 94 which was reduced to allylic alcohol 95. The epoxides 96 and 98, obtained in a ratio of 3:1 respectively by Sharp less epoxidation of 95 with diisopropyl (-)-tartrate, were separated as their 3,5-dinitrobenzoates 97 and 99 . Diol 100, derived from hydride opening of the major epoxide 97, was protected as the bis-3,5-dinitrobenzoate 101, which was oxidatively cleaved at the isopropylidene terminus. Methanolysis of the dinitrobenzoates and acid catalyzed lactonization provided 3-lactone 102, the structure of which was confirmed by X-ray crystallographic analysis. Oxidation of the primary alcohol of 102, followed by introduction of the E-ethylidene group, furnished 31 which has been previously converted to (-)-2 . The Sharpless epoxidation of 95 employing (+)-tartrate furnished 98 and 96 in 96:4 ratio respectively. Epoxide 98 was converted to 102 and hence to 31. Epoxide 98 was also protected as its silyl ether 109 and the olefin was oxidatively cleaved. The resulting carboxylic acid was converted to 110, acid catalyzed opening of which was anchimerically assisted by the ester function to give δ-lactone 112. The primary alcohol of 112 was reduced to a methyl group via iodide 113 and removal of the silyl blocking group from 114 then yielded 102. An approach to the chiral synthesis of (+)-usaramine (5) began from epoxide 98 . The diol 121, derived from opening of 98 with pivalic acid, was protected as the acetonide 122 and the pivalate ester was reduced to give 123. Alcohol 123 was oxidized to carboxylic acid 124 which was converted to methyl ester 125. The latter provided 120, via acid 126, by truncation of the isopropylidene group. Since introduction of the E-ethylidene substituent could not be accomplished on 120, δ-lactone 137 was used as the substrate for the aldol reaction with acetaldehyde. This lactone was prepared from 126 by cleavage of the acetonide, selective protection of the primary hydroxyl of the derived diol as 136, and subsequent lactonization with Mukaiyama's reagent. Introduction of the ethylidene group and deprotection of 138 provided 139. The first chiral synthesis of (-)-140, the dimethyl ester of naturally occurring (+)-retronecic acid (117), was achieved by methanolysis of 139. The ester 130 was prepared by titanate-mediated transesterification of 125 with 2-(trimethylsilyl)ethanol and subsequent oxidative cleavage of the olefin. This carboxyl terminus of 130 was coupled with the retronecine derivative 26 via anhydride 150 to yield 143. A nucleophilic macrolactonization protocol was attempted on 151, which was obtained by selective desilylation of 143, but this unexpectedly provided 153 instead of the macrolactone 149. Further treatment of 153 with excess fluoride at elevated temperature yielded the macrolactone 149, which contains the carbon skeleton and stereochemistry of (+)-usaramine (5) but lacks the ethylidene side chain

Anti-oxidative, anti-hyperglycemic and anti-obesity properties of selected edible leafy plants of Sri Lanka

Five selected edible leafy plants of Sri Lanka were studied in vitro to assess their anti-oxidative, anti-hyperglycemic and anti-obesity properties. Powdered samples of the leafy plants, namely Le-kola pala (LE), Kora kaha (KK), Koppa (KO), Stevia (ST) and Yaki naran (YK) were extracted with hexane, ethyl acetate (EtOAc) and methanol (MeOH) sequentially. The extracts were evaluated for total phenolic content, antioxidant potential and in vitro alpha amylase, alpha-glucosidase and lipase inhibitory activities using relevant assays. The highest alpha-glucosidase inhibitory activity was displayed by YK followed by KO. The highest alpha-amylase inhibitory activity was displayed by LE followed by YK. Among all plant extracts, only LE showed a moderate lipase inhibitory activity. These extracts displayed good antioxidant potential, which correlated well with the enzyme inhibitory activities. This study concluded that the extracts of selected edible leafy plants are a potent source of bioactive compounds that claim various pharmacological properties and can be used as safer alternative remedy for managing diabetes

Volatile profiling aided in the isolation of anti-proliferative lupeol from the roots of Clinacanthus nutans (Burm. f.) Lindau

Isolation of anti-proliferative compounds from plants is always hindered by the complexi-ties of the plant’s nature and tedious processes. Clinacanthus nutans (Burm. f.) Lindau is a medicinal plant with reported anti-proliferative activities. Our study aimed to isolate potential anti-proliferative compounds present in C. nutans plant. To start with, for our study, we came up with a strategy by first profiling the volatile compounds present in the leaf, stem and root of C. nutans using GC-MS. Comparing the plant’s volatile profiles greatly narrowed down our target of study. We decided to start with the isolation and characterization of a pentacyclic terpenoid, i.e., lupeol from the roots of C. nutans, as this compound was found to present abundantly in the roots compared to the leaf or stem. We developed a simple maceration and re-crystallization method, without the necessity to go through the fractionation or column chromatography for the isolation of lupeol. Characterizations of the isolated compound identified the compound as lupeol. The anti-proliferative activity of the isolated lupeol was further investigated against the MCF-7 cell line, which showed comparable anti-proliferative activity with the authentic lupeol and camptothecin. Our strategy to profile every part of the plant first, followed by selection of the most suitable plant part and targeted compound proved useful for further isolation and characterization bioactive compound from C. nutans

Bioactive sesquiterpenes from an endophytic fungus Bipolaris sorokiniana isolated from a popular medicinal plant Costus speciosus

Bipolaris sorokiniana, a fungal endophyte, was isolated from the leaves of Costus speciosus, a popular medicinal plant used to control diabetes. Fermentation of the fungus in potato dextrose broth and chromatographic purification of the ethyl acetate (EtOAc) extracts of the culture broth and mycelium yielded two rare sesquiterpenes helminthosporal acid (1) and helminthosporol (2), together with ergosterol. Compounds 1 and 2 showed a strong phytotoxic effect on lettuce seed germination and toxicity against brine shrimps. Compound 1 also showed antifungal activity. Complete assignments of 1H and 13C NMR data of compound 1 are described for the first time