Judul: Evaluasi Keberadaan dan Posisi Gugus Prenil pada Aktivitas Antioksidan Kuersetin di Cincin A Berdasarkan Teori Fungsional Rapatan B3LYP.
Abstrak: Kuersetin merupakan anggota flavonoid golongan flavonol yang memiliki beberapa aktivitas hayati, salah satunya ialah aktivitas antioksidan. Pada penelitian ini, aktivitas antioksidan kuersetin dan kuersetin berprenil di posisi 6 dan posisi 8 diperkirakan menggunakan 3 parameter, yaitu energi pemutusan ikatan (EPI), potensial ionisasi (PI), dan selisih energi orbital molekul (Egap) pada tingkat B3LYP/6-31G(d). Mekanisme antioksidan yang dikaji adalah pemutusan ikatan antara atom hidrogen dan oksigen pada gugus fenolik baik secara homolitik maupun heterolitik, sehingga perhitungan EPI dan PI memenuhi asumsi tersebut. Secara keseluruhan, keberadaan gugus prenil di posisi 8 pada kuersetin meningkatkan aktivitas antioksidan dengan menurunnya nilai EPI, nilai PI, dan nilai Egap terhadap kuersetin..
Keyword: antioksidan, Egap, EPI, kuersetin, PI, prenil

Judul: Analysis of Antioxidant Activity of Three Flavonoid Compounds from Lime Fruit Using Density Functional Theory
Abstrak: Radikal bebas tubuh dapat diklasifikasikan dari 2 jenis berdasarkan sumbernya, yaitu radikal bebas endogen dan eksogen. Radikal bebas endogen adalah radikal bebas yang berasal dari dalam tubuh sendiri seperti autoksidasi, oksidasi enzimatik dan respiratory burst, sedangkan radikal bebas eksogen adalah radikal bebas yang berasal dari luar tubuh seperti polusi udara, radiasi UV, sinarX, pestisida dan asap rokok. Menghadapi hal ini dibutuhkan antioksidan alami yang meningkatkan imunitas tubuh dengan mengikat radikal bebas. Ketersediaan andtioksidan alami sangat banyak ditemukan pada tanaman lokal seperti jeruk nipis dengan kandungan flavonoid seperti hesperetin, kuersetin, dan naringenin. Diperlukan analisis sifat antioksidan senyawa – senyawa tersebut untuk mengetahui kereaktifan molekul dalam menangkal radikal bebas. Melalui DFT dengan exchange-correlation B3LYP dan basis sets def2/SVP, penulis menganalisis sifat antioksidan hesperetin, kuersetin, dan naringenin. Perhitungan yang dilakukan dengan DFT adalah optimasi molekul, frekuensi vibrasi, dan single point energy. Analisis sifat antioksidan yang diinginkan dengan memperoleh nilai dari parameter BDE rendah, IP rendah, PDE rendah, PA rendah, dan ETE rendah melalui tiga mekanisme HAT, SPLET, dan SET-PT. Selanjutnya dianalisis dengan parameter nilai reaktivitas global yang dipengaruhi oleh nilai energi HOMO dan energi LUMO. Antioksidan yang baik diperoleh dengan nilai parameter reaktivitas global yaitu energi gap kecil, elektronegativitas besar, potensial kimia lebih positif, hardness kecil, softness besar, electrophilicity besar, nucleophilicity kecil, energi ionisasi kecil, dan afinitas elektron besar., Free radicals can be classified into 2 types based on their source, namely endogenous and exogenous free radicals. Endogenous free radicals are free radicals originating from within the body itself such as autoxidation, enzymatic oxidation and respiratory burst, while exogenous free radicals are free radicals originating from outside the body such as air pollution, UV radiation, X-rays, pesticides and cigarette smoke. In dealing with this condition, natural antioxidants are needed to enhance human body’s immune system by scavenging free radicals. Natural antoxidant are abundantly found in local plants such as lime fruits, which contain flavonoids like hesperetin, quercetin, and naringenin. The analysis of the antioxidant properties of these compounds is necessary to understand their molecular reactivity in neutralizing free radicals. Using DFT with the B3LYP exchange-correlation functional and def2/SVP basis sets, the author analyzed the antioxidant properties of hesperetin, quercetin, and naringenin. The DFT calculations involved molecular optimization, vibrational frequency analysis, and single-point energy calculation. The analysis aimed to identify desirable antioxidant properties, characterized by low BDE, low IP, low PDE, low PA, and low ETE, through three mechanisms: HAT, SPLET, and SET-PT. Additionally, the global reactivity values were analyzed, influenced by the HOMO energy and LUMO energy. Excellent antioxidants were identified by having small gap energy, high electronegativity, most positive value of chemical potential, low hardness, high softness, high electrophilicity, low nucleophilicity, low ionization energy, and high electron affinity
Keyword: DFT, Antioxidant, Hesperetin, Quercetin, Naringenin

Judul: Biology and ecology of the buffalo fly, haematobia exigua de meijere (diptera:muscidae)
Abstrak: The life history of the buffalo fly was observed at room temperature of 27°-29.5°C and at a relative humidity of 48-68 percent. The eggs hatched after 17-22 hours, with an average of 18 hours. First instar larvae measured 1.25 + 0.16 mm long and 0.27 + 0.037 mm wide. reach the second larval stage. It took 6-12 hours to the second instar larvae measured 2.676 +0.187 mm long and 0.353 +0.028 mm wide. The second instar took about 12-24 hours to reach the third larval stage. The third instar measured 6.833 + 0.189 mm long and 0.919 + 0.051 mm wide. It took about 2-3 days for the third instar to become pupae. Duration of the pupal stage was about 5-7 days before the adults emerged. Under laboratory condition, the buffalo fly completed its life cycle in 9.5 to 10.5 days, whereas under field condition it took 9-14 days with an average of 10.5 days. The growth ratio which was based on the measurements of the cephalo-pharyngeal skeleton of each instar was 1.797. The preoviposition period was 8-12 days and mating usually occurred on the 6th or 7th day. The longevity of the male was 29 days, whereas it was 32 days in the female. The range of egg production under laboratory condition was between 20-139 per female fly. The belly and hind legs of the carabao were the most preferred habitat either during cloudy and cool dry or shiny and warm day. When the weather was clear and the carabao was in the shade, the flies tended to be more distributed particularly on the shoulder, dewlap, back and horns. The carabaos had relatively fewer Musca sp. and Stomoxys calcitrans than cattle; never the less carabaos had a higher infestation of buffalo fly than cattle. Oviposition occured either during the day or night but the buffalo flies were more active during the night than in the day time. The effect of various lengths of exposure time of manure in relation to the oviposition was profound. observed, the maximum number of the buffalo flies was occurred when the dung was exposed for 30 minutes. With increasing time of exposure the number and variety of insects also increase. It was evident that Sepsidae and psychodidae were the most dominant insects emerging from the dung. The number of buffalo flies also increased with increasing
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